获取Assets目录下的图片显示并上传

 package com.jingle.getlocal;

 import java.io.ByteArrayOutputStream;

 import java.io.InputStream;

 import org.apache.http.Header;

 import sun.misc.BASE64Encoder;

 import com.loopj.android.http.AsyncHttpClient;
 import com.loopj.android.http.AsyncHttpResponseHandler;
 import com.loopj.android.http.RequestParams;

 import android.app.Activity;
 import android.content.res.AssetManager;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;

 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.ImageView;

 public class MainActivity extends Activity {
     private String UPLOAD_URL = "http://192.168.1.101:8080/Login//servlet/UploadImg";

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         initImg();
         initBtnUploadImg();

     }

     private void initBtnUploadImg() {
         Button btn = (Button) findViewById(R.id.btn);
         btn.setOnClickListener(new OnClickListener() {

             public void onClick(View v) {
                 uploadImg();
             }
         });
     }

     private void uploadImg() {
         AsyncHttpClient client = new AsyncHttpClient();
         client.setTimeout(3000);
         RequestParams params = new RequestParams();
         //获取Bitmap对象
         Bitmap bmp = getImg("orca.jpg");
         //获取字节数组输出流
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         //压缩Bitmap对象到字节数组输出流
         bmp.compress(Bitmap.CompressFormat.JPEG, 90, baos);
         //将字节数组输出流转为字节数组
         byte[] ba = baos.toByteArray();
         //将字节数组编码成字符串
         String str = new BASE64Encoder().encode(ba);
         params.put("img", str);

         client.post(UPLOAD_URL, params, new AsyncHttpResponseHandler() {
             public void onSuccess(int arg0, Header[] arg1, byte[] arg2) {
                 Log.i("ace", "post ok..");
             }

             public void onFailure(int arg0, Header[] arg1, byte[] arg2,
                     Throwable arg3) {
                 arg3.printStackTrace();
             }
         });

     }

     private void initImg() {
         ImageView img = (ImageView) findViewById(R.id.img);
         img.setImageBitmap(getImg("orca.jpg"));//assets目录下文件名
     }

     //获取图片的Bitmap对象
     private Bitmap getImg(String file) {
         Bitmap bmp = null;
         //获取AssetsMng对象
         AssetManager am = getResources().getAssets();
         try {
             //打开文件,返回输入流
             InputStream is = am.open(file);
             //Bitmap工厂解码输入流,得到bmp对象
             bmp = BitmapFactory.decodeStream(is);
             is.close();
         } catch (Exception e) {
             e.printStackTrace();
         }
         return bmp;
     }

 }

服务器端:

 package action;

 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintWriter;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import sun.misc.BASE64Decoder;

 public class UploadImg extends HttpServlet {

     private static final long serialVersionUID = -8236824851962797021L;

     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         response.setContentType("text/html");
         doPost(request, response);
     }

     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {

         System.out.println("do post..");
         String imgStr = request.getParameter("img");
         //将字符串解码为字节数组
         byte[] imgByte = new BASE64Decoder().decodeBuffer(imgStr);
         //新建文件输出流
         OutputStream os = new FileOutputStream("E:\\up.jpg");
         //输出流写入字节数组
         os.write(imgByte);
         os.close();

         PrintWriter out = response.getWriter();
         out.flush();
         out.close();
     }

 }