I'm looking for a place where are objects after serialization ? I would like to put serialized objects(created in another app) to my android project and then only load this files in my game. The problem is that I don't know where do I have to put this objects ? and even if I save object from android app it never saves in my project folder. My load and save functions for objects
public static void save(Context context, Map obj, String nazwa)
{
FileOutputStream str = null;
ObjectOutputStream objStr = null;
try {
str = context.openFileOutput(nazwa, Context.MODE_PRIVATE);
objStr = new ObjectOutputStream(str);
objStr.writeObject(obj);
} catch (FileNotFoundException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
} finally
{
try
{
if (objStr != null) objStr.close();
} catch (IOException e) {}
try
{
if (str != null) str.close();
} catch (IOException e) {}
}
}
public static Map load(Context context, String nameFile)
{
Map obj = null;
FileInputStream str_w = null;
ObjectInputStream obj_w = null;
try
{
str_w = context.openFileInput(nameFile);
obj_w = new ObjectInputStream(str_w);
obj = (Map) obj_w.readObject();
} catch (FileNotFoundException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
} catch (ClassNotFoundException e)
{
e.printStackTrace();
} finally
{
try
{
if (obj_w != null) obj_w.close();
} catch (IOException e) {}
try
{
if (str_w != null) str_w.close();
} catch (IOException e) {}
}
return obj;
}
If I copy my object file to /levels/ and use
final Map map2 = MapManager.load(this, "/levels/map1.lvl");
or
final Map map2 = MapManager.load(this, "levels/map1.lvl");
it never works
How should I do it ?
You're storing them as app private files (Context.MODE_PRIVATE) to a folder only the app has access to, so no other application will be able to access them.
I think the easiest way to store them so they can be shared between apps is to store them to the sdcard using:
Environment.getExternalStorageDir();
Be aware to store them as globally readable.
Related
So I am new in programing and i adding a feature in my app which save all sharedpreference key in value in Device internal data folder by using fileoutputStream like this add all data in map and store in jsonobject
private String maptojson(){
Map<String, ?> map = prf.getAll();
JSONObject object = new JSONObject();
for (Map.Entry<String,?> entry : map.entrySet()){
try {
object.put( entry.getKey(), entry.getValue());
} catch (JSONException e) {
e.printStackTrace();
}
}
return object.toString();
}
Now Use FileOutputStream for write file in internal Storage "data'
public void backupSetting() {
Throwable th;
FileOutputStream fileOutputStream;
IOException e;
FileOutputStream fileOutputStream2 = null;
File externalStorageDirectory = Environment.getExternalStorageDirectory();
if (externalStorageDirectory.exists() && externalStorageDirectory.canWrite()) {
if (externalStorageDirectory.getUsableSpace() >= 1048576) {
File file = new File(externalStorageDirectory.toString() + "/data/MyApp/" + "MyAppSetting.ma");
try {
new File(file.getParent()).mkdirs();
file.createNewFile();
fileOutputStream = new FileOutputStream(file);
try {
fileOutputStream.write(maptojson().getBytes());
fileOutputStream.flush();
fileOutputStream.close();
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e2) {
e2.printStackTrace();
}
}
} catch (IOException e3) {
e = e3;
try {
e.printStackTrace();
if (fileOutputStream != null) {
}
} catch (Throwable th2) {
th = th2;
fileOutputStream2 = fileOutputStream;
if (fileOutputStream2 != null) {
try {
fileOutputStream2.close();
} catch (IOException e4) {
e4.printStackTrace();
throw th;
}
}
throw th;
}
}
} catch (IOException e5) {
e = e5;
fileOutputStream = null;
e.printStackTrace();
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e6) {
e6.printStackTrace();
}
}
} catch (Throwable th3) {
th = th3;
if (fileOutputStream2 != null) {
}
try {
throw th;
} catch (Throwable throwable) {
throwable.printStackTrace();
}
}
}
}
Now i want to add restore setting means restore setting by using that file "MyAppSetting.ma". I know i can do it by using FileInputStream but I don't understand how to do? please help if you could
I'm developing an MP3 player with java, using mp3agic to edit .mp3 files metadata. The problem is: I don't know the specific tags of the files to edit the desired data.
