<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="文件上傳" />   <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="上傳文件" />  </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);   //獲取控件   et_file = (EditText) findViewById(R.id.et_upload);  }   //點擊上傳按鈕  public void upload(View v) {   int id = v.getId();   switch (id) {   case R.id.btn_upload:    //獲取上傳文件的路徑    String path = et_file.getText().toString();    //判斷上次路徑是否為空    if (TextUtils.isEmpty(path.trim())) {     Toast.makeText(this, "上次文件路徑不能為空", 1).show();    } else {     //異步的客戶端對象     AsyncHttpClient client = new AsyncHttpClient();     //指定url路徑     String url = "http://172.16.237.144:8080/Login/UploadServlet";     //封裝文件上傳的參數     RequestParams params = new RequestParams();     //根據路徑創建文件     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----------");     }     //執行post請求     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;   }   }  }