标签:des style blog color io os ar java for
最近一个项目中需要自己写个连接池, 写了一个下午,挺辛苦的,但不知道会不会出问题, 所以,贴到博客上,欢迎各路大神指点
1. 配置信息:
/** * */ package cn.mjorcen.db.bean; import java.util.ResourceBundle; import org.apache.log4j.Logger; /** * * 配置信息 * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 3:02:56 PM * @version 1 */ public class Configuration { private ResourceBundle resource; private Logger logger = Logger.getLogger(getClass()); private String driverClassName = "com.mysql.jdbc.Driver"; private String validationQuery = "SELECT 1"; private String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull"; private String user = "root"; private String password = ""; private int initialPoolSize = 3; private int minPoolSize = 3; private int maxPoolSize = 10; private int maxStatements = 30; private int maxIdleTime = 25000; private int idleConnectionTestPeriod = 18000; private int connectionLonger = 3600000; public Configuration() { super(); } public Configuration(String _properties) { super(); init(_properties); } /** * * @param _properties * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 3:08:54 PM * @version 1 */ private void init(String _properties) { resource = ResourceBundle.getBundle(_properties); try { String tmp = ""; setDriverClassName(resource.getString("driverClassName")); setValidationQuery(resource.getString("validationQuery")); setUrl(resource.getString("jdbc_url")); setUser(resource.getString("jdbc_username")); setPassword(resource.getString("jdbc_password")); tmp = resource.getString("initialPoolSize"); if (tmp != null) { setInitialPoolSize(Integer.parseInt(tmp)); } tmp = resource.getString("minPoolSize"); if (tmp != null) { setMinPoolSize(Integer.parseInt(tmp)); } tmp = resource.getString("maxPoolSize"); if (tmp != null) { setMaxPoolSize(Integer.parseInt(tmp)); } tmp = resource.getString("maxStatements"); if (tmp != null) { setMaxStatements(Integer.parseInt(tmp)); } tmp = resource.getString("maxIdleTime"); if (tmp != null) { setMaxIdleTime(Integer.parseInt(tmp)); } tmp = resource.getString("idleConnectionTestPeriod"); if (tmp != null) { setIdleConnectionTestPeriod(Integer.parseInt(tmp)); } tmp = resource.getString("connectionLonger"); if (tmp != null) { setIdleConnectionTestPeriod(Integer.parseInt(tmp)); } } catch (Exception e) { e.printStackTrace(); logger.error(e); } } public ResourceBundle getResource() { return resource; } public void setResource(ResourceBundle resource) { this.resource = resource; } public String getDriverClassName() { return driverClassName; } public void setDriverClassName(String driverClassName) { this.driverClassName = driverClassName; } public String getValidationQuery() { return validationQuery; } public void setValidationQuery(String validationQuery) { this.validationQuery = validationQuery; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public String getUser() { return user; } public void setUser(String user) { this.user = user; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getInitialPoolSize() { return initialPoolSize; } public void setInitialPoolSize(int initialPoolSize) { this.initialPoolSize = initialPoolSize; } public int getMinPoolSize() { return minPoolSize; } public void setMinPoolSize(int minPoolSize) { this.minPoolSize = minPoolSize; } public int getMaxPoolSize() { return maxPoolSize; } public void setMaxPoolSize(int maxPoolSize) { this.maxPoolSize = maxPoolSize; } public int getMaxStatements() { return maxStatements; } public void setMaxStatements(int maxStatements) { this.maxStatements = maxStatements; } public int getMaxIdleTime() { return maxIdleTime; } public void setMaxIdleTime(int maxIdleTime) { this.maxIdleTime = maxIdleTime; } public int getIdleConnectionTestPeriod() { return idleConnectionTestPeriod; } public void setIdleConnectionTestPeriod(int idleConnectionTestPeriod) { this.idleConnectionTestPeriod = idleConnectionTestPeriod; } public int getConnectionLonger() { return connectionLonger; } public void setConnectionLonger(int connectionLonger) { this.connectionLonger = connectionLonger; } }
2. connection 的包装类, 因为mysql 一个连接连接8小时就会被mysql 干掉;所以出此下策;
