Spring整合JDBC实现简单的增删改续-实现基于RowMaper的查询

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Spring整合JDBC实现简单的增删改续-实现基于RowMaper的查询：

在上面一篇

Spring整合JDBC实现简单的增删改 的基础上完成对数据库的查询操作。

首先查看Spring文档资料，Spring文档及镜像下载参考文章：Spring简单学习计划
，里面包含了简单的学习计划！





根据以上文档，编写查询方法，示例代码如下：

[java]
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package org.oms.spring.dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.oms.spring.model.Group;
import org.oms.spring.model.User;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

@Repository("userJdbcDao")
public class UserDao implements IUserDao {
private JdbcTemplate JdbcTemplate;

/**
* Set the JDBC DataSource to obtain connections from.
*/
@Resource
public void setDataSource(DataSource dataSource) {
JdbcTemplate = new JdbcTemplate(dataSource);
}

@Override
public void add(User user, int gid) {
JdbcTemplate
.update("insert into user(username,password,gid,age,birthday,createdate) value (?,?,?,?,?,?)",
user.getUsername(), user.getPassword(), gid,
user.getAge(), user.getBirthDay(), user.getCreateDate());
}

@Override
public void update(User user, int gid) {
JdbcTemplate
.update("update user set username=?,password=?,gid=?,age=?,birthday=?,createdate=? where id=?",
user.getUsername(), user.getPassword(), gid,
user.getAge(), user.getBirthDay(),
user.getCreateDate(), user.getId());
}

@Override
public void delete(int id) {
JdbcTemplate.update("delete from user where id =?", id);
}

@Override
public User load(int id) {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id) where t1.id=?";
/**
* 第一个参数是SQL语句
* 第二个参数是SQL语句中参数值，需要传入一个对象数组
* 第三个是一个RowMapper，这个RowMapper可以完成一个对象和数据库字段的对应，实现这个RowMapper需要实现mapRow方法，
* 在这个mapRow方法中有rs这个参数，通过rs可以有效的获取数据库的字段
* 如果这个方法在DAO中会被重复使用，建议通过内部类来解决，而不要使用匿名的内部类
*/
User u=(User)JdbcTemplate.queryForObject(sql,new Object[]{id} ,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
Group group=new Group();
group.setName(rs.getString("name"));
group.setId(rs.getInt("gid"));
User user=new User();
user.setGroup(group);
user.setId(rs.getInt("uid"));
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
user.setAge(rs.getInt("age"));
user.setBirthDay(rs.getDate("birthday"));
user.setCreateDate(rs.getDate("createdate"));
return user;
}

});
return u;
}

/**
* 上面方法简化
* @param id
* @return
*/
public User loadOther(int id) {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id) where t1.id=?";

User u=(User)JdbcTemplate.queryForObject(sql,new Object[]{id} ,new UserMapper());
return u;
}

@Override
public List<User> list(String sql,Object[] args) {
//查询总条数，获取整数值
String sqlCount="select count(1) from user";
int count=JdbcTemplate.queryForInt(sqlCount);
System.out.println(count);
//查询单列，获取String类型的列表
String sqlCol="select username from user";
List<String> cols=JdbcTemplate.queryForList(sqlCol, String.class);
for (int i = 0; i < cols.size(); i++) {
System.out.println(cols.get(i));
}
//查询多列
String sqlCols="select username,password from user";
List<User> users=JdbcTemplate.query(sqlCols,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user=new User();
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
return user;
}

});

for (int i = 0; i < users.size(); i++) {
System.out.println(users.get(i).toString());
}

//查询列表
return JdbcTemplate.query(sql, args,new UserMapper());
}

/**
* 建议通过内部类来解决，而不要使用匿名的内部类
* @author sunlight
*
*/
private class UserMapper implements RowMapper<User>{

@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
Group group=new Group();
group.setName(rs.getString("name"));
group.setId(rs.getInt("gid"));
User user=new User();
user.setGroup(group);
user.setId(rs.getInt("uid"));
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
user.setAge(rs.getInt("age"));
user.setBirthDay(rs.getDate("birthday"));
user.setCreateDate(rs.getDate("createdate"));
return user;
}

}

}

package org.oms.spring.dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.oms.spring.model.Group;
import org.oms.spring.model.User;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

