Springboot - 员工部门案例

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// 知识点1：
@RequestMapping(value = "/list", method = RequestMethod.GET)
等价于：
@GetMapping("/list")

//知识点2：
private  static Logger logger = LoggerFactory.getLogger(DeptController.class);
等价于
@Slf4j(lombok.extern.slf4j.Slf4j;)

问题记录：

1.如果服务端指定http请求方法，但是请求时用错方法，会报错：

后端项目如果连接不上数据库，接口会报500，返回：

{
  "timestamp": "2023-08-13T07:15:32.930+00:00",
  "status": 500,
  "error": "Internal Server Error",
  "path": "/depts"
}

服务端输出日志：


com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:175) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:446) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:239) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:188) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:359) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:201) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:470) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:100) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-5.0.1.jar:na]
	at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:160) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:118) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:345) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:89) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:64) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:333) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:158) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:110) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:90) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:154) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:142) ~[mybatis-3.5.13.jar:3.5.13]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:425) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at jdk.proxy2/jdk.proxy2.$Proxy59.selectList(Unknown Source) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:224) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:147) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:80) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperProxy$PlainMethodInvoker.invoke(MapperProxy.java:142) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:86) ~[mybatis-3.5.13.jar:3.5.13]
	at jdk.proxy2/jdk.proxy2.$Proxy61.list(Unknown Source) ~[na:na]
	at com.chuangzhou.serivce.impl.DeptServiceImpl.list(DeptServiceImpl.java:20) ~[classes/:na]
	at com.chuangzhou.controller.DeptController.list(DeptController.java:31) ~[classes/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1740) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[na:na]
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480) ~[na:na]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:62) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:150) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:166) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:89) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.NativeSession.connect(NativeSession.java:121) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:945) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:815) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	... 89 common frames omitted
Caused by: java.net.ConnectException: Connection timed out: no further information
	at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]
	at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]
	at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:549) ~[na:na]
	at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:597) ~[na:na]
	at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327) ~[na:na]
	at java.base/java.net.Socket.connect(Socket.java:633) ~[na:na]
	at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:153) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:63) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	... 92 common frames omitted

Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1c3497a7]
2023-08-13T15:15:32.923+08:00 ERROR 15488 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: org.mybatis.spring.MyBatisSystemException] with root cause

java.net.ConnectException: Connection timed out: no further information
	at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]
	at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]
	at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:549) ~[na:na]
	at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:597) ~[na:na]
	at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327) ~[na:na]
	at java.base/java.net.Socket.connect(Socket.java:633) ~[na:na]
	at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:153) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:63) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.NativeSession.connect(NativeSession.java:121) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:945) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:815) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:446) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:239) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:188) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:359) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:201) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:470) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:100) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-5.0.1.jar:na]
	at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:160) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:118) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81) ~[spring-jdbc-6.0.11.jar:6.0.11]
	at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:345) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:89) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:64) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:333) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:158) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:110) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:90) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:154) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:142) ~[mybatis-3.5.13.jar:3.5.13]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:425) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at jdk.proxy2/jdk.proxy2.$Proxy59.selectList(Unknown Source) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:224) ~[mybatis-spring-3.0.2.jar:3.0.2]
	at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:147) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:80) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperProxy$PlainMethodInvoker.invoke(MapperProxy.java:142) ~[mybatis-3.5.13.jar:3.5.13]
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:86) ~[mybatis-3.5.13.jar:3.5.13]
	at jdk.proxy2/jdk.proxy2.$Proxy61.list(Unknown Source) ~[na:na]
	at com.chuangzhou.serivce.impl.DeptServiceImpl.list(DeptServiceImpl.java:20) ~[classes/:na]
	at com.chuangzhou.controller.DeptController.list(DeptController.java:31) ~[classes/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1740) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

问题3：

为什么后端接口映射的路径和前端请求的路径不一致，但是请求成功了？

删除部门信息

注意用的的是路径参数，需要使用@PathVariable 映射到方法形参上

    //根据id删除部门
    @DeleteMapping("/depts/{id}")
    public Result delete(@PathVariable Integer id){
        log.info("根据id{}删除部门信息",id);
        deptService.delete(id);
        return Result.success();
    }
}

