一、在IDEA中建立一個空project工程項目
![](https://img.laitimes.com/img/__Qf2AjLwojIjJCLyojI0JCLiAzNfRHLGZkRGZkRfJ3bs92YsYTMfVmepNHLwUEVNdXVU1kb1cVWvB3MMBjVtJWd0ckW65UbM5WOHJWa5kHT20ESjBjUIF2X0hXZ0xCMx81dvRWYoNHLrdEZwZ1Rh5WNXp1bwNjW1ZUba9VZwlHdssmch1mclRXY39CXldWYtlWPzNXZj9mcw1ycz9WL49zZuBnLzcDO1EDM0QTM0IDNwkTMwIzLc52YucWbp5GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.png)
二、準備工作:
1.mysq驅動jar包:mysql-connector-java-5.1.37-bin.jar
2.jdbc配置檔案:jdbc.properties
三、代碼編寫
1、建立libs檔案夾導入jar包
2、src目錄下建立jdbc.properties配置檔案
# 驅動
driver=com.mysql.jdbc.Driver
# 資料庫位址
url=jdbc:mysql://localhost:3306/my_db
# 使用者名
userName=root
# 密碼
passWord=root
3、抽取JDBCUtil工具類
package com.mollen.demo01;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
import java.sql.*;
import java.util.Properties;
/**
* @ClassNmme: JDBCUtil
* @Author: Mollen
* @CreateDate: 2018-09-08 18:31:30
* @Description:
* JDBCUtils工具類
*/
public class JDBCUtils {
private static String url;
private static String userName;
private static String passWord;
private static String driver;
/**
* 1.讀取配置檔案
*/
static {
try {
//擷取檔案路徑 --> ClassLoader類加載器
ClassLoader classLoader = JDBCUtils.class.getClassLoader();
URL resource = classLoader.getResource("jdbc.properties");
String path = resource.getPath();
//加載檔案
Properties pro = new Properties();
pro.load(new FileReader(path));
//解析檔案
url = pro.getProperty("url");
userName = pro.getProperty("userName");
passWord = pro.getProperty("passWord");
driver = pro.getProperty("driver");
//注冊驅動
Class.forName(driver);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/**
* 2.獲得資料庫連接配接
*/
public static Connection getConn() throws SQLException {
return DriverManager.getConnection(url, userName, passWord);
}
/**
* 3.釋放資源(方法重載)
*/
public static void close(PreparedStatement pstmt, Connection conn) {
close(null,pstmt,conn);
}
public static void close(ResultSet rs, PreparedStatement pstmt, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (pstmt != null) {
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
4.編寫測試類
package com.mollen.demo01;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
/**
* @ClassNmme: Test
* @Author: Mollen
* @CreateDate: 2018-09-08 18:31:37
* @Description:
* 測試類
*/
public class Test {
public static void main(String[] args) {
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
//定義sql
String sql = "SELECT * FROM student";
try {
//1.擷取連接配接
conn = JDBCUtils.getConn();
//2.擷取sql執行對象
pstmt = conn.prepareStatement(sql);
//3.執行sql
rs = pstmt.executeQuery();
//4.周遊集合
while(rs.next()){
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("name:"+name+" age:"+age);
}
}catch (Exception e){
e.printStackTrace();
}finally {
//釋放資源
JDBCUtils.close(rs,pstmt,conn);
}
}
}
四、注意事項
1.案例用的是mysql資料庫驅動
2.jdbc配置檔案建議建在src目錄下
3.資料庫執行對象用的是prepareStatement案例中沒有做參數解析操作
4.資料庫連接配接使用完畢必須釋放資源
摘自:https://blog.csdn.net/mollen/article/details/82532290