一文盘点Java创建实例对象的方式

public static void test() {
    try {
        Class clazz = Class.forName("bean.User");
        //或 Class clazz = User.class;
        User user = (User) clazz.newInstance();
    } catch (InstantiationException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}

public static void test() {
    try {
        Constructor<User> con = User.class.getConstructor();
        User user = con.newInstance();
    } catch (NoSuchMethodException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    } catch (InstantiationException e) {
        e.printStackTrace();
    } catch (InvocationTargetException e) {
        e.printStackTrace();
    }
}

/**
 * 创建User类并实现Serializable接口
 */
public class User implements Serializable {
    private String name;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

/**
 * 通过ObjectOutputStream将对象序列化字节流持久化到本地硬盘
 */
public static void serialization() {
    try {
        User user = new User();
        ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(new File("/Users/xxx/Desktop/User.txt")));
        out.writeObject(user);
        out.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

/**
 * 通过ObjectInputStream从本地硬盘中获取对象字节流反序列化并创建实例对象
 */
public static void deserialization() {
    try {
        ObjectInputStream in = new ObjectInputStream(new FileInputStream(new File("/Users/xxx/Desktop/User.txt")));
        User user = (User) in.readObject();
        in.close();
        user.setName("serializable");
        System.out.println(user.getName());
    } catch (IOException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}

/**
 * 创建User类并实现Cloneable接口，并重写Object类的clone()方法
 */
public class User implements Cloneable {
    private String name;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

public static void main(String[] args) {
    try {
        User cloneUser = new User();
        User copyUser = (User) cloneUser.clone();
        copyUser.setName("lisi");
        System.out.println(copyUser.getName());
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }
}