banxitan

Android Activity MainThread 中不能执行http通信解决办法

今天在做离线文件传输时。用HTTP上传文件。程序一运行　报如下的错误

原因是Google从3开始，强制默认禁止UI主线程发起通信请求　

解决办法： 

把通信的代码转移到子线程里去做， 比较靠谱的是new一个AyncTask，在里面做通信

                          有几个细节性的问题是，

                                第一， 一般原有通信的代码都是共通的API， 被许多个Activity调用， 一个良好的修改方法是在共通API里面new AyncTask

                               第二， 通信的API一般来说都是同步的， 你通信，然后画面主线程需要堵塞住，等待API的通信结果，再决定下面的业务逻辑的走向。

所以，这块可以采取 AyncTask.get()， 让主线程堵塞，直到通信结束。 当然，如果你需要将通信异步的话， 可以用Handler机制来解决


具体调用代码如下：HTTP异

步请求

package com.qqtech.ucstar.utils;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.impl.client.DefaultHttpClient;

import android.os.AsyncTask;

public class HttpReqTask extends AsyncTask<Object, Object, HttpResponse> {

@Override
protected HttpResponse doInBackground(Object arg0) {
String fileUploadUrl = (String) arg0[0];
String streamid = (String) arg0[1];
File file = (File) arg0[2];
//boolean paramBoolean = Boolean.parseBoolean((String) arg0[3]);
//String paramString3 = (String) arg0[4];
HttpClient localHttpClient = new DefaultHttpClient();
//String str1 = "fileName";
File localFile = file;
try {
if ((localFile == null) || (!localFile.exists()))
throw new IOException("文件不存在:" + localFile);
} catch (IOException e1) {
e1.printStackTrace();
}
HttpPost localPostMethod = new HttpPost(fileUploadUrl+"?streamid="+streamid+"&fileencode=UTF-8");
//MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE,null, Charset.forName("UTF-8"));
try {
FileBody bin = new FileBody(file);
reqEntity.addPart("file", bin);
localPostMethod.setEntity(reqEntity);
HttpResponse response = localHttpClient.execute(localPostMethod);
return response;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

}

调用代码如下：


Object[] param = new Object[5];
     param[0] = answer.getUploadURL();
     param[1] = answer.getStreamid();
     param[2] = new File(answer.getFileURL());
     param[3] = "false";
     param[4] = "";
     AsyncTask res = new HttpReqTask().execute(param);
     HttpResponse rep = null;
     rep = (HttpResponse) res.get();
     if (rep.getStatusLine().getStatusCode() == 200) {
      System.out.println("文件上传成功");
     }else{
      System.out.println("文件上传失败");
     }
    }

posted on 2013-07-11 10:51 MikyTan 阅读(1074) 评论(0)  编辑  收藏 所属分类: Android