我使用soap webservices 开发了一个登录表单示例。
在我的应用程序中，我有一个开始活动 HomePage.HomePage 并且我有一个按钮（我的帐户）。当我单击myaccount按钮时，它会成功重定向androidloginexampleactivity。
在这里我输入详细信息username和password. 细节是正确的，这意味着它被重定向到主页并通过username. 我登录成功，但之后它被强制关闭。
这些是我的编码部分：
Homepage.java 是
public class HomePage extends Activity {
private Button account;
private TextView tv;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
Button account = (Button) findViewById(R.id.account);
TextView tv = (TextView) findViewById(R.id.textView1);
tv.setText("Welcome ,"+getIntent().getExtras().getString("username"));
// Listening to register new account link
account.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(getApplicationContext() , AndroidLoginExampleActivity.class);
startActivity(i);
}
});
}
}
AndroidLoginExampleActivity.java
public class AndroidLoginExampleActivity extends Activity {
private final String NAMESPACE = "http://ws.userlogin.com";
private final String URL = "http://192.168.1.168:8085/Login/services/Login?wsdl";
private final String SOAP_ACTION = "http://ws.userlogin.com/authentication";
private final String METHOD_NAME = "authentication";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button login = (Button) findViewById(R.id.btn_login);
login.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
loginAction();
}
});
}
private void loginAction(){
SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
EditText userName = (EditText) findViewById(R.id.tf_userName);
String user_Name = userName.getText().toString();
EditText userPassword = (EditText) findViewById(R.id.tf_password);
String user_Password = userPassword.getText().toString();
//Pass value for userName variable of the web service
PropertyInfo unameProp =new PropertyInfo();
unameProp.setName("userName");//Define the variable name in the web service method
unameProp.setValue(user_Name);//set value for userName variable
unameProp.setType(String.class);//Define the type of the variable
request.addProperty(unameProp);//Pass properties to the variable
//Pass value for Password variable of the web service
PropertyInfo passwordProp =new PropertyInfo();
passwordProp.setName("password");
passwordProp.setValue(user_Password);
passwordProp.setType(String.class);
request.addProperty(passwordProp);
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.setOutputSoapObject(request);
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
try{
androidHttpTransport.call(SOAP_ACTION, envelope);
SoapPrimitive response = (SoapPrimitive)envelope.getResponse();
String status = response.toString();
TextView result = (TextView) findViewById(R.id.tv_status);
result.setText(response.toString());
if(status.equals("Success!"))
{
Intent intent = new Intent(AndroidLoginExampleActivity.this,HomePage.class);
intent.putExtra("username",userName.getText().toString());
startActivity(intent);
}
else
{
// Code for Login failure
}
}
catch(Exception e){
}
}
}
我该如何解决dis错误？
这是我的 logcat 窗口：
07-17 15:52:00.997: E/AndroidRuntime(1798): FATAL EXCEPTION: main
07-17 15:52:00.997: E/AndroidRuntime(1798): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidlogin.ws/com.androidlogin.ws.HomePage}: java.lang.NullPointerException
.
.
.
dalvik.system.NativeStart.main(Native Method)
07-17 15:52:00.997: E/AndroidRuntime(1798): Caused by: java.lang.NullPointerException
07-17 15:52:00.997: E/AndroidRuntime(1798): at com.androidlogin.ws.HomePage.onCreate(HomePage.java:30)