强制关闭应用程序

Question

当我点击登录按钮时，我的应用程序强制关闭......为什么是这样？这是什么解决方案？

我有我的Login_Menu活动如下： -

package com.campuspro.start; 

import java.util.ArrayList; 
import java.util.List; 

import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.message.BasicNameValuePair; 
import org.apache.http.util.EntityUtils; 
import org.json.JSONException; 
import org.json.JSONObject; 

import android.app.Activity; 
import android.app.ProgressDialog; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 


public class Login_Menu extends Activity { 

EditText usname; 
EditText pass; 
TextView tv; 
HttpClient client; 
HttpPost post; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
// TODO Auto-generated method stub 
super.onCreate(savedInstanceState); 
setContentView(R.layout.login_lay); 
tv=(TextView) findViewById(R.id.login_stat_tv); 
usname=(EditText)findViewById(R.id.uname); 
pass=(EditText)findViewById(R.id.pass); 
Button login=(Button)findViewById(R.id.login_but); 
Button cancel=(Button)findViewById(R.id.cancel_but); 

client = new DefaultHttpClient(); 
String url="http://10.0.2.2:7001/proj/login.jsp"; 
post = new HttpPost(url); 
login.setOnClickListener(new View.OnClickListener() { 

    public void onClick(View arg0) { 
     // TODO Auto-generated method stub 
     new login().execute(""); 
    } 
}); 

cancel.setOnClickListener(new View.OnClickListener() { 

    public void onClick(View v) { 
     // TODO Auto-generated method stub 
     usname.getText().clear(); 
     pass.getText().clear(); 
    } 
}); 

} 


private class login extends AsyncTask<String, Void, JSONObject>{ 
ProgressDialog dialog = ProgressDialog.show(Login_Menu.this, "", "Authenticating, Please wait..."); 

    @Override 
    protected JSONObject doInBackground(String... params) { 
    // TODO Auto-generated method stub 
    Log.i("thread", "Doing Something..."); 
    //authentication operation 
try{ 

    List<NameValuePair> pairs = new ArrayList<NameValuePair>(); 
    pairs.add(new BasicNameValuePair("username",usname.getText().toString())); 
    pairs.add(new BasicNameValuePair("password",pass.getText().toString())); 
    post.setEntity(new UrlEncodedFormEntity(pairs)); 
    HttpResponse response = client.execute(post); 
    int status=response.getStatusLine().getStatusCode(); 

    if(status == 200) 
    { 
     HttpEntity e=response.getEntity(); 
     String data=EntityUtils.toString(e); 
     JSONObject last=new JSONObject(data); 
     return last; 

    } 

} 

catch(Exception e) 
{ 
    e.printStackTrace(); 

} 

    return null; 
} 

protected void onPreExecute(){ 
    //dialog.dismiss(); 
    Log.i("thread", "Started..."); 
    dialog.show(); 
} 
protected void onPostExecute(JSONObject result){ 
    Log.i("thread", "Done..."); 
    String name; 
    try { 
     name = result.getString("status"); 

    if(dialog!=null) 
    dialog.dismiss(); 
    if(name.equalsIgnoreCase("yes")){ 
     tv.setText("user found"); 
     Intent myIntent=new Intent("com.campuspro.start.MYMENU"); 
     startActivity(myIntent); 

    }else{ 

    tv.setText("No User Found, please try again!"); 
    } 
    } catch (JSONException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    } 

}} 

我login.jsp页面如下...

<%@page contentType="text/html; charset=UTF-8"%> 
<%@page import="org.json.simple.JSONObject"%> 
<%@page import="java.util.*,java.sql.*"%> 

<%! 

Connection con; 
PreparedStatement ps; 
ResultSet rs; 
String x,y; 

%> 

<% 
Class.forName("oracle.jdbc.driver.OracleDriver"); 
con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","pro","pro"); 
x=request.getParameter("username"); 
y=request.getParameter("password"); 

ps=con.prepareStatement("select * from login_stud where uname=? and pass=?"); 
ps.setString(1,x); 
ps.setString(2,y); 
rs=ps.executeQuery(); 

JSONObject obj=new JSONObject(); 
if(rs.next()) 
{ 
obj.put("status","yes"); 
out.print(obj); 

} 
else 
{ 
obj.put("status","no"); 
out.print(obj); 
} 
out.flush(); 
%> 

这是我的日志猫....

04-15 23:42:06.449: I/thread(276): Started... 
04-15 23:42:06.460: I/thread(276): Doing Something... 
04-15 23:42:07.950: D/dalvikvm(276): GC_FOR_MALLOC freed 3284 objects/170544 bytes in 156ms 
04-15 23:42:10.469: I/thread(276): Done... 
04-15 23:42:10.469: D/AndroidRuntime(276): Shutting down VM 
04-15 23:42:10.469: W/dalvikvm(276): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 
04-15 23:42:10.509: E/AndroidRuntime(276): FATAL EXCEPTION: main 
04-15 23:42:10.509: E/AndroidRuntime(276): java.lang.NullPointerException 
04-15 23:42:10.509: E/AndroidRuntime(276):  at com.campuspro.start.Login_Menu$login.onPostExecute(Login_Menu.java:117) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at  com.campuspro.start.Login_Menu$login.onPostExecute(Login_Menu.java:1) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at android.os.AsyncTask.finish(AsyncTask.java:417) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at android.os.AsyncTask.access$300(AsyncTask.java:127) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at android.os.Handler.dispatchMessage(Handler.java:99) 
    04-15 23:42:10.509: E/AndroidRuntime(276): at android.os.Looper.loop(Looper.java:123) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at android.app.ActivityThread.main(ActivityThread.java:4627) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at java.lang.reflect.Method.invoke(Method.java:521) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
04-15 23:42:10.509: E/AndroidRuntime(276):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

该应用程序被强制关闭，因为MYMENU活性不是Android清单文件中提及。

在开始意图时没有这样的错误。

的过程在AndroidManifest.xml是宣布任何活动：

<activity 
     android:name=".ActivityName" 
     android:label="@string/app_name" 
     > 
     <intent-filter> 
      <action android:name="com.campuspro.start.ACTIVITYNAME" /> 

      <category android:name="android.intent.category.DEFAULT" /> 
     </intent-filter> 
    </activity> 

谢谢

Answer 2

这是根本原因：

Intent myIntent=new Intent("com.campuspro.start.MYMENU"); 
startActivity(myIntent); 

它应该是这样的：

Intent myIntent=new Intent(Login_Menu.this, MYMENU.class); 
startActivity(myIntent);