OnPrimaryClipChangedListener（）仅可使用一次

Question

I'm trying to make a application which toast the word you copied to the clipboard in a WebView for practice. The problem is, this code works for the first word(except somehow it toasts for three times. Sort of blink.); however, when I try to copy a word for the second time, it shows "Unfortunately, (my app's name) has stopped" and stop working. It still shows the website, but the toast function stops. I'm running this program on an emulator and using Eclipse. Following Mr/Ms.jgriffsta's advise, I added a try&catch statement, then for the second time it toasts "Error occured" once, and then toasts the copied word for two times. Again sort of blink.

//ItemDetailActivity.java
public class ItemDetailActivity extends Activity {
    private WebView mWeb;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.item_detail);

        Intent intent = getIntent();

        String link = intent.getStringExtra("LINK");
        mWeb = (WebView)findViewById(R.id.web);
        mWeb.loadUrl(link);

        final ClipboardManager cm = (ClipboardManager)getSystemService(CLIPBOARD_SERVICE);
        cm.addPrimaryClipChangedListener(new OnPrimaryClipChangedListener(){
            @Override
            public void onPrimaryClipChanged(){
                ClipData.Item item = cm.getPrimaryClip().getItemAt(0);
                String text = item.getText().toString();
                Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
            }
        });
    }
}

----LogCat--------

07-18 18:15:07.530: E/chromium(837): [ERROR:gl_surface_egl.cc(153)] No suitable EGL configs found.
07-18 18:15:07.540: E/chromium(837): [ERROR:gl_surface_egl.cc(620)] GLSurfaceEGL::InitializeOneOff failed.
07-18 18:15:07.540: E/chromium(837): [ERROR:gl_surface_egl.cc(153)] No suitable EGL configs found.
07-18 18:15:07.540: E/chromium(837): [ERROR:gl_surface_egl.cc(620)] GLSurfaceEGL::InitializeOneOff failed.
07-18 18:15:07.540: E/chromium(837): [ERROR:gpu_info_collector.cc(86)] gfx::GLSurface::InitializeOneOff() failed
07-18 18:15:10.360: E/chromium(837): [ERROR:simple_backend_impl.cc(186)] File structure does not match the disk cache backend.
07-18 18:15:10.360: E/chromium(837): [ERROR:simple_backend_impl.cc(402)] Simple Cache Backend: wrong file structure on disk: /data/data/com.kariga.rssreader1/app_webview/Cache
07-18 18:16:03.910: E/AndroidRuntime(837): FATAL EXCEPTION: main
07-18 18:16:03.910: E/AndroidRuntime(837): Process: com.kariga.rssreader1, PID: 837
07-18 18:16:03.910: E/AndroidRuntime(837): java.lang.NullPointerException
07-18 18:16:03.910: E/AndroidRuntime(837):  at com.kariga.rssreader1.ItemDetailActivity$1.onPrimaryClipChanged(ItemDetailActivity.java:34)
07-18 18:16:03.910: E/AndroidRuntime(837):  at android.content.ClipboardManager.reportPrimaryClipChanged(ClipboardManager.java:234)
07-18 18:16:03.910: E/AndroidRuntime(837):  at android.content.ClipboardManager$2.handleMessage(ClipboardManager.java:76)
07-18 18:16:03.910: E/AndroidRuntime(837):  at android.os.Handler.dispatchMessage(Handler.java:102)
07-18 18:16:03.910: E/AndroidRuntime(837):  at android.os.Looper.loop(Looper.java:136)
07-18 18:16:03.910: E/AndroidRuntime(837):  at android.app.ActivityThread.main(ActivityThread.java:5017)
07-18 18:16:03.910: E/AndroidRuntime(837):  at java.lang.reflect.Method.invokeNative(Native Method)
07-18 18:16:03.910: E/AndroidRuntime(837):  at java.lang.reflect.Method.invoke(Method.java:515)
07-18 18:16:03.910: E/AndroidRuntime(837):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
07-18 18:16:03.910: E/AndroidRuntime(837):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
07-18 18:16:03.910: E/AndroidRuntime(837):  at dalvik.system.NativeStart.main(Native Method)

----Edited Code with Try&Catch Statement--------

final ClipboardManager cm = (ClipboardManager)getSystemService(CLIPBOARD_SERVICE);
cm.addPrimaryClipChangedListener(new OnPrimaryClipChangedListener(){
    @Override
    public void onPrimaryClipChanged(){
        ClipData.Item item = cm.getPrimaryClip().getItemAt(0);
        try{String text = item.getText().toString();
            Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
        }
        catch(Exception e){
            Toast.makeText(getApplicationContext(), "Error occured", Toast.LENGTH_SHORT).show();
        }
    }
});

----LogCat after edition--------

07-18 18:57:28.780: E/chromium(882): [ERROR:gl_surface_egl.cc(153)] No suitable EGL configs found.
07-18 18:57:28.780: E/chromium(882): [ERROR:gl_surface_egl.cc(620)] GLSurfaceEGL::InitializeOneOff failed.
07-18 18:57:28.790: E/chromium(882): [ERROR:gl_surface_egl.cc(153)] No suitable EGL configs found.
07-18 18:57:28.790: E/chromium(882): [ERROR:gl_surface_egl.cc(620)]  GLSurfaceEGL::InitializeOneOff failed.
07-18 18:57:28.790: E/chromium(882): [ERROR:gpu_info_collector.cc(86)] gfx::GLSurface::InitializeOneOff() failed

Answer 1

(Would Put this as comment if I could)

You don't check for any exceptions, so I would put a try, catch statment on

String text = item.getText().toString(); 

Could you post the error report to the logcat. It should point out the exact reason.