搞的那么麻烦,用下面的吧。 /* * Copyright (c) 1998 by Gefion software. * * Permission to use, copy, and distribute this software for * NON-COMMERCIAL purposes and without fee is hereby granted * provided that this copyright notice appears in all copies. * */import java.io.*; import java.sql.*; import java.util.*; import java.util.Date;/** * This class is a Singleton that provides access to one or many * connection pools defined in a Property file. A client gets * access to the single instance through the static getInstance() * method and can then check-out and check-in connections from a pool. * When the client shuts down it should call the release() method * to close all open connections and do other clean up. */ public class DBConnectionManager { static private DBConnectionManager instance; // The single instance static private int clients; private Vector drivers = new Vector(); private PrintWriter log; private Hashtable pools = new Hashtable();
/** * Returns the single instance, creating one if it's the * first time this method is called. * * @return DBConnectionManager The single instance. */ static synchronized public DBConnectionManager getInstance() { if (instance == null) { instance = new DBConnectionManager(); System.out.println("new instance!"); } clients++; return instance; }
/** * A private constructor since this is a Singleton */ private DBConnectionManager() { init(); }
/** * Returns a connection to the named pool. * * @param name The pool name as defined in the properties file * @param con The Connection */ public void freeConnection(String name, Connection con) { DBConnectionPool pool = (DBConnectionPool) pools.get(name); if (pool != null) { pool.freeConnection(con); } }
/** * Returns an open connection. If no one is available, and the max * number of connections has not been reached, a new connection is * created. * * @param name The pool name as defined in the properties file * @return Connection The connection or null */ public java.sql.Connection getConnection(String name) { DBConnectionPool pool = (DBConnectionPool) pools.get(name); if (pool != null) { return pool.getConnection(); } return null; }
/** * Returns an open connection. If no one is available, and the max * number of connections has not been reached, a new connection is * created. If the max number has been reached, waits until one * is available or the specified time has elapsed. * * @param name The pool name as defined in the properties file * @param time The number of milliseconds to wait * @return Connection The connection or null */ public java.sql.Connection getConnection(String name, long time) { DBConnectionPool pool = (DBConnectionPool) pools.get(name); if (pool != null) { return pool.getConnection(time); } return null; }
/** * Closes all open connections and deregisters all drivers. */ public synchronized void release() { // Wait until called by the last client if (--clients != 0) { return; }
/** * Creates instances of DBConnectionPool based on the properties. * A DBConnectionPool can be defined with the following properties: * <PRE> * <poolname>.url The JDBC URL for the database * <poolname>.user A database user (optional) * <poolname>.password A database user password (if user specified) * <poolname>.maxconn The maximal number of connections (optional) * </PRE> * * @param props The connection pool properties */ private void createPools(Properties props) { Enumeration propNames = props.propertyNames(); while (propNames.hasMoreElements()) { String name = (String) propNames.nextElement(); if (name.endsWith(".url")) { String poolName = name.substring(0, name.lastIndexOf(".")); String url = props.getProperty(poolName + ".url"); if (url == null) { log("No URL specified for " + poolName); continue; } String user = props.getProperty(poolName + ".user"); String password = props.getProperty(poolName + ".password"); String maxconn = props.getProperty(poolName + ".maxconn", "0"); int max; try { max = Integer.valueOf(maxconn).intValue(); } catch (NumberFormatException e) { log("Invalid maxconn value " + maxconn + " for " + poolName); max = 0; } DBConnectionPool pool = new DBConnectionPool(poolName, url, user, password, max); pools.put(poolName, pool); log("Initialized pool " + poolName); } } }
