JDBC&连接池 数据交互改造之旅- 连接池类

/*
 * class  ：  连接池操作类
 * author ： 庄伟斌
 * version： V1.0
 * updatelog：
 * */
package com.landraydev.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;

public class DBConnectionPool {

 private int inUsed = 0;
 private ArrayList freeConnections = new ArrayList();
 private int minConn;
 private int maxConn;
 private String poolname;
 private String dbpassword;
 private String dbuser;
 private String dbdriver;
 private String dburl;

 public DBConnectionPool() {
  // TODO Auto-generated constructor stub
 }

 /*
  * 创建资源池
  */
 public DBConnectionPool(String poolname, String dbdriver, String dburl,
   String dbuser, String dbpassword, int maxconn) {
  this.setPoolname(poolname);
  this.setDbdriver(dbdriver);
  this.setDburl(dburl);
  this.setDbuser(dbuser);
  this.setDbpassword(dbpassword);
  this.setMaxConn(maxconn);
 }

 /*
  * 获取链接池中数据库连接资源 注释：获取链接资源，如果没有空闲链接资源，新增资源
  */
 public synchronized Connection getConnection(long timeout) {
  Connection con = null;
  long startTime = new Date().getTime();
  while ((con = getConnection()) == null) {
   try {
    wait(timeout);
   } catch (java.lang.InterruptedException e) {
    e.printStackTrace();
   }
   if ((new Date().getTime() - startTime >= timeout)) {
    return null;
   }
  }
  return con;
 }

 /*
  * 获取链接池中数据库连接资源注释：获取链接资源，如果没有空闲链接资源，新增资源
  */
 public synchronized Connection getConnection() {
  Connection con = null;

  // 连接分配
  if (this.freeConnections.size() > 0) {
   con = (Connection) this.freeConnections.get(0);
   this.freeConnections.remove(0);
   try {
    if ((con == null) || (con.isClosed()))
     con = getConnection();
   } catch (java.sql.SQLException e) {
    con = getConnection();
   }
  } else {
   con = newConnection();
  }

  // 连接池限额检测
  if (this.maxConn == 0 || this.maxConn <= this.inUsed) {
   System.out.println("连接池 " + this.poolname + "，最大限额" + this.maxConn
     + "现有" + inUsed + "个连接正在使用,您的请求无法响应!");
   con = null;
  }

  // 连接池使用情况设置
  if (con != null) {
   this.inUsed++;
   System.out.println("已获得连接池 " + this.poolname + "的数据库连接资源，连接池最大限额"
     + this.maxConn + "现有" + inUsed + "个连接正在使用!");
  }
  return con;
 }

 /*
  * 新增数据库连接资源 注释：创建数据库连接
  */
 private Connection newConnection() {
  // TODO Auto-generated method stub
  Connection con = null;
  try {
   Class.forName(dbdriver);
   con = DriverManager.getConnection(dburl, dbuser, dbpassword);
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
   System.out.println("数据库驱动程序无法正常运行，请检查驱动设置信息!");
  } catch (java.sql.SQLException e1) {
   e1.printStackTrace();
   System.out.println("无法正常创建数据库连接，请检测数据库网络通讯情况!");
  }
  return con;
 }

 /*
  * 回收数据库连接 注释：数据库操作完成，将连接资源归还给连接池，给其他需要使用的业务使用
  */
 public synchronized void freeConnection(Connection con) {
  this.freeConnections.add(con);
  this.inUsed--;
 }

 /*
  * 释放连接池资源 注释：取消资源池的数据库连接资源
  */
 public synchronized void releasePool() {
  if (this.freeConnections.size() > 0) {
   Connection con = null;
   Iterator allConns = this.freeConnections.iterator();
   while (allConns.hasNext()) {
    con = (Connection) allConns.next();
    try {
     if (con != null)
      con.close();
    } catch (java.sql.SQLException e) {
     e.printStackTrace();
    }
   }
   this.freeConnections.clear();
  }
 }

 /**
  * @return the minConn
  */
 public int getMinConn() {
  return minConn;
 }

 /**
  * @param minConn
  *            the minConn to set
  */
 public void setMinConn(int minConn) {
  this.minConn = minConn;
 }

 /**
  * @return the maxConn
  */
 public int getMaxConn() {
  return maxConn;
 }

 /**
  * @param maxConn
  *            the maxConn to set
  */
 public void setMaxConn(int maxConn) {
  this.maxConn = maxConn;
 }

 /**
  * @return the poolname
  */
 public String getPoolname() {
  return poolname;
 }

 /**
  * @param poolname
  *            the poolname to set
  */
 public void setPoolname(String poolname) {
  this.poolname = poolname;
 }

 /**
  * @return the dbpassword
  */
 public String getDbpassword() {
  return dbpassword;
 }

 /**
  * @param dbpassword
  *            the dbpassword to set
  */
 public void setDbpassword(String dbpassword) {
  this.dbpassword = dbpassword;
 }

 /**
  * @return the dbuser
  */
 public String getDbuser() {
  return dbuser;
 }

 /**
  * @param dbuser
  *            the dbuser to set
  */
 public void setDbuser(String dbuser) {
  this.dbuser = dbuser;
 }

 /**
  * @return the dbdriver
  */
 public String getDbdriver() {
  return dbdriver;
 }

 /**
  * @param dbdriver
  *            the dbdriver to set
  */
 public void setDbdriver(String dbdriver) {
  this.dbdriver = dbdriver;
 }

 /**
  * @return the dburl
  */
 public String getDburl() {
  return dburl;
 }

 /**
  * @param dburl
  *            the dburl to set
  */
 public void setDburl(String dburl) {
  this.dburl = dburl;
 }

}