物件流

• ObjectOutputStream
• ObjectInputStream

ObjectOutputStream

將物件持久化（永久儲存在磁碟上）
注意：要儲存的物件的類要實現序列化介面（serializable）
構造方法

protected ObjectOutputStream()throws IOException,SecurityException

public ObjectOutputStream(OutputStream out)throws IOException

Code:
持久化ArrayList

List<String> arrayList = new ArrayList<>();
arrayList.add("對");
arrayList.add("象");
arrayList.add("流");
arrayList.add("測");
arrayList.add("試");
		
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("C:/w.txt"));
//將arrayList持久化
oos.writeObject(arrayList);

持久化自定義類的物件：

/**
 * @author maple
 *持久化Student， 要實現Serializable介面
 */
public class Student implements Serializable{
/**
	 * serialVersionUID:  這個值，是在兩端【不同的電腦  物件傳遞之後，比較型別的一個依據】
	 * 1.本電腦建立了一個學生物件
	 * 2.當我們把這個物件傳遞到其他電腦的時候，這個物件，要與其他電腦裡面的Student類比較型別	是否一致
	 * 3.除了判斷型別，還會判斷serialVersionUID
	 */
	private static final long
 
 serialVersionUID = 1L;
	private String name;
	private int age;
	public Student(String name, int age) {
		this.name = name;
		this.age = age;
	}
	@Override
	public String toString() {
		return "Student [name=" + name + ", age=" + age + "]";
	}
}

//自己新建一個測試類，將主方法拷貝過去
public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
		Student stu1 = new Student("小米",4);
		Student stu2 = new Student("蘋果",6);
		
		//進行持久化
		/*ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("C:/x.txt"));
		oos.writeObject(stu1);
		oos.writeObject(stu2);
		//這裡在最後放入null是為了標誌已經到末尾了
		oos.writeObject(null);*/
		
		
		
	}

ObjectInputStream

將持久化的物件拿出來
構造方法

protected ObjectInputStream()throws IOException,SecurityException

public ObjectInputStream(InputStream in)throws IOException

//讀取上面持久化的arrayList
ObjectInputStream ois = new ObjectInputStream(new FileInputStream("C:/w.txt"));
Object readObject = ois.readObject();
System.out.println(readObject);

讀取上面自定義Student類的物件

//將持久化的資料拿出來
ObjectInputStream ois = new ObjectInputStream(new FileInputStream("C:/x.txt"));
/*Object object1 = ois.readObject();
Object object2 = ois.readObject();

System.out.println(object1);
System.out.println(object2);*/
Object obj = null;
while ((obj = ois.readObject()) != null) {
	System.out.println(obj);
}