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

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:paddingBottom="@dimen/activity_vertical_margin" 
 android:paddingLeft="@dimen/activity_horizontal_margin" 
 android:paddingRight="@dimen/activity_horizontal_margin" 
 android:paddingTop="@dimen/activity_vertical_margin" 
 tools:context=".MainActivity" > 
 
 <TextView 
  android:id="@+id/textView1" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:text="文件上传" /> 
 
 <EditText 
  android:id="@+id/et_upload" 
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" 
  android:layout_below="@+id/textView1" 
  android:ems="10" 
  android:text="/storage/sdcard0/1.jpg"> 
   
  <requestFocus /> 
 </EditText> 
 
 <Button 
  android:id="@+id/btn_upload" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:layout_below="@+id/et_upload" 
  android:onClick="upload" 
  android:text="上传文件" /> 
 
</RelativeLayout>

package com.example.android_upload; 
 
import java.io.File; 
 
import org.apache.http.Header; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.text.TextUtils; 
import android.view.View; 
import android.widget.EditText; 
import android.widget.Toast; 
 
import com.loopj.android.http.AsyncHttpClient; 
import com.loopj.android.http.AsyncHttpResponseHandler; 
import com.loopj.android.http.RequestParams; 
 
public class MainActivity extends Activity { 
 
 private EditText et_file; 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
  //获取控件 
  et_file = (EditText) findViewById(R.id.et_upload); 
 } 
 
 //点击上传按钮 
 public void upload(View v) { 
  int id = v.getId(); 
  switch (id) { 
  case R.id.btn_upload: 
   //获取上传文件的路径 
   String path = et_file.getText().toString(); 
   //判断上次路径是否为空 
   if (TextUtils.isEmpty(path.trim())) { 
    Toast.makeText(this, "上次文件路径不能为空", 1).show(); 
   } else { 
    //异步的客户端对象 
    AsyncHttpClient client = new AsyncHttpClient(); 
    //指定url路径 
    String url = "http://172.16.237.144:8080/Login/UploadServlet"; 
    //封装文件上传的参数 
    RequestParams params = new RequestParams(); 
    //根据路径创建文件 
    File file = new File(path); 
    try { 
     //放入文件 
     params.put("profile_picture", file); 
    } catch (Exception e) { 
     // TODO: handle exception 
     System.out.println("文件不存在----------"); 
    } 
    //执行post请求 
    client.post(url,params, new AsyncHttpResponseHandler() { 
 
     @Override 
     public void onSuccess(int statusCode, Header[] headers, 
       byte[] responseBody) { 
      if (statusCode == 200) { 
       Toast.makeText(getApplicationContext(), "上次成功", 1) 
         .show(); 
      } 
     } 
 
     @Override 
     public void onFailure(int statusCode, Header[] headers, 
       byte[] responseBody, Throwable error) { 
      error.printStackTrace(); 
     } 
    }); 
 
   } 
   break; 
 
  default: 
   break; 
  } 
 
 } 
 
}