JDBC

jcbc; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties; import org.junit.Test; public class Jdbc { @Test public void jdbcConnection() throws IOException, ClassNotFoundException, SQLException, InstantiationException, IllegalAccessException{ // 步骤：1.注册驱动 // 2.获取连接 // 3.获取Statement对象 /*配置文件jdbc.properties里面的内容 driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/mydb1?useSSL=true user=root password=123456 */ //类加载器加载配置文件 Properties pro = new Properties(); ClassLoader clazz = Jdbc.class.getClassLoader(); //配置文件jdbc.properties在src目录下 InputStream is = clazz.getResourceAsStream("jdbc.properties"); pro.load(is); //检查配置文件是否加载成功 System.out.println(pro.getProperty("driver")); // 注册数据库驱动 Class.forName(pro.getProperty("driver")).newInstance(); // 获取连接，导包的时候是导入import java.sql.Connection; Connection con = DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("user"), pro.getProperty("password")); //获取Statement对象的实例 Statement statement = con.createStatement(); //通过statement操作数据库 ResultSet resultset = statement.executeQuery("Select * from customer"); while(resultset.next()){ System.out.println(resultset.getObject("name")); } } }

 

java中的数据类型与mysql中的数据类型的对应关系

 

 

将数据库的数据存入到List集合中

 

package jcbc;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

import org.junit.Test;

import com.wxhledu.cn.domain.Customer;



public class Jdbc {
    @Test
    public void jdbcConnection() throws IOException, ClassNotFoundException, SQLException, InstantiationException, IllegalAccessException{
//        步骤：1.注册驱动
//            2.获取连接
//            3.获取Statement对象
/*配置文件jdbc.properties里面的内容    driver=com.mysql.jdbc.Driver
                                url=jdbc:mysql://localhost:3306/mydb1?useSSL=true
                    
                                user=root
                                password=123456    */
        
        
        //类加载器加载配置文件
        Properties pro = new Properties();
        ClassLoader clazz = Jdbc.class.getClassLoader();
        //配置文件jdbc.properties在src目录下
        InputStream is = clazz.getResourceAsStream("jdbc.properties");
        pro.load(is);
        //检查配置文件是否加载成功
        System.out.println(pro.getProperty("driver"));
//        注册数据库驱动
        Class.forName(pro.getProperty("driver")).newInstance();
        
//        获取连接，导包的时候是导入import java.sql.Connection;
    
        Connection con = DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("user"), pro.getProperty("password"));
//获取Statement对象的实例
        Statement statement = con.createStatement();
        //通过statement操作数据库
        ResultSet resultset = statement.executeQuery("Select * from customer");
        List<Customer> customers = new ArrayList<Customer>();
        while(resultset.next()){
            Customer customer = new Customer();//建立一个javabean封装Customer
            
            //获取数据库里面的数据，并且封装到customer中
            customer.setGender(resultset.getString("gender"));
            customer.setBirthday(resultset.getDate("birthday"));
            customer.setCellphone(resultset.getString("cellphone"));
            customer.setDescription(resultset.getString("description"));
            customer.setName(resultset.getString("name"));
            customer.setPreference(resultset.getString("preference"));
            customer.setType(resultset.getString("type"));
            
            //将封装好的对象存入到List集合中
            customers.add(customer);
        }
        Iterator it = customers.iterator();
        /*for(Customer c : customers){
            System.out.println(c);
        }
        */
        while(it.hasNext()){
            System.out.println(it.next().toString());
            
        }
        
        
    }

}

 

JDBC

标签：