MySql频繁查询、插入数据

当我们需要频繁地从数据库查询、插入数据时，可以将这些数据库操作汇集写到同一个类里，作为工具类直接调用.

将数据库的具体信息保存在.properties文件中，用log4j作为日志记录

MySql.java代码如下:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

public class Mysql {
    private Connection conn;
    private Statement smt;
    static Logger logger = Logger.getLogger(Mysql.class.getName());
//加载数据库驱动
    static {
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception e) {
            logger.log(Level.ERROR, "Mysql:" + e.getMessage());
        }
    }
//连接数据库
    public Mysql(String url, String user, String pwd) throws Exception {
        conn = DriverManager.getConnection(url, user,pwd);
        smt= conn.createStatement();
    }
//插入数据
    public ResultSet executeQuery(String sql) throws Exception {
        ResultSet rs = null;
        try {
            rs = smt.executeQuery(sql);
        } catch (SQLException e) {
            logger.log(Level.ERROR, sql+"\n" + e.getMessage());
        }
        return rs;
    }
//查询数据
    public void executeInsert(String sql) throws Exception {
        smt.executeUpdate(sql);
        conn.commit();
    }
//关闭数据库
    public void close() throws Exception {
        smt.close();
        conn.close();
    }
}

数据库信息如下:

db.properties

url=jdbc:mysql://10.255.245.6:3306/abc
user=abc
password=123

MySqlTest.java,将MySql作为工具类使用，进行数据库操作

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

import java.io.IOException;
import java.io.InputStream;
import java.sql.ResultSet;
import java.util.Properties;

public class MySqlTest {
    private static String url;
    private static String user;
    private static String password;

    private static Mysql mysql;
    static Logger logger = Logger.getLogger(MySqlTest.class.getName());

    private static Properties prop = new Properties();

    static {
        InputStream is =MySqlTest.class.getClassLoader().getResourceAsStream("db.properties");
        try {
            prop.load(is);
        } catch (IOException e) {
            logger.log(Level.ERROR, "db.properties:" + e.getMessage());
        }
    }

    //初始化MySql
    public  static void initialMySql() throws  Exception{
        url = prop.getProperty("url");
        user = prop.getProperty("user");
        password = prop.getProperty("password");
        mysql = new Mysql(url, user, password);
    }

    //查询mysql数据
    public  static void queryData(String sql) throws  Exception{
        ResultSet rs=mysql.executeQuery(sql);
        while (rs.next()) {
            String str=rs.getString(1);
            System.out.println(str+" ");
        }
        rs.close();        mysql.close();
    }

      //插入数据     public static void insertData(String sql) throws Exception{        mysql.executeInsert(sql);        mysql.close();    }
}