Android 访问WebService的方法

Web Service是实现异构程序之间方法调用的一种机制。Web Service通过一种XML格式的特殊文件来描述方法、参数、调用和返回值，这种格式的XML文件称为WSDL（Web Service Des cription Language），即Web服务器描述语言。Web Service采用的通信协议是SOAP（Simple ObjectAccess Protocol），即简单对象访问协议。

   Java领域的Web Service实现有很多方式，例如Sun公司的XML-RPC、Apache的Axis以及Codehaus的Xfire，但是这些都不适合在资源有限的移动设备中使用。早期的Java ME开发中使用到了KSOAP，近期Google也发布了针对Android的KSOAP jar包。该jar文件的访问地址为http://code.google.com/p/ksoap2-android/downloads/list。

   android 应用程序要访问互联网上的服务，如天气预报，股票信息；则需要通过SOAP传输协议来访问。 首先要得到服务器提供的地址、命名空间、方法名，参数的键和返回值的键；android应用程序通过这些键来传递值。

   具体步骤：

//创建HttpTransportSE对象

HttpTransportSEhttpse = new HttpTransportSE("http://192.168.1.13:8088/testwebservice/LoginPort");

//使用SOAP协议创建Envelop对象

SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);

//实例化SoapObject

SoapObjectsoapObject = new SoapObject("http://bean.lovo.com/","validate");

soapObject.addProperty("arg0", usernameText.getText().toString());

soapObject.addProperty("arg1", pwdText.getText().toString());

//将SoapObject对象设置为SoapSerializationEnvelope对象的传出SOAP消息

envelope.bodyOut = soapObject;

httpse.call(null, envelope);

//获取服务器响应返回的SOAP消息

SoapObject result = (SoapObject) envelope.bodyIn;

//获取返回的数据

String returnStr = result.getProperty("return").toString();

下面的例子是android应用程序访问网络PC服务器。

[html]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106

public class WebServiceActivity extends Activity implementsOnClickListener{      /**用户名和密码编辑框*/     private EditText userText,pwdText;      /**确定按钮*/     private Button okBtn;      /**显示返回值的文本框*/     private TextView infoText;      /**服务地址*/     private static final String SERVICE_URL ="http://192.168.1.100:8080/loginservice/LoginServicePort" ;      /**命名空间*/     private static final String NAME_SPACE ="http://service.lovo.com/";                @Override     public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.main);                        okBtn = (Button) findViewById(R.id.web_service_btn);          userText=(EditText) findViewById(R.id.web_service_username);          pwdText=(EditText) findViewById(R.id.web_service_pwd);          infoText = (TextView) findViewById(R.id.web_service_show_info);          okBtn.setOnClickListener(this);      }      @Override     public void onClick(View v) {                if(v == okBtn){              //连接对象              HttpTransportSE httpSE = new HttpTransportSE(SERVICE_URL);              //通过SOAP1.1协议得到envelop对象              SoapSerializationEnvelope envelop = newSoapSerializationEnvelope(SoapEnvelope.VER11);              //根据命名空间和方法得到SoapObject对象              SoapObject soapObject = new SoapObject(NAME_SPACE,"validate");              //向调用方法传递参数              soapObject.addProperty("arg0", userText.getText().toString());              soapObject.addProperty("arg1", pwdText.getText().toString());              //将soapObject对象设置为envelop对象，传出消息              envelop.bodyOut = soapObject;              try {                  //开始调用远程方法                  httpSE.call(null, envelop);                  //得到远程方法返回的SOAP对象                  SoapObject resultObj = (SoapObject) envelop.bodyIn;                  //得到服务器传回的数据                  String resultStr = resultObj.getProperty("return").toString();                  //处理返回值                  Toast.makeText(this, resultStr, Toast.LENGTH_LONG).show();                  infoText.setText(resultStr);              } catch (Exception e) {                  e.printStackTrace();              }           }      }  }  public class WebServiceActivity extends Activity implementsOnClickListener{ /**用户名和密码编辑框*/ private EditText userText,pwdText; /**确定按钮*/ private Button okBtn; /**显示返回值的文本框*/ private TextView infoText; /**服务地址*/ private static final String SERVICE_URL ="http://192.168.1.100:8080/loginservice/LoginServicePort" ; /**命名空间*/ private static final String NAME_SPACE ="http://service.lovo.com/"; @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);                     okBtn = (Button) findViewById(R.id.web_service_btn);         userText=(EditText) findViewById(R.id.web_service_username);         pwdText=(EditText) findViewById(R.id.web_service_pwd);         infoText = (TextView) findViewById(R.id.web_service_show_info);         okBtn.setOnClickListener(this);     } @Override public void onClick(View v) { if(v == okBtn){ //连接对象 HttpTransportSE httpSE = new HttpTransportSE(SERVICE_URL); //通过SOAP1.1协议得到envelop对象 SoapSerializationEnvelope envelop = newSoapSerializationEnvelope(SoapEnvelope.VER11); //根据命名空间和方法得到SoapObject对象 SoapObject soapObject = new SoapObject(NAME_SPACE, "validate"); //向调用方法传递参数 soapObject.addProperty("arg0", userText.getText().toString()); soapObject.addProperty("arg1", pwdText.getText().toString()); //将soapObject对象设置为envelop对象，传出消息 envelop.bodyOut = soapObject; try { //开始调用远程方法 httpSE.call(null, envelop); //得到远程方法返回的SOAP对象 SoapObject resultObj = (SoapObject) envelop.bodyIn; //得到服务器传回的数据 String resultStr = resultObj.getProperty("return").toString(); //处理返回值 Toast.makeText(this, resultStr, Toast.LENGTH_LONG).show(); infoText.setText(resultStr); } catch (Exception e) { e.printStackTrace(); } } } }

注意：要增加一个network访问权限。    

<uses-permission android:name="android.permission.INTERNET"/>