文件上传只能使用POST
package com.itheima.fileupload;import java.io.File;
import java.io.FileNotFoundException;
import java.io.UnsupportedEncodingException;import org.apache.http.Header;import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;public class MainActivity extends Activity {private EditText et_path;private String uploadUrl = "http://192.168.12.31:8080/upload/UploadServlet";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//找到edittextet_path = (EditText) findViewById(R.id.et_path);}/*** 文件上传的逻辑* @param v*/public void upload(View v){// 拿到path String path = et_path.getText().toString().trim();File file = new File(path); if (file!=null&&file.length()>0) {//文件上传 //1创建asynchttpclien 对象 AsyncHttpClient client = new AsyncHttpClient();//2设置参数，文件RequestParams params = new RequestParams();params.put("username", "james");params.put("password", "123456");try {params.put("profile_picture", file); // Upload a File} catch (FileNotFoundException e) {e.printStackTrace();} //发送一个post请求client.post(uploadUrl, params, new AsyncHttpResponseHandler() {//请求成功的回调@Overridepublic void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {Toast.makeText(getApplicationContext(), "成功", 1).show();}@Overridepublic void onFailure(int statusCode, Header[] headers,byte[] responseBody, Throwable error) {}});}else {Toast.makeText(getApplicationContext(), "请选择上传的文件", 1).show();}}}