Here's my code to get the mp3 track for example:
public static int get_rep(Music msc)
{
try
{
Mp3File file = new Mp3File(msc.get_path());
if (file.hasId3v1Tag())
{
ID3v1 tag = file.getId3v1Tag();
return Integer.parseInt(tag.getTrack());
}
else if (file.hasId3v2Tag())
{
ID3v2 tag = file.getId3v2Tag();
return Integer.parseInt(tag.getTrack());
}
}
catch (UnsupportedTagException e)
{
e.printStackTrace();
}
catch (InvalidDataException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
return -1;
}
Is there a way to get the tag value skipping file.hasId3v1Tag() and file.hasId3v2Tag() verifications?
I tried:
private static Object get_tag(Music msc)
{
try
{
Mp3File file = new Mp3File(msc.get_path());
if (file.hasId3v1Tag())
{
return file.getId3v1Tag();
}
else if (file.hasId3v2Tag())
{
return file.getId3v2Tag();
}
/*
else if(file.hasCustomTag())
{
file.removeCustomTag();
return file.getCustomTag();
}
*/
}
catch (UnsupportedTagException e)
{
e.printStackTrace();
}
catch (InvalidDataException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
return Boolean.FALSE;
}
But I still have to check the tags, then cast the Object value to a tag value, which means I'd have to know it anyway. I'm accepting any suggestions, even exchanging mp3agic.
ID3v2 extends ID3v1, so you should be able to use ID3v1 tag = file.getId3v2Tag(); and be able to extract ID3v1 data from it.
You could try this:
private static ID3v1 get_tag(Music msc) {
try {
Mp3File file = new Mp3File(msc.get_path());
if (file.hasId3v1Tag()) {
return file.getId3v1Tag();
} else if (file.hasId3v2Tag()) {
return file.getId3v2Tag();
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
something is really messed up. I've got a ".ser" document in the assets folder, which stores an ArrayList of Objetcs. In an android application, I want to read this objects. There are a lot of posts related to this issue, however none of them could solve my problem. The strange part is, when I am using similar code in non - android context / "normal" java, it works properly. Here, the last line throws a NullPointerException - What is going wrong?
public void getData() {
ArrayList<MyClass> output= null;
InputStream is = null;
ObjectInputStream ois = null;
try{
is = this.getAssets().open("data.ser");
ois = new ObjectInputStream(is);
output = (ArrayList<MyClass>)ois.readObject();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
ois.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Log.d("TAG", output.get(0).getId());
}
I would create a class and place the array within a single object:
public class ListObjects implements Serializable {
List<MyClass> listMyClass = new ArrayList<>();
public ListObjects(){
}
public List<MyClass> getListMyClass() {
return listMyClass;
}
public void setListMyClass(List<MyClass> listMyClass) {
this.listMyClass = listMyClass;
}
}
I had a similar problem. And it was because the name of the package in the java app was not called the same as the package name in android. And therefore I did not recognize them as equal objects. This is how I do it:
public static Object fromData(byte[] data) {
ObjectInputStream ois = null;
Object object = null;
try {
ois = new ObjectInputStream(
new ByteArrayInputStream(data));
object = ois.readObject();
} catch (Exception ex) {
Logger.getLogger(ModeloApp.class.getName()).log(Level.SEVERE, null, ex);
} finally {
try {
ois.close();
} catch (Exception ex) {
Logger.getLogger(ModeloApp.class.getName()).log(Level.SEVERE, null, ex);
}
}
return object;
}
I need to pass some Bitmaps from one activity to another, and, since the size limit of the Bundle won't let me pass these images (even using a byte array*), I thought that I could use a getter method between these Activities.
