Serializer.java

package serializable;

import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;

import java.io.Externalizable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import lombok.Data;

import org.junit.Before;
import org.junit.Test;

public class Serializer {

	private String filePath;
	private String externalFilePath;
	private User user;
	private AdminUser adminUser;

	@Before
	public void init() {
		filePath = "E:\\test\\serializable\\user.ser";
		externalFilePath = "E:\\test\\serializable\\adminUser.ser";

		user = new User();
		user.setName("kyu");
		user.setAge(32);
		user.setSocialNumber("222222-1111111");

		adminUser = new AdminUser();
		adminUser.setName("adminKyu");
		adminUser.setAge(33);
		user.setSocialNumber("121212121-121212121");
	}

	@Test
	public void 객체직렬화테스트() throws IOException {
		FileOutputStream fos = new FileOutputStream(filePath);
		ObjectOutputStream oos = new ObjectOutputStream(fos);
		oos.writeObject(user);
		oos.close();

		assertThat(true, is(new File(filePath).isFile()));
	}

	@Test
	public void 객체역질렬화테스트() throws IOException, ClassNotFoundException {
		FileInputStream fis = new FileInputStream(filePath);
		ObjectInputStream ois = new ObjectInputStream(fis);
		User user = (User) ois.readObject();
		ois.close();

		assertThat("kyu", is(user.getName()));
		assertThat(32, is(user.getAge()));
		assertThat(null, is(user.getSocialNumber()));
	}

	@Test
	public void externalWrite() throws IOException {
		FileOutputStream fos = new FileOutputStream(externalFilePath);
		ObjectOutputStream oos = new ObjectOutputStream(fos);
		oos.writeObject(adminUser);
		oos.close();

		assertThat(true, is(new File(externalFilePath).isFile()));
	}

	@Test
	public void externalRead() throws IOException, ClassNotFoundException {
		FileInputStream fis = new FileInputStream(externalFilePath);
		ObjectInputStream ois = new ObjectInputStream(fis);
		AdminUser adminUser = (AdminUser) ois.readObject();

		assertThat("adminKyu", is(adminUser.getName()));
		assertThat(33, is(adminUser.getAge()));
		assertThat(null, is(adminUser.getSocialNumber()));
	}
}

@Data
class User implements Serializable {
	private static final long serialVersionUID = 1L;
	private String name;
	private int age;
	private transient String socialNumber;
}

@Data
class AdminUser implements Externalizable {
	private static final long serialVersionUID = 1L;
	private String name;
	private int age;
	private String socialNumber;

	@Override
	public void writeExternal(ObjectOutput out) throws IOException {
		out.writeObject(name);
		out.writeInt(age);
	}

	@Override
	public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
		this.name = (String) in.readObject();
		this.age = in.readInt();
	}
}