07-01 17:47:23.517: E/AndroidRuntime(932): FATAL EXCEPTION: main
07-01 17:47:23.517: E/AndroidRuntime(932): java.lang.RuntimeException: Unable to instantiate application android.app.Application: java.lang.NullPointerException
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.LoadedApk.makeApplication(LoadedApk.java:482)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3938)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.ActivityThread.access$1300(ActivityThread.java:123)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1185)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.os.Handler.dispatchMessage(Handler.java:99)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.os.Looper.loop(Looper.java:137)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.ActivityThread.main(ActivityThread.java:4424)
07-01 17:47:23.517: E/AndroidRuntime(932): at java.lang.reflect.Method.invokeNative(Native Method)
07-01 17:47:23.517: E/AndroidRuntime(932): at java.lang.reflect.Method.invoke(Method.java:511)
07-01 17:47:23.517: E/AndroidRuntime(932): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-01 17:47:23.517: E/AndroidRuntime(932): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-01 17:47:23.517: E/AndroidRuntime(932): at dalvik.system.NativeStart.main(Native Method)
07-01 17:47:23.517: E/AndroidRuntime(932): Caused by: java.lang.NullPointerException
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:362)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.LoadedApk.getClassLoader(LoadedApk.java:305)
07-01 17:47:23.517: E/AndroidRuntime(932): at android.app.LoadedApk.makeApplication(LoadedApk.java:474)
07-01 17:47:23.517: E/AndroidRuntime(932): ... 11 more
当我启动我的应用程序时出现上述错误。此错误不会始终发生，但只会偶尔发生一次（每20-30次启动一次）并且永远不会连续两次发生
有人能告诉我这个错误产生的代码（xml或java）是什么以及如何解决它？ 这是我的代码：
public class ProjectBunkitActivity extends Activity {
Integer z=0,k,i=0;
static String s1;
static String s2;
static String s3;
static int cpd=0;
int day,month,year;
String [] p1,p2,p3,p4,p5,p6;
String so[]=new String[12];
String subj1[]=new String[20];
static String subj2[]=null;
String s,sn;
Button b1,b2,b3;
Button add,sub;
Button btn;
EditText t1,t2,t3;
Exception x;
LinearLayout linearlayout;
DatePicker datePicker;
Date picdate;
static int pos=0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SharedPreferences prefsfile = getSharedPreferences("myfile",0);
linearlayout=(LinearLayout)findViewById(R.id.leny);
t3=(EditText)findViewById(R.id.cls2);
if( prefsfile.getInt("cpd",0)!=0 && prefsfile.getInt("nos",0)!=0 && Timetablledisplay.flag==0 ){
Intent i=new Intent(ProjectBunkitActivity.this,Timetablledisplay.class);
ProjectBunkitActivity.cpd=prefsfile.getInt("cpd", 0);
ProjectBunkitActivity.pos=prefsfile.getInt("nos", 0);
startActivity(i);
finish();
}
else{
Timetablledisplay.flag=1;
}
b1=(Button)findViewById(R.id.btn);
datePicker = (DatePicker) findViewById(R.id.datePicker1);
t1=(EditText)findViewById(R.id.tdys);
t2=(EditText)findViewById(R.id.cls1);
add=(Button)findViewById(R.id.sub1);
sub=(Button)findViewById(R.id.add);
datepicupdate();
b1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
s1=t1.getText().toString();
s2=t2.getText().toString();
s3=t3.getText().toString();
if(s1.compareTo("")!=0 && s2.compareTo("")!=0 && linearlayout.getChildCount()!=0){
s1=t1.getText().toString();
s2=t2.getText().toString();
s3=t3.getText().toString();
cpd=Integer.parseInt(s2);
int l=0;
pos=linearlayout.getChildCount();
String subj[]=new String[pos];
try{
for(int j=0;j<pos;j++)
{
EditText edt1=(EditText)findViewById(j);
sn=edt1.getText().toString();
subj[l++]=sn;
}
}
catch(Exception e)
{
}
subj2=subj;
Toast toast=Toast.makeText(ProjectBunkitActivity.this,subj2[0],Toast.LENGTH_SHORT);
toast.show();
Intent i=new Intent(ProjectBunkitActivity.this,TimetableEdit.class);
i.putExtra("course",s1);
i.putExtra("classes", s2);
i.putExtra("days", s3);
i.putExtra("subject",subj);
startActivity(i);
}else {
Toast toast=Toast.makeText(ProjectBunkitActivity.this,"Please fill all field before proceeding",Toast.LENGTH_SHORT);
toast.show();
}
}
});
add.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
try{
pos=linearlayout.getChildCount();
EditText edt=(EditText) new EditText(getApplicationContext());
edt.setId(pos);
pos++;
s=String.valueOf(pos);
edt.setHint("Enter the subject name");
linearlayout.addView(edt);
}
catch(Exception e)
{
}
}
});
sub.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
try{
pos=linearlayout.getChildCount();
s=String.valueOf(pos);
linearlayout.removeViewAt(pos-1);
pos--;
}catch(Exception n){
}
}
});
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
}
private void datepicupdate() {
// TODO Auto-generated method stub
try{
if(year!=0){
datePicker.updateDate(year, month, day);
}
}catch (Exception e) {
// TODO: handle exception
}
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
try{
int jaz=Integer.parseInt(t2.getText().toString());
day = datePicker.getDayOfMonth();
month = datePicker.getMonth();
year = datePicker.getYear();
SharedPreferences.Editor editor = getSharedPreferences("myfile",0).edit();
editor.putString("text", t1.getText().toString());
editor.putInt("cpd", jaz);
editor.putInt("nos", linearlayout.getChildCount());
editor.putInt("day",day);
editor.putInt("month",month);
editor.putInt("year",year);
if(pos==0)
{
pos=linearlayout.getChildCount();
}
editor.putInt("pos",pos);
int l=0;
try{
for(int j=0;j<=pos-1;j++)
{
EditText edt1=(EditText)findViewById(j);
sn=edt1.getText().toString();
editor.putString("sub0"+l,sn);
l++;
}
}
catch(Exception e)
{
}
editor.commit();
}catch (Exception e) {
// TODO: handle exception
}
}
@Override
protected void onRestart() {
// TODO Auto-generated method stub
super.onRestart();
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
try{
SharedPreferences prefs = getSharedPreferences("myfile",0);
String restoredText = prefs.getString("text", null);
String[] sw=new String[prefs.getInt("cpd",0)];
cpd = prefs.getInt("cpd", 0);
int restoredText2= prefs.getInt("nos", 0);
int pos1=prefs.getInt("pos",2);
int l=0;
if (restoredText != null) {
t1.setText(restoredText, EditText.BufferType.EDITABLE);
t2.setText(""+cpd, EditText.BufferType.EDITABLE);
t3.setText(""+restoredText2, EditText.BufferType.EDITABLE);
day= prefs.getInt("day", 1);
month= prefs.getInt("month", 1);
year= prefs.getInt("year",2012);
datepicupdate();
linearlayout.removeAllViews();
for(int j=0;j<=pos1-1;j++)
{
sw[l]=prefs.getString("sub0"+l,null);
EditText edt1=(EditText) new EditText(getApplicationContext());
edt1.setId(j);
edt1.setHint("Enter the subject name");
edt1.setText(sw[l]);
linearlayout.addView(edt1);
l++;
}
}
}catch (Exception e) {
// TODO: handle exception
}
}
@Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
}
}