(Oracle 技能篇 ) Oracle 连接池实例代码（Java版本）

梦里梦外; 2023-10-18 22:44 72阅读 0赞

第一个：数据库实体类

package com.ryan.configbean;
    
    public class DSConfigBean {
    	 private String type     =""; //数据库类型
    	 private String name     =""; //连接池名字
    	 private String driver   =""; //数据库驱动
    	 private String url      =""; //数据库url
    	 private String username =""; //用户名
    	 private String password =""; //密码
    	 private int maxconn  =0; //最大连接数
    	 /**
    	  * 
    	  */
    	 public DSConfigBean() {
    	  // TODO Auto-generated constructor stub
    	 }
    	public String getType() {
    		return type;
    	}
    	public void setType(String type) {
    		this.type = type;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getDriver() {
    		return driver;
    	}
    	public void setDriver(String driver) {
    		this.driver = driver;
    	}
    	public String getUrl() {
    		return url;
    	}
    	public void setUrl(String url) {
    		this.url = url;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public int getMaxconn() {
    		return maxconn;
    	}
    	public void setMaxconn(int maxconn) {
    		this.maxconn = maxconn;
    	}
    
    }

第二个：数据库连接池

package com.ryan.db;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.Hashtable;
    import java.util.Iterator;
    
    public class DBConnectionPool {
    	 private Connection con=null;
    	 private int inUsed=0;    //使用的连接数
    	 private ArrayList freeConnections = new ArrayList();//容器，空闲连接
    	 private int minConn;     //最小连接数
    	 private int maxConn;     //最大连接
    	 private String name;     //连接池名字
    	 private String password; //密码
    	 private String url;      //数据库连接地址
    	 private String driver;   //驱动
    	 private String user;     //用户名
    	 
    	 /**
    	  * 
    	  */
    	 public DBConnectionPool() {
    	  // TODO Auto-generated constructor stub
    	 }
    	 /**
    	  * 创建连接池
    	  * @param driver
    	  * @param name
    	  * @param URL
    	  * @param user
    	  * @param password
    	  * @param maxConn
    	  */
    	 public DBConnectionPool(String name, String driver,String URL, String user, String password, int maxConn)
    	 {
    	  this.name=name;
    	  this.driver=driver;
    	  this.url=URL;
    	  this.user=user;
    	  this.password=password;
    	  this.maxConn=maxConn;
    	 }
    	 /**
    	  * 用完，释放连接
    	  * @param con
    	  */
    	 public synchronized void freeConnection(Connection con) 
    	 {
    	  this.freeConnections.add(con);//添加到空闲连接的末尾
    	  this.inUsed--;
    	 }
    	 /**
    	  * timeout  根据timeout得到连接
    	  * @param timeout
    	  * @return
    	  */
    	 public synchronized Connection getConnection(long timeout)
    	 {
    	  Connection con=null;
    	  if(this.freeConnections.size()>0)
    	  {
    	   con=(Connection)this.freeConnections.get(0);
    	   if(con==null)con=getConnection(timeout); //继续获得连接
    	  }
    	  else
    	  {
    	   con=newConnection(); //新建连接
    	  }
    	  if(this.maxConn==0||this.maxConn<this.inUsed)
    	  {
    	   con=null;//达到最大连接数，暂时不能获得连接了。
    	  }
    	  if(con!=null)
    	  {
    	   this.inUsed++;
    	  }
    	  return con;
    	 }
    	 /**
    	  * 
    	  * 从连接池里得到连接
    	  * @return
    	  */
    	 public synchronized Connection getConnection()
    	 {
    	  Connection con=null;
    	  if(this.freeConnections.size()>0)
    	  {
    	   con=(Connection)this.freeConnections.get(0);
    	   this.freeConnections.remove(0);//如果连接分配出去了，就从空闲连接里删除
    	   if(con==null)con=getConnection(); //继续获得连接
    	  }
    	  else
    	  {
    	   con=newConnection(); //新建连接
    	  }
    	  if(this.maxConn==0||this.maxConn<this.inUsed)
    	  {
    	   con=null;//等待 超过最大连接时
    	  }
    	  if(con!=null)
    	  {
    	   this.inUsed++;
    	   System.out.println("得到　"+this.name+"　的连接，现有"+inUsed+"个连接在使用!");
    	  }
    	  return con;
    	 }
    	 /**
    	  *释放全部连接
    	  *
    	  */
    	 public synchronized void release()
    	 {
    	  Iterator allConns=this.freeConnections.iterator();
    	  while(allConns.hasNext())
    	  {
    	   Connection con=(Connection)allConns.next();
    	   try
    	   {
    	    con.close();
    	   }
    	   catch(SQLException e)
    	   {
    	    e.printStackTrace();
    	   }
    	   
    	  }
    	  this.freeConnections.clear();
    	   
    	 }
    	 /**
    	  * 创建新连接
    	  * @return
    	  */
    	 private Connection newConnection()
    	 {
    	  try {
    	   Class.forName(driver);
    	   con=DriverManager.getConnection(url, user, password);
    	  } catch (ClassNotFoundException e) {
    	   // TODO Auto-generated catch block
    	   e.printStackTrace();
    	   System.out.println("sorry can't find db driver!");
    	  } catch (SQLException e1) {
    	   // TODO Auto-generated catch block
    	   e1.printStackTrace();
    	   System.out.println("sorry can't create Connection!");
    	  }
    	  return con;
    	  
