Spring --14.Spring中Dao使用JdbcTemplate的二種方式
阿新 • • 發佈：2018-11-19
在Dao中使用JdbcTemplate有二種方式：
(1)、直接Dao中宣告jdbcTemplate、通過set方法注入值
(2)讓Dao繼承JdbcDaoSupport
1、直接在Dao中宣告JdbcTemplate。通過set方法注入JdbcTemplate屬性的值
applicationContext.xml 把Dao配置到Spring中
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!--引入jdbc.properties--> <bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer"> <property name="location" value="classpath:jdbc.properties"></property> </bean> //把Dao配置到Spring中 <bean id="accountDao" class="com.day03.dao.Impl.AccountDaoImpl"> <property name="jdbcTemplate" ref="jdbcTemplate"></property> </bean> <!--配置jdbc模板--> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <!--注入資料--> <property name="dataSource" ref="dataSource"></property> </bean> <!--配置資料來源--> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"> <property name="driverClassName" value="${jdbc.driverClass}"></property> <property name="url" value="${jdbc.url}"></property> <property name="username" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> </beans>
AccountDaoImpl.java //編寫Dao注入JdbcTemplate
package com.day03.dao.Impl; import com.day03.dao.AccountDao; import com.day03.domain.Account; import com.day03.romMapper.AccountRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import java.util.List; /** * 建立AccountDaoImpl實現類，在其中宣告JdbcTemplate屬性，並提供set方法： * @ Author ：ShaoWei Sun. * @ Date ：Created in 21:19 2018/11/14 */ public class AccountDaoImpl implements AccountDao { //宣告JdbcTemplate屬性，並提供set方法。交給Spring容器 private JdbcTemplate jdbcTemplate; public void setJdbcTemplate(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } /** * 儲存使用者 * @param account */ @Override public void save(Account account) { this.jdbcTemplate.update("insert into account values(null,?,?)",account.getName(),account.getMoney()); } /** * 更新使用者 * @param account */ @Override public void update(Account account) { this.jdbcTemplate.update("update account set name = ?, money = ? where id = ? ;",account.getName(),account.getMoney(),account.getId()); } /** * 根據id刪除使用者 * @param id */ @Override public void delete(Long id) { this.jdbcTemplate.update("delete from account where id = ?",id); } /** * 根據id查詢money * @param id */ @Override public Double findMoney(Long id) { Double money = this.jdbcTemplate.queryForObject("select money from account where id = ?", Double.class, id); return money; } @Override public Account findById(Long id) { Account account = jdbcTemplate.queryForObject("select * from account where id = ?", new AccountRowMapper(),id); return account; } @Override public List<Account> findAll() { List<Account> list = jdbcTemplate.query("select * from account",new AccountRowMapper()); return list; } }
TestJdbcTemplate.java //測試
package com.day03.test; import com.alibaba.druid.pool.DruidDataSource; import com.day03.dao.AccountDao; import com.day03.domain.Account; import com.mchange.v2.c3p0.ComboPooledDataSource; import org.apache.commons.dbcp2.BasicDataSource; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.datasource.DriverManagerDataSource; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import java.beans.PropertyVetoException; import java.util.List; /** * @ Author ：ShaoWei Sun. * @ Date ：Created in 19:18 2018/11/14 */ @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration("classpath:applicationContext.xml") public class TestJdbcTemplate { @Autowired private AccountDao accountDao; /** * 測試儲存資料 */ @Test public void test10(){ Account account = new Account(); account.setName("cisco1"); account.setMoney(9999999999d); accountDao.save(account); } @Test public void test12(){ Double money = accountDao.findMoney(4L); System.out.println("money = " + money); } /** * 查詢所有 */ @Test public void test11(){ List<Account> all = accountDao.findAll(); System.out.println("all = " + all); } }
2、讓Dao繼承JdbcDaoSupport
讓AccountDaoImpl.java繼承JdbcDaoSupport
package com.day03.dao.Impl;
import com.day03.dao.AccountDao;
import com.day03.domain.Account;
import com.day03.romMapper.AccountRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import java.util.List;
/**
* 建立AccountDaoImpl實現類，在其中宣告JdbcTemplate屬性，並提供set方法：
* @ Author ：ShaoWei Sun.
