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关于CodeJava的学习笔记——10

news 来源：原创 2025/6/14 14:42:23

一、URL

1、读取网页数据

首先导入import java.net.*;

通过URL访问网页，数据读取到url，然后使用InputStreamReader

URL url = new URL("https://www.etoak.com/static/video/video/four.mp4");

import java.net.*;
import java.io.*;
import java.util.*;
public class TestURLMax{
	public static void main(String[] args)throws Exception{

		http://old.etoak.com/assets/etoak.json
		System.out.println("上面是接口地址..");


		URL url = new URL("http://old.etoak.com/assets/etoak.json");
		URLConnection uc = url.openConnection();
		InputStream is = uc.getInputStream();

		InputStreamReader r = new InputStreamReader(is,"utf-8");
		BufferedReader br = new BufferedReader(r);
		String str;
		Map<String,List<String>> map = new HashMap<>();
		while((str = br.readLine())!=null){
			if(str.contains("name") && str.contains("city")){
				// { "id": "ET002","name": "王磊","price": "&yen;14000","city": "杭州","company": "杭州华数传媒" },
				String name = str.substring(str.indexOf("name")+8,str.indexOf("price")-3);
				String city = str.substring(str.indexOf("city")+8,str.indexOf("company")-3);
				if(map.containsKey(city)){
					List<String> list = map.get(city);
					list.add(name);
				}else{
					List<String> list = new ArrayList<>();
					list.add(name);
					map.put(city,list);
				}
			}
		}
		br.close();
		{
			Map<List<String>,String> temp = new TreeMap<>((a,b) -> a.size() == b.size() ? 1 : Integer.compare(b.size(),a.size()));
			map.forEach((k,v) -> temp.put(v,k));
			temp.entrySet().stream().limit(5).forEach((e) -> {
				List<String> k = e.getKey();
				String v = e.getValue();
				System.out.println(v+" : "+k.size());
				k.forEach((name) -> System.out.print("   "+name));
				System.out.println();
			});
		}

	}
}

2、下载网络资源

1、下载视频

import java.net.*;
import java.io.*;
public class TestURLPlus{
	public static void main(String[] args)throws Exception{
		URL url = new URL("https://www.etoak.com/static/video/video/four.mp4");
		URLConnection uc = url.openConnection();
		InputStream is = uc.getInputStream();
		int total = uc.getContentLength();//得到资源的内容长度
		int current = 0;//当前已经完成的字节数
		int lastPercent = -1;//最近显示过的百分比

		FileOutputStream fos = new FileOutputStream("etoak.mp4");
		byte[] data = new byte[128<<10];
		int len;
		while((len = is.read(data))!=-1){
			fos.write(data,0,len);
			current+=len;
			int percent = (int)(current * 100L / total);
			if(percent != lastPercent){
				System.out.print("\r已经完成"+percent+"%");
				lastPercent = percent;
			}
		}
		fos.close();
		is.close();
	}
}

2、下载图片

import java.net.*;
import java.io.*;
public class TestURL{
	public static void main(String[] args)throws Exception{
		URL url = new URL("http://old.etoak.com/assets/images/zkcs.png");
		URLConnection uc = url.openConnection();//打开连接
		InputStream is = uc.getInputStream();

		FileOutputStream fos = new FileOutputStream("jay.png");
		byte[] data = new byte[16384];
		int len;
		while((len = is.read(data))!=-1){
			fos.write(data,0,len);
		}
		fos.close();
		is.close();
	}
}

