Android TCP 文件客户端与服务器DEMO

原来在CU的blog，后来误删了，现在恢复过来在这里。

主要功能是：

1、TCP服务器提供文件下载服务，服务器支持多线程。

 

2、TCP Client从服务器上下载指定的文件，Client也支持多线程。

 

首先是服务器，服务器是在PC机上，JAVA运行环境，主要参考网上的代码，自己做了支持多线程处理，代码如下：

//file:DownloadServer.java import java.net.*;import java.io.*;class ServerOneDownload extends Thread { private Socket socket = null; private String downloadRoot = null; private static final int Buffer = 8 * 1024; public ServerOneDownload(Socket socket, String downloadRoot) { super(); this.socket = socket; this.downloadRoot = downloadRoot; start(); } // 检查文件是否真实存在，核对下载密码，若文件不存在或密码错误，则返回-1，否则返回文件长度 // 此处只要密码不为空就认为是正确的 private long getFileLength(String fileName, String password) { // 若文件名或密码为null，则返回-1 if ((fileName == null) || (password == null)) return -1; // 若文件名或密码长度为0，则返回-1 if ((fileName.length() == 0) || (password.length() == 0)) return -1; String filePath = downloadRoot + fileName; // 生成完整文件路径 System.out.println("DownloadServer getFileLength----->" + filePath); File file = new File(filePath); // 若文件不存在，则返回-1 if (!file.exists()) return -1; return file.length(); // 返回文件长度 } // 用指定输出流发送指定文件 private void sendFile(DataOutputStream out, String fileName) throws Exception { String filePath = downloadRoot + fileName; // 生成完整文件路径 // 创建与该文件关联的文件输入流 FileInputStream in = new FileInputStream(filePath); System.out.println("DownloadServer sendFile----->" + filePath); byte[] buf = new byte[Buffer]; int len; // 反复读取该文件中的内容，直到读到的长度为-1 while ((len = in.read(buf)) >= 0) { out.write(buf, 0, len); // 将读到的数据，按读到的长度写入输出流 out.flush(); } out.close(); in.close(); } // 提供下载服务 public void download() throws IOException { System.out.println("启动下载... "); System.out.println("DownloadServer currentThread--->" + currentThread().getName()); System.out.println("DownloadServer currentThread--->" + currentThread().getId()); // 获取socket的输入流并包装成BufferedReader BufferedReader in = new BufferedReader(new InputStreamReader( socket.getInputStream())); // 获取socket的输出流并包装成DataOutputStream DataOutputStream out = new DataOutputStream(socket.getOutputStream()); try { String parameterString = in.readLine(); // 接收下载请求参数 // 下载请求参数字符串为自定义的格式，由下载文件相对于下载根目录的路径和 // 下载密码组成，两者间以字符 "@ "分隔，此处按 "@ "分割下载请求参数字符串 String[] parameter = parameterString.split("@ "); String fileName = parameter[0]; // 获取相对文件路径 String password = parameter[1]; // 获取下载密码 // 打印请求下载相关信息 System.out.print(socket.getInetAddress().getHostAddress() + "提出下载请求， "); System.out.println("请求下载文件: " + fileName); // 检查文件是否真实存在，核对下载密码，获取文件长度 long len = getFileLength(fileName, password); System.out.println("download fileName----->" + fileName); System.out.println("download password----->" + password); out.writeLong(len); // 向客户端返回文件大小 out.flush(); // 若获取的文件长度大于等于0,则允许下载，否则拒绝下载 if (len >= 0) { System.out.println("允许下载 "); System.out.println("正在下载文件 " + fileName + "... "); sendFile(out, fileName); // 向客户端发送文件 System.out.println(fileName +": "+"下载完毕 "); } else { System.out.println("下载文件不存在或密码错误，拒绝下载！ "); } } catch (Exception e) { System.out.println(e.toString()); } finally { socket.close(); // 关闭socket } } @Override public void run() { try { download(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } // TODO Auto-generated method stub super.run(); }}public class DownloadServer { private final static int port = 65525; private static String root = "C:// "; // 下载根目录 public static void main(String[] args) throws IOException { String temp = null; // 监听端口 try { // 包装标准输入为BufferedReader BufferedReader systemIn = new BufferedReader(new InputStreamReader( System.in)); while (true) { System.out.print("请输入下载服务器的下载根目录： "); root = systemIn.readLine().trim(); // 从标准输入读取下载根目录 File file = new File(root); // 若该目录确实存在且为目录，则跳出循环 if ((file.exists()) && (file.isDirectory())) { temp = root.substring(root.length() - 1, root.length()); if (!temp.equals("//")) root += "//"; } break; } } catch (Exception e) { System.out.println(e.toString()); } ServerSocket serverSocket = new ServerSocket(port); System.out.println("Server start..."); try { while (true) { Socket socket = serverSocket.accept(); new ServerOneDownload(socket, root); } } finally { serverSocket.close(); } }} 

