mybatis3中注解方式使用mapper
mybatis3中增加了使用注解来配置Mapper的新特性，本篇文章主要介绍其中几个@Provider的使用方式，他们是：@SelectProvider、@UpdateProvider、@InsertProvider和@DeleteProvider。
DROP TABLE IF EXISTS `blog`;
CREATE TABLE `blog` (
`id` int(10) NOT NULL auto_increment,
`title` varchar(200) NOT NULL,
`date` varchar(50) NOT NULL,
`authername` varchar(15) NOT NULL,
`content` varchar(500) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL auto_increment,
`userName` varchar(50) default NULL,
`userAge` int(11) default NULL,
`userAddress` varchar(200) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;第一种 映射器接口中写SQL语句，映射器接口注解：
package com.whut.inter;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.whut.model.User;
//最基本的注解CRUD
public interface IUserDAO {
@Select("select *from User")
public List retrieveAllUsers();
//注意这里只有一个参数，则#{}中的标识符可以任意取
@Select("select *from User where id=#{idss}")
public User retrieveUserById(int id);
@Select("select *from User where id=#{id} and userName like #{name}")
public User retrieveUserByIdAndName(@Param("id")int id,@Param("name")String names);
@Insert("INSERT INTO user(userName,userAge,userAddress) VALUES(#{userName},"
+ "#{userAge},#{userAddress})")
public void addNewUser(User user);
@Delete("delete from user where id=#{id}")
public void deleteUser(int id);
@Update("update user set userName=#{userName},userAddress=#{userAddress}"
+ " where id=#{id}")
public void updateUser(User user);
}
package com.whut.test;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
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 com.whut.inter.IUserDAO;
import com.whut.model.User;
public class TestUser {
private static SqlSessionFactory sqlSessionFactory;
private static Reader reader;
static {
try {
Reader reader = Resources.getResourceAsReader("mybatic-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
// 由于使用了注解，所以在主配置文件没有mapper，需要在代码里显示注册该mapper接口
sqlSessionFactory.getConfiguration().addMapper(IUserDAO.class);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
// testSelectAll();
// testSelectByConditions();
//testAddUser();
//testDeleteUser();
testUpateUser();
}
public static void testSelectAll() {
// sqlSessionFactory.getConfiguration().addMapper(IUserDAO.class);
SqlSession session = sqlSessionFactory.openSession();
try {
IUserDAO userDAO = session.getMapper(IUserDAO.class);
List users = userDAO.retrieveAllUsers();
System.out.println("用户编号\t" + "姓名\t" + "年龄\t住址");
for (User u : users) {
System.out.println(u.getId() + "\t" + u.getUserName() + "\t"
+ u.getUserAge() + "\t" + u.getUserAddress());
}
} finally {
session.close();
}
}
public static void testSelectByConditions() {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserDAO userDAO = session.getMapper(IUserDAO.class);
User u = userDAO.retrieveUserByIdAndName(4, "%spring%");
if (u != null) {
System.out.println("用户编号\t" + "姓名\t" + "年龄\t住址");
System.out.println(u.getId() + "\t" + u.getUserName() + "\t"
+ u.getUserAge() + "\t" + u.getUserAddress());
}
} finally {
session.close();
}
}
public static void testAddUser() {
User u = new User();
u.setUserName("dongtian");
u.setUserAge(51);
u.setUserAddress("hubeisheng");
SqlSession session = sqlSessionFactory.openSession();
try {
IUserDAO userDAO = session.getMapper(IUserDAO.class);
userDAO.addNewUser(u);
session.commit();
} finally {
session.close();
}
}
public static void testDeleteUser() {
SqlSession session = sqlSessionFactory.openSession();
try {
IUserDAO userDAO = session.getMapper(IUserDAO.class);
userDAO.deleteUser(7);
