一.如果集合或陣列，裡面裝的是：
8種基本型別或者它們的包裝類和String，我們使用普通的淺複製就行了
使用 Arrays.copyOf() 或者 new ArrayList(list) 等方法這裡不做程式碼演示很簡單。

二 如果裡面裝的是物件，上邊的淺複製方法就習行不通了。
通常用兩種方法實現深複製：clone() 和 io流複製
第一種：
1.物件實現Cloneable 介面複寫 clone() 方法
程式碼演示如下：
Student類實現了Cloneable介面並複寫clone()方法

public class Student implements Cloneable {

	private String name;

	public Student() {
	}

	public Student(String name) {
		this.name = name;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	protected Student clone() {
		Student student = null;
		try {
			student = (Student)super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return student;
	}
}

 

測試程式碼：

public static void main(final String[] args) {

	//被複制陣列
	ArrayList<Student> studentList = new ArrayList<Student>() {
		{
			add(new Student("AAA"));
			add(new Student("BBB"));
		}
	};

	//目標陣列
	ArrayList<Student> targetStudentList = new ArrayList<Student>();
	//呼叫clone方法賦值
	for (Student stu : studentList) {
		targetStudentList.add(stu.clone());
	}

	//現在改變targerStudentList中物件的狀態
	targetStudentList.get(0).setName("NNN");
	targetStudentList.get(1).setName("MMM");

	//檢視2集合中值的變化
	for (Student stu : studentList) {
		System.out.print(stu.getName()+",");
	}
	System.out.println();
	for (Student stu : targetStudentList) {
		System.out.print(stu.getName()+",");
	}
}
 

輸出結果：

AAA,BBB,
NNN,MMM,

第二種也是比較常見的方法 使用IO流深度複製：

@SuppressWarnings("all")
public static <T> List<T> deepCopy(List<T> src) {
	ObjectOutputStream oos;
	ByteArrayOutputStream bos;
	ByteArrayInputStream bis;
	List<T> resultData = null;
	try {
		bos = new ByteArrayOutputStream();
		oos = new ObjectOutputStream(bos);
		oos.writeObject(src);

		ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(bos.toByteArray()));
		resultData = (List<T>)ois.readObject();
	} catch (IOException e) {
		e.printStackTrace();
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}

	return resultData;
}
 

呼叫方法：

public static void main(final String[] args) throws IOException, ClassNotFoundException {

	//被複制陣列
	ArrayList<Student> studentList = new ArrayList<Student>() {
		{
			add(new Student("AAA"));
			add(new Student("BBB"));
		}
	};

	List<Student> targetStudentList = deepCopy(studentList);
	targetStudentList.get(0).setName("NNN");
	targetStudentList.get(1).setName("MMM");
	//檢視2集合中值的變化
	for (Student stu : studentList) {
		System.out.print(stu.getName()+",");
	}
	System.out.println();
	for (Student stu : targetStudentList) {
		System.out.print(stu.getName()+",");
	}
}

列印結果:

AAA,BBB,
NNN,MMM,