jdbconnection.java

在线投票系统

package com.tool;
import java.sql.*;

public class JDBConnection {
	    private final static String dbDriver = "com.mysql.jdbc.Driver"; //连接sql数据库的方法
	    private final static String url = "jdbc:mysql://127.0.0.1:3306/db_database15";
	    private final static String userName = "root";
	    private final static String password = "111";
	    private Connection con = null;

	    public JDBConnection() {
	        try {
	            Class.forName(dbDriver).newInstance(); //加载数据库驱动
	        } catch (Exception ex) {
	            System.out.println("数据库加载失败");
	        }
	    }

//	创建数据库连接
	    public boolean creatConnection() {
	        try {
	            con = DriverManager.getConnection(url, userName, password);
	            con.setAutoCommit(true);

	        } catch (SQLException e) {
	            System.out.println(e.getMessage());
	            System.out.println("creatConnectionError!");
	        }
	        return true;
	    }

//	对数据库的增加、修改和删除的操作
	    public boolean executeUpdate(String sql) {

	        if (con == null) {
	            creatConnection();
	        }
	        try {
	            Statement stmt = con.createStatement();
	            int iCount = stmt.executeUpdate(sql);
	            System.out.println(sql);
	            System.out.println("操作成功，所影响的记录数为" + String.valueOf(iCount));
	            return true;
	        } catch (SQLException e) {
	            System.out.println(e.getMessage());
	            System.out.println("executeUpdaterError!");
	            return false;
	        }

	    }

//	对数据库的查询操作
	    public ResultSet executeQuery(String sql) {
	        ResultSet rs;
	        try {
	            if (con == null) {
	                creatConnection();
	            }
	            Statement stmt = con.createStatement();
	            try {
	                rs = stmt.executeQuery(sql);
	            } catch (SQLException e) {
	                System.out.println(e.getMessage());
	                return null;
	            }
	        } catch (SQLException e) {
	            System.out.println(e.getMessage());
	            System.out.println("executeQueryError!");
	            return null;
	        }
	        return rs;
	    }

//	关闭数据库的操作
	    public void closeConnection() {
	        if (con != null) {
	            try {
	                con.close();
	            } catch (SQLException e) {
	                e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
	                System.out.println("Failed to close connection!");
	            } finally {
	                con = null;
	            }
	        }
	    }

}