/** * */ package cn.mjorcen.db.bean; import java.sql.Connection; import java.sql.SQLException; import org.apache.log4j.Logger; /** * * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 4:27:30 PM * @version 1 */ public class WarpConnection { private Logger logger = Logger.getLogger(getClass()); private long connectionTime; private long lastWorkTime; private Connection connection; public long getConnectionTime() { return connectionTime; } public void setConnectionTime(long connectionTime) { this.connectionTime = connectionTime; } public Connection getConnection() { return connection; } public void setConnection(Connection connection) { this.connection = connection; } public static WarpConnection warp(Connection connection) { WarpConnection warpConnection = new WarpConnection(); warpConnection.setConnection(connection); warpConnection.setConnectionTime(System.currentTimeMillis()); return warpConnection; } public boolean isTimeOut(long time) { return System.currentTimeMillis() - this.connectionTime >= time; } public long getLastWorkTime() { return lastWorkTime; } public void setLastWorkTime(long lastWorkTime) { this.lastWorkTime = lastWorkTime; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((connection == null) ? 0 : connection.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; WarpConnection other = (WarpConnection) obj; if (connection == null) { if (other.connection != null) return false; } else if (!connection.equals(other.connection)) return false; return true; } /** * 查看链接是否有效 * @param connectionLonger * 连接最大时间 * @return * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 5:21:07 PM * @version 1 * @throws SQLException */ public boolean veryfiConnection(int connectionLonger) { try { if (this.connection == null || this.connection.isClosed() || isTimeOut(connectionLonger)) { return true; } } catch (SQLException e) { e.printStackTrace(); } return false; } }
3.连接池:
/** * */ package cn.mjorcen.db.pool.impl; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.NoSuchElementException; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; import cn.mjorcen.db.bean.Configuration; import cn.mjorcen.db.bean.WarpConnection; import cn.mjorcen.db.pool.PooledDataSource; /** * 简单的线程池实现 * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 3:24:32 PM * @version 1 */ public class AbstractPooledDataSource implements PooledDataSource { protected ConcurrentLinkedQueue<WarpConnection> idleQueue; protected ConcurrentLinkedQueue<WarpConnection> busyQueue; protected ThreadLocal<Connection> threadLocal; protected AtomicInteger totalSize; protected AtomicInteger currentSize; protected boolean available; protected Configuration configuration; final Lock lock = new ReentrantLock();// 锁 // final Condition notFull = lock.newCondition(); // 实例化两个condition final Condition notEmpty = lock.newCondition(); public AbstractPooledDataSource(Configuration configuration) throws Exception { super(); this.configuration = configuration; idleQueue = new ConcurrentLinkedQueue<WarpConnection>(); busyQueue = new ConcurrentLinkedQueue<WarpConnection>(); threadLocal = new ThreadLocal<Connection>(); totalSize = new AtomicInteger(0); currentSize = new AtomicInteger(0); init(); } /** * * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 3:49:36 PM * @version 1 * @throws ClassNotFoundException */ private void init() throws Exception { Class.forName("com.mysql.jdbc.Driver"); for (int i = 0; i < this.configuration.getInitialPoolSize(); i++) { idleQueue.add(WarpConnection.warp(openConnection())); } this.totalSize.set(this.configuration.getInitialPoolSize()); available = true; } protected Connection openConnection() throws SQLException { return DriverManager.getConnection(configuration.getUrl(), configuration.getUser(), configuration.getPassword()); } public Connection getConnection() throws SQLException { Connection connection = threadLocal.get(); if (connection != null) { return connection; } try { lock.lock(); WarpConnection warpConnection = null; try { warpConnection = this.idleQueue.remove(); } catch (NoSuchElementException