javasocket通信實例

1. 用java socket 實現客戶端與伺服器之間的數據的發送與接受。。。雙向的

下面是一個簡單的通訊實例，進行Server和Client之間的文件傳輸。。如果是簡單的文本傳輸的話簡化掉文本操作的內容即可。。

1.伺服器端

package sterning;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerTest {
int port = 8821;

void start() {
Socket s = null;
try {
ServerSocket ss = new ServerSocket(port);
while (true) {
// 選擇進行傳輸的文件
String filePath = "D:\\lib.rar";
File fi = new File(filePath);

System.out.println("文件長度:" + (int) fi.length());

// public Socket accept() throws
// IOException偵聽並接受到此套接字的連接。此方法在進行連接之前一直阻塞。

s = ss.accept();
System.out.println("建立socket鏈接");
DataInputStream dis = new DataInputStream(new BufferedInputStream(s.getInputStream()));
dis.readByte();

DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));
DataOutputStream ps = new DataOutputStream(s.getOutputStream());
//將文件名及長度傳給客戶端。這里要真正適用所有平台，例如中文名的處理，還需要加工，具體可以參見Think In Java 4th里有現成的代碼。
ps.writeUTF(fi.getName());
ps.flush();
ps.writeLong((long) fi.length());
ps.flush();

int bufferSize = 8192;
byte[] buf = new byte[bufferSize];

while (true) {
int read = 0;
if (fis != null) {
read = fis.read(buf);
}

if (read == -1) {
break;
}
ps.write(buf, 0, read);
}
ps.flush();
// 注意關閉socket鏈接哦，不然客戶端會等待server的數據過來，
// 直到socket超時，導致數據不完整。
fis.close();
s.close();
System.out.println("文件傳輸完成");
}

} catch (Exception e) {
e.printStackTrace();
}
}

public static void main(String arg[]) {
new ServerTest().start();
}
}

2.socket的Util輔助類

package sterning;

import java.net.*;
import java.io.*;

public class ClientSocket {
private String ip;

private int port;

private Socket socket = null;

DataOutputStream out = null;

DataInputStream getMessageStream = null;

public ClientSocket(String ip, int port) {
this.ip = ip;
this.port = port;
}

/** *//**
* 創建socket連接
*
* @throws Exception
* exception
*/
public void CreateConnection() throws Exception {
try {
socket = new Socket(ip, port);
} catch (Exception e) {
e.printStackTrace();
if (socket != null)
socket.close();
throw e;
} finally {
}
}

public void sendMessage(String sendMessage) throws Exception {
try {
out = new DataOutputStream(socket.getOutputStream());
if (sendMessage.equals("Windows")) {
out.writeByte(0x1);
out.flush();
return;
}
if (sendMessage.equals("Unix")) {
out.writeByte(0x2);
out.flush();
return;
}
if (sendMessage.equals("Linux")) {
out.writeByte(0x3);
out.flush();
} else {
out.writeUTF(sendMessage);
out.flush();
}
} catch (Exception e) {
e.printStackTrace();
if (out != null)
out.close();
throw e;
} finally {
}
}

public DataInputStream getMessageStream() throws Exception {
try {
getMessageStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
return getMessageStream;
} catch (Exception e) {
e.printStackTrace();
if (getMessageStream != null)
getMessageStream.close();
throw e;
} finally {
}
}

public void shutDownConnection() {
try {
if (out != null)
out.close();
if (getMessageStream != null)
getMessageStream.close();
if (socket != null)
socket.close();
} catch (Exception e) {

}
}
}

3.客戶端

package sterning;

import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;

public class ClientTest {
private ClientSocket cs = null;

private String ip = "localhost";// 設置成伺服器IP

private int port = 8821;

private String sendMessage = "Windwos";

public ClientTest() {
try {
if (createConnection()) {
sendMessage();
getMessage();
}

} catch (Exception ex) {
ex.printStackTrace();
}
}

private boolean createConnection() {
cs = new ClientSocket(ip, port);
try {
cs.CreateConnection();
System.out.print("連接伺服器成功!" + "\n");
return true;
} catch (Exception e) {
System.out.print("連接伺服器失敗!" + "\n");
return false;
}

}

private void sendMessage() {
if (cs == null)
return;
try {
cs.sendMessage(sendMessage);
} catch (Exception e) {
System.out.print("發送消息失敗!" + "\n");
}
}

private void getMessage() {
if (cs == null)
return;
DataInputStream inputStream = null;
try {
inputStream = cs.getMessageStream();
} catch (Exception e) {
System.out.print("接收消息緩存錯誤\n");
return;
}

try {
//本地保存路徑，文件名會自動從伺服器端繼承而來。
String savePath = "E:\\";
int bufferSize = 8192;
byte[] buf = new byte[bufferSize];
int passedlen = 0;
long len=0;

savePath += inputStream.readUTF();
DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(newBufferedOutputStream(new FileOutputStream(savePath))));
len = inputStream.readLong();

System.out.println("文件的長度為:" + len + "\n");
System.out.println("開始接收文件!" + "\n");

while (true) {
int read = 0;
if (inputStream != null) {
read = inputStream.read(buf);
}
passedlen += read;
if (read == -1) {
break;
}
//下面進度條本為圖形界面的prograssBar做的，這里如果是打文件，可能會重復列印出一些相同的百分比
System.out.println("文件接收了" + (passedlen * 100/ len) + "%\n");
fileOut.write(buf, 0, read);
}
System.out.println("接收完成，文件存為" + savePath + "\n");

fileOut.close();
} catch (Exception e) {
System.out.println("接收消息錯誤" + "\n");
return;
}
}

public static void main(String arg[]) {
new ClientTest();
}
}

2. 誰能給一個 Qt 跟 java 用socket通訊的例子,要求java 做服務端,qt 做客戶端,要求雙方都能實時顯示對方發過

提供一個聊天功能的給你
import java.net.*;
import java.io.*;

class My1 extends Thread
{
private Socket skt;

public My1(Socket skt)
{
this.skt = skt;
}

public void run()
{
try
{
BufferedReader br = new BufferedReader(new InputStreamReader(skt.getInputStream()));

for(;;)
{
if(br.readLine()==null) {break;}
System.out.println(br.readLine()); // 阻塞
}
}
catch(Exception e)
{
System.out.println("對方斷線！");
}
}
}

class My2 extends Thread
{
private Socket skt;

public My2(Socket skt)
{
this.skt = skt;
}

public void run()
{
try
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
PrintWriter pw = new PrintWriter(skt.getOutputStream());

for(;;)
{
pw.println("姓名====>："+br.readLine()); // 阻塞
pw.flush();
}
}
catch(Exception e)
{
System.out.println("對方斷線！");
}
}
}

public class Good
{
public static void main(String[] args) throws Exception
{
//連接的目的是：獲得Socket對象
Socket skt;

System.out.print("請輸入<port> 或者：<ip>,<port> ");
// 先選擇角色
String[] ss = new BufferedReader(new InputStreamReader(System.in)).readLine().split(",");
if(ss.length==1)
skt = new ServerSocket(Integer.parseInt(ss[0])).accept();
else
skt = new Socket(ss[0], Integer.parseInt(ss[1]));

System.out.println("連接到：" + skt.getInetAddress().getHostAddress());
// 連接建立，角色消失

new My1(skt).start(); //讀網路
new My2(skt).start(); //讀鍵盤
}
}

3. 用JAVA編寫一個socket通信程序。

埠監聽和建立管道。首先伺服器端綁定監聽埠，然後客戶端socket連接到這個埠，控制台輸入的字元串都會被在這個埠監聽的伺服器接收到。