springboot整合mybatis+jetty笔记以及遇到的问题

1. 图文创建一个springboot Demo(IDEA创建)+目录图+返回json

   springboot创建参考

   

   

    

2. pom.xml　

   1.  <dependencies>
              <!--<dependency>-->
                  <!--<groupId>org.springframework.boot</groupId>-->
                  <!--<artifactId>spring-boot-starter-data-jpa</artifactId>-->
              <!--</dependency>-->
              <dependency>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-starter-web</artifactId>
                  <exclusions>
                      <exclusion>
                          <groupId>org.springframework.boot</groupId>
                          <artifactId>spring-boot-starter-tomcat</artifactId>
                      </exclusion>
                  </exclusions>
              </dependency>
      
              <dependency>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-starter-jetty</artifactId>
              </dependency>
      
              <dependency>
                  <groupId>org.mybatis.spring.boot</groupId>
                  <artifactId>mybatis-spring-boot-starter</artifactId>
                  <version>1.3.2</version>
              </dependency>
      
              <dependency>
                  <groupId>mysql</groupId>
                  <artifactId>mysql-connector-java</artifactId>
                  <!--<scope>runtime</scope>-->
              </dependency>
      
              <dependency>
                  <groupId>org.projectlombok</groupId>
                  <artifactId>lombok</artifactId>
                  <optional>true</optional>
              </dependency>
      
              <dependency>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-starter-test</artifactId>
                  <scope>test</scope>
              </dependency>
      
              <dependency>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-autoconfigure</artifactId>
                  <version>2.1.0.RELEASE</version>
              </dependency>
      
              <dependency>
                  <groupId>javax.servlet</groupId>
                  <artifactId>javax.servlet-api</artifactId>
                  <version>3.1.0</version>
              </dependency>
      
              <dependency>
                  <groupId>com.google.guava</groupId>
                  <artifactId>guava</artifactId>
                  <version>19.0</version>
                  <!--<version>1.1.9</version>-->
              </dependency>
      
              <!--阿里巴巴用来监控mysql线程池-->
              <dependency>
                  <groupId>com.alibaba</groupId>
                  <artifactId>druid</artifactId>
                  <version>1.1.9</version>
              </dependency>
      
          </dependencies>
      
          <build>
              <plugins>
                  <plugin>
                      <groupId>org.springframework.boot</groupId>
                      <artifactId>spring-boot-maven-plugin</artifactId>
                  </plugin>
              </plugins>
          </build>

3. application.properties配置数据库　

   1. server.port=8090
      ## 数据源配置
      spring.datasource.url=jdbc:mysql://localhost:3306/xxx?characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2b8
      spring.datasource.username=root
      spring.datasource.password=123456
      #spring.datasource.driver-class-name=com.mysql.jdbc.Driver
      spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
      mybatis.config-location=classpath:/mybatis/mybatis-config.xml

   2. 有时候url只是配置characterEncoding=utf-8参数 会报错

4. mybaits.xml的配置

   1. <?xml version="1.0" encoding="UTF-8"?>
      <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
              "http://mybatis.org/dtd/mybatis-3-config.dtd">
      <configuration>
          <settings>
              <!--配置关闭缓存-->
              <!--缓存开关-->
              <setting name="cacheEnabled" value="false"/>
              <!--自动启动驼峰原则-->
              <setting name="mapUnderscoreToCamelCase" value="true"/>
              <!-- 允许 JDBC 支持自动生成主键，需要驱动兼容。 如果设置为 true 则这个设置强制使用自动生成主键，尽管一些驱动不能兼容但仍可正常工作（比如 Derby）。 默认值false  -->
              <setting name="useGeneratedKeys" value="true"/>
              <!--  配置默认的执行器。SIMPLE 就是普通的执行器；REUSE 执行器会重用预处理语句（prepared statements）； BATCH 执行器将重用语句并执行批量更新。默认SIMPLE  -->
              <setting name="defaultExecutorType" value="REUSE"/>
              <!-- 设置超时时间，它决定驱动等待数据库响应的秒数。 -->
              <setting name="defaultStatementTimeout" value="600"/>
      
          </settings>
      
          <typeAliases >
              <typeAlias type="com.mooc.house.common.model.User" alias="user"></typeAlias>
          </typeAliases>
      
          <mappers>
              <mapper resource="mapper/myUser.xml"/>
          </mappers>
      
      </configuration>

5. mapper xml的配置

   1. <?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.xx.xx.mapper.UserMapper">
          <select id="xxx" resultType="user">
              select xxx from user
          </select>
      </mapper>

6. controller层

   1. @RestController
      public class UserController {
          @Autowired
          private Userservice userservice;
      
          @RequestMapping("get")
          public List<User> getUsers(){
              return userservice.getUsers();
          }
      
      }

7. service层

   1. @Service
      public class Userservice {
          @Resource
          private UserMapper userMapper;
      
          public List<User> getUsers(){
              return userMapper.findAllUsers();
          }
      }

8. mapper 接口层　

   1. @Mapper
      public interface UserMapper {
      //    查询用户
          public List<User> findAllUsers();
      }

9. 启动jetty

10. 返回json