新增部门信息

需求：

注意：部门名称 2 - 10个字符数据库的字段会做限制，后端业务层不会判断

当上从超过10个字符，但是后端程序没有处理插入数据字段超长异常时就会报：

请求映射：

服务端需要使用@RequestBody注解将请求的json 数据映射到 javabean

    @PostMapping("/depts")
    public Result add(@RequestBody Dept dept){
        log.info("新增部门:{}",dept);
        deptService.add(dept);
        return Result.success();

    }

知识点：抽取公共的路径映射

抽取前：

package com.chuangzhou.controller;

import com.chuangzhou.pojo.Dept;
import com.chuangzhou.pojo.Result;
import com.chuangzhou.serivce.DeptService;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;


@Slf4j
@RestController

public class DeptController {


    @Autowired
    private DeptService deptService;

    @GetMapping("/depts")
    public Result list(){
        log.info("查询全部部门信息");

        List<Dept> depts = deptService.list();

        return Result.success(depts);
    }


    //根据id删除员工
    @DeleteMapping("/depts/{id}")
    public Result delete(@PathVariable Integer id){
        log.info("根据id{}删除部门信息",id);
        deptService.delete(id);
        return Result.success();
    }

    @PostMapping("/depts")
    public Result add(@RequestBody Dept dept){
        log.info("新增部门:{}",dept);
        deptService.add(dept);
        return Result.success();

    }
}

抽取后：

package com.chuangzhou.controller;

import com.chuangzhou.pojo.Dept;
import com.chuangzhou.pojo.Result;
import com.chuangzhou.serivce.DeptService;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;


@Slf4j
@RestController
@RequestMapping("/dept")
public class DeptController {

    @Autowired
    private DeptService deptService;

    @GetMapping
    public Result list(){
        log.info("查询全部部门信息");

        List<Dept> depts = deptService.list();

        return Result.success(depts);
    }


    //根据id删除员工
    @DeleteMapping("{id}")
    public Result delete(@PathVariable Integer id){
        log.info("根据id{}删除部门信息",id);
        deptService.delete(id);
        return Result.success();
    }

    @PostMapping
    public Result add(@RequestBody Dept dept){
        log.info("新增部门:{}",dept);
        deptService.add(dept);
        return Result.success();

    }
}

手动实现分页查询

前置知识：

分页查询，前端需要向后端传入参数：page(页码)，pageSize(每页多少数据)

mysql实现分页：limit 关键字参数

查询第一页数据，每页10条：select * from emp limit (1 - 1) * 10，10，索引 0 - 9
查询第二页数据，每页10条：select * from emp limit (2 - 1) * 10，10，索引 10 - 19
.....
依次类推：
分页查询为：select * from emp limit (page - 1) * pageSize，pageSize

接口需要返回数据：总数和当前查询页码的数据

因此将结果封装在：

@Data
@NoArgsConstructor
@AllArgsConstructor
public class PageBean {

    private Long page;
    private List<Emp> rows;
}

conttroller:

知识点： @RequestParam(defaultValue="") 可以为参数设置默认值

@RestController
public class EmpController {

    @Autowired
    private EmpService empService;

    @GetMapping("/emps")
    public Result list(@RequestParam(defaultValue = "1") Integer page, @RequestParam(defaultValue = "10") Integer pageSize){
        PageBean pageBean = empService.list(page,pageSize);

        return Result.success(pageBean);
    }
}

servie：

@Service
public class EmpServiceImpl implements EmpService {

    @Autowired
    private EmpMapper empMapper;

    @Override
    public PageBean list(Integer page, Integer pageSize) {
        Long count = empMapper.count();
        List<Emp> emps = empMapper.list( (page - 1  ) * pageSize,  pageSize);
        PageBean pageBean = new PageBean(count,emps);
        return pageBean;
    }
}

mapper:

@Mapper
public interface EmpMapper {
    @Select("select count(*)  from emp")
    Long count();


    @Select("select * from emp limit #{page} , #{pageSize}")
    List<Emp> list(Integer page, Integer pageSize);
}

