dbconnectionany.java

农业银行ATM对帐查询系统后台类包的源代码,实现了FTP,数据库管理等等功能

package boco.shabank.dbconnection;

//数据库连接,利用缓冲池技术实现对不同数据源的连接控制
/**
 * <p>Title: dbmanager</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: boco</p>
 * @author xugs
 * @version 1.0
 */
import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date;
import com.sybase.jdbc2.jdbc.SybDriver;
/**
* 管理类DBConnectionManager支持对一个或多个由属性文件定义的数据库连接
* 池的访问.客户程序可以调用getInstance()方法访问本类的唯一实例.
*/
public class DBConnectionAny {
   static private DBConnectionAny instance; // 唯一实例
   static private int clients;
   static private String dbsource;
   public String m_strErrmsg = "No Operation";
   private Vector drivers = new Vector();
        private PrintWriter log;
        private Hashtable pools = new Hashtable();

        public String getErrorMsg() {
                return m_strErrmsg;
        }

   /**
           * 返回唯一实例.如果是第一次调用此方法,则创建实例
                *
                * @return DBConnectionManager 唯一实例
        */
        static synchronized public DBConnectionAny getInstance() {
                if (instance == null) {
                        instance = new DBConnectionAny();
                }
                clients++;
                return instance;
        }
        static synchronized public DBConnectionAny getInstance(Vector vSource) {
                if(dbsource == null)
                    dbsource = vSource.elementAt(1).toString();
                if(dbsource != null && !dbsource.equals(vSource.elementAt(1).toString())){
                    dbsource = vSource.elementAt(1).toString();
                    instance = new DBConnectionAny(vSource);
                }
                if (instance == null) {
                        instance = new DBConnectionAny(vSource);
                }
                clients++;
                return instance;
        }
        /**
                * 建构函数私有以防止其它对象创建本类实例
        */
        private DBConnectionAny() {
                //init();
        }
        public DBConnectionAny(Vector vDBSource) {
                init(vDBSource);
        }
        /**
                * 将连接对象返回给由名字指定的连接池
                *
                * @param name 在属性文件中定义的连接池名字
                * @param con  连接对象
        */
        public void freeConnection(String name, Connection con) {
                DBConnectionPool pool = (DBConnectionPool) pools.get(name);
                if (pool != null) {
                        pool.freeConnection(con);
                }
        }

        /**
                * 获得一个可用的(空闲的)连接.如果没有可用连接,且已有连接数小于最大连接数
                * 限制,则创建并返回新连接
                *
                * @param name  在属性文件中定义的连接池名字
                * @return Connection 可用连接或null
        */
        public Connection getConnection(String name) {
                DBConnectionPool pool = (DBConnectionPool) pools.get(name);
                if (pool != null) {
                        return pool.getConnection(60000);
                }
                return null;
        }

        /**
                * 获得一个可用连接.若没有可用连接,且已有连接数小于最大连接数限制,
                * 则创建并返回新连接.否则,在指定的时间内等待其它线程释放连接.
                *
                * @param name 连接池名字
                * @param time 以毫秒计的等待时间
                * @return Connection 可用连接或null
        */
        public Connection getConnection(String name, long time) {
                DBConnectionPool pool = (DBConnectionPool) pools.get(name);
                if (pool != null) {
                        return pool.getConnection(time);
                }
                return null;
        }

        /**
                * 关闭所有连接,撤销驱动程序的注册
        */
        public synchronized void release() {
        // 等待直到最后一个客户程序调用
                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("撤销JDBC驱动程序 " + driver.getClass().getName()+"的注册");
                        } catch (SQLException e) {
                                log(e, "无法撤销下列JDBC驱动程序的注册: " + driver.getClass().getName());
                        }
                }
        }

        /**
                * 根据指定属性创建连接池实例.
                *
                * @param props 连接池属性
        */
        private void createPools(Properties props) {
                Enumeration propNames = props.propertyNames();
                while (propNames.hasMoreElements()) {
                        String name = (String) propNames.nextElement();
                        //System.out.println("name="+name) ;
                        if (name.endsWith(".url")) {
                                String poolName = name.substring(0, name.lastIndexOf("."));
                                String url = props.getProperty(poolName + ".url");
                                //System.out.println("url="+url) ;
                                if (url == null) {
                                        log("没有为连接池" + poolName + "指定URL");
                                        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("错误的最大连接数限制: " + maxconn + " .连接池: " + poolName);
                                        max = 0;
                                }
                                DBConnectionPool pool = new DBConnectionPool(poolName, url, user, password, max);
                                pools.put(poolName, pool);
                                log("成功创建连接池" + poolName);
                        }
                }
        }

        /**
                * 读取属性完成初始化
        drivers=COM.ibm.db2.jdbc.net.DB2Driver
        logfile=e:\\log.txt
        access.url=jdbc:db2://196.168.1.132:50007/uaop
        access.user=umsp
        access.password=boco
        access.maxconn=5
        */
   private void init(Vector vAllDBS) {
                Properties dbProps = new Properties();
                try {
                        Vector vCol=new Vector();
                        vCol = vAllDBS;
                        dbProps.setProperty(vCol.elementAt(1).toString()+".drivers",vCol.elementAt(2).toString());
                        dbProps.setProperty("logfile","e:\\log2.txt") ;
                        dbProps.setProperty(vCol.elementAt(1).toString()+".url",vCol.elementAt(3).toString() ) ;
                        dbProps.setProperty(vCol.elementAt(1).toString()+".user",vCol.elementAt(4).toString() ) ;
                        dbProps.setProperty(vCol.elementAt(1).toString()+".password",vCol.elementAt(5).toString() ) ;
                        dbProps.setProperty(vCol.elementAt(1).toString()+".maxconn","5" ) ;
                        //System.out.println("vcol="+vCol.elementAt(1)) ;
                }
                catch (Exception e) {