Question

I have tried implementing cross platform serialization between Java and Android. I have used Serializable, and having my code in Android in the same package as in desktop Java.

Source: java-desktop serializing

    Student student=new Student(); 
    student.setName("John");
    student.setSurname("Brown");
    student.setNumber(776012345);

    try {
      FileOutputStream fout = new FileOutputStream("thestudent.dat");
      ObjectOutputStream oos = new ObjectOutputStream(fout);
      oos.writeObject(student);
      oos.close();
    }
      catch (Exception e) { e.printStackTrace(); }

    }

Source: Android – deserializing

File file=new File(getExternalFilesDir(null), "thestudent.dat");

    try {

      FileInputStream fint = new FileInputStream(file);
      ObjectInputStream ois = new ObjectInputStream(fint);
      Student stud=(Student) ois.readObject();
      ois.close();
    }
      catch (Exception e) { e.printStackTrace(); }

}

Student is a class, which implements Serializable. On desktop I serialize instance of student to “thestudent.dat”. I put this file on SD card at Android device and I am trying to deserialize it. I am getting error java.lang.ClassCastException: javaserializace.Student. But why? I have same package when serializing, same package when deserializing. All what is different is project name. Do you see any solution?

Edited – source of Student class:

public class Student implements Serializable {

private String name;
private String surname;
private int number;
private char gender;
private int age;
private long rc;
private int id;

public Student(){
    ;
}

public int getAge() {
    return age;
}

public void setAge(int age) {
    this.age = age;
}

public char getGender() {
    return gender;
}

public void setGender(char gender) {
    this.gender = gender;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public long getRc() {
    return rc;
}

public void setRc(long rc) {
    this.rc = rc;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int getNumber() {
    return number;
}

public void setNumber(int number) {
    this.number = number;
}

public String getSurname() {
    return surname;
}

public void setSurname(String surname) {
    this.surname = surname;
}

}

Answer 1

I am certain that two versions of Student on Both sides are not same.

Because the exception is

java.lang.ClassCastException: javaserializace.Student.

which indicates that Java has successfully deserialized the object but while typecasting it to Student on receiver side, it is throwing exception because types are not same.

A quick way to debug this is to invoke getClass() on received Student object and getName() on Student class on receiver. I am sure that in this case both are different.

And solution will be to ensure that Student on receiver side is of same type.