本文所述为一个Android上传文件的源代码，每一步实现过程都备有详尽的注释，思路比较清楚，学习了本例所述上传文件代码之后，你可以应对其它格式文件的上传。实例中主要实现上传文件至Server的方法，允许Input、Output，不使用Cache，使Androiod上传文件变得轻松。

主要功能代码如下：

package com.test;import java.io.DataOutputStream;import java.io.FileInputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;public class Main extends Activity { /* 变量声明 * newName：上传后在服务器上的文件名称 * uploadFile：要上传的文件路径 * actionUrl：服务器上对应的程序路径 */ private String newName="image.jpg"; private String uploadFile="/data/image.jpg"; private String actionUrl="http://l27.0.0.1/upload/upload.jsp"; private TextView mText1; private TextView mText2; private Button mButton; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mText1 = (TextView) findViewById(R.id.myText2); mText1.setText("文件路径：\n"+uploadFile); mText2 = (TextView) findViewById(R.id.myText3); mText2.setText("上传网址：\n"+actionUrl); mButton = (Button) findViewById(R.id.myButton); mButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { uploadFile(); } }); } private void uploadFile() { String end = "\r\n"; String twoHyphens = "--"; String boundary = "*****"; try { URL url =new URL(actionUrl); HttpURLConnection con=(HttpURLConnection)url.openConnection(); con.setDoInput(true); con.setDoOutput(true); con.setUseCaches(false); con.setRequestMethod("POST"); con.setRequestProperty("Connection", "Keep-Alive"); con.setRequestProperty("Charset", "UTF-8"); con.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary); DataOutputStream ds = new DataOutputStream(con.getOutputStream()); ds.writeBytes(twoHyphens + boundary + end); ds.writeBytes("Content-Disposition: form-data; " + "name=\"file1\";filename=\"" + newName +"\"" + end); ds.writeBytes(end); FileInputStream fStream = new FileInputStream(uploadFile); int bufferSize = 1024; byte[] buffer = new byte[bufferSize]; int length = -1; while((length = fStream.read(buffer)) != -1) { ds.write(buffer, 0, length); } ds.writeBytes(end); ds.writeBytes(twoHyphens + boundary + twoHyphens + end); fStream.close(); ds.flush(); InputStream is = con.getInputStream(); int ch; StringBuffer b =new StringBuffer(); while( ( ch = is.read() ) != -1 ) { b.append( (char)ch ); } showDialog(b.toString().trim()); ds.close(); } catch(Exception e) { showDialog(""+e); } } private void showDialog(String mess) { new AlertDialog.Builder(Main.this).setTitle("Message") .setMessage(mess) .setNegativeButton("确定",new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { } }) .show(); }}

读者如果觉得功能不足的话可以对代码进行扩展与完善，使之更加符合自身的应用需求。