分页插件

为什么使用分页插件？
代码固定且繁琐

使用步骤：

1.引入pom

        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.4.6</version>
        </dependency>

2.修改Dao：

@Mapper
public interface EmpMapper {
    @Select("select * from emp")
    List<Emp> list();
}

修改service：

错误写法：

@Service
public class EmpServiceImpl implements EmpService {

    @Autowired
    private EmpMapper empMapper;

    @Override
    public PageBean list(Integer page, Integer pageSize) {
        //1. 设置分页参数
        PageHelper.startPage(page, pageSize);
        //2. 查询结果并转换
        List<Emp> empList = empMapper.list();
        Page<Emp> p = (Page<Emp>) empList;

        //3. 封装pageBean
        PageBean pageBean = new PageBean(p.getTotal(),p.getResult());
        return pageBean;
    }
}

使用环境：JDK17 + PageHelp 1.4.6

如果使用环境：JDK17 + PageHelp 1.4.2

会报错：java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.github.pagehelper.Page

生效后控制台会输出：

帮我们生成的SQL:

条件分页查询

controller：

@RestController
public class EmpController {

    @Autowired
    private EmpService empService;

    @GetMapping("/emps")
    public Result list(@RequestParam(defaultValue = "1") Integer page,
                       @RequestParam(defaultValue = "10") Integer pageSize,
                       String name, Short gender,
                       @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,
                       @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end){

        PageBean pageBean = empService.list(page,pageSize,name,gender,begin,end);

        return Result.success(pageBean);
    }
}

service：

@Service
public class EmpServiceImpl implements EmpService {

    @Autowired
    private EmpMapper empMapper;

    @Override
    public PageBean list(Integer page, Integer pageSize, String name, Short gender, LocalDate begin, LocalDate end) {
        //1. 设置分页参数
        PageHelper.startPage(page, pageSize);
        //2. 查询结果并转换
        List<Emp> empList = empMapper.list(name, gender, begin, end);
        Page<Emp> p = (Page<Emp>) empList;

        //3. 封装pageBean
        PageBean pageBean = new PageBean(p.getTotal(),p.getResult());
        return pageBean;
    }
}

Dao:

@Mapper
public interface EmpMapper {
    List<Emp> list(String name, Short gender, LocalDate begin, LocalDate end);
}

Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.chuangzhou.mapper.EmpMapper">
    <select id="list" resultType="com.chuangzhou.pojo.Emp">
        select  * from emp
        <where>
            <if test="name != null">
                name like concat('%',#{name},'%')
            </if>
            <if test="gender != null">
                and gender = #{gender}
            </if>
            <if test="begin != null and end != null">
                and entrydate between #{begin}  and #{end}
            </if>
        </where>
        order by update_time desc
    </select>
</mapper>

遇到的问题：

mapper.xml 中增加对空字符串的判断：

<mapper namespace="com.chuangzhou.mapper.EmpMapper">
    <select id="list" resultType="com.chuangzhou.pojo.Emp">
        select  * from emp
        <where>
            <if test="name != null and name != ''">
                name like concat('%',#{name},'%')
            </if>
            <if test="gender != null">
                and gender = #{gender}
            </if>
            <if test="begin != null and end != null">
                and entrydate between #{begin}  and #{end}
            </if>
        </where>
        order by update_time desc
    </select>
</mapper>

批量删除

controller:

    @DeleteMapping("/emps/{ids}")
    public Result delete(@PathVariable List<Integer> ids){
        empService.delete(ids);
        return Result.success();
    }

service:

    @Override
    public void delete(List<Integer> ids) {
        empMapper.delete(ids);
    }

dao:

    void delete(List<Integer> ids);

mapper.xml:

    <delete id="delete">
        delete from emp where id in
        <foreach collection="ids" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>

批量删除成功：

文件上传

html 文件：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>上传文件</title>
</head>
<body>

    <form action="/upload" method="post" enctype="multipart/form-data">
        姓名: <input type="text" name="username"><br>
        年龄: <input type="text" name="age"><br>
        头像: <input type="file" name="image"><br>
        <input type="submit" value="提交">
    </form>

