【发布时间】：2015-10-04 18:35:30
【问题描述】：
如果 ObjectInputStream.objectRead 似乎对我不起作用的原因是因为我错过了一些明显的东西，我不会感到惊讶。
您将在下面找到代码和应用程序日志输出。
不抛出异常。代码执行完毕。
但是，从 SDCard 检索到的文件是空的（由 .size() 为 0 证明）虽然当我在 SDCard 上检查它时它的大小大于 0（几个 KBytes）并且我能够写入文件（追加模式）没有问题（证明 .writeObject 操作后文件大小增加。
我被困住了。我可能错过了一些明显的东西，但我找不到问题。
非常感谢您提供反馈、建议或问题的解决方案。
谢谢，
亚历克斯·唐尼尼
100315-2 上的源代码更新
protected static synchronized void readUserLocationInformation() throws StreamCorruptedException, IOException, ClassNotFoundException
{
ArrayList<userLocationInformation> mUserLocationInformation = new ArrayList<userLocationInformation>();
int mUserLocationInformationSize = mUserLocationInformation.size();
createUserLocationDatabaseOnSdCardStorage();
userLocationInformation userLocationInformationHolder = new userLocationInformation();
userLocationInformationHolder.lat = myAndApsLatlng[0];
userLocationInformationHolder.lon = myAndApsLatlng[1];
System.arraycopy( myAndApsLatlng, 0, userLocationInformationHolder.myAndApsLatlng, 0, myAndApsLatlng.length);
userLocationInformationHolder.estimateTime = System.nanoTime();
mUserLocationInformation.add(userLocationInformationHolder);
mUserLocationInformationSize = mUserLocationInformation.size();
try {
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformationSize - " + mUserLocationInformationSize);
if(mUserLocationInformationSize > 0)
{
for(int f = 0; f < mUserLocationInformationSize; ++f)
{
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).estimateTime - " + mUserLocationInformation.get(f).estimateTime);
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).lat - " + mUserLocationInformation.get(f).lat);
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).lon - " + mUserLocationInformation.get(f).lon);
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//write object to external storage START $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Object objectToBeStoredHolder;
FileOutputStream objectNameFileOutputStream = null;
OutputStream objectNameBufferedOutputStream = null;
ObjectOutputStream objectNameObjectOutputStream = null;
objectToBeStoredHolder = mUserLocationInformation;
try
{
try
{
Log.i(TAG, " - readUserLocationInformation - object - "+userLocationDatabaseFileNameObject);
Log.i(TAG, " - readUserLocationInformation - setting up objectNameFileOutputStream --- ");
objectNameFileOutputStream = new FileOutputStream(objectStorageLocationDirectory+userLocationDatabaseFileNameObject, true);
} catch (IOException e1)
{
e1.printStackTrace();
}
try
{
Log.i(TAG, " - readUserLocationInformation - object - "+userLocationDatabaseFileNameObject);
Log.i(TAG, " - readUserLocationInformation - setting up objectNameBufferedOutputStream --- ");
objectNameBufferedOutputStream = new BufferedOutputStream(objectNameFileOutputStream);
}
catch (Exception e1)
{
e1.printStackTrace();
}
try
{
Log.i(TAG, " - readUserLocationInformation - object - "+userLocationDatabaseFileNameObject);
Log.i(TAG, " - readUserLocationInformation - setting up objectNameObjectOutputStream --- ");
objectNameObjectOutputStream = new ObjectOutputStream(objectNameBufferedOutputStream);
}
catch (Exception e)
{
Log.i(TAG, " - readUserLocationInformation - exception - object - "+userLocationDatabaseFileNameObject);
e.printStackTrace();
}
try
{
Log.i(TAG, " - readUserLocationInformation - objectNameObjectOutputStream.writeObject - object - "+userLocationDatabaseFileNameObject);
objectNameObjectOutputStream.writeObject(objectToBeStoredHolder);
}
finally
{
Log.i(TAG, " - readUserLocationInformation - finally objectNameObjectOutputStream for object - "+userLocationDatabaseFileNameObject);
objectNameObjectOutputStream.flush();
objectNameObjectOutputStream.close();
}
}
catch (Exception e)
{
Log.i(TAG, " - readUserLocationInformation - object - "+userLocationDatabaseFileNameObject);
Log.i(TAG,
" - readUserLocationInformation - FAILED to write object ObjectToBeStored --- ");
e.printStackTrace();
}
//write object to external storage END $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Log.i(TAG, " - readUserLocationInformation - retrieving user location database stored on SDcard as arraylist --- ");
FileInputStream userLocationObjectFileInputStream = null;
ObjectInputStream userLocationInputStream = null;
Log.i(TAG, " - readUserLocationInformation - setting up FileInputStream --- ");
userLocationObjectFileInputStream = new FileInputStream(objectStorageLocationDirectory+userLocationDatabaseFileNameObject);
Log.i(TAG, " - readUserLocationInformation - setting up ObjectInputStream --- ");
userLocationInputStream = new ObjectInputStream(userLocationObjectFileInputStream);
Log.i(TAG, " - readUserLocationInformation - retrieving user location list stored in ArrayList from SDcard --- ");
