Android REST webservice 类

App与后台交互，后台使用的是Jersey RESTful 服务。在APP端使用Android 内部集成的HttpClient接口，无需引入第三方jar包，

import org.apache.http.client.HttpClient;

在网上找到一个歪果人写Android端的REST类，网上文章引用挺多的。

Calling Web Services in Android using HttpClient

public class RestClient {

    private ArrayList <NameValuePair> params;

    private ArrayList <NameValuePair> headers;

    private String url;

    private int responseCode;

    private String message;

    private String response;

    public String getResponse() {

        return response;

    }

    public String getErrorMessage() {

        return message;

    }

    public int getResponseCode() {

        return responseCode;

    }

    public RestClient(String url)

    {

        this.url = url;

        params = new ArrayList<NameValuePair>();

        headers = new ArrayList<NameValuePair>();

    }

    public void AddParam(String name, String value)

    {

        params.add(new BasicNameValuePair(name, value));

    }

    public void AddHeader(String name, String value)

    {

        headers.add(new BasicNameValuePair(name, value));

    }

    public void Execute(RequestMethod method) throws Exception

    {

        switch(method) {

            case GET:

            {

                //add parameters

                String combinedParams = "";

                if(!params.isEmpty()){

                    combinedParams += "?";

                    for(NameValuePair p : params)

                    {

                        String paramString = p.getName() + "=" + URLEncoder.encode(p.getValue(),”UTF-8″);

                        if(combinedParams.length() > 1)

                        {

                            combinedParams  +=  "&" + paramString;  // 如何不是添加第一个key-value时

                        }

                        else

                        {

                            combinedParams += paramString;   // 添加第一个key-value

                        }

                    }

                }

                HttpGet request = new HttpGet(url + combinedParams);

                //add headers

                for(NameValuePair h : headers)

                {

                    request.addHeader(h.getName(), h.getValue());

                }

                executeRequest(request, url);

                break;

            }

            case POST:

            {

                HttpPost request = new HttpPost(url);

                //add headers

                for(NameValuePair h : headers)

                {

                    request.addHeader(h.getName(), h.getValue());

                }

                if(!params.isEmpty()){

                    request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));

                }

                executeRequest(request, url);

                break;

            }

        }

    }

    private void executeRequest(HttpUriRequest request, String url)

    {

        HttpClient client = new DefaultHttpClient();

        HttpResponse httpResponse;

        try {

            httpResponse = client.execute(request);

            responseCode = httpResponse.getStatusLine().getStatusCode();

            message = httpResponse.getStatusLine().getReasonPhrase();

            HttpEntity entity = httpResponse.getEntity();

            if (entity != null) {

                InputStream instream = entity.getContent();

                response = convertStreamToString(instream);

                // Closing the input stream will trigger connection release

                instream.close();

            }

        } catch (ClientProtocolException e)  {

            client.getConnectionManager().shutdown();

            e.printStackTrace();

        } catch (IOException e) {

            client.getConnectionManager().shutdown();

            e.printStackTrace();

        }

    }

    private static String convertStreamToString(InputStream is) {

        BufferedReader reader = new BufferedReader(new InputStreamReader(is));

        StringBuilder sb = new StringBuilder();

        String line = null;

        try {

            while ((line = reader.readLine()) != null) {

                sb.append(line + "\n");

            }

        } catch (IOException e) {

            e.printStackTrace();

        } finally {

            try {

                is.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

        return sb.toString();

    }

}

调用实例：

RestClient client = new RestClient(LOGIN_URL);

client.AddParam("accountType", "GOOGLE");

client.AddParam("source", "tboda-widgalytics-0.1");

client.AddParam("Email", _username);

client.AddParam("Passwd", _password);

client.AddParam("service", "analytics");

client.AddHeader("GData-Version", "2");

try {

    client.Execute(RequestMethod.POST);

} catch (Exception e) {

    e.printStackTrace();

}

String response = client.getResponse();

GET 方法没有问题，但是POST方法就需要考虑了，因为传递内容并不是只有

request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));

比如自己的项目中使用的是：request.setEntity(new StringEntity(obj.toString(),HTTP.UTF_8));

这里的 setEntity 内容是和setHeader 有关系的。

我的项目中应用的两种：postRequest.addHeader("Content-Type", "multipart/mixed");

post 图片的header 

MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("uploaded", bab);
postRequest.setEntity(reqEntity);

POST json 对象的：header 说明

rest.AddHeaders("Content-Type","application/json;charset=utf8");

Entity这样设置的：

request.setEntity(new StringEntity(obj.toString(),HTTP.UTF_8));

所以这个类写的通用型不行。