Android开发-网络通信2

调试了三种通信方法：HttpClient、AsyncHttpClient 和 Volley 。

HttpClient 测试代码^[1]：

public class HttpUtil {
    
    public static void sendRequestWithHttpClient(final String address, final List<NameValuePair> params, final HttpCallbackListener listener)
    {
        new Thread(new Runnable(){
            
            @Override
            public void run(){
                try{
                    
                    HttpPost httpPost= new HttpPost(address);
                    
                    HttpClient httpClient = new DefaultHttpClient();
                    UrlEncodedFormEntity postEntity;
                    postEntity = new UrlEncodedFormEntity(params,"utf-8");
                    httpPost.setEntity(postEntity);
                    HttpResponse httpResponse = httpClient.execute(httpPost);
                    if(httpResponse.getStatusLine().getStatusCode() == 200)
                    {
                        HttpEntity reEntity=httpResponse.getEntity();
                        String reposnse = EntityUtils.toString(reEntity,"utf-8");
                        if(listener != null)
                        {
                            listener.onFinish(reposnse);
                        }
                    }
                    
                }catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }).start();
    }

}

String usertel = et_usertel.getText().toString().trim();
String password = et_password.getText().toString().trim();
                
String url_login = "http://192.168.1.102:8999/weixin/index.php/Home/Index/test";
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("usertel",usertel));
params.add(new BasicNameValuePair("password",password));
                
HttpUtil.sendRequestWithHttpClient(url_login,params,new HttpCallbackListener(){
    @Override
    public void onFinish(String response)
    {
        parseJSONWithJSONObject(response);
    }
    
    @Override
    public void onError(Exception e)
    {
        e.printStackTrace();
    }
});

private void parseJSONWithJSONObject(String jsonData){
    try{
        JSONArray jsonArray= new JSONArray(jsonData);
        Log.d("com.dlwz.playfootball","in parseJSONWithJSONObject");
        
        for(int i=0;i<jsonArray.length();i++)
        {                
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            String name = jsonObject.getString("usertel");
            String password = jsonObject.getString("password");
            Log.d("com.dlwz.playfootball","name:"+name+",password:"+password);
            dialog.dismiss();
            startActivity(new Intent(LoginActivity.this,MainActivity.class));
            
        }
    } catch(Exception e){
        e.printStackTrace();
    }
}

AsyncHttpClient 测试代码^[2] ：

RequestParams params = new RequestParams();
params.put("username", email);
params.put("password", password);
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://192.168.1.102:8081/useraccount/login/dologin",params ,new AsyncHttpResponseHandler() {
 // When the response returned by REST has Http response code '200'
 @Override
 public void onSuccess(String response) {
     // Hide Progress Dialog
     prgDialog.hide();
     try {
              // JSON Object
             JSONObject obj = new JSONObject(response);
             // When the JSON response has status boolean value assigned with true
             if(obj.getBoolean("status")){
                 Toast.makeText(getApplicationContext(), "You are successfully logged in!", Toast.LENGTH_LONG).show();
                 // Navigate to Home screen
                 navigatetoHomeActivity();
             } 
             // Else display error message
             else{
                 errorMsg.setText(obj.getString("error_msg"));
                 Toast.makeText(getApplicationContext(), obj.getString("error_msg"), Toast.LENGTH_LONG).show();
             }
     } catch (JSONException e) {
         // TODO Auto-generated catch block
         Toast.makeText(getApplicationContext(), "Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
         e.printStackTrace();

     }
 }
 // When the response returned by REST has Http response code other than '200'
 @Override
 public void onFailure(int statusCode, Throwable error,
     String content) {
     // Hide Progress Dialog 
     prgDialog.hide();
     // When Http response code is '404'
     if(statusCode == 404){
         Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
     } 
     // When Http response code is '500'
     else if(statusCode == 500){
         Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
     } 
     // When Http response code other than 404, 500
     else{
         Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
     }
 }
});

Volley Post测试代码^[3]：

RequestQueue mQueue = Volley.newRequestQueue(this);
StringRequest stringRequest = new StringRequest(Request.Method.POST,"http://192.168.1.102:8999/weixin/index.php/Home/Index/test",                        
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                Log.d("TAG-onResponse", response);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("TAG-onErrorResponse", error.getMessage(), error);
            }
        }){
    @Override
    protected Map<String, String> getParams() throws AuthFailureError {
        Map<String, String> map = new HashMap<String, String>();
        map.put("username", "mabo@qq.com");
        map.put("password", "123456");
        return map;
    }
 };
mQueue.add(stringRequest);

参考资料：

1、类 HttpUtil 代码参考自《第一行代码 Android》第10章5小节，只是将 HttpURLConnection 换成了 HttpClient。parseJSONWithJSONObject 参考自该书 400 页。该书作者郭霖，csdn博客：http://blog.csdn.net/guolin_blog/ 。

2、该代码参考自 http://programmerguru.com/android-tutorial/android-restful-webservice-tutorial-how-to-call-restful-webservice-in-android-part-3/?utm_source=tuicool 。该文共三部分，通过演示一个包含前端后端的例子介绍了 Restful Webservice 在 Android 开发中的应用。当时调试时 Android 端没什么问题，照着一步步来就没错，但服务器端用 Eclipse EE 创建动态web，在运行时报了错，经调试发现是在 Class.forName(Constants.dbClass) 处报了错，String dbClass = "com.mysql.jdbc.Driver" ，下载了个com.mysql.jdbc.Driver 导入才成功。

3、该代码参考自《第一行代码 Android》作者郭霖的博客：http://blog.csdn.net/guolin_blog/article/details/17482095 。测试该代码遇到了几个问题：首先就是由于防火墙的原因，volley 无法用 Git 直接 clone ，不得不设置代理才成功下载。第二个问题是 volley 的 jar 包生成，网上有不少方法，但在我这没成功。比如 stormzhang 的命令行，郭霖的通过 eclipse 导出 jar 包，可能是由于版本更新的原因，这些方法都没行，后来还是用 Android Studio 顺利编译生成 jar 包。终于可以在工程中顺利使用。第三个问题就是我自己犯的低级错误，web服务端直接用了上面AsyncHttpClient 的服务端程序，Android 端 Post 数据过去，但我没注意到服务器端只能处理 get 的 url ，因为之前用ThinkPhp 时是不用区分 get 和 post 的，处理方式一样。没想到 java 端反而要区分，耗费了不少时间才查出来。