Error in Rest Service in SpringFramework with @Controller annotation

Question

I am writing a simple rest service using springframework and i am getting below error message while trying to access my rest service through chrome browser.

Error Processing Request

Context Path:/simple_app-1.0-SNAPSHOT

Servlet Path:/

Path Info:null

Query String:null

Stack Trace

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException

org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:979)

org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858)

javax.servlet.http.HttpServlet.service(HttpServlet.java:687)

org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)

here is my 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>
    <name>SIMPLE_REST_V1</name>
    <groupId>com.rest.app</groupId>
    <artifactId>simple_app</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <spring.version>4.2.6.RELEASE</spring.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc-portlet</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.0.1</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.4.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.4.1.1</version>
        </dependency>

        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-mapper-asl</artifactId>
            <version>1.9.13</version>
        </dependency>

        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-core-asl</artifactId>
            <version>1.9.13</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.1.1</version>
                <configuration>
                    <failOnMissingWebXml>true</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

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

    <servlet>
        <servlet-name>RestAPI</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/context.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>RestAPI</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

and context.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
                           http://www.springframework.org/schema/mvc
                           http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
                           http://www.springframework.org/schema/context
                           http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.sumit.rest.app"/>
    <mvc:annotation-driven/>

</beans>

RESTController

@Controller
@RequestMapping(value = "/")
public class RESTController {
    private static AtomicLong counter = new AtomicLong();
    private final static String template = "Hello, %s";

    @RequestMapping(method = RequestMethod.GET, headers = "Accept=application/json")
    @ResponseBody
    public Map<String, String> get() {
        Map<String,String> map = new HashMap<>();
        map.put("value","this is the default response");
        return map;
    }


    @RequestMapping(value = "/greet", method = RequestMethod.GET, headers = "Accept=application/json", produces = MediaType.APPLICATION_JSON_VALUE)
    @ResponseBody
    public Greeting getGreeting(@RequestParam(value = "name", defaultValue = "World") String name) {
        Greeting greet =  new Greeting(counter.incrementAndGet(), String.format(template, name));
        System.out.println(greet);
        return greet;
    }
 }

and finally Greet.java

@JsonAutoDetect
public class Greeting {
    public final long id;
    public final String message;

    public Greeting(long id, String message) {
        this.id = id;
        this.message = message;
    }

    public long getId() {
        return id;
    }

    public String getMessage() {
        return message;
    }

    @Override
    public String toString() {
        return "id = "+this.id + " and name = "+this.message;
    }
}

could you please point out where am i missing or making mistake ?

the response which i am expecting on the browser is the json representation of the Greet class's object.

the above code is sample code from https://spring.io/guides/gs/rest-service/ but the only difference is that what i am trying is the non-spring boot version of that sample.

below is the screenshot of the error

any help would be appreciated !

Thanks in anticipation.

What is the package name of RESTController ? – Vasu Nov 13 '16 at 11:54 — Vasu, Nov 13 '16 at 11:54
Can you post the complete stack trace of the exception ? – Vasu Nov 13 '16 at 12:03 — Vasu, Nov 13 '16 at 12:03
What is the URL you are using in the browser/client ? – Vasu Nov 13 '16 at 12:24 — Vasu, Nov 13 '16 at 12:24

score 0 · Answer 1 · edited May 23 '17 at 12:07

0

There are 2 kinds of application contexts set up in your case

(which is decribed clear enough here Purpose of ContextLoaderListener – Spring MVC and here).

In short If you've configured everything in one spring configuration file then you don't need the ContextLoaderListener, while you use

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

it will search for applicationContext.xml under WEB-INF, I guess you don't have this file so just remove this declaration.

If you use wildFly 8.1, upgrade it to newer version.

edited May 23 '17 at 12:07

Community

1
1

answered Nov 13 '16 at 14:40

Fevly Pallar

3,059
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I tried it but it is still not working. I have attached the screenshot could you please have a look at it. – sumit Nov 13 '16 at 17:54
This *null pointer* exception comes from the API classes, as you see it works just fine on me. There are some quite similar reports from WildFly - 8.1 users and older JBoss , if this is your case then upgrade the wildfly to ver.8.2 – Fevly Pallar Nov 13 '16 at 18:45
How do you get to know if i am using WildFly - 8.1 ? – sumit Nov 13 '16 at 18:48
Yes ! I tried this in tomcat and yes it is working in there even with the contextLoaderListener. Any idea to run it with Wildfly 8.1 ? – sumit Nov 13 '16 at 18:54
Nah, just upgrade it, a lot of people had got through hard times using widlfly with (especially) Spring boot, and I don't want you to be one of those people. – Fevly Pallar Nov 13 '16 at 18:58

Error in Rest Service in SpringFramework with @Controller annotation

1 Answers1