使用Java配置Spring RESTFUL API Webapp

Question

I'm having some trouble trying to set up a RESTFUL API using Spring Framework and Spring Security + Jersey .

I could deploy a Jersey rest api and request resources successfully but when I also implemented Spring (Framework + Spring security) things are getting out of hand.

I've worked before with old Spring versions where configuration was made with XML files, but I would like to play and learn how to config it with Java annotations only. I'm having trouble with this as I can't get past applicationContext.xml . I simply don't want to put an XML file, I just want to configure my small rest api webapp with Java annotations only.

When I added Spring Security config lines to my web.xml and tried to request any resource, this error appeared:

No WebApplicationContext found: no ContextLoaderListener or DispatcherServlet registered?

So, I also added this snippet to my web.xml :

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

Then, I created a new configuration class for Spring, a simple one:

@Configuration
@ComponentScan({
    "com.myapp.rest.api", 
    "com.myapp.business.services"
})
public class SpringApplicationConfig {

}

I restarted my Tomcat again and tried to request any resource, then it started to complain about not finding the applicationContext.xml file, which I didn't provide, but I don't know why it is still trying to find it if I have another class with @Configuration annotation. How can I configure Spring without using applicationContext.xml ?

Note: I am aware of Spring MVC and Spring Boot , but I'm currently playing with Jersey and using Spring Framework for dependency injection, also Spring Security for auth and security stuff obviously.

Below my web.xml :

<?xml version="1.0" encoding="UTF-8"?>
<!-- This web.xml file is not required when using Servlet 3.0 container, 
    see implementation details http://jersey.java.net/nonav/documentation/latest/jax-rs.html -->
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <servlet>
        <servlet-name>Jersey Web Application</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>com.myapp.rest.api</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey Web Application</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

    <!-- SPRING SECURITY -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

And my pom.xml :

<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/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.myapp</groupId>
    <artifactId>api</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>api</name>

    <build>
        <finalName>my api</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <inherited>true</inherited>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <!-- JERSEY (2) -->
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
        </dependency>
        <!-- Soporte JSON -->
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-moxy</artifactId>
        </dependency>

    <!-- SPRING + SPRING SECURITY -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-web</artifactId>
            <version>${spring-security.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-config</artifactId>
            <version>${spring-security.version}</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>${servlet-api.version}</version>
            <scope>provided</scope>
        </dependency>

        <!-- JACKSON - JSON -->
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <!--  LOG4J2 -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>${log4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <!--  JWT TOKEN -->
        <dependency>
            <groupId>com.nimbusds</groupId>
            <artifactId>nimbus-jose-jwt</artifactId>
            <version>${jose.jwt.version}</version>
        </dependency>


    </dependencies>


    <properties>
        <jose.jwt.version>4.39.2</jose.jwt.version>
        <spring-security.version>4.2.3.RELEASE</spring-security.version>
        <spring.version>4.3.9.RELEASE</spring.version>
        <log4j.version>2.8.2</log4j.version>
        <jersey.version>2.9.1</jersey.version>
        <jackson.version>2.8.9</jackson.version>
        <servlet-api.version>3.1.0</servlet-api.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
</project>

Answer 1

You are missing some important points in web.xml

 // For java config, you don't want to use .xml 
  // you have to include AnnotationConfigWebApplicationContext
    <context-param>
        <param-name>contextClass</param-name>
        <param-value>
org.springframework.web.context.support.AnnotationConfigWebApplicationContext
      </param-value>
    </context-param>

    // Location of your Configuration class
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>my.package.AppConfig</param-value>
    </context-param>

    // To load context
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    // Spring Servlet
    <servlet>
        <servlet-name>SpringApplication</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
   // Your controllers
        <init-param>
            <param-name>jersey.config.server.provider.classnames</param-name>
            <param-value>my.package.controllers.HomeController</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    // Servlet url mapping
    <servlet-mapping>
        <servlet-name>SpringApplication</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>

Adding controller class

@Component
@Path("/home")
public class HomeController {

UPDATE : As it was told that author of question is interested in just Spring DI, not involving Spring MVC, below is simple config bootstrapping WebApplicationInitializer to configure the ServletContext programmatically, without web.xml. Note that this would require Servlet 3.0+ container.

public class ApplicationInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext)  throws ServletException {

        AnnotationConfigWebApplicationContext context 
          = new AnnotationConfigWebApplicationContext();

        servletContext.addListener(new ContextLoaderListener(context));
        servletContext.setInitParameter(
          "contextConfigLocation", "com.package.my");
    }
}