二、BigOne

该项目的需求是，在一堆消费数据中，有很多消费为0 的订单，那么在计算最终金额的时候，我们也会计算金额为0的部分，那么他们的名字就会存在Map中，那么最终我们不希望，这些吗，没有任何消费的人进入展示的列表里面，那么就需要我们进行遍历删除。考察的主要是前面的综合知识。

import java.util.*;
import java.io.*;

public class Exec2{
	static Map<String,List<Person>> map = new HashMap<>();
	public static void main(String[] args)throws Exception{
		FileInputStream file = new  FileInputStream("data.txt");
		InputStreamReader r = new InputStreamReader(file,"utf-8");
		BufferedReader br = new BufferedReader(r);
		String str;
		a:while((str = br.readLine()) != null){
			String ax = str.substring(0,2);
			String bx = str.substring(2,4);
			int cx = Integer.valueOf(str.substring(6,7));
			//System.out.println(bx);
			if(map.containsKey(ax)){
				for(Person p : map.get(ax)){
					if(p.name.equals(bx)){
						p.addcost(cx);
						continue a;
					}
				}
				Person p = new Person(bx,cx);
				map.get(ax).add(p);
			}else{
				List<Person> list = new ArrayList<>();
				Person p = new Person(bx,cx);
				list.add(p);
				map.put(ax,list);
			}
		}

/**
		map.forEach((k,v) -> {
			System.out.println(k);
			v.forEach(x -> System.out.println("	" + x));
			});


		Map<List<Person>,String> temp = new TreeMap<>();
		map.forEach((k,v) -> {

			temp.put(v,k);
			});
*/

		map.forEach((k,v) -> {
			System.out.println(k);
			for(Iterator<Person> car = v.iterator(); car.hasNext(); ){
				Person x = car.next();//取出遍历的元素
				if(x.cost == 0)car.remove();
			}
			v.forEach(x -> System.out.println("	" + x));
			});




		//System.out.println(map);
	}
}

class Person{
	String name;
	int cost;
	public Person(String name,int cost){
		this.name = name;
		this.cost = cost;
		}
	public void addcost(int ax ){
		cost = cost + ax;
		}
	public String toString(){
		return name + " 花费 " + cost;
		}
}

三、服务端与客户端

练习1

client

import java.io.*;
import java.net.*;
import javax.swing.*;
public class TestClient01{
	public static void main(String[] args)throws Exception{
		while(true){
			String str = JOptionPane.showInputDialog(null,"请输入内容:");
			if("88".equals(str)){
				break;
			}
			Socket skt = new Socket("192.168.31.236",17888);
			OutputStream os = skt.getOutputStream();
			OutputStreamWriter w = new OutputStreamWriter(os,"GBK");
			PrintWriter pw = new PrintWriter(w,true);
			pw.println(str);
			pw.close();
			skt.close();
		}
	}
}

server

import java.net.*;
import java.io.*;
import java.util.concurrent.*;
public class TestServer01{
	public static void main(String[] args)throws Exception{
		ExecutorService es = Executors.newFixedThreadPool(5);

		ServerSocket server = new ServerSocket(17888);//1024
		boolean isRunning = true;
		while(isRunning){
			Socket skt = server.accept();
			ServerThread st = new ServerThread(skt);
			es.submit(st);
		}
		server.close();

		es.shutdown();
	}
}
class ServerThread extends Thread{
	Socket skt;
	public ServerThread(Socket skt){
		this.skt = skt;
	}
	@Override
	public void run(){
		try{
			InputStream is = skt.getInputStream();
			InputStreamReader r = new InputStreamReader(is,"GBK");
			BufferedReader br = new BufferedReader(r);
			String str = br.readLine();
			String ip = skt.getInetAddress().toString();
			System.out.println(ip + " : " + str);
			br.close();
			skt.close();
		}catch(Exception e){
			System.out.println(skt.getInetAddress() +"出事了");
			//e.printStackTrace();
		}
	}
}

