WebService是一種基於SOAP協議的遠程調用標準,通過webservice可以將不同操作系統平臺、不同語言、不同技術整合到一塊。在Android SDK中並沒有提供調用WebService的庫,因此,需要使用第三方的SDK來調用WebService。PC版本的WEbservice客戶端庫非常豐富,例如Axis2,CXF等,但這些開發包對於Android系統過於龐大,也未必很容易移植到Android系統中。因此,這些開發包並不是在我們的考慮范圍內。適合手機的WebService客戶端的SDK有一些,比較常用的有Ksoap2,可以從http://code.google.com/p/ksoap2-android/downloads/list進行下載;將下載的ksoap2-android-assembly-2.4-jar-with-dependencies.jar包復制到Eclipse工程的lib目錄中,當然也可以放在其他的目錄裡。同時在Eclipse工程中引用這個jar包。
具體調用調用webservice的方法為:
(1) 指定webservice的命名空間和調用的方法名,如:
SoapObject request =new SoapObject(http://service,”getName”);
SoapObject類的第一個參數表示WebService的命名空間,可以從WSDL文檔中找到WebService的命名空間。第二個參數表示要調用的WebService方法名。
(2) 設置調用方法的參數值,如果沒有參數,可以省略,設置方法的參數值的代碼如下:
Request.addProperty(“param1”,”value”);
Request.addProperty(“param2”,”value”);
要註意的是,addProperty方法的第1個參數雖然表示調用方法的參數名,但該參數值並不一定與服務端的WebService類中的方法參數名一致,隻要設置參數的順序一致即可。
(3) 生成調用Webservice方法的SOAP請求信息。該信息由SoapSerializationEnvelope對象描述,代碼為:
SoapSerializationEnvelope envelope=new
SoapSerializationEnvelope(SoapEnvelope.VER11);
Envelope.bodyOut = request;
創建SoapSerializationEnvelope對象時需要通過SoapSerializationEnvelope類的構造方法設置SOAP協議的版本號。該版本號需要根據服務端WebService的版本號設置。在創建SoapSerializationEnvelope對象後,不要忘瞭設置SOAPSoapSerializationEnvelope類的bodyOut屬性,該屬性的值就是在第一步創建的SoapObject對象。
(4) 創建HttpTransportsSE對象。通過HttpTransportsSE類的構造方法可以指定WebService的WSDL文檔的URL:
HttpTransportSE ht=new HttpTransportSE(“http://192.168.18.17:80
/axis2/service/SearchNewsService?wsdl”);
(5)使用call方法調用WebService方法,代碼:
ht.call(null,envelope);
Call方法的第一個參數一般為null,第2個參數就是在第3步創建的SoapSerializationEnvelope對象。
(6)使用getResponse方法獲得WebService方法的返回結果,代碼:
SoapObject soapObject =( SoapObject) envelope.getResponse();
以下為簡單的實現一個天氣查看功能的例子:
public class WebService extends Activity {
private static final String NAMESPACE = “http://WebXml.com.cn/”;
// WebService地址
private static String URL = “http://www.webxml.com.cn/
webservices/weatherwebservice.asmx”;
private static final String METHOD_NAME = “getWeatherbyCityName”;
private static String SOAP_ACTION = “http://WebXml.com.cn/
getWeatherbyCityName”;
private String weatherToday;
private Button okButton;
private SoapObject detail;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
okButton = (Button) findViewById(R.id.ok);
okButton.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
showWeather();
}
});
}
private void showWeather() {
String city = “武漢”;
getWeather(city);
}
@SuppressWarnings(“deprecation”)
public void getWeather(String cityName) {
try {
System.out.println(“rpc——“);
SoapObject rpc = new SoapObject(NAMESPACE, METHOD_NAME);
System.out.println(“rpc” + rpc);
System.out.println(“cityName is ” + cityName);
rpc.addProperty(“theCityName”, cityName);
AndroidHttpTransport ht = new AndroidHttpTransport(URL);
ht.debug = true;
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
SoapEnvelope.VER11);
envelope.bodyOut = rpc;
envelope.dotNet = true;
envelope.setOutputSoapObject(rpc);
ht.call(SOAP_ACTION, envelope);
SoapObject result = (SoapObject) envelope.bodyIn;
detail = (SoapObject) result
.getProperty(“getWeatherbyCityNameResult”);
System.out.println(“result” + result);
System.out.println(“detail” + detail);
Toast.makeText(WebService.this, detail.toString(),
Toast.LENGTH_LONG).show();
parseWeather(detail);
return;
} catch (Exception e) {
e.printStackTrace();
}
}
private void parseWeather(SoapObject detail)
throws UnsupportedEncodingException {
String date = detail.getProperty(6).toString();
weatherToday = “今天:” + date.split(” “)[0];
weatherToday = weatherToday + ”
天氣:” + date.split(” “)[1];
weatherToday = weatherToday + ”
氣溫:”
+ detail.getProperty(5).toString();
weatherToday = weatherToday + ”
風力:”
+ detail.getProperty(7).toString() + ”
“;
System.out.println(“weatherToday is ” + weatherToday);
Toast.makeText(WebService.this, weatherToday,
Toast.LENGTH_LONG).show();
}
}