Android 10.0 sharedpereference保存数据断开电源数据丢失题目办理 - IT评测·应用市场-qidao123.com

frameworks/base/core/java/android/content/SharedPreferences.java
frameworks/base/core/java/android/app/SharedPreferencesImpl.java

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public interface SharedPreferences {
/**
* Interface definition for a callback to be invoked when a shared
* preference is changed.
*/
public interface OnSharedPreferenceChangeListener {
/**
* Called when a shared preference is changed, added, or removed. This
* may be called even if a preference is set to its existing value.
*
* This callback will be run on your main thread.
*
*/
void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key);
}
/*public interface OnSharedPreferenceChangeListener {
/**
* Called when a shared preference is changed, added, or removed. This
* may be called even if a preference is set to its existing value.
*
* This callback will be run on your main thread.
*
* Note: This callback will not be triggered when preferences are cleared via
* {@link Editor#clear()}.
*
* @param sharedPreferences The {@link SharedPreferences} that received
* the change.
* @param key The key of the preference that was changed, added, or
* removed.
*/
void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key);
}*/
/**
* Interface used for modifying values in a {@link SharedPreferences}
* object. All changes you make in an editor are batched, and not copied
* back to the original {@link SharedPreferences} until you call {@link #commit}
* or {@link #apply}
*/
public interface Editor {
/**
* Set a String value in the preferences editor, to be written back once
* {@link #commit} or {@link #apply} are called.
*
* @param key The name of the preference to modify.
* @param value The new value for the preference. Passing {@code null}
* for this argument is equivalent to calling {@link #remove(String)} with
* this key.
*
* @return Returns a reference to the same Editor object, so you can
* chain put calls together.
*/
Editor putString(String key, @Nullable String value);
/**
* Set a set of String values in the preferences editor, to be written
* back once {@link #commit} or {@link #apply} is called.
*
* @param key The name of the preference to modify.
* @param values The set of new values for the preference. Passing {@code null}
* for this argument is equivalent to calling {@link #remove(String)} with
* this key.
* @return Returns a reference to the same Editor object, so you can
* chain put calls together.
*/
Editor putStringSet(String key, @Nullable Set<String> values);
Editor putInt(String key, int value);
Editor putLong(String key, long value);
Editor putFloat(String key, float value);
Editor putBoolean(String key, boolean value);
Editor remove(String key);
Editor clear();
boolean commit();
void apply();
}
.....
}

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//add core start
//do sync
public static void fileSync() {
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//sync
Runtime runtime = Runtime.getRuntime();
try {
runtime.exec("sync");
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
//add core end
@Override
public Editor clear() {
synchronized (mEditorLock) {
mClear = true;
return this;
}
}
@Override
public void apply() {
final long startTime = System.currentTimeMillis();
final MemoryCommitResult mcr = commitToMemory();
final Runnable awaitCommit = new Runnable() {
@Override
public void run() {
try {
mcr.writtenToDiskLatch.await();
} catch (InterruptedException ignored) {
}
if (DEBUG && mcr.wasWritten) {
Log.d(TAG, mFile.getName() + ":" + mcr.memoryStateGeneration
+ " applied after " + (System.currentTimeMillis() - startTime)
+ " ms");
}
}
};
QueuedWork.addFinisher(awaitCommit);
Runnable postWriteRunnable = new Runnable() {
@Override
public void run() {
awaitCommit.run();
QueuedWork.removeFinisher(awaitCommit);
}
};
SharedPreferencesImpl.this.enqueueDiskWrite(mcr, postWriteRunnable);
// Okay to notify the listeners before it's hit disk
// because the listeners should always get the same
// SharedPreferences instance back, which has the
// changes reflected in memory.
notifyListeners(mcr);
+ fileSync();
}
@Override
public boolean commit() {
long startTime = 0;
if (DEBUG) {
startTime = System.currentTimeMillis();
}
MemoryCommitResult mcr = commitToMemory();
SharedPreferencesImpl.this.enqueueDiskWrite(
mcr, null /* sync write on this thread okay */);
try {
mcr.writtenToDiskLatch.await();
} catch (InterruptedException e) {
return false;
} finally {
if (DEBUG) {
Log.d(TAG, mFile.getName() + ":" + mcr.memoryStateGeneration
+ " committed after " + (System.currentTimeMillis() - startTime)
+ " ms");
}
}
notifyListeners(mcr);
+ fileSync();
return mcr.writeToDiskResult;
}

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