session.commit();
} finally {
session.close();
}
}
public static void testUpateUser() {
User u = new User();
u.setId(4);
u.setUserName("dongtian");
u.setUserAge(51);
u.setUserAddress("hubeisheng");
SqlSession session = sqlSessionFactory.openSession();
try {
IUserDAO userDAO = session.getMapper(IUserDAO.class);
userDAO.updateUser(u);
session.commit();
} finally {
session.close();
}
}
} 第二种 映射器接口调用SqlBuilder生成的SQL进行执行
映射器接口
package com.whut.inter;
import java.util.List;
import org.apache.ibatis.annotations.CacheNamespace;
import org.apache.ibatis.annotations.DeleteProvider;
import org.apache.ibatis.annotations.InsertProvider;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.SelectProvider;
import org.apache.ibatis.annotations.UpdateProvider;
import org.apache.ibatis.type.JdbcType;
import com.whut.model.Blog;
import com.whut.sqlTool.BlogSqlProvider;
@CacheNamespace(size=100)
public interface IBlogDAO {
@SelectProvider(type = BlogSqlProvider.class, method = "getSql")
@Results(value ={
@Result(id=true, property="id",column="id",javaType=Integer.class,jdbcType=JdbcType.INTEGER),
@Result(property="title",column="title",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="date",column="date",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="authername",column="authername",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="content",column="content",javaType=String.class,jdbcType=JdbcType.VARCHAR),
})
public Blog getBlog(@Param("id") int id);
@SelectProvider(type = BlogSqlProvider.class, method = "getAllSql")
@Results(value ={
@Result(id=true, property="id",column="id",javaType=Integer.class,jdbcType=JdbcType.INTEGER),
@Result(property="title",column="title",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="date",column="date",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="authername",column="authername",javaType=String.class,jdbcType=JdbcType.VARCHAR),
@Result(property="content",column="content",javaType=String.class,jdbcType=JdbcType.VARCHAR),
})
public List getAllBlog();
@SelectProvider(type = BlogSqlProvider.class, method = "getSqlByTitle")
@ResultMap(value = "sqlBlogsMap")
//这里调用resultMap，这个是SQL配置文件中的,必须该SQL配置文件与本接口有相同的全限定名
//注意文件中的namespace路径必须是使用@resultMap的类路径
public List getBlogByTitle(@Param("title")String title);
@InsertProvider(type = BlogSqlProvider.class, method = "insertSql")
public void insertBlog(Blog blog);
@UpdateProvider(type = BlogSqlProvider.class, method = "updateSql")
public void updateBlog(Blog blog);
@DeleteProvider(type = BlogSqlProvider.class, method = "deleteSql")
@Options(useCache = true, flushCache = false, timeout = 10000)
public void deleteBlog(int ids);
} package com.whut.sqlTool;
import java.util.Map;
import static org.apache.ibatis.jdbc.SqlBuilder.*;
public class BlogSqlProvider {
private final static String TABLE_NAME = "blog";
public String getSql(Map parameter) {
BEGIN();
//SELECT("id,title,authername,date,content");
SELECT("*");
FROM(TABLE_NAME);
//注意这里这种传递参数方式，#{}与map中的key对应，而map中的key又是注解param设置的
WHERE("id = #{id}");
return SQL();
}
public String getAllSql() {
BEGIN();
SELECT("*");
FROM(TABLE_NAME);
return SQL();
}
public String getSqlByTitle(Map parameter) {
String title = (String) parameter.get("title");
BEGIN();
SELECT("*");
FROM(TABLE_NAME);
if (title != null)
WHERE(" title like #{title}");
return SQL();
}
public String insertSql() {
BEGIN();
INSERT_INTO(TABLE_NAME);
VALUES("title", "#{title}");
// VALUES("title", "#{tt.title}");
//这里是传递一个Blog对象的，如果是利用上面tt.方式，则必须利用Param来设置别名
