


Java backend development: API MVC framework development using Java Spring MVC
Jun 17, 2023 am 10:27 AMJava back-end development is a very important technology that is the core of modern Internet applications. Java backend development mainly involves API MVC framework development. In this article, I will introduce how to use Java Spring MVC for API MVC framework development.
Java Spring MVC is a very powerful open source framework, which is mainly used for the development of web applications. It uses the MVC (Model-View-Controller) architectural pattern to enable developers to develop Web applications more efficiently. Java Spring MVC is very easy to learn and use. It uses Java EE standard technologies, including Servlets, JSP, JSTL, Hibernate and other Java EE frameworks.
First, we need to install Java and Eclipse IDE. Java is generally pre-installed. If not, you need to go to the official website (https://www.oracle.com/java/technologies/javase-downloads.html) to download Java and follow the installation program prompts to install it. Eclipse IDE can be downloaded from the official website (https://www.eclipse.org/downloads/packages/release/2020-09/r/eclipse-ide-enterprise-java-developers).
Next, we need to create a new Java Spring MVC project. In the Eclipse IDE, select File > New > Other, then select Spring Legacy Project in the pop-up dialog box, and then select Spring MVC Project. Then we need to specify the name and location of the project. We can choose the default configuration or a custom configuration. Once completed, we can start using the Java Spring MVC framework.
In Java Spring MVC, the controller is the core of the MVC framework. It is mainly responsible for processing HTTP requests and displaying corresponding responses. We can define the controller class and its methods through annotations. For example:
@Controller @RequestMapping("/hello") public class HelloWorldController { @RequestMapping(method = RequestMethod.GET) public String helloWorld(ModelMap model) { model.addAttribute("message", "Hello World!"); return "hello"; } }
The above code defines a controller class called HelloWorldController, which handles HTTP GET requests on the /hello URL. The method helloWorld adds a property called "message" to the ModelMap and returns a view name called "hello".
View is the HTML page that website users ultimately see. In Java Spring MVC, JSP is usually used as the view. We can return the view name in the controller and Java Spring MVC will automatically find the JSP file corresponding to that name. For example:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Hello World!</title> </head> <body> <h1>${message}</h1> </body> </html>
The above code is a JSP file named "hello". It uses an EL expression to display the value of the attribute named "message" added in the controller.
Between the controller and the view, we use the model to pass data. The model uses the ModelMap class to save attribute values. Controllers can add properties to the model, and views can use EL expressions to get properties from the model. For example:
@Controller public class LoginController { @RequestMapping(value = "/login", method = RequestMethod.POST) public String login(@RequestParam("username") String username, @RequestParam("password") String password, ModelMap model) { if (username.equals("admin") && password.equals("password")) { model.addAttribute("username", username); return "home"; } else { return "login"; } } }
The above code defines a controller named LoginController that handles HTTP POST requests on the /login URL. The method login compares the username and password obtained from the request with the hardcoded values. If the validation passes, it will add a property called "username" to the ModelMap and then return a view name called "home". Otherwise, it returns a view name called "login".
Finally, we need to configure DispatcherServlet in the Web.xml file. In Java Spring MVC, DispatcherServlet forwards all HTTP requests to the corresponding controller. We can define its URL mapping in the Web.xml file. For example:
<servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
The above is a Web.xml file configuration example. It maps all URLs into a Servlet named "dispatcher". We can define the configuration file of the Spring MVC framework in DispatcherServlet. For example:
<context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/dispatcher-servlet.xml</param-value> </context-param>
The above is the location configuration of the Spring MVC configuration file. It indicates that the configuration file of the Spring MVC framework is located in the /WEB-INF/dispatcher-servlet.xml file. In this file we can define controllers, views and models and the relationships between them.
In short, Java Spring MVC is a very excellent API MVC framework. In this article, I introduced how to use the Java Spring MVC framework for API MVC framework development. In the actual development process, we can choose the appropriate framework according to project needs to improve the development efficiency and quality of Web applications.
The above is the detailed content of Java backend development: API MVC framework development using Java Spring MVC. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