/** * Loads properties and initializes the instance with its values. */ private void init() { InputStream is = getClass().getResourceAsStream("/db.properties"); try{ if(is==null)is = new FileInputStream("c:/db.properties"); }catch(Exception e){e.printStackTrace();} Properties dbProps = new Properties(); try { dbProps.load(is); } catch (Exception e) { System.err.println("Can't read the properties file. " + "Make sure db.properties is in the CLASSPATH"); return; } String logFile = dbProps.getProperty("logfile", "DBConnectionManager.log"); System.out.println("Log:"+logFile); try { log = new PrintWriter(new FileWriter(logFile, true), true); } catch (Exception e) { System.err.println("Can't open the log file: " + logFile); log = new PrintWriter(System.err); } loadDrivers(dbProps); createPools(dbProps); }
/** * Loads and registers all JDBC drivers. This is done by the * DBConnectionManager, as opposed to the DBConnectionPool, * since many pools may share the same driver. * * @param props The connection pool properties */ private void loadDrivers(Properties props) { String driverClasses = props.getProperty("drivers"); StringTokenizer st = new StringTokenizer(driverClasses); while (st.hasMoreElements()) { String driverClassName = st.nextToken().trim(); try { Driver driver = (Driver) Class.forName(driverClassName).newInstance(); DriverManager.registerDriver(driver); drivers.addElement(driver); log("Registered JDBC driver " + driverClassName); } catch (Exception e) { log("Can't register JDBC driver: " + driverClassName + ", Exception: " + e); } } }
/** * Writes a message to the log file. */ private void log(String msg) { log.println(new Date() + ": " + msg); }
/** * Writes a message with an Exception to the log file. */ private void log(Throwable e, String msg) { log.println(new Date() + ": " + msg); e.printStackTrace(log); }
/** * This inner class represents a connection pool. It creates new * connections on demand, up to a max number if specified. * It also makes sure a connection is still open before it is * returned to a client. */ class DBConnectionPool { private int checkedOut; private Vector freeConnections = new Vector(); private int maxConn; private String name; private String password; private String URL; private String user;
/** * Creates new connection pool. * * @param name The pool name * @param URL The JDBC URL for the database * @param user The database user, or null * @param password The database user password, or null * @param maxConn The maximal number of connections, or 0 * for no limit */ public DBConnectionPool(String name, String URL, String user, String password, int maxConn) { this.name = name; this.URL = URL; this.user = user; this.password = password; this.maxConn = maxConn; }
/** * Checks in a connection to the pool. Notify other Threads that * may be waiting for a connection. * * @param con The connection to check in */ public synchronized void freeConnection(Connection con) { // Put the connection at the end of the Vector freeConnections.addElement(con); checkedOut--; notifyAll(); }
/** * Checks out a connection from the pool. If no free connection * is available, a new connection is created unless the max * number of connections has been reached. If a free connection * has been closed by the database, it's removed from the pool * and this method is called again recursively. */ public synchronized java.sql.Connection getConnection() { java.sql.Connection con = null; if (freeConnections.size() > 0) { // Pick the first Connection in the Vector // to get round-robin usage con = (java.sql.Connection) freeConnections.firstElement(); freeConnections.removeElementAt(0); try { if (con.isClosed()) { log("Removed bad connection from " + name); // Try again recursively con = getConnection(); } } catch (SQLException e) { log("Removed bad connection from " + name); // Try again recursively con = getConnection(); } } else if (maxConn == 0 || checkedOut < maxConn) { con = newConnection(); } if (con != null) { checkedOut++; } return con; }
