Java中的属性 clone() 方法及示例

Java.util.Properties.clone()方法用于创建此实例的浅表副本，其中包含此 Properties 实例中的所有元素。

句法：

public Object clone()

参数：该方法不带任何参数

返回值：该函数返回克隆的 Object，它是此 Properties 实例的浅拷贝。

下面的程序说明了Java.util.Properties.clone() 方法。

示例 1：

// Java code illustrating clone() method
  
import java.util.*;
  
class PropertiesDemo {
    public static void main(String arg[])
    {
        Properties gfg = new Properties();
        Set URL;
        String str;
  
        gfg.put("ide",
                "ide.geeksforgeeks.org");
        gfg.put("contribute",
                "write.geeksforgeeks.org");
        gfg.put("quiz",
                "quiz.geeksforgeeks.org");
  
        // checking what's in table
        System.out.println("Current Properties: "
                           + gfg.toString());
  
        System.out.println("\nCloning the Properties");
        Properties cloned = (Properties)gfg.clone();
  
        // checking what's in table now
        System.out.println("Cloned Properties: "
                           + cloned.toString());
    }
}

输出：

Current Properties: {contribute=write.geeksforgeeks.org, quiz=quiz.geeksforgeeks.org, ide=ide.geeksforgeeks.org}

Cloning the Properties
Cloned Properties: {contribute=write.geeksforgeeks.org, quiz=quiz.geeksforgeeks.org, ide=ide.geeksforgeeks.org}

示例 2：

// Java code illustrating clone() method
  
import java.util.*;
  
class PropertiesDemo {
    public static void main(String arg[])
    {
        Properties gfg = new Properties();
        Set URL;
        String str;
  
        gfg.put(1, "Geeks");
        gfg.put(2, "GeeksforGeeks");
        gfg.put(3, "Geek");
  
        // checking what's in table
        System.out.println("Current Properties: "
                           + gfg.toString());
  
        System.out.println("\nCloning the Properties");
        Properties cloned = (Properties)gfg.clone();
  
        // checking what's in table now
        System.out.println("Cloned Properties: "
                           + cloned.toString());
    }
}

输出：

Current Properties: {3=Geek, 2=GeeksforGeeks, 1=Geeks}

Cloning the Properties
Cloned Properties: {3=Geek, 2=GeeksforGeeks, 1=Geeks}

参考： https://docs.oracle.com/javase/9/docs/api/ Java/util/Properties.html#clone–