import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ResourceBundle;
public class ConnectionPool {
private static String driverClassName;
private static String url;
private static String username;
private static String password;
private static int initCapacity; // 初始化数量
private static int maxCapacity; // 最大数量
private static List<NotifyConnection> poolList = new ArrayList<>(); // 连接池容器
static {
ResourceBundle oBundle = ResourceBundle.getBundle("db");
driverClassName = oBundle.getString("jdbc.driverClassName");
url = oBundle.getString("jdbc.url");
username = oBundle.getString("jdbc.userName");
password = oBundle.getString("jdbc.password");
initCapacity = Integer.valueOf(oBundle.getString("jdbc.connectionPool.initCapacity"));
maxCapacity = Integer.valueOf(oBundle.getString("jdbc.connectionPool.maxCapacity"));
initConnectionPool();
}
/*
* 初始化连接池
*/
private static void initConnectionPool() {
poolList = new ArrayList<>();
for (int i=0; i<initCapacity; i++) {
addConnctionToPool();
}
}
/*
* 向连接池中添加连接
*/
private static void addConnctionToPool(){
if (poolList.size() < maxCapacity) {
synchronized (poolList) {
if (poolList.size() < maxCapacity) {
Connection oConnection;
do {
oConnection = createConnection();
if (null == oConnection) { // 建立连接池异常，重试
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
} while (null == oConnection);
NotifyConnection oNotifyConnection = new NotifyConnection(oConnection);
poolList.add(oNotifyConnection);
}
}
}
}
/*
* 创建连接
*/
private static Connection createConnection(){
Connection oConnection = null;
try {
Class.forName(driverClassName);
oConnection = DriverManager.getConnection(url, username, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return oConnection;
}
/**
* 从连接池获取连接
*
* @return
* @author zhangh-ag
* @date 2017年6月7日
*
*/
public static Connection getConnection() {
Connection oConnection = null;
Iterator<NotifyConnection> oIterator = poolList.iterator();
NotifyConnection oNotifyConnection;
while (oIterator.hasNext()) {
oNotifyConnection = oIterator.next();
if (!oNotifyConnection.isUsed) {
synchronized (oNotifyConnection) {
if (!oNotifyConnection.isUsed) {
oNotifyConnection.setIsUsed(true);
oConnection = oNotifyConnection.getConnection();
break;
}
}
}
}
if (null == oConnection) {
if (poolList.size() < maxCapacity) {
addConnctionToPool();
} else {
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return getConnection();
}
}
return oConnection;
}
/**
* 归还连接
*
* @param con
* @param statement
* @param resultSet
* @author zhangh-ag
* @date 2017年6月7日
*
*/
public static void closeConnection(Connection con, Statement statement, ResultSet resultSet) {
if (null != resultSet) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null != statement) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null != con) {
NotifyConnection oNotifyConnection;
Connection oConnection;
Iterator<NotifyConnection> oIterator = poolList.iterator();
while (oIterator.hasNext()) {
oNotifyConnection = oIterator.next();
oConnection = oNotifyConnection.getConnection();
if (con.equals(oConnection)) {
oNotifyConnection.setIsUsed(false);
break;
}
}
}
}
/**
* 归还连接
*
* @param con
* @param statement
* @param resultSet
* @author zhangh-ag
* @date 2017年6月7日
*
*/
public static void closeConnection(Connection con, PreparedStatement statement, ResultSet resultSet) {
if (null != resultSet) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null != statement) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null != con) {
NotifyConnection oNotifyConnection;
Connection oConnection;
Iterator<NotifyConnection> oIterator = poolList.iterator();
while (oIterator.hasNext()) {
oNotifyConnection = oIterator.next();
oConnection = oNotifyConnection.getConnection();
if (con.equals(oConnection)) {
oNotifyConnection.setIsUsed(false);
break;
}
}
}
}
/**
* 连接不可用，销毁该连接
*
* @param connection
* @author zhangh-ag
* @date 2017年6月7日
*
*/
public static void destoryConnection(Connection connection) {
NotifyConnection oNotifyConnection;
Iterator<NotifyConnection> oIterator = poolList.iterator();
Connection con;
while (oIterator.hasNext()) {
oNotifyConnection = oIterator.next();
con = oNotifyConnection.getConnection();
if (con.equals(connection)) {
oIterator.remove();
break;
}
}
}
//连接池中连接实体
static class NotifyConnection {
private Boolean isUsed;
private Connection connection;
public NotifyConnection(Connection connection) {
isUsed = false;
this.connection = connection;
}
public Boolean getIsUsed() {
return isUsed;
}
public void setIsUsed(Boolean isUsed) {
this.isUsed = isUsed;
}
public Connection getConnection() {
return connection;
}
public void setConnection(Connection connection) {
this.connection = connection;
}
}
}