2.6、测试
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTest {
@Autowired
private UserMapper userMapper;
@Test
public void testInsert(){
User user = new User();
user.setAge(20);
user.setEmail("test@itcast.cn");
user.setName("曹操");
user.setUserName("caocao");
user.setPassword("123456");
int result = this.userMapper.insert(user); //返回的result是受影响的行数,并不是自增
后的id
System.out.println("result = " + result);
System.out.println(user.getId()); //自增后的id会回填到对象中
}
@Test
public void testSelectById(){
User user = this.userMapper.selectById(8L);
System.out.println(user);
}
}
3、插件
3.1、mybatis的插件机制
MyBatis 允许你在已映射语句执行过程中的某一点进行拦截调用。默认情况下,MyBatis 允许使用插件来拦截的方法
调用包括:
1. Executor (update, query, flushStatements, commit, rollback, getTransaction, close, isClosed)
2. ParameterHandler (getParameterObject, setParameters)
3. ResultSetHandler (handleResultSets, handleOutputParameters)
4. StatementHandler (prepare, parameterize, batch, update, query)
我们看到了可以拦截Executor接口的部分方法,比如update,query,commit,rollback等方法,还有其他接口的
一些方法等。
总体概括为:
1. 拦截执行器的方法
2. 拦截参数的处理
3. 拦截结果集的处理
4. 拦截Sql语法构建的处理
拦截器示例:
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.*;
import java.util.Properties;
@Intercepts({@Signature(
type= Executor.class,
method = "update",
args = {MappedStatement.class,Object.class})})
public class MyInterceptor implements Interceptor {
@Override
public Object intercept(Invocation invocation) throws Throwable {
//拦截方法,具体业务逻辑编写的位置
return invocation.proceed();
}
@Override
public Object plugin(Object target) {
//创建target对象的代理对象,目的是将当前拦截器加入到该对象中
return Plugin.wrap(target, this);
}
@Override
public void setProperties(Properties properties) {
//属性设置
}
}
注入到Spring容器:
/**
* 自定义拦截器
*/
@Bean
public MyInterceptor myInterceptor(){
return new MyInterceptor();
}
或者通过xml配置,mybatis-config.xml:
<?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>
<plugins>
<plugin interceptor="cn.itcast.mp.plugins.MyInterceptor"></plugin>
</plugins>
</configuration>