我有一个 ArrayList，其中包含大约 1000 个联系人详细信息。打开需要 30 秒。所以我将此列表存储在android的内部存储中。我在安装它的数据后检查应用程序的详细信息显示 16 kb，以前是 0。所以数据正在存储，但是当我尝试从列表中读取数据时，应用程序以 nullpointerexception 关闭。
我的主要课程是：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
//Remove notification bar
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
listcontact = (GridView)findViewById(R.id.listapp);
ImageView img=(ImageView)findViewById(R.id.imageView1);
listcontact.setEmptyView(img);
try {
aa = readFromInternalStorage();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(aa.isEmpty()){
getnumber(this.getContentResolver());
}
else{
adapt=new ContactAdapter(MainActivity.this, aa);
listcontact.setAdapter(adapt);
}
edittext = (EditText)findViewById(R.id.edit_search);
edittext.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int start, int before, int count) {
// TODO Auto-generated method stub
//MainActivity.this.adapt.getFilter().filter(s);
int textlength = cs.length();
ArrayList<ContactStock> tempArrayList = new ArrayList<ContactStock>();
for(ContactStock c: aa){
String srch= c.getNumber().replaceAll(" ", "");
if (textlength <= c.getName().length() || textlength <= srch.length()) {
if (c.getName().toLowerCase().contains(cs.toString().toLowerCase()) || srch.toLowerCase().contains(cs.toString().toLowerCase())) {
tempArrayList.add(c);
}
}
}
adapt = new ContactAdapter(MainActivity.this, tempArrayList);
listcontact.setAdapter(adapt);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
class Info {
public String name;
public String phone;
public String picture;
@Override
public String toString() {
return name + " " + phone;
}
}
public void getnumber(ContentResolver cr) {
Cursor phone = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " ASC");
while (phone.moveToNext()) {
Info info = new Info();
ids=phone.getInt(phone.getColumnIndex(ContactsContract.CommonDataKinds.Phone.PHOTO_ID));
info.phone=phone.getString(phone.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
info.name=phone.getString(phone.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
long id=Long.valueOf(ids);
byte[] imagearray = queryContactImage(ids);
System.out.println("...........name");
aa.add(new ContactStock(info.name,info.phone,imagearray));
}
saveToInternalStorage(aa);
phone.close();
adapt=new ContactAdapter(MainActivity.this, aa);
listcontact.setAdapter(adapt);
}
private byte[] queryContactImage(int imageDataRow) {
Cursor c = getContentResolver().query(ContactsContract.Data.CONTENT_URI, new String[] {
ContactsContract.CommonDataKinds.Photo.PHOTO
}, ContactsContract.Data._ID + "=?", new String[] {
Integer.toString(imageDataRow)
}, null);
byte[] imageBytes = null;
if (c != null) {
if (c.moveToFirst()) {
imageBytes = c.getBlob(0);
}
c.close();
}
return imageBytes;
}
public void saveToInternalStorage(ArrayList<ContactStock> aList) {
try {
FileOutputStream fos = openFileOutput(NAME, Context.MODE_PRIVATE);
ObjectOutputStream of = new ObjectOutputStream(fos);
of.writeObject(aList);
of.flush();
of.close();
fos.close();
}
catch (Exception e) {
Log.e("InternalStorage", e.getMessage());
}
}
@SuppressWarnings("unchecked")
public ArrayList<ContactStock> readFromInternalStorage() throws ClassNotFoundException {
ArrayList<ContactStock> toReturn = null;
FileInputStream fis;
try {
fis = openFileInput(NAME);
ObjectInputStream oi = new ObjectInputStream(fis);
toReturn = (ArrayList<ContactStock>) oi.readObject();
oi.close();
} catch (FileNotFoundException e) {
Log.e("InternalStorage", e.getMessage());
} catch (IOException e) {
Log.e("InternalStorage", e.getMessage());
}
return toReturn;
}
任何帮助将不胜感激。提前致谢。
更新 ：-
我的堆栈跟踪是
logcat 中的错误
03-11 12:47:52.037: E/InternalStorage(2919): Read an exception; java.io.NotSerializableException: com.webshine.quickdialplus.ContactStock
03-11 12:47:52.039: E/AndroidRuntime(2919): FATAL EXCEPTION: main
03-11 12:47:52.039: E/AndroidRuntime(2919): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.webshine.quickdialerwidget/com.webshine.quickdialplus.MainActivity}: java.lang.NullPointerException
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2343)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread.access$600(ActivityThread.java:162)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.os.Handler.dispatchMessage(Handler.java:107)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.os.Looper.loop(Looper.java:194)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread.main(ActivityThread.java:5371)
03-11 12:47:52.039: E/AndroidRuntime(2919): at java.lang.reflect.Method.invokeNative(Native Method)
03-11 12:47:52.039: E/AndroidRuntime(2919): at java.lang.reflect.Method.invoke(Method.java:525)
03-11 12:47:52.039: E/AndroidRuntime(2919): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
03-11 12:47:52.039: E/AndroidRuntime(2919): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
03-11 12:47:52.039: E/AndroidRuntime(2919): at dalvik.system.NativeStart.main(Native Method)
03-11 12:47:52.039: E/AndroidRuntime(2919): Caused by: java.lang.NullPointerException
03-11 12:47:52.039: E/AndroidRuntime(2919): at com.webshine.quickdialplus.MainActivity.onCreate(MainActivity.java:62)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.Activity.performCreate(Activity.java:5122)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1081)
03-11 12:47:52.039: E/AndroidRuntime(2919): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
03-11 12:47:52.039: E/AndroidRuntime(2919): ... 11 more