/** * Checks out a connection from the pool. If no free connection * is available, a new connection is created unless the max * number of connections has been reached. If a free connection * has been closed by the database, it's removed from the pool * and this method is called again recursively. * <P> * If no connection is available and the max number has been * reached, this method waits the specified time for one to be * checked in. * * @param timeout The timeout value in milliseconds */ public synchronized java.sql.Connection getConnection(long timeout) { long startTime = new Date().getTime(); java.sql.Connection con; while ((con = getConnection()) == null) { try { wait(timeout); } catch (InterruptedException e) {} if ((new Date().getTime() - startTime) >= timeout) { // Timeout has expired return null; } } return con; }
/** * Closes all available connections. */ public synchronized void release() { Enumeration allConnections = freeConnections.elements(); while (allConnections.hasMoreElements()) { java.sql.Connection con = (java.sql.Connection) allConnections.nextElement(); try { con.close(); log("Closed connection for pool " + name); } catch (SQLException e) { log(e, "Can't close connection for pool " + name); } } freeConnections.removeAllElements(); }
/** * Creates a new connection, using a userid and password * if specified. */ private java.sql.Connection newConnection() { java.sql.Connection con = null; try { if (user == null) { con = DriverManager.getConnection(URL); } else { con = DriverManager.getConnection(URL, user, password); } log("Created a new connection in pool " + name); } catch (SQLException e) { log(e, "Can't create a new connection for " + URL); return null; } return con; } } }
to skyyoung(路人甲): 我用的正是你所给的这个程序(都是从网上down下来的) 但如果原样引用,有一个问题,一个连接从头到尾都保持着,直到服务关掉才将该连接关闭,有资料说这样是不太好,时间太长,所以我对其进行修改,你能告诉报错是什么意思么? java.sql.SQLException: 不支持的 Oracle 版本。支持的最低版本为 7.2.3。无法创建下列URL的连接: jdbc:oracle:thin:@192.168.3.52:1521:wasadmin
/*
* Copyright (c) 1998 by Gefion software.
*
* Permission to use, copy, and distribute this software for
* NON-COMMERCIAL purposes and without fee is hereby granted
* provided that this copyright notice appears in all copies.
*
*/import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date;/**
* This class is a Singleton that provides access to one or many
* connection pools defined in a Property file. A client gets
* access to the single instance through the static getInstance()
* method and can then check-out and check-in connections from a pool.
* When the client shuts down it should call the release() method
* to close all open connections and do other clean up.
*/
public class DBConnectionManager {
static private DBConnectionManager instance; // The single instance
static private int clients; private Vector drivers = new Vector();
private PrintWriter log;
private Hashtable pools = new Hashtable();
/**
* Returns the single instance, creating one if it's the
* first time this method is called.
*
* @return DBConnectionManager The single instance.
*/
static synchronized public DBConnectionManager getInstance() {
if (instance == null) {
instance = new DBConnectionManager();
System.out.println("new instance!");
}
clients++;
return instance;
}
/**
* A private constructor since this is a Singleton
*/
private DBConnectionManager() {
init();
}
/**
* Returns a connection to the named pool.
*
* @param name The pool name as defined in the properties file
* @param con The Connection
*/
public void freeConnection(String name, Connection con) {
DBConnectionPool pool = (DBConnectionPool) pools.get(name);
if (pool != null) {
pool.freeConnection(con);
}
}
/**
* Returns an open connection. If no one is available, and the max
* number of connections has not been reached, a new connection is
* created.
*
* @param name The pool name as defined in the properties file
* @return Connection The connection or null
*/
public java.sql.Connection getConnection(String name) {
DBConnectionPool pool = (DBConnectionPool) pools.get(name);
if (pool != null) {
return pool.getConnection();
}
return null;
}
/**
* Returns an open connection. If no one is available, and the max
* number of connections has not been reached, a new connection is
* created. If the max number has been reached, waits until one
* is available or the specified time has elapsed.
*
* @param name The pool name as defined in the properties file
* @param time The number of milliseconds to wait
* @return Connection The connection or null
*/
public java.sql.Connection getConnection(String name, long time) {
DBConnectionPool pool = (DBConnectionPool) pools.get(name);
if (pool != null) {
return pool.getConnection(time);
}
return null;
}
/**
* Closes all open connections and deregisters all drivers.