mUserLocationInformation = (ArrayList) userLocationInputStream.readObject();
mUserLocationInformationSize = mUserLocationInformation.size();
Log.i(TAG, "readUserLocationInformation - mUserLocationInformationSize - "+mUserLocationInformationSize);
if(mUserLocationInformationSize > 0)
{
for(int f = 0; f < mUserLocationInformationSize; ++f)
{
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).estimateTime - " + mUserLocationInformation.get(f).estimateTime);
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).lat - " + mUserLocationInformation.get(f).lat);
Log.i(TAG, " - readUserLocationInformation - mUserLocationInformation.get(f).lon - " + mUserLocationInformation.get(f).lon);
}
}
}
应用程序日志 - 更新于 100315-2
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - mUserLocationInformationSize - 1
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - mUserLocationInformation.get(f).estimateTime - 6768145557155
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - mUserLocationInformation.get(f).lat - 42.35552279549794
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - mUserLocationInformation.get(f).lon - -71.17862967362912
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - object - userLocationDatabaseFileNameObject
10-05 18:11:51.548: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - setting up objectNameFileOutputStream ---
10-05 18:11:51.549: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - object - userLocationDatabaseFileNameObject
10-05 18:11:51.549: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - setting up objectNameBufferedOutputStream ---
10-05 18:11:51.549: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - object - userLocationDatabaseFileNameObject
10-05 18:11:51.549: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - setting up objectNameObjectOutputStream ---
10-05 18:11:51.549: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - objectNameObjectOutputStream.writeObject - object - userLocationDatabaseFileNameObject
10-05 18:11:51.551: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - finally objectNameObjectOutputStream for object - userLocationDatabaseFileNameObject
10-05 18:11:51.552: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - retrieving user location database stored on SDcard as arraylist ---
10-05 18:11:51.552: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - setting up FileInputStream ---
10-05 18:11:51.552: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - setting up ObjectInputStream ---
10-05 18:11:51.552: I/ContinuousLocationTrackingService(10206): - readUserLocationInformation - retrieving user location list stored in ArrayList from SDcard ---
10-05 18:11:51.553: I/ContinuousLocationTrackingService(10206): readUserLocationInformation - mUserLocationInformationSize - 0
createUserLocationDatabaseOnSdCardStorage() 的源代码
protected static void createUserLocationDatabaseOnSdCardStorage()
{
boolean userLocationdatabaseCreateActionResult = false;
if(!userLocationDatabaseObject.exists())
{
try {
userLocationdatabaseCreateActionResult = userLocationDatabaseObject.createNewFile();
} catch (IOException e) {
Log.i(TAG, "createUserLocationDatabaseOnSdCardStorage - FAILED to create userLocationDatabaseObject --- ");
e.printStackTrace();
}
if (userLocationdatabaseCreateActionResult) {
Log.i(TAG, "createUserLocationDatabaseOnSdCardStorage - userLocationDatabaseObject created successfully --- ");
} else {
Log.i(TAG, "createUserLocationDatabaseOnSdCardStorage - userLocationDatabaseObject not created --- ");
}
}
else
{
Log.i(TAG, "createUserLocationDatabaseOnSdCardStorage - userLocationDatabaseObject already exists --- ");
}
}
userLocationInformation 类的定义
public static class userLocationInformation implements Serializable, Comparator<userLocationInformation>
{
public long estimateTime = 0l;
public double lat;
public double lon;
public double[] myAndApsLatlng = new double[10];
public double alternateLatitude = 0.0;
public double alternateLongitude = 0.0;
public double locationAltitude = 0.0;
public long locationTime = 0;
public float locationSpeed = 0.0f;
public float locationAccuracy = 0.0f;
public float locationBearing = 0.0f;
@Override
public int compare(userLocationInformation one, userLocationInformation another) {
long estimateTimeOne = one.estimateTime;
long estimateTimeAnother = another.estimateTime;
return (one.estimateTime < another.estimateTime ? -1 :
(estimateTimeOne == estimateTimeAnother ? 0 : 1));
}
}
【问题讨论】：
-
不要这样写代码。依赖于前一个 try 块中代码成功的代码应该在同一个 try 块内。
-
谢谢。我去做。关于为什么 objectRead 不检索文件（并且没有抛出异常）的任何想法？谢谢
-
显然，我的意思是 readObject。对不起
-
当您的代码处于不可读和无效状态时，请不要这样做。修复它，重新测试，并在必要时编辑您的帖子。
-
去掉所有try/catch块后，结果还是一样，mUserLocationInformation还是空。
标签： java android arraylist objectinputstream