springBoot入门
一、springBoot概念
1）创建独立的spring应用程序
2）直接内嵌tomcat、jetty和undertow（不需要打包成war包部署，直接jar包）
二、入门程序：
1. 引入依赖
2.创建引导类
/** * @SpringBootApplication：组合注解： * @SpringBootConfiguration：声明为springBoot的配置类 * @EnableAutoConfiguration：开启自动配置 * @ComponentScan：开启注解扫描 */ @SpringBootApplication public class UserApplication { public static void main(String[] args) { SpringApplication.run(UserApplication.class); } }
3.编写controller
@RestController @RequestMapping("user") public class UserController { @GetMapping("hello") public String test(){ return "hello ssm"; } }
4.1.整合springMvc
1) 添加全局配置文件
application.yml中配置端口：默认为8080
#映射端口
server.port = 80
2）访问静态资源
默认静态资源路径：
classpath:/resources/
classpath:/static/
classpath:/public/
只要静态资源放在这些目录中任何一个，SpringMVC都会帮我们处理
4.2. 添加拦截器
使用java配置的方式，配置拦截器，方法：
@Component public class MyInterceptor implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("preHandle method is running!"); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("postHandle method is running!"); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("afterCompletion method is running!"); } }
2).定义配置类，注册拦截器
@Configuration public class MvcConfiguration implements WebMvcConfigurer { @Autowired private MyInterceptor myInterceptor; /** * 重写接口中的addInterceptors方法，添加自定义拦截器 * @param registry */ @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(myInterceptor).addPathPatterns("/**"); } }
4.3.整合连接池
在pom.xml中引入启动器，springBoot会自动引入；
<!--jdbc的启动器，默认使用HikariCP连接池--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!--不要忘记数据库驱动，因为springboot不知道我们使用的什么数据库，这里选择mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>
配置参数在application.yml中：
# 连接四大参数
spring.datasource.url=jdbc:mysql://localhost:3306/heima
spring.datasource.username=root
spring.datasource.password=root
# 可省略，SpringBoot自动推断
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.hikari.idle-timeout=60000
spring.datasource.hikari.maximum-pool-size=30
spring.datasource.hikari.minimum-idle=10
4.4.整合mybatis
1) pom.xml中引入mybatis的启动器
<!--mybatis --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency>
2）在application.yml中引入配置
# mybatis 别名扫描
mybatis.type-aliases-package=cn.itcast.pojo
# mapper.xml文件位置,如果没有映射文件，请注释掉
mybatis.mapper-locations=classpath:mappers/*.xml
注意：
@Mapper public interface UserMapper { }
4.5.整合通用mapper
1) 在pom.xml中引入通用mapper的启动器
<!-- 通用mapper --> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>2.0.2</version> </dependency>
2）然后让mapper接口继承Mapper<实体类>
@Mapper public interface UserMapper extends tk.mybatis.mapper.common.Mapper<User>{ }
4.6.整合事务
1）在引入jdbc或者web的启动器，就已经引入事务相关的依赖及默认配置了；
2）使用：在相应的方法上加上@Transactional
@Service public class UserService { @Autowired private UserMapper userMapper; public User queryById(Long id){ return this.userMapper.selectByPrimaryKey(id); } @Transactional public void deleteById(Long id){ this.userMapper.deleteByPrimaryKey(id); } }
4.6.启动测试
@RestController @RequestMapping("user") public class UserController { @Autowired private UserService userService; @GetMapping("{id}") public User queryUserById(@PathVariable("id")Long id){ return this.userService.queryById(id); } @GetMapping("hello") public String test(){ return "hello ssm"; } }
pom.xml文件：
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.itcast.user</groupId> <artifactId>itcast-user</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.6.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!--jdbc的启动器，默认使用HikariCP连接池--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <!--不要忘记数据库驱动，因为springboot不知道我们使用的什么数据库，这里选择mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!--mybatis --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!-- 通用mapper --> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>2.0.2</version> </dependency> </dependencies> </project>
application.yml文件中的配置
server.port=80
logging.level.org.springframework=debug
spring.datasource.url=jdbc:mysql://localhost:3306/heima
spring.datasource.username=root
spring.datasource.password=root
# mybatis 别名扫描
mybatis.type-aliases-package=cn.itcast.pojo
# mapper.xml文件位置,如果没有映射文件，请注释掉
# mybatis.mapper-locations=classpath:mappers/*.xml
