本文向大家介紹了簡單的MySQL連接池，用于App服務端比較合適，，具體內容如下
| /** * 連接池類 */package com.junones.test; import java.sql.Connection;import java.sql.SQLException;import java.util.HashMap;import java.util.Map;import java.util.Map.Entry; import com.mysql.jdbc.jdbc2.optional.MysqlDataSource; public class MySQLPool { private static volatile MySQLPool pool; private MysqlDataSource ds; private Map<Connection, Boolean> map; private String url = "jdbc:mysql://localhost:3306/test"; private String username = "root"; private String password = "root1234"; private int initPoolSize = 10; private int maxPoolSize = 200; private int waitTime = 100; private MySQLPool() { init(); } public static MySQLPool getInstance() { if (pool == null) { synchronized (MySQLPool.class) { if(pool == null) { pool = new MySQLPool(); } } } return pool; } private void init() { try { ds = new MysqlDataSource(); ds.setUrl(url); ds.setUser(username); ds.setPassword(password); ds.setCacheCallableStmts(true); ds.setConnectTimeout(1000); ds.setLoginTimeout(2000); ds.setUseUnicode(true); ds.setEncoding("UTF-8"); ds.setZeroDateTimeBehavior("convertToNull"); ds.setMaxReconnects(5); ds.setAutoReconnect(true); map = new HashMap<Connection, Boolean>(); for (int i = 0; i < initPoolSize; i++) { map.put(getNewConnection(), true); } } catch (Exception e) { e.printStackTrace(); } } public Connection getNewConnection() { try { return ds.getConnection(); } catch (SQLException e) { e.printStackTrace(); } return null; } public synchronized Connection getConnection() { Connection conn = null; try { for (Entry<Connection, Boolean> entry : map.entrySet()) { if (entry.getValue()) { conn = entry.getKey(); map.put(conn, false); break; } } if (conn == null) { if (map.size() < maxPoolSize) { conn = getNewConnection(); map.put(conn, false); } else { wait(waitTime); conn = getConnection(); } } } catch (Exception e) { e.printStackTrace(); } return conn; } public void releaseConnection(Connection conn) { if (conn == null) { return; } try { if(map.containsKey(conn)) { if (conn.isClosed()) { map.remove(conn); } else { if(!conn.getAutoCommit()) { conn.setAutoCommit(true); } map.put(conn, true); } } else { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } }} /** * 測試類 */package com.junones.test; import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement; public class TestMySQLPool { private static volatile int a; private synchronized static void incr() { a++; } public static void main(String[] args) throws InterruptedException { int times = 10000; long start = System.currentTimeMillis(); for (int i = 0; i < times; i++) { new Thread(new Runnable() { @Override public void run() { MySQLPool pool = MySQLPool.getInstance(); Connection conn = pool.getConnection(); Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery("select id, name from t_test"); while (rs.next()) { System.out.println(rs.getInt(1) + ", " + rs.getString(2)); } } catch (SQLException e) { e.printStackTrace(); } finally { incr(); if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (stmt != null) { try { stmt.close(); } catch (SQLException e) { } } pool.releaseConnection(conn); } } }).start(); } while (true) { if (a == times) { System.out.println("finished, time:" + (System.currentTimeMillis() - start)); break; } Thread.sleep(100); } }} |
