Home Java Javagetting Started Java implements copying list

Java implements copying list

Sep 11, 2020 pm 03:51 PM
java list

Java implements copying list

Background:

At first I wanted to copy a collection when entering a new page and save it for subsequent operations, so I just wrote List A=List B, later I found that when operating B, the data in A will also change accordingly.

(Video tutorial recommendation: java course)

It was found through query that directly using "=" is equivalent to an array with the same content in java pointing to the same address, that is After shallow copying, A and B point to the same address. The consequence is that changing B will also change A, because changing B means changing the content of the address pointed to by B. Since A also points to the same address, A and B are changed together. To copy an independent array, you can use the following method:

public class GoodsBean extends HttpResult implements Cloneable{
@Override
protected Object clone() throws CloneNotSupportedException {
    GoodsBean o = null;
    try {
        o = (GoodsBean) super.clone();
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }
    return o;
}
public  ArrayList<GoodsBean> deep_clone(ArrayList<GoodsBean> cells, ArrayList<GoodsBean> clone_cells){
    for(GoodsBean c : cells){
        try {
            clone_cells.add((GoodsBean) c.clone());
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
    }
    return clone_cells;
}
}
Copy after login

Related recommendations: java introductory tutorial

The above is the detailed content of Java implements copying list. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
WWE 2K25: How To Unlock Everything In MyRise
1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Perfect Number in Java Perfect Number in Java Aug 30, 2024 pm 04:28 PM

Guide to Perfect Number in Java. Here we discuss the Definition, How to check Perfect number in Java?, examples with code implementation.

Random Number Generator in Java Random Number Generator in Java Aug 30, 2024 pm 04:27 PM

Guide to Random Number Generator in Java. Here we discuss Functions in Java with examples and two different Generators with ther examples.

Weka in Java Weka in Java Aug 30, 2024 pm 04:28 PM

Guide to Weka in Java. Here we discuss the Introduction, how to use weka java, the type of platform, and advantages with examples.

Smith Number in Java Smith Number in Java Aug 30, 2024 pm 04:28 PM

Guide to Smith Number in Java. Here we discuss the Definition, How to check smith number in Java? example with code implementation.

Java Spring Interview Questions Java Spring Interview Questions Aug 30, 2024 pm 04:29 PM

In this article, we have kept the most asked Java Spring Interview Questions with their detailed answers. So that you can crack the interview.

Break or return from Java 8 stream forEach? Break or return from Java 8 stream forEach? Feb 07, 2025 pm 12:09 PM

Java 8 introduces the Stream API, providing a powerful and expressive way to process data collections. However, a common question when using Stream is: How to break or return from a forEach operation? Traditional loops allow for early interruption or return, but Stream's forEach method does not directly support this method. This article will explain the reasons and explore alternative methods for implementing premature termination in Stream processing systems. Further reading: Java Stream API improvements Understand Stream forEach The forEach method is a terminal operation that performs one operation on each element in the Stream. Its design intention is

TimeStamp to Date in Java TimeStamp to Date in Java Aug 30, 2024 pm 04:28 PM

Guide to TimeStamp to Date in Java. Here we also discuss the introduction and how to convert timestamp to date in java along with examples.

Java Program to Find the Volume of Capsule Java Program to Find the Volume of Capsule Feb 07, 2025 am 11:37 AM

Capsules are three-dimensional geometric figures, composed of a cylinder and a hemisphere at both ends. The volume of the capsule can be calculated by adding the volume of the cylinder and the volume of the hemisphere at both ends. This tutorial will discuss how to calculate the volume of a given capsule in Java using different methods. Capsule volume formula The formula for capsule volume is as follows: Capsule volume = Cylindrical volume Volume Two hemisphere volume in, r: The radius of the hemisphere. h: The height of the cylinder (excluding the hemisphere). Example 1 enter Radius = 5 units Height = 10 units Output Volume = 1570.8 cubic units explain Calculate volume using formula: Volume = π × r2 × h (4

See all articles