* @ Date ：Created in 21:19 2018/11/14
*/
public class AccountDaoImpl2 extends JdbcDaoSupport implements AccountDao {
// //宣告JdbcTemplate屬性，並提供set方法。交給Spring容器
// private JdbcTemplate jdbcTemplate;
//
// public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
// this.jdbcTemplate = jdbcTemplate;
// }
/**
* 儲存使用者
* @param account
*/
@Override
public void save(Account account) {
this.getJdbcTemplate().update("insert into account values(null,?,?)",account.getName(),account.getMoney());
}
/**
* 更新使用者
* @param account
*/
@Override
public void update(Account account) {
this.getJdbcTemplate().update("update account set name = ?, money = ? where id = ? ;",account.getName(),account.getMoney(),account.getId());
}
/**
* 根據id刪除使用者
* @param id
*/
@Override
public void delete(Long id) {
this.getJdbcTemplate().update("delete from account where id = ?",id);
}
/**
* 根據id查詢money
* @param id
*/
@Override
public Double findMoney(Long id) {
Double money = this.getJdbcTemplate().queryForObject("select money from account where id = ?", Double.class, id);
return money;
}
@Override
public Account findById(Long id) {
Account account = getJdbcTemplate().queryForObject("select * from account where id = ?", new AccountRowMapper(),id);
return account;
}
@Override
public List<Account> findAll() {
List<Account> list = getJdbcTemplate().query("select * from account",new AccountRowMapper());
return list;
}
}
給Dao注入DataSource、不需要JdbcTemplate、因為繼承了JdbcDaoSupport這個類中已重寫了JdbcTemplate
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--引入jdbc.properties-->
<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
<property name="location" value="classpath:jdbc.properties"></property>
</bean>
<!--<context:property-placeholder location="classpath:jdbc.properties"/>-->
<bean id="accountDao" class="com.day03.dao.Impl.AccountDaoImpl2">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--<!–配置jdbc模板–>-->
<!--<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">-->
<!--<!–注入資料–>-->
<!--<property name="dataSource" ref="dataSource"></property>-->
<!--</bean>-->
<!--配置資料來源-->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driverClass}"></property>
<property name="url" value="${jdbc.url}"></property>
<property name="username" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
</beans>TestJdbcTemplate.java測試類
package com.day03.test;
import com.alibaba.druid.pool.DruidDataSource;
import com.day03.dao.AccountDao;
import com.day03.domain.Account;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbcp2.BasicDataSource;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.beans.PropertyVetoException;
import java.util.List;
/**
* @ Author ：ShaoWei Sun.
* @ Date ：Created in 19:18 2018/11/14
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext2.xml")
public class TestJdbcTemplate2 {
@Autowired
private AccountDao accountDao;
/**
* 測試儲存資料
*/
@Test
public void test10(){
Account account = new Account();
account.setName("cisco1");
account.setMoney(9999999999d);
accountDao.save(account);
}
@Test
public void test12(){
Double money = accountDao.findMoney(4L);
System.out.println("money = " + money);
}
/**
* 查詢所有
*/
@Test
public void test11(){
List<Account> all = accountDao.findAll();
System.out.println("all = " + all);
}
}
JdbcDaoSupport.java原始碼
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.springframework.jdbc.core.support;
import java.sql.Connection;
import javax.sql.DataSource;
import org.springframework.dao.support.DaoSupport;
import org.springframework.jdbc.CannotGetJdbcConnectionException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.jdbc.support.SQLExceptionTranslator;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
public abstract class JdbcDaoSupport extends DaoSupport {
@Nullable
private JdbcTemplate jdbcTemplate;
public JdbcDaoSupport() {
}
public final void setDataSource(DataSource dataSource) {
if (this.jdbcTemplate == null || dataSource != this.jdbcTemplate.getDataSource()) {
this.jdbcTemplate = this.createJdbcTemplate(dataSource);
this.initTemplateConfig();
}
}
protected JdbcTemplate createJdbcTemplate(DataSource dataSource) {
return new JdbcTemplate(dataSource);
}
@Nullable
public final DataSource getDataSource() {
return this.jdbcTemplate != null ? this.jdbcTemplate.getDataSource() : null;
}
public final void setJdbcTemplate(@Nullable JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
this.initTemplateConfig();
}
@Nullable
public final JdbcTemplate getJdbcTemplate() {
return this.jdbcTemplate;
}
protected void initTemplateConfig() {
}
protected void checkDaoConfig() {
if (this.jdbcTemplate == null) {
throw new IllegalArgumentException("'dataSource' or 'jdbcTemplate' is required");
}
}
protected final SQLExceptionTranslator getExceptionTranslator() {
JdbcTemplate jdbcTemplate = this.getJdbcTemplate();
Assert.state(jdbcTemplate != null, "No JdbcTemplate set");
return jdbcTemplate.getExceptionTranslator();
}
protected final Connection getConnection() throws CannotGetJdbcConnectionException {
DataSource dataSource = this.getDataSource();
Assert.state(dataSource != null, "No DataSource set");
return DataSourceUtils.getConnection(dataSource);
}
protected final void releaseConnection(Connection con) {
DataSourceUtils.releaseConnection(con, this.getDataSource());
}
}
二個版本Dao的區別：
第一種在Dao類中定義JdbcTemplate的方式，適用於所有配置方式（xml和註解都可以）
第二種讓Dao繼承JdbcDaoSupport的方式，只能用於基於XML的方式，註解用不了。