（Android）JavaSocket编程，文件上传到服务器，客户端Android，服务器端J2SE

article/2025/10/15 1:53:23

SD卡中有encrypt.png文件

在E盘可以看到，从模拟器SD卡中发送来的文件

服务器端代码，我这里是使用CMD命令演示的。服务端等待客户端连接，然后接收客户端的数据。包括文件名，大小，和文件数据。

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;public class FileServer {private int port = 8821;private ServerSocket ss;private Socket socket;/** 数据输入流，读取来自网络的数据流 **/private DataInputStream dis;/** 数据输出流，将来自网络的数据流写入文件 **/private DataOutputStream dos;private String savePath = "E:\\";public void startServer() {// 已经传输的文件大小int passedlength = 0;// 文件总大小long length = 0;// 缓存大小int bufferSize = 8192;// 缓存byte[] buf = new byte[bufferSize];try {ss = new ServerSocket(port);socket = ss.accept();dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));} catch (IOException e) {e.printStackTrace();}try {// 将文件名字读取进来savePath += dis.readUTF();// 文件的长度读取进来（实际只是为了显示进度）length = dis.readLong();} catch (IOException e) {e.printStackTrace();}try {dos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(savePath)));} catch (FileNotFoundException e) {e.printStackTrace();}while (true) {int read = 0;if (dis != null) {try {read = dis.read(buf);} catch (IOException e) {e.printStackTrace();}}passedlength += read;if (read == -1) {break;}// 下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比System.out.println("文件接收了" + (passedlength * 100 / length) + "%\n");try {dos.write(buf, 0, read);} catch (IOException e) {e.printStackTrace();}}if (dos != null) {try {dos.close();} catch (IOException e) {e.printStackTrace();}dos = null;}if (dis != null) {try {dis.close();} catch (IOException e) {e.printStackTrace();}dis = null;}if (socket != null) {try {socket.close();} catch (IOException e) {e.printStackTrace();}socket = null;}if (ss != null) {try {ss.close();} catch (IOException e) {e.printStackTrace();}ss = null;}System.out.println("接收完成，文件存为" + savePath + "\n");}public static void main(String[] args) {FileServer fileServer = new FileServer();fileServer.startServer();}
}

Android端代码（客户端）还是要记住在Manifest中添加网络访问权限

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical" ><TextViewandroid:layout_width="fill_parent"android:layout_height="wrap_content"android:textStyle="bold"android:gravity="center"android:text="文件上传测试" /><Buttonandroid:id="@+id/myButton"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="开始上传" /></LinearLayout>

文件操作类，主要是使用了里面的获取SD路径的函数

package com.zeph.android.fileclient;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;import android.content.Context;
import android.os.Environment;public class FileHelper {private Context context;/** SD卡是否存在 **/private boolean hasSD = false;/** SD卡的路径 **/private String SDPATH;/** 当前程序包的路径 **/private String FILESPATH;public FileHelper(Context context) {this.context = context;hasSD = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);SDPATH = Environment.getExternalStorageDirectory().getPath();FILESPATH = this.context.getFilesDir().getPath();}/*** 在SD卡上创建文件* * @throws IOException*/public File createSDFile(String fileName) throws IOException {File file = new File(SDPATH + "//" + fileName);if (!file.exists()) {file.createNewFile();}return file;}/*** 删除SD卡上的文件* * @param fileName*/public boolean deleteSDFile(String fileName) {File file = new File(SDPATH + "//" + fileName);if (file == null || !file.exists() || file.isDirectory())return false;return file.delete();}/*** 读取SD卡中文本文件* * @param fileName* @return*/public String readSDFile(String fileName) {StringBuffer sb = new StringBuffer();File file = new File(SDPATH + "//" + fileName);try {FileInputStream fis = new FileInputStream(file);int c;while ((c = fis.read()) != -1) {sb.append((char) c);}fis.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return sb.toString();}public String getFILESPATH() {return FILESPATH;}public String getSDPATH() {return SDPATH;}public boolean hasSD() {return hasSD;}
}

Activity类，里面的startClient函数完成文件传输到服务器 注意代码里面IP地址填写你自己的。

package com.zeph.android.fileclient;import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;public class FileClientActivity extends Activity {private Socket socket;// 这里填写你的IP地址private String ip = "192.168.0.1";private int port = 8821;private DataInputStream dis;private DataOutputStream dos;private Button myButton;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);myButton = (Button) findViewById(R.id.myButton);myButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {new Thread() {public void run() {startClient("encrypt.png");}}.start();}});}public void startClient(String fileName) {FileHelper helper = new FileHelper(getApplicationContext());String filePath = helper.getSDPATH() + "//" + fileName;File file = new File(filePath);try {socket = new Socket(ip, port);dis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));dos = new DataOutputStream(socket.getOutputStream());} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}try {dos.writeUTF(file.getName());dos.flush();dos.writeLong((long) file.length());dos.flush();} catch (IOException e) {e.printStackTrace();}int bufferSize = 8192;byte[] buf = new byte[bufferSize];while (true) {int read = 0;if (dis != null) {try {read = dis.read(buf);} catch (IOException e) {e.printStackTrace();}}if (read == -1) {break;}try {dos.write(buf, 0, read);dos.flush();} catch (IOException e) {e.printStackTrace();}}try {dis.close();dos.close();socket.close();} catch (IOException e) {e.printStackTrace();}}
}