e) { warpConnection = getWarpConnection(); } veryfiConnection(warpConnection); warpConnection.setLastWorkTime(System.currentTimeMillis()); this.busyQueue.add(warpConnection); threadLocal.set(warpConnection.getConnection()); return warpConnection.getConnection(); } finally { lock.unlock(); } } /** * 检查链接状态 * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 5:17:06 PM * @version 1 * @param warpConnection * @throws SQLException */ private void veryfiConnection(WarpConnection warpConnection) throws SQLException { if (!warpConnection.veryfiConnection(this.configuration .getConnectionLonger())) { warpConnection.setConnection(openConnection()); } } /** * * @return * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 4:44:52 PM * @version 1 * @throws SQLException */ private WarpConnection getWarpConnection() throws SQLException { WarpConnection warpConnection = null; if (this.totalSize.get() < configuration.getMaxPoolSize()) { warpConnection = WarpConnection.warp(openConnection()); this.totalSize.addAndGet(1); return warpConnection; } while (true) { try { warpConnection = this.idleQueue.remove(); return warpConnection; } catch (NoSuchElementException e) { try { this.notEmpty.wait(); } catch (InterruptedException e1) { e1.printStackTrace(); } } } } public void destroy() { this.available = false; ConcurrentLinkedQueue<WarpConnection> _idleQueue = this.idleQueue; ConcurrentLinkedQueue<WarpConnection> _busyQueue = this.busyQueue; this.idleQueue = null; this.busyQueue = null; this.threadLocal = null; for (WarpConnection connection : _idleQueue) { closeQuiet(connection.getConnection()); } } private void closeQuiet(Connection connection) { if (connection != null) { try { connection.close(); } catch (SQLException e) { e.printStackTrace(); } } } public void release(Connection connection) throws Exception { try { lock.lock(); if (this.available) { WarpConnection warpConnection = null; for (WarpConnection element : this.busyQueue) { if (element.getConnection().equals(connection)) { warpConnection = element; break; } } this.busyQueue.remove(warpConnection); this.idleQueue.add(warpConnection); System.out.println("busyQueue = " + busyQueue.size()); System.out.println("idleQueue = " + idleQueue.size()); threadLocal.set(null); notEmpty.signal();// 一旦插入就唤醒取数据线程 } else { closeQuiet(connection); } } catch (Exception e) { e.printStackTrace(); } finally { lock.unlock(); } } public boolean isAvailable() { return available; } }
调用类:
/** * */ package cn.mjorcen.db.test; import java.sql.Connection; import java.sql.SQLException; import java.util.concurrent.Executor; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import cn.mjorcen.db.bean.Configuration; import cn.mjorcen.db.pool.impl.AbstractPooledDataSource; /** * * * @author mjorcen * @email mjorcen@gmail.com * @dateTime Oct 5, 2014 4:00:09 PM * @version 1 */ public class Client { public static void main(String[] args) throws Exception { Configuration conf = new Configuration("product_db"); final AbstractPooledDataSource dataSource = new AbstractPooledDataSource( conf); ExecutorService executor = Executors.newFixedThreadPool(10); Runnable r = new Runnable() { public void run() { try { for (int i = 0; i < 3; i++) { Connection connection = dataSource.getConnection(); System.out.println(Thread.currentThread().getName() + " : " + connection); Thread.sleep(3000); dataSource.release(connection); } } catch (Exception e) { e.printStackTrace(); } } }; for (int i = 0; i < 10; i++) { executor.execute(r); } // Connection connection = dataSource.getConnection(); // connection = dataSource.getConnection(); // System.out.println(connection); // dataSource.release(connection); } }
配置文件:
driverClassName=com.mysql.jdbc.Driver validationQuery=SELECT 1 jdbc_url=jdbc:mysql://115.29.36.149:3306/sai_zd?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull jdbc_username=c jdbc_password=c initialPoolSize=3 minPoolSize=3 maxPoolSize=10 maxStatements=30 maxIdleTime=25000 idleConnectionTestPeriod=18000 connectionLonger=3
标签:des style blog color io os ar java for
原文地址:http://www.cnblogs.com/mjorcen/p/4007341.html