VALUES("date", "#{date}");
VALUES("authername", "#{authername}");
VALUES("content", "#{content}");
return SQL();
}
public String deleteSql() {
BEGIN();
DELETE_FROM(TABLE_NAME);
WHERE("id = #{id}");
return SQL();
}
public String updateSql() {
BEGIN();
UPDATE(TABLE_NAME);
SET("content = #{content}");
WHERE("id = #{id}");
return SQL();
}
}
package com.whut.test;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
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 com.whut.inter.IBlogDAO;
import com.whut.model.Blog;
/**
* 注意这里是一种利用SqlBuilder以及多种设置来注解使用
* @author zxl
*
*/
public class TestBlog {
private static SqlSessionFactory sqlSessionFactory;
private static Reader reader;
static {
try {
Reader reader = Resources.getResourceAsReader("mybatic-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
// 由于使用了注解，所以在主配置文件没有mapper，需要在代码里显示注册该mapper接口
//sqlSessionFactory.getConfiguration().addMapper(IBlogDAO.class);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
//testOneBlog();
//testAllBlog();
//testBlogByTitle();
//testAddBlog();
//testDeleteBlog();
testUpdateBlog();
}
public static void testOneBlog()
{
SqlSession session=sqlSessionFactory.openSession();
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
Blog blog=dao.getBlog(2);
System.out.println(blog.getId()+"\t"+blog.getAuthername()+"\t"+blog.getTitle());
}finally{
session.close();
}
}
public static void testAllBlog()
{
SqlSession session=sqlSessionFactory.openSession();
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
List blogs=dao.getAllBlog();
System.out.println("编号\t作者\t标题");
for(Blog blog:blogs)
System.out.println(blog.getId()+"\t"+blog.getAuthername()+"\t"+blog.getTitle());
}finally{
session.close();
}
}
public static void testBlogByTitle()
{
SqlSession session=sqlSessionFactory.openSession();
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
List blogs=dao.getBlogByTitle("%word%");
System.out.println("编号\t作者\t标题");
for(Blog blog:blogs)
System.out.println(blog.getId()+"\t"+blog.getAuthername()+"\t"+blog.getTitle());
}finally{
session.close();
}
}
public static void testAddBlog()
{
SqlSession session=sqlSessionFactory.openSession();
Blog blog=new Blog();
blog.setTitle("chuntian");
blog.setAuthername("xiaohua");
blog.setDate("2013/12/25");
blog.setContent("bushuangyayya");
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
dao.insertBlog(blog);
session.commit();
}finally{
session.close();
}
}
public static void testDeleteBlog()
{
SqlSession session=sqlSessionFactory.openSession();
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
dao.deleteBlog(5);
session.commit();
}finally{
session.close();
}
}
public static void testUpdateBlog()
{
SqlSession session=sqlSessionFactory.openSession();
Blog blog=new Blog();
blog.setId(6);
blog.setTitle("daxuexiaoyuan");
blog.setAuthername("xiaohua");
blog.setDate("2013/2/25");
blog.setContent("冷死了");
try{
IBlogDAO dao=session.getMapper(IBlogDAO.class);
dao.updateBlog(blog);
session.commit();
}finally{
session.close();
}
}
} 1） 在利用注解配置映射器接口的时候，必须要通过
sqlSessionFactory.getConfiguration().addMapper(IBlogDAO.class);来对给映射器接口注册，如果映射器接口中使用了@ResultMap注解，则由于已经在mybatis-config.xml配置了Mapper，则就不需要再次在代码中添加mapper。
2）当方法有多个参数的时候，为了与SQL语句中的#{}对应，一般可以使用@Param("")来为每个参数命别名，使得该别名与#{}对应。当参数只有一个的时候，不需要别名。
3 在进行更新删除添加的时候，如果传递的是一个实体对象，则SQL可以直接使用实体的属性。
4）映射器接口调用SqlBuilder中的方法，都是将参数转换为Map中的key，可以在SqlBuilder的方法中利用Map来获取传递的参数值，进而进行逻辑操作判断。
5）注解中对于返回多条记录的查询可以直接利用@Results和@Result来配置映射，或者利用@ResultMap来调用SQL配置文件中的ResultMap。