练习2

client

import java.io.*;
import java.net.*;
public class TestClient02{
	public static void main(String[] args)throws Exception{
		Socket skt = new Socket("192.168.31.236",17666);
		InputStream is = skt.getInputStream();
		FileOutputStream fos = new FileOutputStream("okk.jpg");
		byte[] data = new byte[16384];
		int len;
		while((len = is.read(data))!=-1){
			fos.write(data,0,len);
		}
		fos.close();
		is.close();
	}
}

server

import java.net.*;
import java.io.*;
import java.util.concurrent.*;
public class TestServer02{
	public static void main(String[] args)throws Exception{
		ExecutorService es = Executors.newCachedThreadPool();
		ServerSocket server = new ServerSocket(17666);
		boolean isRunning = true;
		while(isRunning){
			Socket skt = server.accept();
			EtoakThread et = new EtoakThread(skt);
			es.submit(et);
		}
		server.close();
		es.shutdown();
	}
}
class EtoakThread implements Runnable{
	Socket skt;
	public EtoakThread(Socket skt){
		this.skt = skt;
	}
	@Override
	public void run(){
		try{
			FileInputStream fis = new FileInputStream("jay.jpg");
			OutputStream os = skt.getOutputStream();
			byte[] data = new byte[16384];
			int len;
			while((len = fis.read(data))!=-1){
				os.write(data,0,len);
			}
			os.close();
			fis.close();
			System.out.println(skt.getInetAddress() + " 到此一游~");
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}

练习3

client

import javax.swing.*;
import java.net.*;
import java.io.*;
/*
	1.采集用户数据
	2.校验数据是否合法
	3.连接后台服务器
	4.将采集到的数据发送给服务器
	5.接收服务器处理完成的结果
	6.将结果展现给用户
*/
public class TestClient03{
	public static void main(String[] args)throws Exception{
		String name = JOptionPane.showInputDialog(null,"请输入姓名:");
		if(name == null || name.trim().length() == 0){
			JOptionPane.showMessageDialog(null,"手呢?!");
			return;
		}
		Socket skt = new Socket("192.168.31.236",12666);
		PrintWriter pw = new PrintWriter(new OutputStreamWriter(skt.getOutputStream(),"UTF-8"),true);
		pw.println(name);
		BufferedReader br = new BufferedReader(new InputStreamReader(skt.getInputStream(),"GBK"));
		String result = br.readLine();
		br.close();
		pw.close();
		skt.close();
		JOptionPane.showMessageDialog(null,name+" : " + result);

	}
}

server

import java.util.*;
import java.net.*;
import java.io.*;
import java.util.concurrent.*;
public class TestServer03{
	public static void main(String[] args)throws Exception{
		ExecutorService es = Executors.newCachedThreadPool();
		ServerSocket server = new ServerSocket(12666);
		boolean isRunning = true;
		while(isRunning){
			Socket skt = server.accept();
			ComputeThread ct = new ComputeThread(skt);
			es.submit(ct);
		}
		server.close();
		es.shutdown();
	}
}

class ComputeThread implements Callable<String>{
	Socket skt;
	public ComputeThread(Socket skt){
		this.skt = skt;
	}
	@Override
	public String call()throws Exception{
		//1.接 接收客户端发送来的名字(字符串)
		InputStream is = skt.getInputStream();
		InputStreamReader r = new InputStreamReader(is,"UTF-8");
		BufferedReader br = new BufferedReader(r);
		String name = br.readLine();
		//2.化 对数据进行运算处理 X.compute();
		String result = X.compute(name);
		//3.发 接处理结果(字符串)发还给客户端
		OutputStream os = skt.getOutputStream();
		OutputStreamWriter w = new OutputStreamWriter(os,"GBK");
		PrintWriter pw = new PrintWriter(w,true);
		pw.println(result);
		pw.close();
		br.close();
		skt.close();
		System.out.println(skt.getInetAddress() + " -> "+ name + " -> " + result);
		return null;
	}
}

class X{
	public static String compute(String name){
		if(name.contains("吴") || name.toLowerCase().contains("v"))
			return "天机不可泄露";

		String[] data = {"牢狱之灾","命运多舛","平平淡淡","大富大贵","天命之子"};
		int hash = name.hashCode();
		long now = System.currentTimeMillis() / (24L*60*60*1000);
		now = now * 17 / 11 * 23 / 13;
		hash += now;
		hash = Math.abs(hash);
		int x = hash % data.length;
		return data[x];

	}
}