由于公司的框架体系太成熟，所以工作一段时间后导致最底层的东西几乎忘掉，今天趁闲暇时间又把jdbc基础捡了一下并写了一个较为通用的工具类，其中包括事务模板，简单查询，修改，有不足的地方忘大牛们多提建议，拍转，工具类主要包括DaoSupport、DaoSupportTemplate、DaoSupportAction。
1、DaoSupport 工具类，封装了自己实现的连接池和jdbc简单的查询和修改。
/**
* Alipay.com Inc.
* Copyright (c) 2004-2013 All Rights Reserved.
*/
package com.jinfeng.practice.util;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.List;
import java.util.Properties;
import com.jinfeng.practice.util.impl.DaoSupportTemplateImpl;
/**
* dao支持类
*
* @author feng.jin
* @version $Id: DaoSupport.java, v 0.1 2013-8-7 上午10:58:28 feng.jin Exp $
*/
public class DaoSupport {
/** 数据连接池 */
private static final List<Connection> connectionPool = new LinkedList<Connection>();
/** 驱动 */
private static String driver;
/** url*/
private static String url;
/** username */
private static String username;
/** password */
private static String password;
/** properties */
private static final Properties properties = new Properties();
/** 最大连接数 */
private static final int MAX = 10;
/** 活跃连接数 */
private static int activeNum = 10;
/** 已用连接数 */
private static int usedNum = 0;
/** 连接 */
private Connection conn = null;
/** 语句平台 */
private PreparedStatement preparedStatement = null;
/** 模板 */
private final DaoSupportTemplate daoSupportTemplate;
/**
* constructor
*/
public DaoSupport() {
daoSupportTemplate = new DaoSupportTemplateImpl();
daoSupportTemplate.setDaoSupport(this);
}
static {
try {
//1.【初始化数据连接需要的数据】
properties.load(DaoSupport.class.getResourceAsStream("/config/datasource.properties"));
driver = properties.getProperty("jdbc.driver");
url = properties.getProperty("jdbc.url");
username = properties.getProperty("jdbc.username");
password = properties.getProperty("jdbc.password");
Class.forName(driver);
//2.【初始化连接池】
for (int i = 0; i < 10; i++) {
Connection conn = DriverManager.getConnection(url, username, password);
connectionPool.add(conn);
}
} catch (IOException e) {
System.out.println(e);
} catch (ClassNotFoundException e) {
System.out.println(e);
} catch (SQLException e) {
System.out.println(e);
}
}
/**
* 获取连接
*
* @return
*/
public synchronized Connection getConnection() {
if (conn == null) {
if (connectionPool != null && connectionPool.size() >= 0) {
conn = connectionPool.get(0);
connectionPool.remove(0);
activeNum--;
usedNum++;
} else {
throw new RuntimeException("当前使用的连接数已经超过" + MAX + ", 连接池没有足够的数据库连接!");
}
} else {
return conn;
}
return conn;
}
/**
* 获取语句执行器
*
* @param conn
* @param sql
* @param params
* @return
*/
public PreparedStatement getPreparedStatement(Connection conn, String sql, List<Object> params) {
try {
if (preparedStatement == null) {
preparedStatement = conn.prepareStatement(sql);
}
if (params != null) {
for (int i = 0; i < params.size(); i++) {
Object param = params.get(i);
preparedStatement.setObject(i + 1, param);
}
}
} catch (SQLException e) {
System.out.println(e);
}
return preparedStatement;
}
public int excuteUpdate(String sql, List<Object> params) {
conn = getConnection();
int i = 0;
PreparedStatement preparedStatement = getPreparedStatement(conn, sql, params);
try {
i = preparedStatement.executeUpdate(sql);
} catch (SQLException e) {
System.out.println(e);
}
return i;
}
/**
* 释放连接
*/
public synchronized void close() {
if (conn != null) {
connectionPool.add(conn);
conn = null;
activeNum++;
usedNum--;
}
}
/**
* 释放指定连接
*/
public synchronized void close(Connection conn) {
if (conn != null) {
connectionPool.add(conn);
conn = null;
activeNum++;
usedNum--;
}
}
/** *
* 执行查询
*
* @param sql
* @param params
* @return
*/
public ResultSet excuteQuery(String sql, List<Object> params) {
Connection conn = getConnection();
PreparedStatement preparedStatement = getPreparedStatement(conn, sql, params);
ResultSet resultSet = null;
try {
resultSet = preparedStatement.executeQuery();
} catch (SQLException e) {
System.out.println(e);
}
return resultSet;
}
/**
* Getter method for property <tt>daoSupportTemplate</tt>.
*
* @return property value of daoSupportTemplate
*/
public DaoSupportTemplate getDaoSupportTemplate() {
return daoSupportTemplate;
}
}
2、DaoSupportTemplate 模板，用于处理事务相关的操作，中间可用用户自行实现
/**
* Alipay.com Inc.
* Copyright (c) 2004-2013 All Rights Reserved.
*/
package com.jinfeng.practice.util;
import java.sql.Connection;
/**
* 模板
*
* @author feng.jin
* @version $Id: DaoSupportTemplate.java, v 0.1 2013-8-7 下午03:51:59 feng.jin Exp $
*/
public interface DaoSupportTemplate {
/**
* 执行
*
* @param conn
* @param daoSupportCallBack
*/
public void excute(Connection conn, DaoSupportCallBack daoSupportCallBack);
/**
* 获取
*
* @return
*/
public DaoSupport getDaoSupport();
/**
* 设置
*
* @param daoSupport
*/
public void setDaoSupport(DaoSupport daoSupport);
}
3、DaoSupportTemplateImpl 模板实现
/**
* Alipay.com Inc.
* Copyright (c) 2004-2013 All Rights Reserved.
*/
package com.jinfeng.practice.util.impl;
import java.sql.Connection;
import com.jinfeng.practice.util.DaoSupport;
import com.jinfeng.practice.util.DaoSupportCallBack;
import com.jinfeng.practice.util.DaoSupportTemplate;
/**
* 模板
*
* @author feng.jin
* @version $Id: DaoSupportTemplateImpl.java, v 0.1 2013-8-7 下午03:54:00 feng.jin Exp $
*/
public class DaoSupportTemplateImpl implements DaoSupportTemplate {
private DaoSupport daoSupport;
/**
* @see com.jinfeng.practice.util.DaoSupportTemplate#excute(java.sql.Connection)
*/
@Override
public void excute(Connection conn, DaoSupportCallBack daoSupportCallBack) {
try {
conn.setAutoCommit(false);
daoSupportCallBack.process();
conn.commit();
} catch (Exception e) {
System.out.println(e);
try {
conn.rollback();
} catch (Exception e1) {
System.out.println("回滚失败" + e);
}
} finally {
daoSupport.close(conn);
}
}
/**
* Getter method for property <tt>daoSupport</tt>.
*
* @return property value of daoSupport
*/
public DaoSupport getDaoSupport() {
return daoSupport;
}
/**
* Setter method for property <tt>daoSupport</tt>.
*
* @param daoSupport value to be assigned to property daoSupport
*/
public void setDaoSupport(DaoSupport daoSupport) {
this.daoSupport = daoSupport;
}
}
4、DaoSupportCallBack 回调
/**
* Alipay.com Inc.
* Copyright (c) 2004-2013 All Rights Reserved.
*/
package com.jinfeng.practice.util;
/**
* 回调
*
* @author feng.jin
* @version $Id: DaoSupportCallBack.java, v 0.1 2013-8-7 下午03:59:18 feng.jin Exp $
*/
public interface DaoSupportCallBack {
public void process();
}