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POError in : java.io.InvalidClassException
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copied!<p>I am working on this and getting this error cannot put my finger on the error:</p> <p>This my class:</p> <pre><code>package stdaccmdmngmt; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.util.Date; import java.util.HashSet; import java.util.Set; import javax.swing.JOptionPane; /** * * @author princess */ public class Student1 implements Serializable { public static Set<Student1> listOfStudents = new HashSet<Student1>(); public static File outFile = new File("StudentRegistry.dat"); // Data memebers private String studentID; private String name; private Date dateOfReg; //Constructor Student1(String number,String name) { this.studentID = number; this.name = name; dateOfReg = new Date(); } public String getName() { return name; } public String getStudentID() { return studentID; } public Date getDateOfReg() { return dateOfReg; } public void register() throws FileNotFoundException, IOException, ClassNotFoundException { Set<Student1> sss = new HashSet<Student1>(); ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(outFile)); oos.writeObject(sss); oos.close(); } public static HashSet<Student> getListOfStudents() throws FileNotFoundException, IOException, ClassNotFoundException { HashSet ss; File inFile = new File("StudentRegistry.dat"); ObjectInputStream ois = new ObjectInputStream(new FileInputStream(inFile)); Set<Student> aNewSet = (HashSet<Student>) ois.readObject(); return (HashSet<Student>) aNewSet; } public static Student getStudentbyID(String a) throws FileNotFoundException, IOException, ClassNotFoundException { Set<Student> aNewSet = new HashSet<Student>(); aNewSet = Student.getListOfStudents(); Student result = null; for (Student x :aNewSet) { if (x.getStudentID().equalsIgnoreCase(a)) { result = x; break; } } if (result == null) { JOptionPane.showMessageDialog(null, "Apartment not found"); } return result; } @Override public String toString() { // include the code to retrieve assigned apartment return "Name: " + name +" StudentID: "+ studentID + " Registered On: " + dateOfReg; } @Override public boolean equals(Object another) { Student1 stud = (Student1)another; return this.name.equals(stud.name)&& this.studentID.equals(stud.studentID); } @Override public int hashCode() { int hash = name.hashCode(); return hash; } } </code></pre> <p>and this is the testing Class :</p> <pre><code>package stdaccmdmngmt; import java.io.FileNotFoundException; import java.io.IOException; import java.util.HashSet; import java.util.Set; import java.util.logging.Level; import java.util.logging.Logger; /** * * @author princess */ public class Test { public static void main (String[]args) throws FileNotFoundException, ClassNotFoundException, IOException { Student1 s = new Student1("12345","Sasha"); try { s.register(); } catch (FileNotFoundException ex) { Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex); } catch (ClassNotFoundException ex) { Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex); } Set<Student> nnn; nnn = Student.getListOfStudents(); for (Student x : nnn) System.out.println(x.toString()); } } * @author princess */ public class Student1 implements Serializable { public static Set<Student1> listOfStudents = new HashSet<Student1>(); public static File outFile = new File("StudentRegistry.dat"); // Data memebers private String studentID; private String name; private Date dateOfReg; //Constructor Student1(String number,String name) { this.studentID = number; this.name = name; dateOfReg = new Date(); } public String getName() { return name; } public String getStudentID() { return studentID; } public Date getDateOfReg() { return dateOfReg; } public void register() throws FileNotFoundException, IOException, ClassNotFoundException { Set<Student1> sss = new HashSet<Student1>(); ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(outFile)); oos.writeObject(sss); oos.close(); } public static HashSet<Student> getListOfStudents() throws FileNotFoundException, IOException, ClassNotFoundException { HashSet ss; File inFile = new File("StudentRegistry.dat"); ObjectInputStream ois = new ObjectInputStream(new FileInputStream(inFile)); Set<Student> aNewSet = (HashSet<Student>) ois.readObject(); return (HashSet<Student>) aNewSet; } public static Student getStudentbyID(String a) throws FileNotFoundException, IOException, ClassNotFoundException { Set<Student> aNewSet = new HashSet<Student>(); aNewSet = Student.getListOfStudents(); Student result = null; for (Student x :aNewSet) { if (x.getStudentID().equalsIgnoreCase(a)) { result = x; break; } } if (result == null) { JOptionPane.showMessageDialog(null, "Apartment not found"); } return result; } @Override public String toString() { // include the code to retrieve assigned apartment return "Name: " + name +" StudentID: "+ studentID + " Registered On: " + dateOfReg; } @Override public boolean equals(Object another) { Student1 stud = (Student1)another; return this.name.equals(stud.name)&& this.studentID.equals(stud.studentID); } @Override public int hashCode() { int hash = name.hashCode(); return hash; } } </code></pre> <p>...........................</p> <p>and I am getting this error :</p> <pre><code>run: Exception in thread "main" java.io.InvalidClassException: stdaccmdmngmt.Student; local class incompatible: stream classdesc serialVersionUID = -3040096452457271695, local class serialVersionUID = -4849175799723926283 at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:562) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1583) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) at java.util.HashSet.readObject(HashSet.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) at stdaccmdmngmt.Student.getListOfStudents(Student.java:76) at stdaccmdmngmt.Test.main(Test.java:34) Java Result: 1 BUILD SUCCESSFUL (total time: 3 seconds) </code></pre> <p>Any help?</p> <p>Thanks in advance :)</p>

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