 

File Download Client

Client输入IP和文件名即可直接从服务器上下载，还是看代码。

 

//file:DownLoadClient.java package org.piaozhiye.study;import java.io.IOException;import java.net.Socket;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;public class DownLoadClient extends Activity { private Button download = null; private EditText et_serverIP = null; private EditText et_fileName= null; private String downloadFile = null; private final static int PORT = 65525; private final static String defaultIP = "192.168.0.100"; private static String serverIP = null; private Socket socket; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); download = (Button)findViewById(R.id.download); et_serverIP= (EditText)findViewById(R.id.et_serverip); et_fileName = (EditText)findViewById(R.id.et_filename); et_serverIP.setText("192.168.0.100"); download.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { serverIP = et_serverIP.getText().toString(); if(serverIP == null){ serverIP = defaultIP; } System.out.println("DownLoadClient serverIP--->" + serverIP ); System.out.println("DownLoadClient MainThread--->" + Thread.currentThread().getId() ); try{ socket = new Socket(serverIP, PORT); }catch(IOException e){ } downloadFile = et_fileName.getText().toString(); Thread downFileThread = new Thread(new DownFileThread(socket, downloadFile)); downFileThread.start(); System.out.println("DownLoadClient downloadFile--->" + downloadFile ); } }); }} 

file:DownFileThread.java

 

package org.piaozhiye.study;import java.io.BufferedInputStream;import java.io.DataInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.Socket;public class DownFileThread extends Thread { private Socket socket; private String downloadFile; private final static int Buffer = 8 * 1024; public DownFileThread(Socket socket, String downloadFile) { super(); this.socket = socket; this.downloadFile = downloadFile; } public Socket getSocket() { return socket; } public void setSocket(Socket socket) { this.socket = socket; } public String getDownloadFile() { return downloadFile; } public void setDownloadFile(String downloadFile) { this.downloadFile = downloadFile; } // 向服务器提出下载请求，返回下载文件的大小 private long request(String fileName, String password) throws IOException { // 获取socket的输入流并包装成DataInputStream DataInputStream in = new DataInputStream(socket.getInputStream()); // 获取socket的输出流并包装成PrintWriter PrintWriter out = new PrintWriter(new OutputStreamWriter( socket.getOutputStream())); // 生成下载请求字符串 String requestString = fileName + "@ " + password; out.println(requestString); // 发出下载请求 out.flush(); return in.readLong(); // 接收并返回下载文件长度 } // 接收并保存文件 private void receiveFile(String localFile) throws Exception { // 获取socket的输入流并包装成BufferedInputStream BufferedInputStream in = new BufferedInputStream( socket.getInputStream()); // 获取与指定本地文件关联的文件输出流 FileOutputStream out = new FileOutputStream(localFile); byte[] buf = new byte[Buffer]; int len; // 反复读取该文件中的内容，直到读到的长度为-1 while ((len = in.read(buf)) >= 0) { out.write(buf, 0, len); // 将读到的数据，按读到的长度写入输出流 out.flush(); } out.close(); in.close(); } // 从服务器下载文件 public void download(String downloadFile) throws Exception { try { String password = "password"; // String downloadFile ="imissyou.mp3"; String localpath = "/sdcard/"; String localFile = localpath + downloadFile; long fileLength = request(downloadFile, password); // 若获取的文件长度大于等于0，说明允许下载，否则说明拒绝下载 if (fileLength >= 0) { System.out.println("fileLength: " + fileLength + " B"); System.out.println("downing..."); receiveFile(localFile); // 从服务器接收文件并保存至本地文件 System.out.println("file:" + downloadFile + " had save to " + localFile); } else { System.out.println("download " + downloadFile + " error! "); } } catch (IOException e) { System.out.println(e.toString()); } finally { socket.close(); // 关闭socket } } @Override public void run() { System.out.println("DownFileThread currentThread--->" + DownFileThread.currentThread().getId()); // TODO Auto-generated method stub try { download(downloadFile); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } super.run(); } } 

 

layout.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" ><TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:paddingLeft="10dp" android:paddingRight="10dp" android:paddingTop="5dp" android:paddingBottom="5dp" android:text="服务器IP:" /> <EditText android:id="@+id/et_serverip" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingLeft="10dp" android:paddingRight="10dp" android:paddingTop="5dp" android:paddingBottom="5dp" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:paddingLeft="10dp" android:paddingRight="10dp" android:paddingTop="5dp" android:paddingBottom="5dp" android:text="下载文件名:" /> <EditText android:id="@+id/et_filename" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingLeft="10dp" android:paddingRight="10dp" android:paddingTop="5dp" android:paddingBottom="5dp" /> <Button android:id="@+id/download" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="download" /></LinearLayout> 

同时别忘了权限：

<uses-permission android:name="android.permission.INTERNET" />