谁有连结池的例子？

package pool;import java.sql.*;
import java.util.*;
import java.io.*;class ConnectionReaper extends Thread {    private JDCConnectionPool pool;
    private final long delay=300000;    ConnectionReaper(JDCConnectionPool pool) {
        this.pool=pool;
    }    public void run() {
        while(true) {
           try {
              sleep(delay);
           } catch( InterruptedException e) { }
           pool.reapConnections();
        }
    }
}public class JDCConnectionPool {   private Vector connections;
   private String url, user, password;
   final private long timeout=60000;
   private ConnectionReaper reaper;
   final private int poolsize=10;   public JDCConnectionPool(String url, String user, String password) {
      this.url = url;
      this.user = user;
      this.password = password;
      connections = new Vector(poolsize);
      reaper = new ConnectionReaper(this);
      reaper.start();
   }   public synchronized void reapConnections() {      long stale = System.currentTimeMillis() - timeout;
      Enumeration connlist = connections.elements();

      while((connlist != null) && (connlist.hasMoreElements())) {
          JDCConnection conn = (JDCConnection)connlist.nextElement();          if((conn.inUse()) && (stale >conn.getLastUse()) &&
                                            (!conn.validate())) {
      removeConnection(conn);
         }
      }
   }   public synchronized void closeConnections() {

      Enumeration connlist = connections.elements();      while((connlist != null) && (connlist.hasMoreElements())) {
          JDCConnection conn = (JDCConnection)connlist.nextElement();
          removeConnection(conn);
      }
   }   private synchronized void removeConnection(JDCConnection conn) {
       connections.removeElement(conn);
   }
   public synchronized Connection getConnection() throws SQLException {       JDCConnection c;
       for(int i = 0; i < connections.size(); i++) {
           c = (JDCConnection)connections.elementAt(i);
           if (c.lease()) {
              return c;
           }
       }       Connection conn = DriverManager.getConnection(url, user, password);
       c = new JDCConnection(conn, this);
       c.lease();
       connections.addElement(c);
       return c;
  }    public synchronized void returnConnection(JDCConnection conn) {
      conn.expireLease();
   }
}

package pool;import java.sql.*;
import java.util.*;
import java.io.*;public class JDCConnection implements Connection {    private JDCConnectionPool pool;
    private Connection conn;
    private boolean inuse;
    private long timestamp;
    public JDCConnection(Connection conn, JDCConnectionPool pool) {
        this.conn=conn;
        this.pool=pool;
        this.inuse=false;
        this.timestamp=0;
    }    public synchronized boolean lease() {
       if(inuse)  {
           return false;
       } else {
          inuse=true;
          timestamp=System.currentTimeMillis();
          return true;
       }
    }
    public boolean validate() {
try {
            conn.getMetaData();
        }catch (Exception e) {
    return false;
}
return true;
    }    public boolean inUse() {
        return inuse;
    }    public long getLastUse() {
        return timestamp;
    }    public void close() throws SQLException {
        pool.returnConnection(this);
    }    protected void expireLease() {
        inuse=false;
    }    protected Connection getConnection() {
        return conn;
    }    public PreparedStatement prepareStatement(String sql) throws SQLException {
        return conn.prepareStatement(sql);
    }    public CallableStatement prepareCall(String sql) throws SQLException {
        return conn.prepareCall(sql);
    }    public Statement createStatement() throws SQLException {
        return conn.createStatement();
    }    public String nativeSQL(String sql) throws SQLException {
        return conn.nativeSQL(sql);
    }    public void setAutoCommit(boolean autoCommit) throws SQLException {
        conn.setAutoCommit(autoCommit);
    }    public boolean getAutoCommit() throws SQLException {
        return conn.getAutoCommit();
    }    public void commit() throws SQLException {
        conn.commit();
    }    public void rollback() throws SQLException {
        conn.rollback();
    }    public boolean isClosed() throws SQLException {
        return conn.isClosed();
    }    public DatabaseMetaData getMetaData() throws SQLException {
        return conn.getMetaData();
    }    public void setReadOnly(boolean readOnly) throws SQLException {
        conn.setReadOnly(readOnly);
    }

    public boolean isReadOnly() throws SQLException {
        return conn.isReadOnly();
    }    public void setCatalog(String catalog) throws SQLException {
        conn.setCatalog(catalog);
    }    public String getCatalog() throws SQLException {
        return conn.getCatalog();
    }    public void setTransactionIsolation(int level) throws SQLException {
        conn.setTransactionIsolation(level);
    }    public int getTransactionIsolation() throws SQLException {
        return conn.getTransactionIsolation();
    }    public SQLWarning getWarnings() throws SQLException {
        return conn.getWarnings();
    }    public void clearWarnings() throws SQLException {
        conn.clearWarnings();
    }
}

