使用JDBC的DAO支持类

最新推荐文章于 2021-06-11 01:06:05 发布

最新推荐文章于 2021-06-11 01:06:05 发布 · 82 阅读

文章标签：

#java

本文详细介绍了Spring框架中DAO支持类的使用方法，包括如何通过不同的方式注入数据源，以及如何利用这些支持类进行数据库操作。

用了Template，就会感觉能不能不每次都搞个

private JdbcTemplate jdbcTemplate;

public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}

怪烦人的，当然spring也没那么傻。

DAO支持类：

可以直接给dataSource，也可以给Template，因为它不光有：

/**
* Set the JdbcTemplate for this DAO explicitly,
* as an alternative to specifying a DataSource.
*/
public final void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
initTemplateConfig();
}

还有

/**
* Set the JDBC DataSource to be used by this DAO.
*/
public final void setDataSource(DataSource dataSource) {
if (this.jdbcTemplate == null || dataSource != this.jdbcTemplate.getDataSource()) {
this.jdbcTemplate = createJdbcTemplate(dataSource);
initTemplateConfig();
}
}

----------

用一下：

package cn.partner4java.daosupport;

import cn.partner4java.bean.User;

public interface HelloJdbcDaoSupport {
/**
* 保存测试
* @param user
*/
public void saveUser(User user);

/**
* 获取
* @param id 索引
* @return
*/
public User getUserById(int id);
}

package cn.partner4java.daosupport;

import cn.partner4java.bean.User;

public interface HelloNamedParameterJdbcDaoSupport {
public void saveUser(User user);
}

package cn.partner4java.daosupport;

import cn.partner4java.bean.User;

public interface HelloSimpleJdbcDaoSupport {
public void saveUser(User user);
/**
* 获取
* @param id 索引
* @return
*/
public User getUserById(int id);
}

----

实现类

package cn.partner4java.daosupport.impl;

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

import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloJdbcDaoSupport;

public class HelloJdbcDaoSupportBean extends JdbcDaoSupport implements
HelloJdbcDaoSupport {

public User getUserById(int id) {
List users = this.getJdbcTemplate().query(USER_SELECT, new Object[]{id}, new RowMapper() {
public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt(1));
user.setUsername(rs.getString(2));
user.setPassword(rs.getString(3));
return user;
}
}) ;
return users.size() > 0 ? (User)users.get(0):null;
}

private static final String USER_SELECT = "select id,username,password from user where id = ?";

public void saveUser(User user) {
this.getJdbcTemplate().update(USER_INSERT, new Object[] {user.getUsername(),user.getPassword()});
}

private static final String USER_INSERT = "insert into user (username, password) values (?,?)";
}

package cn.partner4java.daosupport.impl;

import java.util.HashMap;
import java.util.Map;

import org.springframework.jdbc.core.namedparam.NamedParameterJdbcDaoSupport;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloNamedParameterJdbcDaoSupport;

public class HelloNamedParameterJdbcDaoSupportBean extends
NamedParameterJdbcDaoSupport implements
HelloNamedParameterJdbcDaoSupport {

public void saveUser(User user) {
Map parameters = new HashMap();
parameters.put("username", user.getUsername());
parameters.put("password", user.getPassword());
this.getNamedParameterJdbcTemplate().update(USER_INERT, parameters);
}

private static final String USER_INERT = "insert into user (username,password) values (:username, :password)";

}

package cn.partner4java.daosupport.impl;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.jdbc.core.simple.ParameterizedRowMapper;
import org.springframework.jdbc.core.simple.SimpleJdbcDaoSupport;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloSimpleJdbcDaoSupport;

public class HelloSimpleJdbcDaoSupportBean extends SimpleJdbcDaoSupport
implements HelloSimpleJdbcDaoSupport {

public void saveUser(User user) {
Map parameters = new HashMap();
parameters.put("username", user.getUsername());
parameters.put("password", user.getPassword());
//下面两种都可以
this.getSimpleJdbcTemplate().update(USER_INERT, parameters);
//this.getSimpleJdbcTemplate().update(USER_INSERT, user.getUsername(), user.getPassword());
}

private static final String USER_INERT = "insert into user (username,password) values (:username, :password)";
private static final String USER_INSERT = "insert into user (username, password) values (?,?)";

public User getUserById(int id) {
List<User> users = this.getSimpleJdbcTemplate().query(USER_SELECT,
new ParameterizedRowMapper<User>() {
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt(1));
user.setUsername(rs.getString(2));
user.setPassword(rs.getString(3));
return user;
}
}, id);
return users.size() > 0 ? (User)users.get(0):null;
}

private static final String USER_SELECT = "select id,username,password from user where id = ?";

}

----

测试一下

package cn.partner4java.daosupport.junit;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloJdbcDaoSupport;
import junit.framework.TestCase;

public class HelloJdbcDaoSupportBeanTest extends TestCase {
private HelloJdbcDaoSupport helloJdbcDaoSupport;

@Override
protected void setUp() throws Exception {
ApplicationContext ac = new ClassPathXmlApplicationContext("beans-jdbcdaosupport.xml");
helloJdbcDaoSupport = (HelloJdbcDaoSupport) ac.getBean("helloJdbcDaoSupport");
}

public void testSaveUser(){
User user = new User();
user.setUsername("心烦鸟");
user.setPassword("123");
helloJdbcDaoSupport.saveUser(user);
}

public void testGetUserById(){
System.out.println(helloJdbcDaoSupport.getUserById(1));
}

}

package cn.partner4java.daosupport.junit;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloNamedParameterJdbcDaoSupport;
import junit.framework.TestCase;

public class HelloNamedParameterJdbcDaoSupportBeanTest extends TestCase {
private HelloNamedParameterJdbcDaoSupport helloNamedParameterJdbcDaoSupport;

@Override
protected void setUp() throws Exception {
super.setUp();
ApplicationContext ac = new ClassPathXmlApplicationContext("beans-jdbcdaosupport.xml");
helloNamedParameterJdbcDaoSupport = (HelloNamedParameterJdbcDaoSupport) ac.getBean("helloNamedParameterJdbcDaoSupport");
}

public void testSaveUser(){
User user = new User();
user.setUsername("面霸");
user.setPassword("123");
helloNamedParameterJdbcDaoSupport.saveUser(user);
}

}

package cn.partner4java.daosupport.junit;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.partner4java.bean.User;
import cn.partner4java.daosupport.HelloSimpleJdbcDaoSupport;
import junit.framework.TestCase;

public class HelloSimpleJdbcDaoSupportBeanTest extends TestCase {
private HelloSimpleJdbcDaoSupport helloSimpleJdbcDaoSupport;

@Override
protected void setUp() throws Exception {
ApplicationContext ac = new ClassPathXmlApplicationContext("beans-jdbcdaosupport.xml");
helloSimpleJdbcDaoSupport = (HelloSimpleJdbcDaoSupport) ac.getBean("helloSimpleJdbcDaoSupport");
}

public void testSaveUser(){
User user = new User();
user.setUsername("心烦鸟");
user.setPassword("123");
helloSimpleJdbcDaoSupport.saveUser(user);
}

public void testGetUserById(){
System.out.println(helloSimpleJdbcDaoSupport.getUserById(2));
}

}