*/
public synchronized void release() {
// Wait until called by the last client
if (--clients != 0) {
return;
}
Enumeration allPools = pools.elements();
while (allPools.hasMoreElements()) {
DBConnectionPool pool = (DBConnectionPool) allPools.nextElement();
pool.release();
}
Enumeration allDrivers = drivers.elements();
while (allDrivers.hasMoreElements()) {
Driver driver = (Driver) allDrivers.nextElement();
try {
DriverManager.deregisterDriver(driver);
log("Deregistered JDBC driver " + driver.getClass().getName());
}
catch (SQLException e) {
log(e, "Can't deregister JDBC driver: " + driver.getClass().getName());
}
}
}
/**
* Creates instances of DBConnectionPool based on the properties.
* A DBConnectionPool can be defined with the following properties:
* <PRE>
* <poolname>.url The JDBC URL for the database
* <poolname>.user A database user (optional)
* <poolname>.password A database user password (if user specified)
* <poolname>.maxconn The maximal number of connections (optional)
* </PRE>
*
* @param props The connection pool properties
*/
private void createPools(Properties props) {
Enumeration propNames = props.propertyNames();
while (propNames.hasMoreElements()) {
String name = (String) propNames.nextElement();
if (name.endsWith(".url")) {
String poolName = name.substring(0, name.lastIndexOf("."));
String url = props.getProperty(poolName + ".url");
if (url == null) {
log("No URL specified for " + poolName);
continue;
}
String user = props.getProperty(poolName + ".user");
String password = props.getProperty(poolName + ".password");
String maxconn = props.getProperty(poolName + ".maxconn", "0");
int max;
try {
max = Integer.valueOf(maxconn).intValue();
}
catch (NumberFormatException e) {
log("Invalid maxconn value " + maxconn + " for " + poolName);
max = 0;
}
DBConnectionPool pool =
new DBConnectionPool(poolName, url, user, password, max);
pools.put(poolName, pool);
log("Initialized pool " + poolName);
}
}
}
/**
* Loads properties and initializes the instance with its values.
*/
private void init() {
InputStream is = getClass().getResourceAsStream("/db.properties");
try{
if(is==null)is = new FileInputStream("c:/db.properties");
}catch(Exception e){e.printStackTrace();}
Properties dbProps = new Properties();
try {
dbProps.load(is);
}
catch (Exception e) {
System.err.println("Can't read the properties file. " +
"Make sure db.properties is in the CLASSPATH");
return;
}
String logFile = dbProps.getProperty("logfile", "DBConnectionManager.log");
System.out.println("Log:"+logFile);
try {
log = new PrintWriter(new FileWriter(logFile, true), true);
}
catch (Exception e) {
System.err.println("Can't open the log file: " + logFile);
log = new PrintWriter(System.err);
}
loadDrivers(dbProps);
createPools(dbProps);
}
/**
* Loads and registers all JDBC drivers. This is done by the
* DBConnectionManager, as opposed to the DBConnectionPool,
* since many pools may share the same driver.
*
* @param props The connection pool properties
*/
private void loadDrivers(Properties props) {
String driverClasses = props.getProperty("drivers");
StringTokenizer st = new StringTokenizer(driverClasses);
while (st.hasMoreElements()) {
String driverClassName = st.nextToken().trim();
try {
Driver driver = (Driver)
Class.forName(driverClassName).newInstance();
DriverManager.registerDriver(driver);
drivers.addElement(driver);
log("Registered JDBC driver " + driverClassName);
}
catch (Exception e) {
log("Can't register JDBC driver: " +
driverClassName + ", Exception: " + e);
}
}
}
/**
* Writes a message to the log file.
*/
private void log(String msg) {
log.println(new Date() + ": " + msg);
}
/**
* Writes a message with an Exception to the log file.
*/
private void log(Throwable e, String msg) {
log.println(new Date() + ": " + msg);
e.printStackTrace(log);
}
/**
* This inner class represents a connection pool. It creates new
* connections on demand, up to a max number if specified.
* It also makes sure a connection is still open before it is
* returned to a client.
