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TuringflyTuringfly
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IO
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‎Java-8/src/io/IteractingWithUsers.java

Lines changed: 77 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,77 @@
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package io;
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import java.io.BufferedReader;
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import java.io.Console;
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import java.io.IOException;
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import java.util.Arrays;
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/**
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*
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* @author chengfeili
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* Jun 14, 2017 3:18:58 PM
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*
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* The Console class is a singleton.
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*
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* This is a bug #122429 of eclipse
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*
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*/
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public class IteractingWithUsers {
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public void readLineTest() throws IOException {
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Console console = System.console();
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if (console == null) {
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throw new RuntimeException("Console not available");
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} else {
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console.writer().print("How excited are you about your trip today? ");
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console.flush();
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String excitementAnswer = console.readLine();
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String name = console.readLine("Please enter your name: ");
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Integer age = null;
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console.writer().print("What is your age? ");
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console.flush();
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BufferedReader reader = new BufferedReader(console.reader());
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String value = reader.readLine();
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age = Integer.valueOf(value);
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console.writer().println();
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console.format("Your name is " + name);
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console.writer().println();
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console.format("Your age is " + age);
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console.printf("Your excitement level is: " + excitementAnswer);
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}
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}
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/**
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* By disabling echoing, the user does not see the text they are typing.
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*
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* The readPassword() method returns an array of characters instead of a
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* String. String values are added to a shared memory pool for performance
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* reasons in Java. This means that if a password that a user typed in were
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* to be returned to the process as a String , it might be available in the
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* String pool long after the user entered it.
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*/
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public void readPasswordTest() {
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Console console = System.console();
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if (console == null) {
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throw new RuntimeException("Console not available");
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} else {
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char[] password = console.readPassword("Enter your password: ");
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console.format("Enter your password again: ");
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console.flush();
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char[] verify = console.readPassword();
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boolean match = Arrays.equals(password, verify);
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// Immediately clear passwords from memory
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// Arrays.fill(password, 'x');
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for (int i = 0; i < password.length; i++) {
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password[i] = 'x';
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}
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for (int i = 0; i < verify.length; i++) {
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verify[i] = 'x';
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}
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console.format("Your password was " + (match ? "correct" : "incorrect"));
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}
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}
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public static void main(String[] args) {
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}
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}

‎Java-8/src/io/StreamsContinue.java

Lines changed: 123 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,21 @@
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package io;
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3-
import java.io.*;
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import java.io.BufferedInputStream;
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import java.io.BufferedOutputStream;
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import java.io.BufferedReader;
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import java.io.BufferedWriter;
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import java.io.EOFException;
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import java.io.File;
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import java.io.FileInputStream;
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import java.io.FileOutputStream;
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import java.io.FileReader;
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import java.io.FileWriter;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.ObjectInputStream;
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import java.io.ObjectOutputStream;
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import java.io.OutputStream;
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import java.io.Serializable;
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import java.util.ArrayList;
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import java.util.List;
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@@ -16,8 +31,7 @@ public class StreamsContinue {
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public void fileInputOutputStream() throws IOException {
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File source = new File("Zoo.class");
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File destination = new File("ZooCopy.class");
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try (InputStream in = new FileInputStream(source);
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OutputStream out = new FileOutputStream(destination)) {
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try (InputStream in = new FileInputStream(source); OutputStream out = new FileOutputStream(destination)) {
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int b;
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while ((b = in.read()) != -1) {
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out.write(b);
@@ -59,7 +73,7 @@ public void fileReaderWiter() throws IOException {
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}
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// BufferedReader
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public static List<String> readFile(File source) throws IOException {
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public List<String> readFile(File source) throws IOException {
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List<String> data = new ArrayList<String>();
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try (BufferedReader reader = new BufferedReader(new FileReader(source))) {
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String s;
@@ -71,15 +85,119 @@ public static List<String> readFile(File source) throws IOException {
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}
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// BufferedWriter
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public static void writeFile(List<String> data, File destination) throws IOException {
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public void writeFile(List<String> data, File destination) throws IOException {
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try (BufferedWriter writer = new BufferedWriter(new FileWriter(destination))) {
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for (String s : data) {
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writer.write(s);
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}
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}
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}
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// Deserialize
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public List<Animal> getAnimals(File dataFile) throws IOException, ClassNotFoundException {
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List<Animal> animals = new ArrayList<Animal>();
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try (ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(new FileInputStream(dataFile)))) {
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while (true) {
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Object object = in.readObject();
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if (object instanceof Animal)
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animals.add((Animal) object);
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}
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} catch (EOFException e) {
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// File end reached
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}
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return animals;
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}
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// Serialize
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public static void createAnimalsFile(List<Animal> animals, File dataFile) throws IOException {
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try (ObjectOutputStream out = new ObjectOutputStream(
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new BufferedOutputStream(new FileOutputStream(dataFile)))) {
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for (Animal animal : animals)
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out.writeObject(animal);
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}
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}
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public static void main(String[] args) throws IOException {
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}
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}
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/**
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* Any class can implement the Serializable interface since there are no
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* required methods to implement.
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*
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* Note that the requirement for properly marking an object as Serializable may
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* involve nested objects.
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*
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* Therefore, any object references contained within the Tail class must belong
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* to classes that are also marked as Serializable , and so on.
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*
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* Besides transient instance variables, static class members will also be
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* ignored during the serialization and deserialization process.
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*
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* Why Not Mark Every Class as Serializable ?
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*
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* The reason that we do not is that there are some classes that we want to
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* instruct the JVM not to serialize. In particular, process-heavy classes such
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* as the Thread class or any of the Stream classes would be diffi cult, often
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* impossible, to save to persistent storage, since much of their work involves
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* managing JVM processes or resources in real time.
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*
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*/
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class Animal implements Serializable {
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private static final long serialVersionUID = 1L;
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private String name;
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private int age;
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private char type;
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public Animal(String name, int age, char type) {
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this.name = name;
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this.age = age;
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this.type = type;
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}
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public String getName() {
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return name;
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}
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public int getAge() {
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return age;
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}
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public char getType() {
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return type;
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}
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public String toString() {
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return "Animal [name=" + name + ", age=" + age + ", type=" + type + "]";
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}
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}
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class Animal1 implements Serializable {
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private static final long serialVersionUID = 2L;
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private transient String name;
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private transient int age = 10;
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private static char type = 'C';
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{
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this.age = 14;
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}
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public Animal1() {
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this.name = "Unknown";
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this.age = 12;
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this.type = 'Q';
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}
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public Animal1(String name, int age, char type) {
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this.name = name;
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this.age = age;
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this.type = type;
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}
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// Same methods as before
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// [Animal [name=null, age=0, type=P], Animal [name=null, age=0, type=P]]
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/*
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* As expected, you can see that the values for name and age are lost on
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* serialization and not set again during deserialization.
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*/
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}

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