集合、多线程、网络编程、JDBC、连接池、反射、综合应用

1、使用TCP连接服务器和客户端。　　

2、结合反射的知识、创建JDBC和连接池。

3、客户端输入信息并保存到一个对象中，发送到服务器。

4、服务器接收对象，通过JDBC存储进数据库中。

5、把服务器放到线程中，保持启动状态。

6、客户端读取数据库的数据信息，放到集合中。

7、遍历集合，输出数据库的数据。

服务器和客户端的项目结构：

服务器

客户端

实体类：

package com.luo.project.pojo;

import java.io.Serializable;

public class User implements Serializable{
	/**
	 * 
	 */
	private Integer id;
	private String name;
	private Integer age;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
	public User(Integer id, String name, Integer age) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
	}
	public User() {
		super();
		// TODO Auto-generated constructor stub
	}
	

}

　　

 Dao层：

package com.luo.project.dao;

import java.util.List;

import com.luo.project.pojo.User;

public interface UserDao {
//	插入用户
	public int insertUser(User user);
	
//	查询所有用户
	public List<User> queryAllUser();

}

Dao实现层：

package com.luo.project.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.alibaba.druid.stat.JdbcConnectionStat;
import com.luo.project.dao.UserDao;
import com.luo.project.pojo.User;
import com.luo.project.util.JDBCUtil;


public class UserDaoImpl implements UserDao {

	@Override
	public int insertUser(User user) {
	
		return JDBCUtil.insertUser(user);
	}

	@Override
	public List<User> queryAllUser() {
		
		return JDBCUtil.queryAllUser(User.class);
	}

}

JDBC工具类：

package com.luo.project.util;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.sql.DataSource;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.luo.project.pojo.User;

public class JDBCUtil {
	// 创建读取文件的properties类
	private static Properties properties = new Properties();
	
	private static DataSource dataSource=null;

	static {
		try {
			System.out.println("正在创建类加载器...");
			// 获取类加载器
			ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
			// 通过加载器获取项目下的配置文件的字节流
			InputStream inputStream = contextClassLoader.getResourceAsStream("db.properties");
			System.out.println("正在加载配置文件...");
			// 加载配置文件
			properties.load(inputStream);
			
			System.out.println("配置文件加载完毕...");
			
			dataSource=DruidDataSourceFactory.createDataSource(properties);

			Class.forName(properties.getProperty("driverClassName"));
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public static Connection getConnection() {

		try {
			return  dataSource.getConnection();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			throw new RuntimeException("连接失败！", e);
		}
	}

	public static void close(Connection connection, PreparedStatement ps, ResultSet rs) {
		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} finally {
				if (ps != null) {
					try {
						ps.close();
					} catch (SQLException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} finally {
						if (rs != null) {
							try {
								rs.close();
							} catch (SQLException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
					}
				}
			}
		}
	}
	
	
	public static int insertUser(Object obj) {
//		String sql="insert into User(name,age) values(?,?)";
		StringBuilder sb=new StringBuilder();
		sb.append("insert into ");
		sb.append(obj.getClass().getSimpleName());
		sb.append("(");
		Field[] fields = obj.getClass().getDeclaredFields();
		for (Field field : fields) {
			String fieldName = field.getName();
			sb.append(fieldName+",");
		}
		sb.deleteCharAt(sb.length()-1);
		sb.append(")");
		sb.append("values (");
		for (Field field : fields) {
			sb.append("?,");
		}
		sb.deleteCharAt(sb.length()-1);
		sb.append(")");
		
		Connection connection=null;
		PreparedStatement ps=null;
		try {			
			connection=JDBCUtil.getConnection();
			connection.setAutoCommit(false);
			ps= connection.prepareStatement(sb.toString());
			
			for(int i=0;i<fields.length;i++){
//				字段数组
				Field field = fields[i];
				field.setAccessible(true);
				Object fieldValue = field.get(obj);
				ps.setObject(i+1, fieldValue);
				
			}
		
			int row = ps.executeUpdate();	
			connection.commit();
			return row;						
			
		} catch (SQLException e) {
			try {
				connection.rollback();
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			JDBCUtil.close(connection, ps, null);
		}
		
		return 0;
	}
	
	
	

	public static <T> List<T> queryAllUser(Class<T> clz) {
//		String sql="select * from user";
		String sql="select * from "+ clz.getSimpleName();
		Connection connection=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		List<T> list=new ArrayList<T>();
		
		try {
			
			connection=JDBCUtil.getConnection();
			connection.setAutoCommit(false);
			ps = connection.prepareStatement(sql);
			rs = ps.executeQuery();
			while(rs.next()){
				T object = clz.newInstance();
				
