Android从前台传图片文件到后台Servlet，报错。但是后台通过JSP直接传文件是可以传成功。

public class MainActivity extends Activity { EditText et_path; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_path=(EditText) findViewById(R.id.et_path); } public void upload(View view){ String path = et_path.getText().toString().trim(); File file = new File(Environment.getExternalStorageDirectory(),"info.txt"); if(file.exists()&file.length()>0){ //创建异步请求对象 AsyncHttpClient client = new AsyncHttpClient(); //输入要请求的url String url = "http://172.16.4.143:8080/LoginTest/UploadFileServlet"; //请求的参数对象 RequestParams params = new RequestParams(); //将参数加入到参数对象中 params.put("username", "dql"); try { params.put("filename",file); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } client.post(url, params, new AsyncHttpResponseHandler() { @Override public void onSuccess(int code, Header[] arg1, byte[] arg2) { System.out.println("请求码："+code); if(code==200){ //表示请求成功 Toast.makeText(MainActivity.this, "上传成功", 0).show(); } } @Override public void onFailure(int code, Header[] arg1, byte[] arg2, Throwable arg3) { arg3.printStackTrace(); System.out.println("请求码："+code); Toast.makeText(MainActivity.this, "上传失败", 0).show() } }); }else{ Toast.makeText(MainActivity.this, "文件不存在", 0).show(); }

只是数据从前台传到后台的话,写个form表单,post提交,后台servlet接收就好了,也可以jsp接收数据,很多方法。

额