Android访问WCF服务

时间:2011-12-27 23:31来源: 作者:admin 点击: 次

服务的开发流程我们按照服务契约(ServiceContract), 服务实现(Service), 实体对象模型(Model) 及服务发布的流程来介绍.
由于自己对Http请求的链接认识的比较浅,对于有些问题没法做出清楚明了的解释, Android访问WCF这篇文章我会贴出来代码, 让后说明一下关注的地方, 不做深入研究.
一. 服务契约(Contract)view plain
1.       [ServiceContract]
2.          public interface IAccountJsonService
3.          {
4.             [OperationContract(Name = "GetAccountDataJson")]
5.             [WebGet(RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, UriTemplate = "GetAccountData", BodyStyle = WebMessageBodyStyle.Bare)]
6.             List<Account> GetAccountData();
7.
8.             [OperationContract(Name = "SendMessageJson")]
9.             [WebInvoke(Method = "GET", ResponseFormat = WebMessageFormat.Json, UriTemplate = "SendMessage/{Message}", BodyStyle = WebMessageBodyStyle.Bare)]
10.             string SendMessage(string Message);
11.          }

此契约定义了两个方法, GetAccountData(获取Account数据列表, 方法不带参数), SendMessage, 获取从客户端传过来的数据, 并返回;
1. 这里面注意WebInvoke(SendMessage方法)这个Attribute, Method代表了Http的访问方法, 我们这是从服务器获取数据，是请求数据，所以用GET, 这个也可以用另外一个Attribute来替代-WebGet(GetAccountData方法);
2. 我们要给客户端返回Json数据,我们只需在WebInvoke or WebGet Attribute中指定ResponseFormat的格式即可, 这个从名字命名就可以看出来是制定返回的数据格式的.
3. 要注意UriTemplate属性, 这个是指定我们请求时的方法路径, 后面给出示例.
二. 服务实现(Service)view plain
1.       public class AccountService : IAccountJsonService
2.       {
3.          public List<Account> GetAccountData()
4.          {
5.             return MockAccount.AccountList;
6.          }
7.          public string SendMessage(string Message)
8.          {
9.             return " Message:" + Message;
10.          }
11.       }

此处只是实现了IAccountJsonService接口.
三. 实体对象模型&模拟数据实体类定义:view plain
1.       [DataContract]
2.          public class Account
3.          {
4.             [DataMember]
5.             public string Name { get; set; }
6.             [DataMember]
7.             public int Age { get; set; }
8.             [DataMember]
9.             public string Address { get; set; }
10.             [DataMember]
11.             public DateTime Birthday { get; set; }
12.          }

模拟数据:
view plain
1.       public class MockAccount
2.          {
3.             public static List<Account> AccountList
4.             {
5.                get
6.                {
7.                      var list = new List<Account>();
8.                      list.Add(new Account { Name = "Bill Gates", Address = "YouYi East Road", Age = 56, Birthday = DateTime.Now });
9.                      list.Add(new Account { Name = "Steve Paul Jobs", Address = "YouYi West Road", Age = 57, Birthday = DateTime.Now });
10.                      list.Add(new Account { Name = "John D. Rockefeller", Address = "YouYi North Road", Age = 65, Birthday = DateTime.Now });
11.                      return list;
12.                }
13.             }
14.          }

模拟数据返回一个Account的列表, 含有三条模拟数据, Birthday用DateTime.Now可是随时查看数据是不是最新生成的.

四. 服务发布
在这个例子里面, 我们的服务采用Console的发布形式, 如果采用IIS发布, 只要参考WCF的服务配置信息, 在IIS环境下配置就OK了.
WCF配置信息
view plain
1.       <system.serviceModel>
2.       <behaviors>
3.          <serviceBehaviors>
4.             <behavior name="">
5.             <serviceMetadata httpGetUrl="mex" httpGetEnabled="true"/>
6.             <serviceDebug httpHelpPageEnabled="true" includeExceptionDetailInFaults="true"/>
7.             </behavior>
8.          </serviceBehaviors>
9.          <endpointBehaviors>
10.             <behavior name="WebHttpBindingBehavior">
11.             <webHttp/>
12.             </behavior>
13.          </endpointBehaviors>
14.       </behaviors>
15.
16.       <services>
17.          <service name="Hosting.AccountService">
18.             <endpoint address="xml" binding="webHttpBinding"  contract="Hosting.IAccountXmlService" behaviorConfiguration="WebHttpBindingBehavior"/>
19.             
20.             <host>
21.             <baseAddresses>
22.                <add baseAddress="http://127.0.0.1:82/AccountService"/>
23.             </baseAddresses>
24.             </host>
25.          </service>
26.       </services>
27.       </system.serviceModel>

