Programmer Group

                  The back end is as written in the previous two articles.         The front end picked up a front-end page from the Internet and used the JavaScript library jQuery to simplify the operation of DOM and BOM. I want to use ajax technology to initiate HTTP requests and ...

Spring MVC has three ways to handle exceptions: Use the simple exception handler SimpleMappingExceptionResolver provided by Spring MVC.Implement the exception handling interface HandlerExceptionResolver of Spring and customize your own exception handler.Use the @ ExceptionHandler annotation to implement exception handling 1. @ExceptionHandler  ...

Basic type packing class There are eight basic data types in Java, but these data are basic data. It becomes difficult to perform complex operations on them. What shall I do? In the actual program use, the data entered by the user on the program interface is stored in string type. In the process of program development, we need to convert t ...

reference type Definition: the data type represented by the actual value reference of the type (similar to the pointer in C). If you assign a reference type to a variable, the variable references (or "points") the original value. Do not create any copies. Reference types include class, interface, delegate, and boxed value types. ...

preface This article introduces the three characteristics of object-oriented. Tip: the following is the main content of this article. The following cases can be used for reference 1, Encapsulation 1. Concept It is one of the three characteristics of object-oriented (encapsulation, inheritance and polymorphism). It is the simulation ...

1, JDBC introduction JDBC(Java Database Connectivity) is a common interface (a set of API s) independent of a specific database management system and general SQL database access and operation. It defines the standard Java class libraries used to access the database (java.sql,javax.sql). These class libraries can be used to access database ...

Source: blog.csdn.net/wangwenpeng0529/article/details/105769978 brief introduction Java. Util. Concurrent (JUC) package is provided in Java 5.0. In this package, tool classes commonly used in concurrent programming are added to define custom subsystems similar to threads, including thread pool, asynchronous IO and lightweight task framework; ...

Analysis of EventBus principle 1, Overview As we all know, EventBus is used for data communication within app, which can achieve good decoupling effect. The traditional broadcast or callback mode has the characteristics of high code coupling, messy code and not suitable for maintenance. EventBus uses the subscriber / publisher mode, with conc ...

ThreadLocal principle 1, Introduction to ThreadLocal ThreadLocal can realize that each thread has its own copy of local variables, and different threads will not interfere with each other. It mainly solves the problem of allowing each thread to bind its own value. By using the get() and set() methods, it can obtain the default value or change ...

Title: 5 Basic Java Which of the following is the language function stored in java In the bag? () java.lang java.io java.net java.util Resolution: java.lang Package contains Packaging String class Math class —— Include function Class class Object class java.util Provide tool classes including collection fr ...