db.java

用java开发的一个企业的DRP系统源码

package com.bjsxt.drp.util;

import java.sql.*;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

public class DB {
	
	public static Connection getConn() {
		Connection conn = null;
//		try {
//			Class.forName("com.mysql.jdbc.Driver");
//			conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/drp?user=root&password=root");
//		} catch (ClassNotFoundException e) {
//			e.printStackTrace();
//		} catch (SQLException e) {
//			e.printStackTrace();
//		}
		DataSource ds = null;
		try {
			Context initContext = new InitialContext();
			Context ctx = (Context)initContext.lookup("java:comp/env");
			ds = (DataSource)ctx.lookup("jdbc/drp");
			System.out.println("DataSource.getConnection()");
			conn = ds.getConnection();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}
	
	public static Statement getStatement(Connection conn) {
		Statement stmt = null; 
		try {
			if(conn != null) {
				stmt = conn.createStatement();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return stmt;
	}
	
	public static ResultSet getResultSet(Statement stmt, String sql) {
		ResultSet rs = null;
		try {
			if(stmt != null) {
				rs = stmt.executeQuery(sql);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return rs;
	}
	
	public static void closeConn(Connection conn) {
		try {
			if(conn != null) {
				conn.close();
				conn = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
	public static void closeStmt(Statement stmt) {
		try {
			if(stmt != null) {
				stmt.close();
				stmt = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
	public static void closeRs(ResultSet rs) {
		try {
			if(rs != null) {
				rs.close();
				rs = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}