以前写过的一个例子,仅供参考:
package com.demo.dbconnect;
import java.sql.*;
class DBHandle {
private Connection con = null;
private Statement stat = null;
private ResultSet res = null;
public DBHandle() {
try {
//1、加载驱动
Class.forName("com.mysql.jdbc.Driver");
//2、连接数据库
con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/数据库名称",
"数据库用户",
"数据库密码");
//3、创建Statement
stat = con.createStatement();
} catch (Exception e) {
e.printStackTrace();
}
}
//查询数据
public void searchData() {
//4、定义sql语句
String sql = " select * from usertable ";
try {
//5、执行sql语句并返回结果集
res = stat.executeQuery(sql);
while (res.next()) {
String username = res.getString("username");
int age = res.getInt("age");
String sex = res.getString("sex");
System.out.println(username + "\t" + age + "\t" + sex);
}
//6、关闭数据库连接(注意关闭顺序)
if (res != null) {
res.close();
}
if (stat != null) {
stat.close();
}
if (con != null) {
con.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
public class Demo {
public static void main(String[] args) {
new DBHandle().searchData();
}
}