package com.bnd.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Objects;

/** 

* @author 作者 mbql: 

* @version 創(chuàng)建時間：2021年1月10日 下午5:14:16 

* 類說明 	JDBC操作數(shù)據(jù)庫工具類

*/
public class JdbcUtils {
	
	private static final String driverName = "com.mysql.jdbc.Driver";		// 數(shù)據(jù)庫驅(qū)動名稱
	
	private static final String url = "jdbc:mysql://39.108.146.20:3307/jsp?useUnicode=true&characterEncoding=utf-8";	// 數(shù)據(jù)庫url
	
	private static final String userName = "root";			// 用戶名
	
	private static final String password = "123456";	 // 用戶密碼
	
	private static Connection conn = null;					// 數(shù)據(jù)庫連接對象
	
	private static PreparedStatement preparedStatement = null;	// 執(zhí)行操作對象
	
	static {
		
		try {
			Class.forName(driverName);		// 2、注冊數(shù)據(jù)庫驅(qū)動
			conn = DriverManager.getConnection(url, userName, password);	// 3、獲取數(shù)據(jù)庫連接
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	/**
	 * 查詢數(shù)據(jù)
	 * @return	返回查詢到結(jié)果
	 */
	public static ResultSet queryData() {
		ResultSet result = null;
		String sql = "select id, name, pwd from user";		// 定義預(yù)編譯SQL
		try {
			preparedStatement = conn.prepareStatement(sql);			// 4、執(zhí)行預(yù)編譯SQL操作
			result = preparedStatement.executeQuery();	// 5、執(zhí)行查詢操作
			while (result.next()) {
				int id = result.getInt(1);
				String name = result.getString(2);
				String pwd = result.getString(3);
				System.out.println("id：" + id + "--> name：" + name + "--> pwd：" + pwd);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			// 7、釋放資源
			close(conn, preparedStatement, result);
		}
		return result;
	}
	
	/**
	 * 添加數(shù)據(jù)
	 * @return	返回受影響行數(shù)
	 */
	public static int addData() {
		String sql = "insert into user(name,pwd) values(?, ?)";
		try {
			preparedStatement = conn.prepareStatement(sql);		// 4、執(zhí)行預(yù)編譯SQL操作
			preparedStatement.setString(1, "tom");
			preparedStatement.setString(2, "abc123");
			int count = preparedStatement.executeUpdate();			// 6、執(zhí)行添加操作
			if (count > 0) {
				return count;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			// 7、釋放資源
			close(conn, preparedStatement, null);
		}			
		return -1;
	}
	
	/**
	 * 更新數(shù)據(jù)
	 * @return	返回受影響行數(shù)
	 */
	public static int updateData() {
		String sql = "update user set name = ?, pwd = ? where id = ?";
		try {
			preparedStatement = conn.prepareStatement(sql);		// 4、執(zhí)行預(yù)編譯SQL操作
			preparedStatement.setString(1, "sueno");
			preparedStatement.setString(2, "qwe123");
			preparedStatement.setInt(3, 10);
			int count = preparedStatement.executeUpdate();			// 6、執(zhí)行添加操作
			if (count > 0) {
				return count;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			// 7、釋放資源
			close(conn, preparedStatement, null);
		}			
		return -1;
	}
	
	
	/**
	 * 刪除數(shù)據(jù)
	 * @return	返回受影響行數(shù)
	 */
	public static int deleteData() {
		String sql = "delete from user where id = ?";
		try {
			preparedStatement = conn.prepareStatement(sql);		// 4、執(zhí)行預(yù)編譯SQL操作
			preparedStatement.setInt(1, 11);
			int count = preparedStatement.executeUpdate();			// 6、執(zhí)行添加操作
			if (count > 0) {
				return count;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {
			// 7、釋放資源
			close(conn, preparedStatement, null);
		}			
		return -1;
	}
	
	/**
	 * 釋放資源
	 * @param conn	關(guān)閉數(shù)據(jù)庫連接
	 * @param statement	關(guān)閉數(shù)據(jù)庫操作對象
	 * @param rs	關(guān)閉結(jié)果集操作對象
	 */
	public static void close(Connection conn, Statement statement, ResultSet rs) {
		if (Objects.nonNull(rs)) {
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (Objects.nonNull(statement)) {
			try {
				statement.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (Objects.nonNull(conn)) {
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}

package com.bnd.util;

import java.sql.ResultSet;

/** 

* @author 作者 mbql: 

* @version 創(chuàng)建時間：2021年1月10日 下午6:00:30 

* 類說明 

*/
public class TestJdbc {
	
	public static void main(String[] args) {
		// 獲取用戶數(shù)據(jù)
//		ResultSet rs = JdbcUtils.queryData();
//		System.out.println(rs);
		
		// 添加用戶數(shù)據(jù)
//		int count = JdbcUtils.addData();
//		if (count > 0) {
//			System.out.println("添加成功！");
//		}
		
		// 更新用戶數(shù)據(jù)
//		int count = JdbcUtils.updateData();
//		if (count > 0) {
//			System.out.println("更新成功！");
//		}
		
		// 刪除用戶數(shù)據(jù)
//		int count = JdbcUtils.deleteData();
//		if (count > 0) {
//			System.out.println("刪除成功！");
//		}
	}
}