				Field[] Fields =  clz.getDeclaredFields();
				for (Field field : Fields) {
					String fieldName = field.getName();
					
					Object value = rs.getObject(fieldName);
					field.setAccessible(true);
					field.set(object, value);
	
					
				}
							
				list.add(object);
				
			}
			connection.commit();
			return list;
			
			
		} catch (Exception e) {
			e.printStackTrace();
			try {
				connection.rollback();
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
		}finally{
			JDBCUtil.close(connection, ps, rs);
		}
		return null;
	}

}

服务器的主类和线程类：　

主类：

package com.luo.project.test;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.net.ServerSocket;
import java.net.Socket;

import com.luo.project.dao.impl.UserDao;
import com.luo.project.dao.impl.UserDaoImpl;
import com.luo.project.pojo.User;
import com.luo.project.thread.LoginThread;

//服务器
public class Service {
		
	public static void main(String[] args) throws IOException  {
		System.out.println("服务器启动...");
		ServerSocket serverSocket=serverSocket = new ServerSocket(9000);
		
//	每次客户端连接，都会实例一个socket对象
		while(true){
			Socket socket=serverSocket.accept();
			LoginThread loginThread = new LoginThread(socket);
			loginThread.start();
			
		}
		
		
	}

}

　　

　　线程：

package com.luo.project.thread;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.net.ServerSocket;
import java.net.Socket;

import com.luo.project.dao.impl.UserDao;
import com.luo.project.dao.impl.UserDaoImpl;
import com.luo.project.pojo.User;

public class LoginThread extends Thread {
	private Socket socket;
	public LoginThread(Socket socket) {
		super();
		this.socket=socket;
	}
	
	
	@Override
	public void run() {
		InputStream inputStream=null;
		ObjectInputStream objectInputStream=null;
		try {

			
			System.out.println("客户端已连接!");						
//			接受客户端的数据
			inputStream = socket.getInputStream();
			objectInputStream=new ObjectInputStream(inputStream);
			User user = (User) objectInputStream.readObject();
			System.out.println(user);
			
//			将数据存入数据库中
			UserDao userDao=new UserDaoImpl();
			int row = userDao.insertUser(user);
			System.out.println("数据被影响的行数:"+row);
			
			
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
	}
}

　

客户端的主类：

package com.luo.project.test;

import java.io.IOException;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import com.luo.project.dao.UserDao;
import com.luo.project.dao.impl.UserDaoImpl;
import com.luo.project.pojo.User;

//客户端
public class Client {

	public static void main(String[] args) {
		System.out.println("客户端启动...");
		Socket socket=null;
		OutputStream outputStream=null;
		Scanner scanner=new Scanner(System.in);
		ObjectOutputStream objectOutputStream=null;
		List<User> list=new ArrayList<>();
		try {
			socket=new Socket("127.0.0.1",9000);
			outputStream= socket.getOutputStream();
			objectOutputStream=new  ObjectOutputStream(outputStream);
				
			//向服务器发送数据
			System.out.print("请输入用户名称：");
			String name = scanner.nextLine();
			System.out.print("请输入用户年龄：");
			int age = scanner.nextInt();
			
			User user=new User(null, name, age);						
			objectOutputStream.writeObject(user);
			objectOutputStream.flush();
			
			
			//遍历数据库
			UserDao userDao=new UserDaoImpl();
			List<User> users = userDao.queryAllUser();
			System.out.println("遍历数据库：");
			for (User u : users) {
				System.out.println(u);
			}
					
			
			
			
			
			
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			try {				
				objectOutputStream.close();
				outputStream.close();
				socket.close();
				
				
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		}
		
	}

}

　　

db.properties配置文件

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/first_project
username=root
password=123456
maxActive=10

　　

　

测试类：

package com.luo.project.test;

import java.util.List;

import org.junit.Test;

import com.luo.project.dao.impl.UserDao;
import com.luo.project.dao.impl.UserDaoImpl;
import com.luo.project.pojo.User;

public class UserTest {
	private UserDao userDao=new UserDaoImpl();
	
	@Test
	public void insertTest(){
		User user=new User(null, "乔布斯", 45);
		int insertUser = userDao.insertUser(user);
		System.out.println(insertUser);
	}
	
	@Test
	public void queryAllUser(){
		List<User> queryAllUser = userDao.queryAllUser();
		for (User user : queryAllUser) {
			System.out.println(user);
		}
	}

}

　

数据库表：