import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
/**
 * 服務(wù)器端
 */
public class TCPFileUpload_Server {
    public static void main(String[] args) throws Exception {
        //思路
        //在本機(jī) 的8888端口監(jiān)聽, 等待連接
        ServerSocket serverSocket = new ServerSocket(8888);
        System.out.println("服務(wù)器端，監(jiān)聽8888端口，等待連接");
        //當(dāng)沒有客戶端連接8888端口時(shí)，程序會(huì) 阻塞, 等待連接
        //如果有客戶端連接，則會(huì)返回Socket對(duì)象，程序繼續(xù)
        Socket socket = serverSocket.accept();
        //通過socket.getInputStream() 讀取客戶端寫入到數(shù)據(jù)通道的數(shù)據(jù), 并轉(zhuǎn)換成字節(jié)數(shù)組
        BufferedInputStream bufferedInputStream = new BufferedInputStream(socket.getInputStream());
        byte[] bytes = StreamUtils.streamToByteArray(bufferedInputStream);
        //寫入指定路徑
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream("src\\G.jpg"));
        bufferedOutputStream.write(bytes);
        //關(guān)閉IO流
        bufferedOutputStream.close();
        //向客戶端回復(fù)收到圖片
        BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
        bufferedWriter.write("收到圖片!");
        bufferedWriter.flush();
        socket.shutdownOutput();
        //關(guān)閉所有流
        bufferedWriter.close();
        bufferedInputStream.close();
        socket.close();
        serverSocket.close();
    }
}

import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
/**
 * 客戶端
 */
public class TCPFileUpload_Client {
    public static void main(String[] args) throws Exception {
        //連接服務(wù)端 (ip , 端口）
        //解讀:連接本機(jī)的 8888端口, 如果連接成功，返回Socket對(duì)象
        Socket socket = new Socket(InetAddress.getLocalHost(), 8888);
        System.out.println("客戶端 連接端口:" + socket.getPort());
        //創(chuàng)建讀取磁盤文件IO流
        BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream("src/P.jpg"));
        //獲取字節(jié)數(shù)組
        byte[] bytes = StreamUtils.streamToByteArray(bufferedInputStream);
        //通過Socket獲取到輸出流,將bytes發(fā)送到服務(wù)端
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(socket.getOutputStream());
        bufferedOutputStream.write(bytes);
        //關(guān)閉流對(duì)象,socket,刷新，添加終止符
        bufferedInputStream.close();
        bufferedOutputStream.flush();
        socket.shutdownOutput();
        //接受回復(fù)消息
        //此處可調(diào)用Utils的方法
//        String s = "";
//        while ((s = bufferedReader.readLine()) != null)
//            System.out.println(s);
        System.out.println(StreamUtils.streamToString(socket.getInputStream()));
        //關(guān)閉所有流
        bufferedOutputStream.close(); //socket的包裝流不要過早關(guān)閉
        socket.close();
    }
}

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
/**
 * 此類用于演示關(guān)于流的讀寫方法
 */
public class StreamUtils {
    /**
     * 功能：將輸入流轉(zhuǎn)換成byte[]
     *
     * @param is 輸入流
     * @return byte數(shù)組
     * @throws Exception IO流異常
     */
    public static byte[] streamToByteArray(InputStream is) throws Exception {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();//創(chuàng)建輸出流對(duì)象
        byte[] b = new byte[1024];
        int len;
        while ((len = is.read(b)) != -1) {
            bos.write(b, 0, len);
        }
        byte[] array = bos.toByteArray();
        bos.close();
        return array;
    }
    /**
     * 功能：將InputStream轉(zhuǎn)換成String
     *
     * @param is 輸入流
     * @return 字符串
     * @throws Exception IO流異常
     */
    public static String streamToString(InputStream is) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder builder = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) { //當(dāng)讀取到 null時(shí)，就表示結(jié)束
            builder.append(line + "\r\n");
        }
        return builder.toString();
    }
}

 Socket socket = new Socket(ip,port); 

OutputStream cos = socket.getOutputStream();
cos.write("你好服務(wù)器".getBytes());  

InputStream cis = socket.getInputStream()
//設(shè)置一個(gè)緩沖數(shù)組 temp數(shù)組大小大于所接收的數(shù)據(jù)量
byte[] temp = new byte[1024];
int len = cis.read(temp);
//將所接守的字節(jié)轉(zhuǎn)換為字符串 這里使用 temp.toString()會(huì)有亂碼
System.out.println(new String(temp,0,len));

socket.close();

ServerSocket server = new ServerSocket(port:8888);

Socket socket = server.accept();

//獲得流對(duì)象
InputStream sis = socket.getInputStream();
OutputStream sos = socket.getOutputStream();
//打印從客戶端獲得的數(shù)據(jù)
byte[] temp = new btye[1024];
sis.read(temp);
System.out.println(new String(temp));
//對(duì)客戶端發(fā)出返回信息
sos.write("你也好,客戶端".getBytes());

socket.close();
server.close();

import java.io.*;
import java.net.*;
public class TCPClient {
    public static void main(String[] args) throws IOException {
        FileInputStream fis = new FileInputStream("C:\\Users\\子陌\\Pictures\\1.jpg");
        Socket socket = new Socket("192.168.1.8",8888);
        OutputStream cos = socket.getOutputStream();
        InputStream cis = socket.getInputStream();
        int len =0;
        byte[] bytes = new byte[1024];
        while((len = fis.read(bytes))!=-1){
            cos.write(bytes,0,len);
        }
        socket.shutdownOutput();
        byte[] bytes1 = new byte[1024];
        int len1=0;
        len1 =cis.read(bytes1);
        System.out.println(new String(bytes1));
        socket.close();
        fis.close();
    }
}

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;
public class TCPSever {
    public static void main(String[] args) throws IOException {
        //這里ServerSocket要放到外面
        ServerSocket server = new ServerSocket(8888);
        while(true) { 
            new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try{
                            //先把a(bǔ)ccept響應(yīng)放到前面
                            Socket socket = server.accept();
                            String fileName = "itcast" + System.currentTimeMillis() + new Random().nextInt();
                            File file = new File("D:\\TCPUpLoad");
                            if (!file.exists()) {
                                file.mkdirs();
                            }
                            FileOutputStream fos = new FileOutputStream(file + "\\" + fileName + ".jpg");//這里file既是File類也可以當(dāng)作路徑名稱
                            //FileOutPutStream 會(huì)自動(dòng)生成空文件
                            InputStream sis = socket.getInputStream();
                            OutputStream sos = socket.getOutputStream();
                            int len = 0;
                            byte[] bytes = new byte[1024];
                            while ((len = sis.read(bytes)) != -1) {
                                fos.write(bytes, 0, len);
                            }
                            sos.write("已經(jīng)收到".getBytes());
                            socket.close();
                            fos.close();
                            //重點(diǎn)：要將資源全部釋放，不然會(huì)占用線程或者端口
                        }catch(IOException e)
                        {
                            System.out.println(e);
                        }
                    }
                }).start();
        }
        //server.close();
    }
}

String fileName = "itcast" + System.currentTimeMillis() + new Random().nextInt(9999); 

FileOutStream fos = new FileOutStream(...) 

 while((len = fis.read(bytes))!=-1)
       {
            cos.write(bytes,0,len);
        }
        socket.shutdownOutput();