    	 }
    	public int getInUsed() {
    		return inUsed;
    	}
    	public void setInUsed(int inUsed) {
    		this.inUsed = inUsed;
    	}
    	public int getMinConn() {
    		return minConn;
    	}
    	public void setMinConn(int minConn) {
    		this.minConn = minConn;
    	}
    	public int getMaxConn() {
    		return maxConn;
    	}
    	public void setMaxConn(int maxConn) {
    		this.maxConn = maxConn;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public String getUrl() {
    		return url;
    	}
    	public void setUrl(String url) {
    		this.url = url;
    	}
    	public String getDriver() {
    		return driver;
    	}
    	public void setDriver(String driver) {
    		this.driver = driver;
    	}
    	public String getUser() {
    		return user;
    	}
    	public void setUser(String user) {
    		this.user = user;
    	}
    	 
    }

第三个：数据库连接池管理

package com.ryan.db;
    
    import java.sql.Connection;
    import java.util.Enumeration;
    import java.util.Hashtable;
    import java.util.Iterator;
    import java.util.Vector;
    
    import com.ryan.configbean.DSConfigBean;
    
    public class DBConnectionManager {
    		 static private DBConnectionManager instance;//唯一数据库连接池管理实例类
    		 static private int clients;                 //客户连接数
    		 private Vector drivers  = new Vector();//驱动信息
    		 private Hashtable pools=new Hashtable();//连接池
    		 /**
    		  * 实例化管理类
    		  */
    		 public DBConnectionManager() {
    		  // TODO Auto-generated constructor stub
    //		  this.init();
    		 }
    		 /**
    		  * 得到唯一实例管理类
    		  * @return
    		  */
    		 static synchronized public DBConnectionManager getInstance()
    		 {
    		  if(instance==null)
    		  {
    		   instance=new DBConnectionManager();
    		  }
    		  return instance;
    		  
    		 }
    		 /**
    		  * 释放连接
    		  * @param name
    		  * @param con
    		  */
    		 public void freeConnection(String name, Connection con)
    		 {
    		  DBConnectionPool pool=(DBConnectionPool)pools.get(name);//根据关键名字得到连接池
    		  if(pool!=null)
    		  pool.freeConnection(con);//释放连接 
    		 }
    		 /**
    		  * 得到一个连接根据连接池的名字name
    		  * @param name
    		  * @return
    		  */
    		 public Connection getConnection(String name)
    		 {
    		  DBConnectionPool pool=null;
    		  Connection con=null;
    		  pool=(DBConnectionPool)pools.get(name);//从名字中获取连接池
    		  con=pool.getConnection();//从选定的连接池中获得连接
    		  if(con!=null)
    		  System.out.println("得到连接。。。");
    		  return con;
    		 }
    		 /**
    		  * 得到一个连接，根据连接池的名字和等待时间
    		  * @param name
    		  * @param time
    		  * @return
    		  */
    		 public Connection getConnection(String name, long timeout)
    		 {
    		  DBConnectionPool pool=null;
    		  Connection con=null;
    		  pool=(DBConnectionPool)pools.get(name);//从名字中获取连接池
    		  con=pool.getConnection(timeout);//从选定的连接池中获得连接
    		  System.out.println("得到连接。。。");
    		  return con;
    		 }
    		 /**
    		  * 释放所有连接
    		  */
    		 public synchronized void release()
    		 {
    		  Enumeration allpools=pools.elements();
    		  while(allpools.hasMoreElements())
    		  {
    		   DBConnectionPool pool=(DBConnectionPool)allpools.nextElement();
    		   if(pool!=null)pool.release();
    		  }
    		  pools.clear();
    		 }
    		 /**
    		  * 创建连接池
    		  * @param props
    		  */
    		 private void createPools(DSConfigBean dsb)
    		 {
    			  DBConnectionPool dbpool = (DBConnectionPool)pools.get(dsb.getName());
    			  if(dbpool==null){
    				  DBConnectionPool dbpool1=new DBConnectionPool();
    				  dbpool1.setName(dsb.getName());
    				  dbpool1.setDriver(dsb.getDriver());
    				  dbpool1.setUrl(dsb.getUrl());
    				  dbpool1.setUser(dsb.getUsername());
    				  dbpool1.setPassword(dsb.getPassword());
    				  dbpool1.setMaxConn(dsb.getMaxconn());
    				  System.out.println("ioio:"+dsb.getMaxconn());
    				  pools.put(dsb.getName(), dbpool1);
    			  }
    		 }
    		 /**
    		  * 初始化连接池的参数
    		  */
    		 public void init(DSConfigBean dscBean)
    		 {
    		  //加载驱动程序
    //		  this.loadDrivers();
    		  //创建连接池
    	      System.out.println("创建连接池。。。");
    		   this.createPools(dscBean);
    		  System.out.println("创建连接池完毕。。。");
    		 }
    		 public DSConfigBean loadDrivers(String name){
    			    DSConfigBean dscBean=new DSConfigBean();
    			    dscBean.setType("oracle");
    			    dscBean.setName(name);
    			    dscBean.setDriver("oracle.jdbc.driver.OracleDriver");
    			    dscBean.setUrl("jdbc:oracl:thin:@192.168.1.88:1521:orcl");
    			    dscBean.setUsername("dwgj");
    			    dscBean.setPassword("dwgj116");
    			    dscBean.setMaxconn(1000);
    			    return dscBean;
    		 }
    	public static void main(String []args){
    		DBConnectionManager   connectionMan=DBConnectionManager .getInstance();//得
    		//得到连接
    		   String name="oracle";//从上下文得到你要访问的数据库的名字
    		   Connection  con=connectionMan.getConnection(name);
    		   
    		   connectionMan.freeConnection(name,con);//释放，但并未断开连接
    	}
    }