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Le modèle MVC Spring-Boot n'est pas en cours de chargement (404 introuvable)

J'ai une application Spring-Boot MVC extrêmement simple qui ne fonctionne pas. Un contrôleur avec une page non chargée et recevant un 404 introuvable.

Je mets une instruction System.out.println ("Page d'accueil") dans la méthode du contrôleur et confirme qu'elle est mappée et qu'elle est déclenchée correctement, mais que le modèle ne se charge pas.

L'erreur:

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Nov 06 23:43:51 EST 2014
There was an unexpected error (type=Not Found, status=404).

La structure du dossier:

src/main/Java
 +-Application.Java
 +-WebController.Java

src/main/resources
 +-templates
   +-index.html

Sortie de la console abrégée:

Server initialized with port: 8080
Starting service Tomcat
Starting Servlet Engine: Apache Tomcat/7.0.55
Initializing Spring embedded WebApplicationContext
Root WebApplicationContext: initialization completed in 1947 ms
Mapping servlet: 'dispatcherServlet' to [/]
Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
Mapped "{[/],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public Java.lang.String app.WebController.index()
Tomcat started on port(s): 8080/http
Started Application in 5.552 seconds (JVM running for 6.366)
Home Page
Home Page
Home Page

Configuration:

@EnableAutoConfiguration
@Configuration
@ComponentScan
public class Application extends WebMvcConfigurerAdapter {
    public static void main(String[] args) {
         ConfigurableApplicationContext context = SpringApplication.run(Application.class);
    }
}

Manette:

@Controller
public class WebController {
    @RequestMapping(value="/")
    public String index(){
        System.out.println("Home Page");
        return "index";
    }
}

index.html:

<!DOCTYPE html>
<html lang="en">
<body>
 <h1>Hello</h1>    
</body>
</html>

J'ai une application Spring-Boot MVC extrêmement simple qui ne fonctionne pas. Un contrôleur avec une page non chargée et recevant un 404 introuvable.

Je mets une instruction System.out.println ("Page d'accueil") dans la méthode du contrôleur et confirme qu'elle est mappée et qu'elle est déclenchée correctement, mais que le modèle ne se charge pas.

L'erreur:

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Nov 06 23:43:51 EST 2014
There was an unexpected error (type=Not Found, status=404).

La structure du dossier:

src/main/Java
 +-Application.Java
 +-WebController.Java

src/main/resources
 +-templates
   +-index.html

Sortie de la console abrégée:

Server initialized with port: 8080
Starting service Tomcat
Starting Servlet Engine: Apache Tomcat/7.0.55
Initializing Spring embedded WebApplicationContext
Root WebApplicationContext: initialization completed in 1947 ms
Mapping servlet: 'dispatcherServlet' to [/]
Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
Mapped "{[/],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public Java.lang.String app.WebController.index()
Tomcat started on port(s): 8080/http
Started Application in 5.552 seconds (JVM running for 6.366)
Home Page
Home Page
Home Page

Configuration:

@EnableAutoConfiguration
@Configuration
@ComponentScan
public class Application extends WebMvcConfigurerAdapter {
    public static void main(String[] args) {
         ConfigurableApplicationContext context = SpringApplication.run(Application.class);
    }
}

Manette:

@Controller
public class WebController {
    @RequestMapping(value="/")
    public String index(){
        System.out.println("Home Page");
        return "index";
    }
}

index.html:

<!DOCTYPE html>
<html lang="en">
<body>
 <h1>Hello</h1>    
</body>
</html>

POM:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.Apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.Apache.org/POM/4.0.0 http://maven.Apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.App</groupId>
    <artifactId>App</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>App</name>
    <description>App</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.1.8.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>   
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>1.4.181</version>
        </dependency>
        <!--dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-redis</artifactId>
        </dependency--> 
        <dependency>
            <groupId>com.firebase</groupId>
            <artifactId>firebase-client</artifactId>
            <version>1.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>2.10.4</version>
        </dependency>
    </dependencies>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>App.Application</start-class>
        <Java.version>1.7</Java.version>
    </properties>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>http://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>http://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>   

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>
javaspringspring-mvcspring-boot
30
szxnyc

Il semble que Thymeleaf ne soit pas sur votre chemin de classe.

Ajoutez cette dépendance:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

et tout devrait fonctionner alors.

Si vous rencontrez toujours des problèmes, je vous recommande de créer un nouveau projet avec http://start.spring.io/

51
Maciej Walkowiak

suivez ce lien. Un bel exemple donné http://spring.io/guides/gs/handling-form-submission/

src/principal/Java/hello/GreetingController.Java

package hello;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
@Controller
public class GreetingController {
    @GetMapping("/greeting")
    public String greetingForm(Model model) {
        model.addAttribute("greeting", new Greeting());
        return "greeting";
    }
    @PostMapping("/greeting")
    public String greetingSubmit(@ModelAttribute Greeting greeting) {
        return "result";
    }
}

src/main/resources/templates/greeting.html

<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Getting Started: Handling Form Submission</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1>Form</h1>
    <form action="#" th:action="@{/greeting}" th:object="${greeting}" method="post">
        <p>Id: <input type="text" th:field="*{id}" /></p>
        <p>Message: <input type="text" th:field="*{content}" /></p>
        <p><input type="submit" value="Submit" /> <input type="reset" value="Reset" /></p>
    </form>
</body>
</html>

src/main/resources/templates/result.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Getting Started: Handling Form Submission</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1>Result</h1>
    <p th:text="'id: ' + ${greeting.id}" />
    <p th:text="'content: ' + ${greeting.content}" />
    <a href="/greeting">Submit another message</a>
</body>
</html>

src/main/Java/hello/Application.Java

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}
2
Saurabh

Essayez de créer un projet de démarrage de printemps à partir de ce site Web http://start.spring.io/ , qui est un initialiseur de printemps utilisé pour créer un projet Maven avec un démarrage de printemps. Ajoutez des dépendances web et thymeleaf et générez un projet. Importez le projet dans votre IDE en tant que projet ou utilisez la suite d'outils Spring).

DemoApplication.Java:

@Controller
@SpringBootApplication
public class DemoApplication {
  public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
  }
  @RequestMapping(value = "/homepage" , method = RequestMethod.GET  )
  public String sample()
  {
    return "home";
  }
}

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.Apache.org/POM/4.0.0"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.Apache.org/POM/4.0.0 http://maven.Apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.2.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <Java.version>1.7</Java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

home.html:

<!DOCTYPE html>

<html>
<head>
    <meta charset="UTF-8"></meta>
    <title>HomePage</title>
</head>
<body>
    <h1>MY Spring Boot Home Page</h1>
</body>
</html>
1
Ezhil vikraman