@Repository("userJdbcDao")
public class UserDao implements IUserDao {
private JdbcTemplate JdbcTemplate;

/**
* Set the JDBC DataSource to obtain connections from.
*/
@Resource
public void setDataSource(DataSource dataSource) {
JdbcTemplate = new JdbcTemplate(dataSource);
}

@Override
public void add(User user, int gid) {
JdbcTemplate
.update("insert into user(username,password,gid,age,birthday,createdate) value (?,?,?,?,?,?)",
user.getUsername(), user.getPassword(), gid,
user.getAge(), user.getBirthDay(), user.getCreateDate());
}

@Override
public void update(User user, int gid) {
JdbcTemplate
.update("update user set username=?,password=?,gid=?,age=?,birthday=?,createdate=? where id=?",
user.getUsername(), user.getPassword(), gid,
user.getAge(), user.getBirthDay(),
user.getCreateDate(), user.getId());
}

@Override
public void delete(int id) {
JdbcTemplate.update("delete from user where id =?", id);
}

@Override
public User load(int id) {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id) where t1.id=?";
/**
* 第一个参数是SQL语句
* 第二个参数是SQL语句中参数值，需要传入一个对象数组
* 第三个是一个RowMapper，这个RowMapper可以完成一个对象和数据库字段的对应，实现这个RowMapper需要实现mapRow方法，
* 在这个mapRow方法中有rs这个参数，通过rs可以有效的获取数据库的字段
* 如果这个方法在DAO中会被重复使用，建议通过内部类来解决，而不要使用匿名的内部类
*/
User u=(User)JdbcTemplate.queryForObject(sql,new Object[]{id} ,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
Group group=new Group();
group.setName(rs.getString("name"));
group.setId(rs.getInt("gid"));
User user=new User();
user.setGroup(group);
user.setId(rs.getInt("uid"));
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
user.setAge(rs.getInt("age"));
user.setBirthDay(rs.getDate("birthday"));
user.setCreateDate(rs.getDate("createdate"));
return user;
}

});
return u;
}

/**
* 上面方法简化
* @param id
* @return
*/
public User loadOther(int id) {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id) where t1.id=?";

User u=(User)JdbcTemplate.queryForObject(sql,new Object[]{id} ,new UserMapper());
return u;
}

@Override
public List<User> list(String sql,Object[] args) {
//查询总条数，获取整数值
String sqlCount="select count(1) from user";
int count=JdbcTemplate.queryForInt(sqlCount);
System.out.println(count);
//查询单列，获取String类型的列表
String sqlCol="select username from user";
List<String> cols=JdbcTemplate.queryForList(sqlCol, String.class);
for (int i = 0; i < cols.size(); i++) {
System.out.println(cols.get(i));
}
//查询多列
String sqlCols="select username,password from user";
List<User> users=JdbcTemplate.query(sqlCols,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user=new User();
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
return user;
}

});

for (int i = 0; i < users.size(); i++) {
System.out.println(users.get(i).toString());
}

//查询列表
return JdbcTemplate.query(sql, args,new UserMapper());
}

/**
* 建议通过内部类来解决，而不要使用匿名的内部类
* @author sunlight
*
*/
private class UserMapper implements RowMapper<User>{

@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
Group group=new Group();
group.setName(rs.getString("name"));
group.setId(rs.getInt("gid"));
User user=new User();
user.setGroup(group);
user.setId(rs.getInt("uid"));
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
user.setAge(rs.getInt("age"));
user.setBirthDay(rs.getDate("birthday"));
user.setCreateDate(rs.getDate("createdate"));
return user;
}

}

}

这部分内容是我们经常查询遇到的，所以我在上面直接添加到查询列表方法中了：

[java]
view plaincopyprint?

