关于ConnectionPooljar数据连接池文件包的制作流程.docx

关于ConnectionPool.jar数据连接池文件包的制作流程目的：制作通用型数据连接池文件包，便于应用于通用工程结构：工程包内classes目录内1.ConnectionPool ：连接池管理程序|_ConnectionPool.java|_ConnectionWrapper.java|_LogFile.java|_LogWriter.java|_MakeDateTime.java|_PoolManager.java2. com ：MySql JDBC驱动程序3. org ：MySql JDBC驱动程序4. net ：MSSqlserver JTDS 驱动程序5. javax ：Oracle JDBC 驱动程序6. oracle ：Oracle JDBC 驱动程序制作流程：1. 新建一个工程命名为Pool，在工程内建立一个war模块命名为Poolwar；2. 在工程内新建class文件，文件的包起名为ConnectionPool；3. 依次新建下列文件：ConnectionPool.java、ConnectionWrapper.java、LogFile.java、LogWriter.java、MakeDateTime.java、PoolManager.java4. 将Oracle for JDBC驱动classes12.jar文件用winrar解压缩，得到javax和oracle两个文件夹，将这两个文件夹复制到Pool工程内的classes目录下；5. 将MS-Sqlserver for JDBC驱动jtds-1.2.jar文件用winrar解压缩，得到net这个文件夹，将这个文件夹复制到Pool工程内的classes目录下；6. 将MySql for JDBC驱动mysql-connector-java-3.0.16-ga-bin.jar文件用winrar解压缩，得到com和org两个文件夹，将这两个文件夹复制到Pool工程内的classes目录下；7. 如果需要添加其他驱动程序，可参照4-6进行；8. 选择JBuilder工具条上Wizards-àArchive Builder ；9.Archive Builder Step 1 of 5 : Archive Type 选择Basic（具体类型含义参考JBuilerX使用手册）；10. Archive Builder Step 2 of 5 : 将Name 和 File 命名为需要的名字，这里同意将其命名为ConnectionPool，其他的选项均不做更改；11Archive Builder Step 3 of 5 : 指定结构文件包含内容，这里不做任何修改；12Archive Builder Step 4 of 5 : 将servlet 选择为 Allways include all classes and resources;13Archive Builder Step 4 of 5 : 保持默认状态不改变，按finish完成结构文件的定义；14在工程窗口用鼠标右键点 ConnectionPool 结构，然后选择make 生成结构文件；使用方法：1. 将该jar文件添加到 ToolsàConfigure Librarise 中；2. 新加工程，在工程 Required Librarise 中添加该库文件；3. 在工程中新建一个“连接池初始化类”负责建立数据连接；4. 在工程中新建一属性文件-db.properties，负责描述数据库驱动及用户信息等，该属性文件存放的位置在PoolManager.java中定义；5. 在PoolManager.java中默认为“./ db.properties”,该位置表示在/WEB-INF 目录下；附录：文件代码*文件开始*db.properties /属性文件*XBDBManager Propertiespoolname = sqlpool oraclepool 注：中间以空格分隔drivers = net.sourceforge.jtds.jdbc.Driver oracle.jdbc.driver.OracleDriver 注：中间以空格分隔logfile = d:logfile.txtsqlpool.url = jdbc:jtds:sqlserver:/10.1.1.2:1433;DatabaseName=pdasqlpool.initconns=50sqlpool.maxconns=80sqlpool.user = pdasqlpool.password = pdapass1234oraclepool.url = jdbc:oracle:thin:172.168.72.8:1521:infodboraclepool.initconns=50oraclepool.maxconns=80oraclepool.user = tjoldoraclepool.password = tjold*文件结束*文件开始*ConnectionPool.java*package ConnectionPool;import java.io.*;import java.sql.*;import java.util.*;public class ConnectionPool private String name; private String URL; private String user; private String password; private int maxConns; private int timeOut; private LogWriter logWriter; private int checkedOut; private Vector freeConnections = new Vector(); public ConnectionPool(String name, String URL, String user, String password, int maxConns, int initConns, int timeOut, PrintWriter pw, int logLevel) this.name = name; this.URL = URL; this.user = user; this.password = password; this.maxConns = maxConns; this.timeOut = timeOut > 0 ? timeOut : 5; logWriter = new LogWriter(name, logLevel, pw); initPool(initConns); logWriter.log("New pool created", LogWriter.INFO); String lf = System.getProperty("line.separator"); logWriter.log( " url=" + URL + " user=" + user + / " password=" + password + " initconns=" + initConns + " maxconns=" + maxConns + " logintimeout=" + this.timeOut, LogWriter.INFO); logWriter.log(getStats(), LogWriter.INFO); private void initPool(int initConns) for (int i = 0; i < initConns; i+) try Connection pc = newConnection(); freeConnections.addElement(pc); catch (SQLException e) public Connection getConnection() throws SQLException logWriter.log("Request for connection received", LogWriter.DEBUG); try Connection conn = getConnection(timeOut * 1000); return new ConnectionWrapper(conn, this); catch(SQLException e) logWriter.log(e, "Exception getting connection", logWriter.ERROR); throw e; synchronized void wrapperClosed(Connection conn) freeConnections.addElement(conn); checkedOut-; notifyAll(); logWriter.log("Returned wrapperClosed to pool", LogWriter.INFO); logWriter.log(getStats(), LogWriter.INFO); private synchronized Connection getConnection(long timeout) throws SQLException / Get a pooled Connection from the cache or a new one. / Wait if all are checked out and the max limit has / been reached. long startTime = System.currentTimeMillis(); long remaining = timeout; Connection conn = null; while (conn = getPooledConnection() = null) try logWriter.log("Waiting for connection. Timeout=" + remaining, LogWriter.DEBUG); wait(remaining); catch (InterruptedException e) remaining = timeout - (System.currentTimeMillis() - startTime); if (remaining <= 0) / Timeout has expired logWriter.log("Time-out while waiting for connection", LogWriter.DEBUG); throw new SQLException("getConnection() timed-out"); / Check if the Connection is still OK if (!isConnectionOK(conn) / It was bad. Try again with the remaining timeout logWriter.log("Removed selected bad connection from pool", LogWriter.ERROR); return getConnection(remaining); checkedOut+; logWriter.log("Delivered getConnection from pool", LogWriter.INFO); logWriter.log(getStats(), LogWriter.INFO); return conn; private boolean isConnectionOK(Connection conn) Statement testStmt = null; try if (!conn.isClosed() / Try to createStatement to see if it's really alive testStmt = conn.createStatement(); testStmt.close(); else return false; catch (SQLException e) if (testStmt != null) try testStmt.close(); catch (SQLException se) logWriter.log(e, "Pooled Connection was not okay", LogWriter.ERROR); return false; return true; private Connection getPooledConnection() throws SQLException Connection conn = null; if (freeConnections.size() > 0) / Pick the first Connection in the Vector / to get round-robin usage conn = (Connection) freeConnections.firstElement(); freeConnections.removeElementAt(0); else if (maxConns = 0 | checkedOut < maxConns) conn = newConnection(); return conn; private Connection newConnection() throws SQLException Connection conn = null; if (user = null) conn = DriverManager.getConnection(URL); else conn = DriverManager.getConnection(URL, user, password); logWriter.log("Opened a new connection", LogWriter.INFO); logWriter.log(getStats(), LogWriter.INFO); return conn; public synchronized void freeConnection(Connection conn) / Put the connection at the end of the Vector freeConnections.addElement(conn); checkedOut-; notifyAll(); logWriter.log("Returned freeConnection to pool", LogWriter.INFO); logWriter.log(getStats(), LogWriter.INFO); public synchronized void release() Enumeration allConnections = freeConnections.elements(); while (allConnections.hasMoreElements() Connection con = (Connection) allConnections.nextElement(); try con.close(); logWriter.log("release Closed connection", LogWriter.INFO); catch (SQLException e) logWriter.log(e, "release Couldn't close connection", LogWriter.ERROR); freeConnections.removeAllElements(); private String getStats() return "Total connections: " + (freeConnections.size() + checkedOut) + " Available: " + freeConnections.size() + " Checked-out: " + checkedOut; *文件结束*文件开始*ConnectionWrapper.java*package ConnectionPool;import java.sql.*;import java.util.*;/* * This class is a wrapper around a Connection, overriding the * close method to just inform the pool that it's available for * reuse again, and the isClosed method to return the state * of the wrapper instead of the Connection. */class ConnectionWrapper implements Connection / realConn should be private but we use package scope to / be able to test removal of bad connections Connection realConn; private ConnectionPool pool; private boolean isClosed = false; public ConnectionWrapper(Connection realConn, ConnectionPool pool) this.realConn = realConn; this.pool = pool; /* * Inform the ConnectionPool that the ConnectionWrapper * is closed. */ public void close() throws SQLException isClosed = true; pool.wrapperClosed(realConn); /* * Returns true if the ConnectionWrapper is closed, false * otherwise. */ public boolean isClosed() throws SQLException return isClosed; /* * Wrapped methods. */ public void clearWarnings() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); realConn.clearWarnings(); public void commit() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); realCmit(); public Statement createStatement() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.createStatement(); public boolean getAutoCommit() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.getAutoCommit(); public String getCatalog() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.getCatalog(); public DatabaseMetaData getMetaData() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.getMetaData(); public int getTransactionIsolation() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.getTransactionIsolation(); public SQLWarning getWarnings() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed"); return realConn.getWarnings(); public boolean isReadOnly() throws SQLException if (isClosed) throw new SQLException("Pooled connection is closed");