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- Java.io package classes
- Java.io - Home
- Java.io - BufferedInputStream
- Java.io - BufferedOutputStream
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- Java.io - BufferedWriter
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- Java.io - ByteArrayOutputStream
- Java.io - CharArrayReader
- Java.io - CharArrayWriter
- Java.io - Console
- Java.io - DataInputStream
- Java.io - DataOutputStream
- Java.io - File
- Java.io - FileDescriptor
- Java.io - FileInputStream
- Java.io - FileOutputStream
- Java.io - FilePermission
- Java.io - FileReader
- Java.io - FileWriter
- Java.io - FilterInputStream
- Java.io - FilterOutputStream
- Java.io - FilterReader
- Java.io - FilterWriter
- Java.io - InputStream
- Java.io - InputStreamReader
- Java.io - LineNumberInputStream
- Java.io - LineNumberReader
- Java.io - ObjectInputStream
- Java.io - ObjectInputStream.GetField
- Java.io - ObjectOutputStream
- io - ObjectOutputStream.PutField
- Java.io - ObjectStreamClass
- Java.io - ObjectStreamField
- Java.io - OutputStream
- Java.io - OutputStreamWriter
- Java.io - PipedInputStream
- Java.io - PipedOutputStream
- Java.io - PipedReader
- Java.io - PipedWriter
- Java.io - PrintStream
- Java.io - PrintWriter
- Java.io - PushbackInputStream
- Java.io - PushbackReader
- Java.io - RandomAccessFile
- Java.io - Reader
- Java.io - SequenceInputStream
- Java.io - SerializablePermission
- Java.io - StreamTokenizer
- Java.io - StringBufferInputStream
- Java.io - StringReader
- Java.io - StringWriter
- Java.io - Writer
- Java.io package extras
- Java.io - Interfaces
- Java.io - Exceptions
- Java.io package Useful Resources
- Java.io - Discussion
Java.io.ObjectInputStream getField.defaulted() Method
Description
The java.io.ObjectInputStream.getField.defaulted(String name) method skips bytes.
Declaration
Following is the declaration for java.io.ObjectInputStream.getField.defaulted() method.
public abstract boolean defaulted(String name)
Parameters
name − The name of the field.
Return Value
This method returns true, if and only if the named field is defaulted.
Exception
IOException − If there are I/O errors while reading from the underlying InputStream.
IllegalArgumentException − If name does not correspond to a serializable field.
Example
The following example shows the usage of java.io.ObjectInputStream.getField.defaulted() method.
package com.tutorialspoint; import java.io.*; public class ObjectInputStreamDemo implements Serializable { public static void main(String[] args) { try { // create a new file with an ObjectOutputStream FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // write something in the file oout.writeObject(new Example()); oout.flush(); oout.close(); // create an ObjectInputStream for the file we created before ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // read an object from the stream and cast it to Example Example a = (Example) ois.readObject(); // get if variable string is default in Example class System.out.println("" + a.isDefault); // print the string of a System.out.println("" + a.string); } catch (Exception ex) { ex.printStackTrace(); } } static public class Example implements Serializable { static String string = "Hello World!"; static boolean isDefault; // assign a new serialPersistentFields private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("string", String.class) }; // create a custom readObject method private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { // get the field and assign it at string variable ObjectInputStream.GetField fields = in.readFields(); // check if string is defaulted, meaning if it has no value isDefault = fields.defaulted("string"); string = (String) fields.get("string", null); } // create a custom writeObject method private void writeObject(ObjectOutputStream out) throws IOException { // write into the ObjectStreamField array the variable string ObjectOutputStream.PutField fields = out.putFields(); fields.put("string", string); out.writeFields(); } } }
Let us compile and run the above program, this will produce the following result −
false Hello World!
java_io_objectinputstream.getfield.htm
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