dbconnection.java

利用struts开发的一个分页源码示例,可以直接导入到myeclipse下.

package com.yourcompany.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

public class DBConnection {

	/* 数据访问组件 */
	    private static DBConnection instance = null;

	    //取得连接
	    public static synchronized Connection getConnection() {
	        if (instance == null){
	            instance = new DBConnection();
	        }
	        return instance._getConnection();
	    }

	    private DBConnection(){
	        super();
	    }
/**
 * 创建连接
 * @return
 */
private  Connection _getConnection(){
	        try{
	            String sDBDriver  = null;
	            String sConnection   = null;
	            String sUser = null;
	            String sPassword = null;

	            Properties p = new Properties();
	            InputStream is = getClass().getResourceAsStream("/com/yourcompany/struts/db.properties");
	          
	            p.load(is);
	            sDBDriver = p.getProperty("DBDriver");
	          
	            sConnection = p.getProperty("Connection");
	            sUser = p.getProperty("User");
	            sPassword = p.getProperty("Password");

	            Properties pr = new Properties();
	            pr.put("user",sUser);
	            pr.put("password",sPassword);
	            pr.put("characterEncoding", "UTF-8");
	            pr.put("useUnicode", "TRUE");

	            Class.forName(sDBDriver).newInstance();
	            return DriverManager.getConnection(sConnection,pr);
	        }
	        catch(Exception se){
	            System.out.println(se);
	            return null;
	        }
	    }
/**
 * 根据sql语句返回一个结果集
 */
	    
     public static ResultSet getResultSet(String sql) throws SQLException{
       return 	DBConnection.getConnection().createStatement().executeQuery(sql);
		}
     /**
      * 根据sql语句返回一个整型，主要用于增加，删除，修改
      */
		public static int getSql(String sql) throws Exception{
			return DBConnection.getConnection().createStatement().executeUpdate(sql);
		}
		/**
		 * 
		 * @param ps
		 * @param rs
		 */
	    public static void clearConn(PreparedStatement ps,ResultSet rs){
	    	   closeResultSet(rs);
	    	   closePreparedStatement(ps);
	    	   }

	    	   public static void clearConn(PreparedStatement ps,Connection con){
	    	   //closeResultSet(rs);
	    	   closePreparedStatement(ps);
	    	   freeConncetion(con);
	    	   }


	    	 public static void clearConn(Connection con, PreparedStatement ps,ResultSet rs){
	    	   closeResultSet(rs);
	    	   closePreparedStatement(ps);
	    	   freeConncetion(con);
	    	 }
	    	 /**
	    	  * 释放连接池中的所有Connection
	    	  *
	    	  * @throws SQLException
	    	  */
	    	 public static void freeConncetion(Connection conn){
	    	   try{
	    	     if(conn != null) conn.close();
	    	   }catch(SQLException Ex_Connection){
	    	         System.out.println("SQLException when close Connection. "+Ex_Connection);
	    	   }
	    	 }


	    	 /**
	    	  * 释放连接池中的所有ResultSet
	    	  *
	    	  * @throws SQLException
	    	  */
	    	 public static void closeResultSet(ResultSet resultset){
	    	   try{
	    	     if(resultset != null) resultset.close();
	    	   }catch(SQLException Ex_Resultset){
	    	     System.out.println("SQLException when close ResultSet. "+Ex_Resultset);
	    	   }
	    	 }

	    	 /**
	    	  * 释放连接池中的所有PreparedStatement
	    	  *
	    	  * @throws SQLException
	    	  */
	    	 public static void closePreparedStatement(PreparedStatement ps){
	    	   try {
	    	     if (ps != null) ps.close();
	    	   } catch (SQLException Ex_Statement) {
	    	     System.out.println("SQLException when close PreparedStatement."+Ex_Statement);
	    	   }
	    	 }

	    	 public static void rollBack(Connection conn)
	    	 {
	    	   try{
	    	     conn.rollback();
	    	   }catch(SQLException se){
	    	     System.out.println("SQLException when close rollBack."+se);
	    	   }
	    	 }


	public static void main(String[] args) {
		Connection conn=DBConnection.getConnection();
		System.out.print(conn);
		// TODO 自动生成方法存根

	}

}