java中封装JDBC工具类的实例分析

package com.qianfeng.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
 * JDBC工具类
 * 有获取连接的方法
 * @author dushine
 */
public class JDBCUtil {
/**
 * 获取数据库连接的方法
 * @return Connection conn
 * @throws SQLException
 */
public static Connection getConnection() throws SQLException {
String url = "jdbc:mysql://localhost:3306/class?useSSL=false";
String user = "root";
String password = "root";
Connection conn = DriverManager.getConnection(url,user,password);
return conn;
}
/**
 * 释放连接的方法
 * @param conn
 * @throws SQLException
 */
public static void releaseSourse(Connection conn) throws SQLException {
if (conn != null) {
conn.close();
}
}
/**
 * 释放连接的方法
 * @param conn 数据库连接对象
 * @param stmt 执行SQL语句的对象
 * @throws SQLException
 */
public static void releaseSourse(Connection conn,Statement stmt) throws SQLException {
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
/**
 * 释放连接的方法
 * @param conn 数据库连接对象
 * @param stmt 执行SQL语句的对象
 * @param resultSet 执行SQL语句的返回的结果集
 * @throws SQLException
 */
public static void releaseSourse(Connection conn,Statement stmt,ResultSet resultSet) throws SQLException {
if (resultSet != null) {
resultSet.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
}
}

public class JDBCUtil {
  //连接对象
  private Connection connection = null;
  //数据库操作对象
  private PreparedStatement ps = null;
  //数据库连接地址
  private static String url = "jdbc:mysql://localhost:3306/";
  //用户名
  private static String user = "root";
  //密码
  private static String password = "123456";
  //静态代码块 注册驱动
  //类加载的时候，只执行一次
  static{
    try {
      Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }

  //获取连接对象
  public Connection getConnection(){
    //Connection conn = null;
    try {
      connection = DriverManager.getConnection(url,user,password);
    } catch (SQLException e) {
      e.printStackTrace();
      System.out.println("数据库连接失败....");
    }
    System.out.println("数据库连接成功...");
    return connection;
  }

  //获取数据库操作对象
  public PreparedStatement createPreparedStatement(String sql){
    connection = getConnection();
    try {
      ps = connection.prepareStatement(sql);
    } catch (SQLException e) {
      e.printStackTrace();
    }
    return ps;
  }

  //释放资源
  public void close(){
    //释放连接对象
    if (connection != null) {
      try {
        connection.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
    //释放数据库操作对象
    if (ps != null) {
      try {
        ps.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
    System.out.println("释放资源成功...");
  }
  //方法的重载
  public void close(ResultSet reuslt){
    // 调用释放资源的方法
    close();
    // 释放查询结果集对象
    if (reuslt != null) {
      try {
        reuslt.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }

}