</body>
</html>

三要素：

请求方法：post
<input type='file'>
enctype="multipart/form-data"

enctype 的默认值：application/x-www-form-urlencoded

使用enctype 默认值上传txt：

请求头：

请求体：

使用enctype = multipart/form-data 上txt：

请求头：

请求体：

请求头中的 boundary 是什么东东？

浏览器自动生成的分隔符，帮忙区分表单的每一个项

可以在controller 上使用接口 org.springframework.web.multipart.MultipartFile 来接收表单提交的 file 类型：

请求后会生产临时文件，存储位置在 MultipartFile => part => location ,每一个临时文件存储的就是一个表单项

本地文件存储

@RestController
@Slf4j
public class UploadController {


    @PostMapping("/upload")
    public Result upload(String username, Integer age, MultipartFile image) throws Exception {
        log.info("文件上传接收到的参数：{}，{}，{}",username,age,image);

        //获得原始文件名
        String originalFilename = image.getOriginalFilename();
        //组装唯一文件名
        int index = originalFilename.lastIndexOf(".");
        String uuid = UUID.randomUUID().toString();
        String extendName = originalFilename.substring(index);
        String newName = uuid + extendName;

        //存储文件
        image.transferTo(new File("E:\\images\\" + newName));

        return Result.success();
    }
}

上传成功：

但是上传超过 1M 文件的错误时，springboot 会报错:

org.apache.tomcat.util.http.fileupload.impl.FileSizeLimitExceededException: The field image exceeds its maximum permitted size of 1048576 bytes.
	at org.apache.tomcat.util.http.fileupload.impl.FileItemStreamImpl$1.raiseError(FileItemStreamImpl.java:117) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.checkLimit(LimitedInputStream.java:76) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.read(LimitedInputStream.java:135) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at java.base/java.io.FilterInputStream.read(FilterInputStream.java:106) ~[na:na]
	at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:96) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:292) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.Request.parseParts(Request.java:2800) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.Request.getParts(Request.java:2701) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.RequestFacade.getParts(RequestFacade.java:774) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:93) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.<init>(StandardMultipartHttpServletRequest.java:86) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.multipart.support.StandardServletMultipartResolver.resolveMultipart(StandardServletMultipartResolver.java:112) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1219) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1053) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:914) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:590) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.11.jar:6.0.11]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658) ~[tomcat-embed-core-10.1.11.jar:6.0]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.11.jar:6.0.11]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1740) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.11.jar:10.1.11]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

在application.properties 中加入配置即可(默认为1M)：

# 配置单个文件的最大限制
spring.servlet.multipart.max-file-size=10MB
# 配置一个请求的上传文件的最大限制
spring.servlet.multipart.max-request-size=100MB

阿里云OSS

使用步骤：

阿里云使用流程：

获取accesskey：

查看示例：

快速入门：

访问地址：

实现上传：

package com.chuangzhou;

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;

import java.io.ByteArrayInputStream;
import java.io.FileInputStream;

public class Demo {

    public static void main(String[] args) throws Exception {
        // Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-beijing.aliyuncs.com";
     
        String acccessId = "LTAI5tANBBkyFojb67sHP4de";
        String secretKey = "yk2N5y5NwjC9kUochZtGKSpz2VnTQm";
        
        // 填写Bucket名称，例如examplebucket。
        String bucketName = "blias";
        // 填写Object完整路径，例如exampledir/exampleobject.txt。Object完整路径中不能包含Bucket名称。
        String objectName = "C:\\Users\\86158\\Desktop\\Snipaste_2023-06-07_22-54-23.png";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint,acccessId, secretKey);

        try {
            ossClient.putObject(bucketName, objectName,new FileInputStream(objectName));
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

成功上传：

上传成功后会为每个图片生成一个可访问的url

添加员工时实现文件上传

流程：

1.导入OSS工具类：

package com.chuangzhou.utils;

import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.UUID;

/**
 * 阿里云 OSS 工具类
 */
// 交给Spring 管理
@Component
public class AliOSSUtils {

    private String endpoint = "https://oss-cn-beijing.aliyuncs.com";
    private String accessKeyId = "LTAI5tANBBkyFojb67sHP4de";
    private String accessKeySecret = "yk2N5y5NwjC9kUochZtGKSpz2VnTQm";
    private String bucketName = "blias";