//查询总条数，获取整数值
String sqlCount="select count(1) from user";
int count=JdbcTemplate.queryForInt(sqlCount);
System.out.println(count);
//查询单列，获取String类型的列表
String sqlCol="select username from user";
List<String> cols=JdbcTemplate.queryForList(sqlCol, String.class);
for (int i = 0; i < cols.size(); i++) {
System.out.println(cols.get(i));
}
//查询多列
String sqlCols="select username,password from user";
List<User> users=JdbcTemplate.query(sqlCols,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user=new User();
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
return user;
}

});

for (int i = 0; i < users.size(); i++) {
System.out.println(users.get(i).toString());
}

//查询总条数，获取整数值
String sqlCount="select count(1) from user";
int count=JdbcTemplate.queryForInt(sqlCount);
System.out.println(count);
//查询单列，获取String类型的列表
String sqlCol="select username from user";
List<String> cols=JdbcTemplate.queryForList(sqlCol, String.class);
for (int i = 0; i < cols.size(); i++) {
System.out.println(cols.get(i));
}
//查询多列
String sqlCols="select username,password from user";
List<User> users=JdbcTemplate.query(sqlCols,new RowMapper<User>(){
@Override
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user=new User();
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
return user;
}

});

for (int i = 0; i < users.size(); i++) {
System.out.println(users.get(i).toString());
}

测试代码：

[java]
view plaincopyprint?

package org.oms.spring.test;

import static org.junit.Assert.*;

import java.util.Date;
import java.util.List;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.oms.spring.dao.IGroupDao;
import org.oms.spring.dao.IUserDao;
import org.oms.spring.model.Group;
import org.oms.spring.model.User;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

/**
* 当使用了以下注释之后，就可以直接在Test中进行依赖注入
*
* @author sunlight
*
*/
// 让Junit运行在Spring的测试环境中

@RunWith(SpringJUnit4ClassRunner.class)
// 加载beans.xml文件
@ContextConfiguration("/beans.xml")
public class TestJdbc {

@Resource(name = "userJdbcDao")
private IUserDao userJdbcDao;

@Resource(name="groupJdbcDao")
private IGroupDao groupJdbcDao;

@Test
public void testAdd() {
Group group=new Group("test1");
groupJdbcDao.add(group);
System.out.println(group.getId());

User user = new User("我是Spring","123", 20, new Date(), new Date());
userJdbcDao.add(user,group.getId());
}

@Test
public void testUpdate() {
User user = new User("Spring","123", 20, new Date(), new Date());
user.setId(2);
userJdbcDao.update(user,1);
}

@Test
public void testDel() {
userJdbcDao.delete(2);
}

@Test
public void testLoad() {
User user=userJdbcDao.load(1);
System.out.println(user);
}

@Test
public void testList() {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id)";
List<User> users=userJdbcDao.list(sql, null);
for (int i = 0; i < users.size(); i++) {

System.out.println(users.get(i).toString());
}
}
}

package org.oms.spring.test;

import static org.junit.Assert.*;

import java.util.Date;
import java.util.List;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.oms.spring.dao.IGroupDao;
import org.oms.spring.dao.IUserDao;
import org.oms.spring.model.Group;
import org.oms.spring.model.User;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

/**
* 当使用了以下注释之后，就可以直接在Test中进行依赖注入
*
* @author sunlight
*
*/
// 让Junit运行在Spring的测试环境中
@RunWith(SpringJUnit4ClassRunner.class)
// 加载beans.xml文件
@ContextConfiguration("/beans.xml")
public class TestJdbc {

@Resource(name = "userJdbcDao")
private IUserDao userJdbcDao;

@Resource(name="groupJdbcDao")
private IGroupDao groupJdbcDao;

@Test
public void testAdd() {
Group group=new Group("test1");
groupJdbcDao.add(group);
System.out.println(group.getId());

User user = new User("我是Spring","123", 20, new Date(), new Date());
userJdbcDao.add(user,group.getId());
}

@Test
public void testUpdate() {
User user = new User("Spring","123", 20, new Date(), new Date());
user.setId(2);
userJdbcDao.update(user,1);
}

@Test
public void testDel() {
userJdbcDao.delete(2);
}

@Test
public void testLoad() {
User user=userJdbcDao.load(1);
System.out.println(user);
}

@Test
public void testList() {
String sql="select t1.id uid ,t1.*,t2.* from user t1 left join `group` t2 on (t1.gid=t2.id)";
List<User> users=userJdbcDao.list(sql, null);
for (int i = 0; i < users.size(); i++) {

System.out.println(users.get(i).toString());
}
}
}

测试结果：



上面是JdbcTemplate实现的增删改操作（也就是参数带 “？”），下面的文档有使用 NamedParameterJdbcTemplate 实现，此方法以后实现!









以上就是JDBC简单实现增删改的操作，下节实现用模板设计模式实现此功能！