Question

我正在制作Android应用程序而且我遇到了一些问题。

我正在做的是尝试从连接到数据库的远程服务器上的PHP文件中获取信息。但是我在Logcat中得到Exception：null，我的代码：

        httpclient=new DefaultHttpClient();
        System.out.println("1");
        httppost= new HttpPost("MYSITE/MYPHP.PHP");
        System.out.println("1");
        nameValuePairs = new ArrayList<NameValuePair>(1);
        System.out.println("1");
        nameValuePairs.add(new BasicNameValuePair("uid",userConfig.uid));
        System.out.println("1");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        System.out.println("1");
        response=httpclient.execute(httppost);
        System.out.println("1");
        ResponseHandler<String> responseHandler = new BasicResponseHandler();
        System.out.println("1");
        final String response = httpclient.execute(httppost, responseHandler);
        System.out.println("Response: " + response);
        runOnUiThread(new Runnable() {
            public void run() {
                System.out.println("Response: " + response);
                dialog.dismiss();
            }
        });

    }catch(Exception e){
        System.out.println("Exception: " + e.getMessage());
    }

＆＃39; System.out.println（＆＃34; 1＆＃34;）;＆＃39;用于调试。

我的logcat输出

10-10 22:53:44.382  24228-24228/PACKAGENAME  I/System.out﹕ 1
10-10 22:53:44.382  24228-24228/PACKAGENAME  I/System.out﹕ 1
10-10 22:53:44.382  24228-24228/PACKAGENAME  I/System.out﹕ 1
10-10 22:53:44.382  24228-24228/PACKAGENAME  I/System.out﹕ 1
10-10 22:53:44.383  24228-24228/PACKAGENAME  I/System.out﹕ 1
10-10 22:53:44.407  24228-24228/PACKAGENAME  I/System.out﹕ Exception: null

所以你可以看到它得到了这一行

response=httpclient.execute(httppost);

我不知道发生了什么，是的，我确实拥有适当的权限！

Answer 1

你是从主线程运行的吗？

Android不允许您在主线程上执行长时间运行的操作（如HTTP请求等网络操作）。 Android documentation

Answer 2

问题可能与多部分实体有关，请参阅下面的代码。经过测试。调整它以满足您的需求。

public static String post(String url, String imagePath, String apikey) {
String response = null;
try {
    DefaultHttpClient httpClient = new DefaultHttpClient();
    HttpPost httpPost = new HttpPost(url);

    MultipartEntityBuilder entity = MultipartEntityBuilder.create();
    entity.addPart("xyz", new FileBody(new File(imagePath)));
    entity.addPart("abc", new StringBody(apikey,
            ContentType.TEXT_PLAIN));
    httpPost.setEntity(entity.build());

    HttpResponse httpResponse = httpClient.execute(httpPost);
    HttpEntity httpEntity = httpResponse.getEntity();
    response = EntityUtils.toString(httpEntity);

} catch (UnsupportedEncodingException e) {
    e.printStackTrace();
} catch (ClientProtocolException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}
return response;

}

完全难倒，HTTP客户端Android

2 个答案: