Mapper通用接口：
使用mapper的通用接口，需要依赖一个com.github.abel533.Mapper的类。
com.github.abel533
mapper
2.3.4
然后，在mybatis-config.xml中配置，需要配置通用mapper的插件
定义Mapper层的接口，可以继承Mapper接口，参数为POJO类
public interface UserMapper extends Mapper {
}
这个时候就不需要直接定义mapper层的Mapper.xml的映射文件，只需要在mybatis-config.xml中扫描包就行了。
下面是mapper接口里面的方法与测试：
package mjf.haihan.mybatis.test;
import java.io.InputStream;
import java.util.List;
import mjf.haihan.mybatis.dao.UserMapper;
import mjf.haihan.mybatis.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.*;
import com.github.abel533.entity.Example;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
public class Test {
private UserMapper userMapper;
@Before
public void setUp() throws Exception {
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession sqlSession = sqlSessionFactory.openSession(true);
userMapper = sqlSession.getMapper(UserMapper.class);
}
@org.junit.Test
public void testSelectOne() {
//使用前提只能查询返回值为一条或者0条记录
User user = new User();
user.setId(1L);
User selectOne = this.userMapper.selectOne(user);
System.out.println(selectOne);
}
@org.junit.Test
public void testSelect() {
User user1 = new User();
user1.setSex(1);
user1.setName("张伟");
List list = this.userMapper.select(user1);
for (User user : list) {
System.out.println(user);
}
}
@org.junit.Test
public void testSelectCount() {
User user1 = new User();
user1.setSex(1);
// user1.setName("张伟");
int selectCount = this.userMapper.selectCount(user1);
System.out.println(selectCount);
}
@org.junit.Test
public void testSelectByPrimaryKey() {
//根据主键来查询
User user1 = new User();
user1.setId(1L);
User user = this.userMapper.selectByPrimaryKey(user1);
System.out.println(user);
}
@org.junit.Test
public void testInsert() {
User user = new User();
//user.setId(null);
user.setUserName("kl3asdg");
this.userMapper.insert(user);
System.out.println(user.getId());
}
@org.junit.Test
public void testInsertSelective() {
User user = new User();
// user.setId(null);
user.setUserName("kl4asdg");
this.userMapper.insertSelective(user);
}
@org.junit.Test
public void testDelete() {
User user = new User();
user.setId(18L);
int delete = this.userMapper.delete(user);
System.out.println(delete);
}
@org.junit.Test
public void testDeleteByPrimaryKey() {
User user = new User();
user.setId(16L);
int count = this.userMapper.deleteByPrimaryKey(user);
System.out.println(count);
}
@org.junit.Test
public void testUpdateByPrimaryKey() {
User user = new User();
user.setId(13L);
user.setUserName("abcd123");
this.userMapper.updateByPrimaryKey(user);
}
@org.junit.Test
public void testUpdateByPrimaryKeySelective() {
User user = new User();
user.setId(13L);
user.setUserName("abcd123");
this.userMapper.updateByPrimaryKeySelective(user);
}
//--------------------------------多条件查询-------------------------------------------------
@org.junit.Test
public void testSelectCountByExample() {
Example example = new Example(User.class);
example.createCriteria().andBetween("id", 2, 5);
int selectCountByExample = this.userMapper.selectCountByExample(example);
System.out.println(selectCountByExample);
}
@org.junit.Test
public void testDeleteByExample() {
Example example = new Example(User.class);
example.createCriteria().andBetween("id", 12, 14);
this.userMapper.deleteByExample(example);
}
@org.junit.Test
public void testSelectByExample() {
Example example = new Example(User.class);
example.createCriteria().andBetween("id", 2, 5);
List selectByExample = this.userMapper.selectByExample(example);
for (User user : selectByExample) {
System.out.println(user);
}
}
@org.junit.Test
public void testUpdateByExampleSelective() {
User user = new User();
user.setName("xxx");
Example example = new Example(User.class);
example.createCriteria().andEqualTo("sex", 2);
this.userMapper.updateByExampleSelective(user, example);
}
@org.junit.Test
public void testUpdateByExample() {
User user = new User();
user.setUserName("lasdf213");
user.setName("x12xx");
Example example = new Example(User.class);
example.createCriteria().andEqualTo("id", 3);
this.userMapper.updateByExample(user, example);
}
}
Mybatis的分页组件：
需要在pom.xml中依赖管理分页的组件管理，pagehelper和jsqlparser
com.github.pagehelper
pagehelper
3.7.5
com.github.jsqlparser
jsqlparser
0.9.1
相同的是也是需要在mybatis-config.xml中配置插件：
下面是案例，需要注意的是：使用pageHelper的时候，只有紧跟在pageHelper.start(xx,xx)的第一个查询方法会被分页。
@Test
public void testqu(){
PageHelper.startPage(2, 2);
List info = userDAO.queryAll();
PageInfo users = new PageInfo(info);
for (User user : info) {
System.out.println(user);
}
System.out.println(users.getTotal());
}