Spring: detects the types of devices that access the website.

Spring: detects the types of devices that access the website.

[This tutorial is translated from the Spring official website and deleted as appropriate.]

You will set up

Create a Spring MVC project to detect the device types (mobile phones, computers, tablets) that access the website, and dynamically switch the displayed view.

Tools

A text editor, JDK 3.0 and later, Maven 1.11 + or Gradle +. (Maven will be used in this article)

Pom. xml list:

 
     
  
   4.0.0
      
  
   org.springframework
      gs-device-detection    
  
   0.1.0
      
          
   
    org.springframework.boot
           spring-boot-starter-parent        
   
    1.1.5.RELEASE
       
      
          
               
    
     org.springframework.boot
                spring-boot-starter-web        
           
               
    
     org.springframework.mobile
                spring-mobile-device        
       
      
          
   
    hello.Application
       
      
          
               
    
                      maven-compiler-plugin             
                
                    
     
      org.springframework.boot
                     spring-boot-maven-plugin            
            
       
      
          
               
    
     spring-releases
                
    
     Spring Milestone Repository
                
    
     http://repo.spring.io/libs-release
            
       
          
          
               
    
     spring-releases
                
    
     Spring Milestone Repository
                
    
     http://repo.spring.io/libs-release
            
       
  
 

Create a project
First, create a directory structure that complies with Maven specifications, src/main/java/hello

[Plain]View plaincopy

1. ── Src
2. ── Main
3. ── Java
4. ── Hello Automatic Configuration:

   Observe pom. xml and find the new Spring Mobile dependency. In this way, Spring Boot automatically configures DeviceResolverHandlerInterceptor and DeviceHandlerMethodArgumentResolver. The former (DeviceResolverHandlerInterceptor) checks the User-Agent header in the request. The header information can be used to determine whether the request is from a mobile phone, a computer, or a tablet. The latter (DeviceHandlerMethodArgumentResolver) allows Spring MVC to use parsed Device objects in a controller method.

   
   

   The following is a list of controllers:

   package hello;import org.springframework.mobile.device.Device;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;@Controllerpublic class DeviceDetectionController {    @RequestMapping("/detect-device")    public @ResponseBody String detectDevice(Device device) {        String deviceType = "unknown";        if (device.isNormal()) {            deviceType = "normal";        } else if (device.isMobile()) {            deviceType = "mobile";        } else if (device.isTablet()) {            deviceType = "tablet";        }        return "Hello " + deviceType + " browser!";    }}

   
   In this example, not relying on a view technology (such as JSP) in HTML to parse data, but writing strings directly to HTTP Response. The @ ResponseBody annotation tells Spring MVC to write a returned object to the response body, instead of rendering a model to a view.

   
   

   The Application class is as follows:

   package hello;import org.springframework.boot.autoconfigure.EnableAutoConfiguration;import org.springframework.boot.SpringApplication;import org.springframework.context.annotation.ComponentScan;@ComponentScan@EnableAutoConfigurationpublic class Application {    public static void main(String[] args) {        SpringApplication.run(Application.class, args);    }}

   
   Here, the application is also run in the built-in Tomcat of Spring. @ ComponentScan tells Spring to Recursively search for classes with @ Component annotations under the hello package. This ensures that DeviceDetectionController is found and registered, because @ Controller is also a type of @ Component.

   @ EnableAutoConfiguration refers to the content of the current class loading path, which is switched to a reasonable default configuration. This application requires default built-in tomcat configuration (tomcat-embed-core.jar) and Spring MVC default configuration (spring-webmvc.jar ).

   
   

   The method for packaging and execution is similar to that in the previous article,[Plain]View plaincopy
   1. Mvn clean package then,

      java -jar target/gs-device-detection-0.1.0.jar

      
      In case of any exceptions, the console displays:

      
      

      
      

      Computer Browser access:

      
      

      The IP address of the author is 192.168.1.106, which is accessed by mobile phone,