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POAndroid readObject exception, cannot cast String to ObjectStreamClass
 

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  1. POAndroid readObject exception, cannot cast String to ObjectStreamClass
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    <p>I am working on an android project that loads data remotely, saves it into an array (if the data is new), writes it to disk as a serializeable, then reads it from disk to load an ArrayList.</p> <p>Sometimes the ArrayList populates with the data, sometimes it doesn't and the program crashes.</p> <p>I receive a runtime exception stating: java.land.ClassCastException: java.lang.String cannot be cast to java.io.ObjectStreamClass.</p> <p>Sometimes I also receive a java.io.StreamCorruptedException, and sometimes I receive and EOFException.</p> <p>Going through the exception tree, it seems to be originating from this call:</p> <pre><code>personsArray = (ArrayList&lt;Person&gt;) in.readObject(); </code></pre> <p>Now, sometimes the data loads fine without issues, most of the time the program crashes.</p> <p>Here is the code that saves the data to disk:</p> <pre><code>public static boolean saveFromRemoteSource(Context c, ArrayList&lt;?&gt; source){ //Save context context = c; //Save source to local file File file = context.getFileStreamPath(PERSONS_FILE); //Status if successful in saving boolean savedStatus = false; try { if(!file.exists()){ file.createNewFile(); }else{ //file already exists so don't do anything } //now load the data into the file FileOutputStream fos = context.openFileOutput(PERSONS_FILE, Context.MODE_PRIVATE); ObjectOutputStream oos = new ObjectOutputStream(fos); oos.writeObject(source); oos.close(); savedStatus = true; } catch(IOException e){ e.printStackTrace(); savedStatus = false; } return savedStatus; } </code></pre> <p>Here is the code that reads the data from disk:</p> <pre><code> public static boolean loadPersonsArray(Context c){ context = c; boolean loadStatus = false; File file = context.getFileStreamPath(PERSONS_FILE); try{ if(!file.exists()){ file.createNewFile(); }else { //File is already created, do nothing } BufferedReader br = new BufferedReader(new FileReader(file)); if (br.readLine() != null) { FileInputStream fis = context.openFileInput(PERSONS_FILE); ObjectInputStream in = new ObjectInputStream(fis); personsArray = (ArrayList&lt;Person&gt;) in.readObject(); in.close(); fis.close(); loadStatus = true; } br.close(); } catch(IOException e){ e.printStackTrace(); Log.d("TAG", "IOException PERSONS_FILE file: " + e); loadStatus = false; } catch (ClassNotFoundException e) { e.printStackTrace(); Log.d("TAG", "ClassNotFoundException PERSONS_FILE file classnotfound: " + e); } return loadStatus; } </code></pre> <p>This is the Person class:</p> <pre><code> import java.io.Serializable; public class Person implements Serializable, Comparable&lt;Person&gt;{ //Person class private static final long serialVersionUID = 1L; private String personID; private String personName; private boolean displayPerson; //default constructor public Person(){ super(); } public Person(String personID, String personName, boolean displayPerson){ super(); this.personID = personID; this.personName = personName; this.displayPerson = displayPerson; } //Accessor Methods public String getPersonID(){ return personID; } public String getPersonName(){ return personName; } public boolean getDisplayPerson(){ return displayPerson; } //setter methods public void setPersonID(String personID){ this.personID = personID; } public void setPersonName(String personName){ this.personName = personName; } public void setDisplayPerson(boolean displayPerson){ this.displayPerson = displayPerson; } @Override public String toString(){ return this.getPersonName().replaceAll("[^A-Za-z0-9]", "") + this.getDisplayPerson(); } public int compareTo(Person otherPerson) { if(!(otherPerson instanceof Person)){ throw new ClassCastException("Not a valid Person object!"); } Person tempPerson = (Person)otherPerson; if(this.getPersonName().compareToIgnoreCase(tempPerson.getPersonName()) &gt; 0){ return 1; }else if(this.getPersonName().compareToIgnoreCase(tempPerson.getPersonName()) &lt; 0){ return -1; }else{ return 0; } } } </code></pre> <p>Where the data comes from to be written to the file</p> <pre><code> private void downloadPersons(){ HashMap&lt;String, String&gt; params = new HashMap&lt;String, String&gt;(); Kumulos.call("selectAllPersons", params, new ResponseHandler() { @Override public void didCompleteWithResult(Object result) { ArrayList&lt;Object&gt; personsList = new ArrayList&lt;Object&gt;(); for(Object o : (ArrayList&lt;?&gt;)result){ Person person = new Person(); person.setPersonID(replaceNandT((String) ((HashMap&lt;?,?&gt;) o).get("personID"))); person.setLawName(replaceNandT((String) ((HashMap&lt;?,?&gt;) o).get("personName"))); person.setDisplayLaw(stringToBool((String)((HashMap&lt;?,?&gt;) o).get("displayPerson"))); if(person.getDisplayPerson()==true){ personsList.add(person); } } //Save personsList to a file if(PersonsLoader.saveFromRemoteSource(context, personsList)){ updateVersionNumber(); isFinished=true; Log.d("TAG", "PersonsLoader.saveFromRemoteSource(context, personsList) success"); } } }); } </code></pre> <p>So what do you think is happening at this call?</p>
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    1. COMost likely whatever is writing the file has bugs. This sounds very much like a file with corrupted bookkeeping information.
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      1. USchrylis
    2. COThis is the code that reads data *from* the disk. Where is the writing code? And the stack trace?
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      1. POAndroid readObject exception, cannot cast String to ObjectStreamClass
      1. USuser207421
    3. COI use this to save it File file = ontext.getFileStreamPath(PERSONS_FILE);
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      1. USM Jesse
 

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