控制台进行服务的托管发布

view plain
1.       class Program
2.          {
3.             static void Main(string[] args)
4.             {
5.                using (ServiceHost host = new ServiceHost(typeof(AccountService)))
6.                {
7.                      host.Open();
8.                      Console.WriteLine("AccountService Address:");
9.                      foreach (var endpoint in host.Description.Endpoints)
10.                      {
11.                         Console.WriteLine(endpoint.Address.ToString());
12.                      }
13.                      Console.WriteLine("AccountService Started,Press any key to stop service...");
14.                      Console.ReadKey();
15.                      host.Close();
16.                }
17.             }
18.          }

本章目的: 实现在Android客户端请求我们上篇建立的WCF数据服务.
此部分分为建立Http请求跟接受WCF 返回的数据.
一. 建立Http请求的方法
view plain
1.       protected String getRequest(String url, DefaultHttpClient client)
2.                   throws Exception {
3.             String result = null;
4.             int statusCode = 0;
5.             HttpGet getMethod = new HttpGet(url);
6.             Log.d(TAG, "do the getRequest,url=" + url + "");
7.             try {
8.                   getMethod.setHeader("User-Agent", USER_AGENT);
9.                   // HttpParams params = new HttpParams();
10.
11.                   // 添加用户密码验证信息
12.                   // client.getCredentialsProvider().setCredentials(
13.                   // new AuthScope(null, -1),
14.                   // new UsernamePasswordCredentials(mUsername, mPassword));
15.
16.                   HttpResponse httpResponse = client.execute(getMethod);
17.                   // statusCode == 200 正常
18.                   statusCode = httpResponse.getStatusLine().getStatusCode();
19.                   Log.d(TAG, "statuscode = " + statusCode);
20.                   // 处理返回的httpResponse信息
21.                   result = retrieveInputStream(httpResponse.getEntity());
22.             } catch (Exception e) {
23.                   Log.e(TAG, e.getMessage());
24.                   throw new Exception(e);
25.             } finally {
26.                   getMethod.abort();
27.             }
28.             return result;
29.          }

参数URL: 我们要请求的地址
Client:  这个可以直接用new DefaultHttpClient(new BasicHttpParams()) 来初始化.
这个方法中需要注意RetrieveInputStream方法, 这个是当Http请求完成之后, 用来处理服务器返回数据的方法,

二. 接受从WCF端传回的数据
view plain
1.       protected  String retrieveInputStream(HttpEntity httpEntity) {
2.             int  length = (int) httpEntity.getContentLength();
3.             if  (length < 0)
4.                   length = 10000;
5.             StringBuffer stringBuffer = new  StringBuffer(length);
6.             try  {
7.                   InputStreamReader inputStreamReader = new  InputStreamReader(
8.                         httpEntity.getContent(), HTTP.UTF_8);
9.                   char  buffer[] = new char[length];
10.                   int  count;
11.                   while  ((count = inputStreamReader.read(buffer, 0, length - 1)) > 0) {
12.                      stringBuffer.append(buffer, 0, count);
13.                   }
14.             } catch  (UnsupportedEncodingException e) {
15.                   Log.e(TAG, e.getMessage());
16.             } catch  (IllegalStateException e) {
17.                   Log.e(TAG, e.getMessage());
18.             } catch  (IOException e) {
19.                   Log.e(TAG, e.getMessage());
20.             }
21.             return  stringBuffer.toString();
22.          }

此方法在接受到WCF服务端返回的数据之后,  转换程String类型返回.
附加内容:
view plain
1.       private static final String BASE_URL = "http://10.0.2.2:82/BlogCategoryService/";
2.       private static final String EXTENSION = "Json/";;
3.       private static final String TAG = "API";
4.       private static final String USER_AGENT = "Mozilla/4.5";
5.
6.       public JSONObject getObject(String sbj) throws JSONException, Exception {
7.          return new JSONObject(getRequest(BASE_URL + EXTENSION + sbj));
8.       }
9.
10.       public JSONArray getArray(String sbj) throws JSONException,
11.             Exception {
12.          return new JSONArray(getRequest(BASE_URL + EXTENSION + sbj));
13.       }
14.
15.       protected String getRequest(String url) throws Exception {
16.          return getRequest(url, new DefaultHttpClient(new BasicHttpParams()));
17.       }

请求数据之前封装方法:

总结：此篇主要说明了Http请求的的两个阶段, 建立请求跟接受服务器返回的数据, 在下篇再主要说明如何处理服务端返回的JSON数据,并把数据显示在UI上面.(责任编辑：admin)

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Android访问WCF服务