JAVA学习随笔之JDBC的典型用法之DriverManager

作为管理一组JDBC驱动的基础的服务。

一、getConnection方法

//一个参数

public static Connection getConnection(String url) throws SQLException

//String url：数据库URL

//两个参数

public static Connection getConnection(String url,Properties info) throws SQLException

//String url：数据库URL

//Properties info：一系列字符串键值对用来作为连接参数，一般至少包括user和password两个属性。

//三个参数

public static Connection getConnection(String url, String user,String password) throws SQLException

//String url：数据库URL//String user:连接数据库的用户名//String password：连接数据库的密码

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Properties;

public class TestDriverManager {

public void testConnection() throws Exception {
Class.forName("com.mysql.jdbc.Driver");

//一个参数
// DriverManager.getConnection("com.mysql.jdbc.Driver");
//两个参数
Connection connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/user_info", createPropeties());
//三个参数
// Connection connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/user_info", "root", "root");

Statement statement = connection.createStatement();
ResultSet query = statement.executeQuery("select * from test;");
while (query.next()) {
System.out.println(query.getInt(1));
}
}

/**
* 用于声明一个存储用户名和密码的Properties对象
* @return Properties
*/
public Properties createPropeties(){
Properties properties = new Properties();
properties.setProperty("user", "root");
properties.setProperty("password", "root");
return properties;
}

public static void main(String[] args) throws Exception {
new TestDriverManager().testConnection();
;
}
}