package pool;import java.sql.*;
import java.util.*;
public class JDCConnectionDriver implements Driver {    public static final String URL_PREFIX = "jdbc:jdc:";
    private static final int MAJOR_VERSION = 1;
    private static final int MINOR_VERSION = 0;
    private JDCConnectionPool pool;    public JDCConnectionDriver(String driver, String url,
                                 String user, String password)
                            throws ClassNotFoundException,
                               InstantiationException, IllegalAccessException,
                                SQLException
    {
        DriverManager.registerDriver(this);
        Class.forName(driver).newInstance();
        pool = new JDCConnectionPool(url, user, password);
    }    public Connection connect(String url, Properties props)
                                       throws SQLException {
        if(!url.startsWith(URL_PREFIX) {
             return null;
        }
        return pool.getConnection();
    }    public boolean acceptsURL(String url) {
        return url.startsWith(URL_PREFIX);
    }    public int getMajorVersion() {
        return MAJOR_VERSION;
    }    public int getMinorVersion() {
        return MINOR_VERSION;
    }    public DriverPropertyInfo[] getPropertyInfo(String str, Properties props) {
        return new DriverPropertyInfo[0];
    }    public boolean jdbcCompliant() {
        return false;
    }
}

如何jdbc支持jdbc2.0自带pool的话，还是用它吧

刚写的！main方法是个测试！
还有个管理连接池的类(DBConnectManager)没写出来，应该比较简单！
DBConnectManager应该是对DBConnectionPool的封装，并保证生成一个或
DBConnectionPool的实例！
import oracle.jdbc.driver.OracleDriver;
import java.sql.*;
import java.util.*;public class DBConnectionPool {private static String driver = "oracle.jdbc.driver.OracleDriver";
private String url = "JDBC:Oracle:thin:@soft2server:1521:oracledb";
private Vector pool = new Vector();
private String user ="dickensi";
private String password = "112233";
private static int MAXCON = 10;  public DBConnectionPool() {
  }  public boolean newConnection(){
    Connection con = null;
    if(pool.size() < MAXCON)
    {
    try{
       con = DriverManager.getConnection(url,user,password);
      }
      catch(Exception e){System.out.println("Database connect failure!");}
      pool.add(con);
      System.out.println("Create a connection["+(pool.size()-1)+"]"+con.toString());
      return true;
      }
    return false;
  }  public Connection getConnection(){
    if(pool.size() <= 0)
    {
      while(newConnection());
    }
    Connection con = (Connection) pool.firstElement();
    pool.remove(0);
    return con;
  }  public void realseConnection(Connection con){
      try{
         if(pool.size()<10){
            pool.add(con);
          }
         else{con.close();}
         con = null;
      }
      catch(Exception e){}
  }  public void realeasePool(){
    Connection con = null;
    for(int i=0;i<pool.size();i++)
    {
      con = (Connection)pool.get(i);
      try{
        con.close();
      }
      catch(Exception e){}
    }
    pool.clear();
    System.out.println("realease all pool to "+ pool.size());
  }  public void getPoolInfo(){
    for(int i =0;i<pool.size();i++)
    {
       System.out.println(""+i+pool.get(i).toString());
    }
  }  public static void main(String[] args) {
    Connection[] con = new Connection[20];
  try{
    Class.forName(driver);
    }
    catch(Exception e)
    {System.out.println("Db driver load failure!");}
    DBConnectionPool dbPool = new DBConnectionPool();
    while(dbPool.newConnection()) ;
    System.out.println("----------------------------initial---------------------------");
//    dbPool.getPoolInfo();
    for(int i=0;i<15;i++)
    {
       con[i] = dbPool.getConnection();
    System.out.println("----------------------------get one---------------------------");
    dbPool.getPoolInfo();
    }
    dbPool.getPoolInfo();
    for(int i=14;i>=0;i--)
    {
//    System.out.println("realease:"+con[i].toString());
//    try{
//    con[i].close();
//    }catch (Exception ee){}
    dbPool.realseConnection(con[i]);
    System.out.println("----------------------------realease one---------------------------");
//    dbPool.getPoolInfo();
    }
    System.out.println("--------------------------realease all------------------------");
    dbPool.getPoolInfo();
    dbPool.realeasePool();
  }
}

其实这些东东在sun提供的文档中找到，你试着去找找吧。

调试易

谁有连结池的例子？

解决方案 »