JDBCTest:
package com.test.example;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import com.mysql.jdbc.Driver;
import com.test.util.JDBCUtil;
public class JDBCTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
//1. 注册驱动
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
//2. 建立连接 参数一： 协议 + 访问的数据库 ， 参数二： 用户名 ， 参数三： 密码。
connection = DriverManager.getConnection("jdbc:mysql://localhost/jdbc", "root", "root");
//3. 创建statement ， 跟数据库打交道，一定需要这个对象
statement = connection.createStatement();
//4. 执行查询 ， 得到结果集
String sql = "select * from stu";
resultSet = statement.executeQuery(sql);
//5. 遍历查询每一条记录
while(resultSet.next()){
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
int age = resultSet.getInt("age");
System.out.println("id="+id+",name="+name+",age="+age);
}
// resultSet.close();
// Statement.close();
// connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
JDBCUtil.close(connection, resultSet, statement);
}
}
}
JDBCUtil:
package com.test.util;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCUtil {
public static void close(Connection connection,ResultSet resultSet,Statement statement){
closeRS(resultSet);
closeSt(statement);
closeConn(connection);
}
private static void closeRS(ResultSet resultSet){
try {
if(resultSet !=null){
resultSet.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
resultSet = null;
}
}
private static void closeSt(Statement statement){
try {
if(statement !=null){
statement.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
statement = null;
}
}
private static void closeConn(Connection connection){
try {
if(connection !=null){
connection.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
connection = null;
}
}
}
运行结果:
数据库表:
