JDBC(四)——對JDBC封裝，簡化操作

JDBC工具類

使用資源文件。

//資源文件 db.properties
mysqlDriver=com.mysql.cj.jdbc.Driver
mysqlUrl=jdbc\:mysql\://localhost\:3306/testjdbc
mysqlUser=root
mysqlPwd=root

工具類，提供獲得數據庫連接，關閉流兩個功能。

package com.wxy;

import java.io.IOException;
import java.sql.*;
import java.util.Properties;

/**
 * 對jdbc的封裝
 */
public class JDBCUtil {
    static Properties pros = null;
    static {
        pros = new Properties();
        try {
            pros.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("db.properties"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static Connection getMysqlConn(){
        try {
            Class.forName(pros.getProperty("mysqlDriver"));
            return DriverManager.getConnection(pros.getProperty("mysqlUrl"), pros.getProperty("mysqlUser"),pros.getProperty("mysqlPwd"));
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            return null;
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }
    public static void close(ResultSet rs, Statement stmt,Connection conn){
        if(rs != null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(stmt != null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(conn != null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    public static void close(Statement stmt,Connection conn){
        if(stmt != null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(conn != null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    public static void close(Connection conn){
        if(conn != null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}