*/
class DBConnectionPool {
private int checkedOut;
private Vector freeConnections = new Vector();
private int maxConn;
private String name;
private String password;
private String URL;
private String user;
/**
* Creates new connection pool.
*
* @param name The pool name
* @param URL The JDBC URL for the database
* @param user The database user, or null
* @param password The database user password, or null
* @param maxConn The maximal number of connections, or 0
* for no limit
*/
public DBConnectionPool(String name, String URL, String user, String password,
int maxConn) {
this.name = name;
this.URL = URL;
this.user = user;
this.password = password;
this.maxConn = maxConn;
}
/**
* Checks in a connection to the pool. Notify other Threads that
* may be waiting for a connection.
*
* @param con The connection to check in
*/
public synchronized void freeConnection(Connection con) {
// Put the connection at the end of the Vector
freeConnections.addElement(con);
checkedOut--;
notifyAll();
}
/**
* Checks out a connection from the pool. If no free connection
* is available, a new connection is created unless the max
* number of connections has been reached. If a free connection
* has been closed by the database, it's removed from the pool
* and this method is called again recursively.
*/
public synchronized java.sql.Connection getConnection() {
java.sql.Connection con = null;
if (freeConnections.size() > 0) {
// Pick the first Connection in the Vector
// to get round-robin usage
con = (java.sql.Connection) freeConnections.firstElement();
freeConnections.removeElementAt(0);
try {
if (con.isClosed()) {
log("Removed bad connection from " + name);
// Try again recursively
con = getConnection();
}
}
catch (SQLException e) {
log("Removed bad connection from " + name);
// Try again recursively
con = getConnection();
}
}
else if (maxConn == 0 || checkedOut < maxConn) {
con = newConnection();
}
if (con != null) {
checkedOut++;
}
return con;
}
/**
* Checks out a connection from the pool. If no free connection
* is available, a new connection is created unless the max
* number of connections has been reached. If a free connection
* has been closed by the database, it's removed from the pool
* and this method is called again recursively.
* <P>
* If no connection is available and the max number has been
* reached, this method waits the specified time for one to be
* checked in.
*
* @param timeout The timeout value in milliseconds
*/
public synchronized java.sql.Connection getConnection(long timeout) {
long startTime = new Date().getTime();
java.sql.Connection con;
while ((con = getConnection()) == null) {
try {
wait(timeout);
}
catch (InterruptedException e) {}
if ((new Date().getTime() - startTime) >= timeout) {
// Timeout has expired
return null;
}
}
return con;
}
/**
* Closes all available connections.
*/
public synchronized void release() {
Enumeration allConnections = freeConnections.elements();
while (allConnections.hasMoreElements()) {
java.sql.Connection con = (java.sql.Connection) allConnections.nextElement();
try {
con.close();
log("Closed connection for pool " + name);
}
catch (SQLException e) {
log(e, "Can't close connection for pool " + name);
}
}
freeConnections.removeAllElements();
}
/**
* Creates a new connection, using a userid and password
* if specified.
*/
private java.sql.Connection newConnection() {
java.sql.Connection con = null;
try {
if (user == null) {
con = DriverManager.getConnection(URL);
}
else {
con = DriverManager.getConnection(URL, user, password);
}
log("Created a new connection in pool " + name);
}
catch (SQLException e) {
log(e, "Can't create a new connection for " + URL);
return null;
}
return con;
}
}
}
我用的正是你所给的这个程序(都是从网上down下来的)
但如果原样引用,有一个问题,一个连接从头到尾都保持着,直到服务关掉才将该连接关闭,有资料说这样是不太好,时间太长,所以我对其进行修改,你能告诉报错是什么意思么?
java.sql.SQLException: 不支持的 Oracle 版本。支持的最低版本为 7.2.3。无法创建下列URL的连接: jdbc:oracle:thin:@192.168.3.52:1521:wasadmin