    /**
     * 实现上传图片到OSS
     */
    public String upload(MultipartFile file) throws IOException {
        // 获取上传的文件的输入流
        InputStream inputStream = file.getInputStream();

        // 避免文件覆盖
        String originalFilename = file.getOriginalFilename();
        String fileName = UUID.randomUUID().toString() + originalFilename.substring(originalFilename.lastIndexOf("."));

        //上传文件到 OSS
        OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);
        ossClient.putObject(bucketName, fileName, inputStream);

        //文件访问路径
        String url = endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + fileName;
        // 关闭ossClient
        ossClient.shutdown();
        return url;// 把上传到oss的路径返回
    }

}

2.改造UploadController，返回上传到OSS后的图片的url，以便新增员工的接口使用：

package com.chuangzhou.controller;

import com.chuangzhou.pojo.Result;
import com.chuangzhou.utils.AliOSSUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.util.UUID;

@RestController
@Slf4j
public class UploadController {
    @Autowired
    private AliOSSUtils aliOSSUtils;

    @PostMapping("/upload")
    public Result upload(String username, Integer age, MultipartFile image) throws Exception {

        String file = aliOSSUtils.upload(image);

        return Result.success(file);
    }
}

测试成功：

前端项目新增员工：

图片正常展示，数据库存储oss 返回的url：

配置文件

参数化配置

AliOSSUtils 工具类存在的问题：

问题解决：

将oss 的相关配置项加入到spring 配置文件当中：

aliyun
  oss
    endpoint: https://oss-cn-beijing.aliyuncs.com
    accessKeyId: LTAI5tANBBkyFojb67sHP4de
    accessKeySecret: yk2N5y5NwjC9kUochZtGKSpz2VnTQm
    bucketName: blias

采用@Value("${}") 的方式可以直接获取配置文件的值

注解：ConfigurationPropeties

作用：

采用@Value 注解的方式获取配置文件的信息太过繁琐，因此需要一种自动将配置文件的值映射到JavaBean的方法

需要注意的是：

步骤1 编写properties 类：

package com.chuangzhou.utils;


import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Data
@Component
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliOSSProperties {

    private String endpoint;
    private String accessKeyId;
    private String accessKeySecret;
    private String bucketName;
}

步骤2：

在使用的地方直接注入：

package com.chuangzhou.utils;

import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.UUID;

/**
 * 阿里云 OSS 工具类
 */
@Component
public class AliOSSUtils {

    @Autowired
    private AliOSSProperties aliOSSProperties;
    /**
     * 实现上传图片到OSS
     */
    public String upload(MultipartFile file) throws IOException {
        String endpoint = aliOSSProperties.getEndpoint();
        String accessKeyId = aliOSSProperties.getAccessKeyId();
        String bucketName = aliOSSProperties.getBucketName();
        String accessKeySecret = aliOSSProperties.getAccessKeySecret();

        // 获取上传的文件的输入流
        InputStream inputStream = file.getInputStream();

        // 避免文件覆盖
        String originalFilename = file.getOriginalFilename();
        String fileName = UUID.randomUUID().toString() + originalFilename.substring(originalFilename.lastIndexOf("."));

        //上传文件到 OSS
        OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);
        ossClient.putObject(bucketName, fileName, inputStream);

        //文件访问路径
        String url = endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + fileName;
        // 关闭ossClient
        ossClient.shutdown();
        return url;// 把上传到oss的路径返回
    }

}

如果引入以下依赖, 在编写配置文件的时候会有提示信息：

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>

效果：

yml/yaml 格式的配置文件

常见配置文件格式对比：

改造后使用application.yml 配置如下：

# 数据库连接配置
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.184.152:3306/blias
    username: root
    password: 123456
  servlet:
    multipart:
      max-file-size: 10MB
      max-request-size: 100MB


mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true

posted @ 2023-08-12 16:26 chuangzhou 阅读(40) 评论(0) 编辑收藏举报

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