Java

Today made a simple mistake:list books = adapter.data;for (book book:books) {if (book.id = = bookId) {Books.remove    ); }} results encountered java.util.ConcurrentModificationException, initially thought to be an Android operation not the same

Contains Duplicate IIIGiven an array of integers, find out whether there is II distinct indices i and J in the array such th At the difference between nums[i] and Nums[j] are at most T and the difference between I and J I S at the most K.

Reprint Please specify source: Z_zhaojun's BlogOriginal address: http://blog.csdn.net/u012975705/article/details/50411033Title Address: https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/Remove duplicates from Sorted List IIGiven a

Sequential access to objects in the aggregation, primarily for collections. One is the object that needs to be traversed, that is, the aggregation object, and the second is the iterator object, which is used to iterate over the clustered object.

Reprint Please specify source: Z_zhaojun's BlogOriginal address: http://blog.csdn.net/u012975705/article/details/50412899Title Address: https://leetcode.com/problems/linked-list-cycle-ii/Linked List Cycle

What is a built-in object?is a set of objects created by the Web container and does not need to be built-in objects that can be used directly with the New keyword.The nine main built-in objects for JSPs:Commonly used are: Out object, Request object,

NullPointerException: is a run-time exception (RuntimeException), also known as a non-check exceptionSo when we throw this class of exception instances, there is no need to add throws at the method declaration to enumerate the throws of the class

In the previous blog ("Java Concurrency Programming Combat"-–aqs (ii): Acquire locks, release locks), it is mentioned that when a thread joins into the CLH queue, if it is not the head node it is necessary to determine if the node needs to be

In the previous section we talked about the common methods of collection, as well as the previous chapters where we introduced the AddAll method of collection, which we introduced to its point of attention.Note that, in the common method, the basic

In this chapter we will introduce the common methods of collection.We take ArrayList as an example below.Package Com.ray.ch14;import Java.util.arraylist;import Java.util.iterator;public class Test {public static void main ( String[] args) {arraylist

Linked list: is a common basic data structure, is a linear table, but does not store data in a linear order, but in each node in the village to the next node pointer.In a linked list data structure, a recursive algorithm is required. Recursive

The collection framework often uses generics to specify the type of elements that are stored in the collection, to guarantee the unity of the collection, to remove elements from the collection, and to avoid type casts, so we use the usual way to

Mybatis environment and mybatis environment Configuration Step 1: Download the jar package and import it 1. mysql driver package 2. mybatis environment package Step 2: Create a MYSQL database Because this is used for testing, only the test-usreinfo

Install the EGit plug-in (see the Eclipse version table ).Recently added the egit plug-in to eclipse. The git option is not displayed after you download and install the plug-in online. The official website shows the corresponding eclipse version of

Design Mode (20) --- status Mode Definition: Allows an object to change its behavior when its internal state changes. This object looks like it has changed its class.Normal Mode State: Abstract state role --- "Interface or abstract class, which

[Java concurrent programming practice] ----- "J. U. C": AQS Analysis (2): Getting and Releasing locks The previous blog briefly introduced AQS. Next we will take a look at the AQS acquisition and lock release.Obtain the AQS lock AQS includes the

There is no getter for property named & #39; * & #39; in & #39; class java. lang. String & #39; source code analysis There is no getter for property named '*' in 'class java.lang.String'This error occurs because mybatis isparameterType="String"SQL

Getting started with java-15.1 filling containers (1) This section describes filling containers. Like Arrays, Arrays. fill is a filling method, which is also available in containers. 1. Collections. nCopies This method is to generate a certain type

Build a Java development environment, Determine your operating system version and download and install JDK 1. Download JDK Windows: Right-click my computer and choose Properties. For example: 2. Download JDK : Http://www.oracle.com/index.html (1)

Java Web series: Spring MVC basics,1. Web MVC Basics The essence of MVC is the presentation layer model. We take the view model as the center and separate the view and controller. Just like the layered mode, we take the business logic as the center