-But, since I'm still not a master in Android (Java), I don't know if that would make any difference, and, if it does, what should I watch out for when using it.
the byte array did reduce the total size(at about 60%), but it still wasn't enough
scaling down is a way out, but just in case any other solution works
save your object in a file
private void saveDataToFile() {
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = getContext().openFileOutput("fileName", Context.MODE_PRIVATE);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (NullPointerException e) {
}
ObjectOutputStream objectOutputStream = null;
try {
objectOutputStream = new ObjectOutputStream(fileOutputStream);
} catch (IOException e) {
e.printStackTrace();
} catch (NullPointerException e) {
}
try {
if (objectOutputStream != null) {
objectOutputStream.writeObject(yourObject); //which data u want to save
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (objectOutputStream != null) {
objectOutputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
Retrieve the object from another activity
private void getDataFromFile() {
FileInputStream fileInputStream = null;
try {
fileInputStream = getContext().openFileInput("fileName");
} catch (FileNotFoundException e) {
e.printStackTrace();
return;
}
ObjectInputStream objectInputStream = null;
try {
objectInputStream = new ObjectInputStream(fileInputStream);
} catch (IOException |NullPointerException e) {
e.printStackTrace();
}
try {
yourObject = (ObjectClass) objectInputStream.readObject();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
objectInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Pass through Uri by writing getter method in POJO class
If you want to use getter setter, just create URI of your bitmap and pass to setter method in POJO class and then retrieve using getter method of POJO class.
I am developing a project which involves JSON manipulation in Java using JSON API. There are many places where I need to read values from JSON file. The API provides checked exceptions for the same. Everytime I use the API to read JSON values, I am forced to write try catch block. As a result, there is a large number of try catch blocks. It makes the code look messy.
String Content = "";
try {
read = new BufferedReader(new FileReader("Data.json"));
}
catch(Exception e) {
System.out.println("File Not found");
}
try {
while((line = read.readLine() ) != null) {
Content = Content+line;
}
} catch (IOException e) {
e.printStackTrace();
}
try {
ResponseArr = new JSONArray( Content );
} catch (JSONException e) {
e.printStackTrace();
}
try {
ResponseObj = ResponseArr.getJSONObject(1).getJSONArray("childrens");
} catch (JSONException e) {
e.printStackTrace();
}
try {
StoreResponse = ResponseArr.getJSONObject(0).getJSONArray("childrens");
} catch (JSONException e) {
e.printStackTrace();
}
Is there any way to avoid this ?A single try catch block would not suffice and the statements are not dependent. Each read statement requires a separate try catch block as I have to log the details of places while catching the exception. Can I invoke a common method whenever I have a code to read JSON data, like sending the code as a paramater to a method which would take care of the exception handling or some other way round ?
Since (all?) the subsequent statements are dependent on the previous it makes no sense having that many try/catch blocks. I would rather put the code inside one try/catch and handle the exceptions by type
Pseudo-code:
String Content = "";
try {
read = new BufferedReader(new FileReader("Data.json"));
while((line = read.readLine() ) != null) {
Content = Content+line;
}
ResponseArr = new JSONArray( Content );
ResponseObj = ResponseArr.getJSONObject(1).getJSONArray("childrens");
} catch (JSONException e) {
e.printStackTrace();
} catch(FileNotFoundException)
System.out.println("File Not found");
}
// and so on
As some are suggesting, you might want to let all these exceptions bubble up (not catching them) since you're not doing anything meaningful when catching them. However, I think that depends on the calling context.
If you are handling all exceptions in the same way, why not combine them in one try/ catch clause
for example like this :
try {
while((line = read.readLine() ) != null) {
Content = Content+line;
}
ResponseArr = new JSONArray( Content );
ResponseObj = ResponseArr.getJSONObject(1).getJSONArray("childrens");
} catch (Exception e) {
e.printStackTrace();
}
Try like this
String Content = "";
try {
read = new BufferedReader(new FileReader("Data.json"));
while((line = read.readLine() ) != null) {
Content = Content+line;
}
ResponseArr = new JSONArray( Content );
ResponseObj = ResponseArr.getJSONObject(1).getJSONArray("childrens");
}
catch (IOException e) {
e.printStackTrace();
}
catch (JSONException e) {
e.printStackTrace();
}
catch(Exception e) {
System.out.println("File Not found");
}