There are three common methods to traverse Map in Java: 1. Use entrySet to obtain keys and values at the same time, which is suitable for most scenarios; 2. Use keySet or values to traverse keys or values respectively; 3. Use Java8's forEach to simplify the code structure. entrySet returns a Set set containing all key-value pairs, and each loop gets the Map.Entry object, suitable for frequent access to keys and values; if only keys or values are required, you can call keySet() or values() respectively, or you can get the value through map.get(key) when traversing the keys; Java 8 can use forEach((key,value)->

In Java, Comparable is used to define default sorting rules internally, and Comparator is used to define multiple sorting logic externally. 1.Comparable is an interface implemented by the class itself. It defines the natural order by rewriting the compareTo() method. It is suitable for classes with fixed and most commonly used sorting methods, such as String or Integer. 2. Comparator is an externally defined functional interface, implemented through the compare() method, suitable for situations where multiple sorting methods are required for the same class, the class source code cannot be modified, or the sorting logic is often changed. The difference between the two is that Comparable can only define a sorting logic and needs to modify the class itself, while Compar

To deal with character encoding problems in Java, the key is to clearly specify the encoding used at each step. 1. Always specify encoding when reading and writing text, use InputStreamReader and OutputStreamWriter and pass in an explicit character set to avoid relying on system default encoding. 2. Make sure both ends are consistent when processing strings on the network boundary, set the correct Content-Type header and explicitly specify the encoding with the library. 3. Use String.getBytes() and newString(byte[]) with caution, and always manually specify StandardCharsets.UTF_8 to avoid data corruption caused by platform differences. In short, by

JavaScript data types are divided into primitive types and reference types. Primitive types include string, number, boolean, null, undefined, and symbol. The values are immutable and copies are copied when assigning values, so they do not affect each other; reference types such as objects, arrays and functions store memory addresses, and variables pointing to the same object will affect each other. Typeof and instanceof can be used to determine types, but pay attention to the historical issues of typeofnull. Understanding these two types of differences can help write more stable and reliable code.

InJava,thestatickeywordmeansamemberbelongstotheclassitself,nottoinstances.Staticvariablesaresharedacrossallinstancesandaccessedwithoutobjectcreation,usefulforglobaltrackingorconstants.Staticmethodsoperateattheclasslevel,cannotaccessnon-staticmembers,

std::chrono is used in C to process time, including obtaining the current time, measuring execution time, operation time point and duration, and formatting analysis time. 1. Use std::chrono::system_clock::now() to obtain the current time, which can be converted into a readable string, but the system clock may not be monotonous; 2. Use std::chrono::steady_clock to measure the execution time to ensure monotony, and convert it into milliseconds, seconds and other units through duration_cast; 3. Time point (time_point) and duration (duration) can be interoperable, but attention should be paid to unit compatibility and clock epoch (epoch)

HashMap implements key-value pair storage through hash tables in Java, and its core lies in quickly positioning data locations. 1. First use the hashCode() method of the key to generate a hash value and convert it into an array index through bit operations; 2. Different objects may generate the same hash value, resulting in conflicts. At this time, the node is mounted in the form of a linked list. After JDK8, the linked list is too long (default length 8) and it will be converted to a red and black tree to improve efficiency; 3. When using a custom class as a key, the equals() and hashCode() methods must be rewritten; 4. HashMap dynamically expands capacity. When the number of elements exceeds the capacity and multiplies by the load factor (default 0.75), expand and rehash; 5. HashMap is not thread-safe, and Concu should be used in multithreaded

ReentrantLock provides more flexible thread control in Java than synchronized. 1. It supports non-blocking acquisition locks (tryLock()), lock acquisition with timeout (tryLock(longtimeout, TimeUnitunit)) and interruptible wait locks; 2. Allows fair locks to avoid thread hunger; 3. Supports multiple condition variables to achieve a more refined wait/notification mechanism; 4. Need to manually release the lock, unlock() must be called in finally blocks to avoid resource leakage; 5. It is suitable for scenarios that require advanced synchronization control, such as custom synchronization tools or complex concurrent structures, but synchro is still recommended for simple mutual exclusion requirements.
