Java read object input stream into arraylist?
The method below is supposed to read a binary file into an arrayList
. But getting a java.io.EOFException
:
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2553) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1296) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350) at .... Read(Tester.java:400) at .... main(Tester.java:23)
Line 23 at main just calls the method, line 400 is the while loop below. Any ideas?
private static void Read() {
try {
ObjectInputStream objIn = new ObjectInputStream(new FileInputStream("/file.bin"));
while (objIn.readObject() != null) {
list.add((Libreria) objIn.readObject());
}
objIn.close();
} catc开发者_Python百科h(Exception e) {
e.printStackTrace();
}
}
As per the other answers you are reading twice in the loop. Your other problem is the null test. readObject()
only returns null if you have written a null, not at EOS, so there's not much point in using it as a loop termination test. The correct termination of a readObject()
loop is
catch (EOFException exc)
{
in.close();
break;
}
The problem is that you are calling readObject() twice in the loop. Try this instead:
MediaLibrary obj = null;
while ((obj = (MediaLibrary)objIn.readObject()) != null) {
libraryFromDisk.add(obj);
}
You're reading an object in the while test:
while (objIn.readObject() != null)
Then you're reading the next object in:
libraryFromDisk.add((MediaLibrary) objIn.readObject());
So in one iteration you should read only one object
private static void Load() {
try {
ObjectInputStream objIn = new ObjectInputStream(new FileInputStream("/file.bin"));
Object object = objIn.readObject();
while (object != null) {
libraryFromDisk.add((MediaLibrary) object);
object = objIn.readObject();
}
objIn.close();
} catch(Exception e) {
e.printStackTrace();
}
}
You can try this. Good luck!
private static void Load() {
try {
ObjectInputStream objIn = new ObjectInputStream(new FileInputStream("/file.bin"));
boolean check=true;
while (check) {
try{
object = objIn.readObject();
libraryFromDisk.add((MediaLibrary) object);
}catch(EOFException ex){
check=false;
}
}
objIn.close();
} catch(Exception e) {
e.printStackTrace();
}
}
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