Why does Jersey ignore my Jackson annotations?

Question

I use Jersey and Jackson to create a simple JSON API.

Some of the serializable objects have custom enumeration fields. By default, these enums are converted to a string based on enum vale - I would like the enums to have slightly more complex serializations .

I use Jackson annotations in the listing, but the endpoint seems to ignore them. I turned my wheels trying to figure out what the problem was, and now I am turning to you.

Transfer code

package org.example.code; import com.fasterxml.jackson.annotation.JsonFormat; import com.fasterxml.jackson.annotation.JsonProperty; @JsonFormat(shape= JsonFormat.Shape.OBJECT) public enum ExampleEnum { YES (1, "Yes indeed"), NO (2, "No way buddy") private final Integer code; private final String description; ExampleEnum(final Integer code, final String description) { this.code = code; this.description = description; } @JsonProperty("code") public Integer getCode() { return code; } @JsonProperty("description") public String getDescription() { return description; } } 

API code

 package org.example.webservice.impl; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.Response; import org.example.code.ExampleEnum; @Path("/example") public class ExampleService { @GET @Path("/test") @Produces({MediaType.APPLICATION_JSON}) public ExampleEnum getExampleEnum() { return ExampleEnum.YES; } } 

When I call the endpoint of example/test , the output is YES I want the result to be something like the lines { code: 1, description: "Yes indeed" }

Configuration files below ...

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/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.example</groupId> <artifactId>api</artifactId> <version>0.0.1</version> <packaging>war</packaging> <name>example API</name> <url>http://example.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>javax.ws.rs</groupId> <artifactId>javax.ws.rs-api</artifactId> <version>2.0.1</version> </dependency> <dependency> <groupId>javax.annotation</groupId> <artifactId>javax.annotation-api</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.6.0</version> </dependency> <dependency> <groupId>org.glassfish.jersey.containers</groupId> <artifactId>jersey-container-servlet-core</artifactId> <version>2.18</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.3</version> <configuration> <source>1.7</source> <target>1.7</target> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.2</version> <configuration> <url>http://localhost:8080/manager/text</url> <server>TomcatServer</server> <path>/example</path> </configuration> </plugin> </plugins> </build> </project> 

web.xml

 <?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" 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_3_0.xsd"> <display-name></display-name> <servlet> <display-name>Example Servlet</display-name> <servlet-name>Example Servlet</servlet-name> <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class> <init-param> <param-name>jersey.config.server.provider.packages</param-name> <param-value>org.example.webservice.impl</param-value> </init-param> <init-param> <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name> <param-value>true</param-value> </init-param> <init-param> <param-name>jersey.config.server.provider.classnames</param-name> <param-value>org.glassfish.jersey.filter.LoggingFilter;org.glassfish.jersey.media.multipart.MultiPartFeature</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Example Servlet</servlet-name> <url-pattern>/services/*</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app> 

Answer 1

So a few things:

• com.sun.jersey.api.json.POJOMappingFeature for Jersey 1.x, so you can get rid of this.

• MOXy is the default provider in Glassfish, so if you want to use Jackson you need to disable MOXy. You can do this by adding this <init-param>

   <init-param> <param-name>jersey.config.server.disableMoxyJson</param-name> <param-value>true</param-value> </init-param> 

• Then, as @Alexey Gavrilov pointed out, add the Jackson provider

   <dependency> <groupId>com.fasterxml.jackson.jaxrs</groupId> <artifactId>jackson-jaxrs-json-provider</artifactId> <version>2.6.0</version> </dependency> 

• You can register this provider by adding the package to the packages for scanning.

   <init-param> <param-name>jersey.config.server.provider.packages</param-name> <param-value> org.example.webservice.impl, com.fasterxml.jackson.jaxrs.json </param-value> </init-param> 

Another thing that is not related to this issue that I could point out is that Glassfish already has an implementation in Jersey, which is a very old version of 2.x, possibly 2.0. When you add runtime dependencies, they may conflict. I would do one of two things, either put all the Jersey dependencies in the provided <scope> , or if you have requirements for a later version, you might want to examine the Jersey version in Glassfish. Check out Jersey 2 Update in GlassFish 4

Answer 2

Glassfish has json json inside of itself and may have conflicts with explicit json jars that you specified in pom.xml.

There are several other compilations on the maven website for each flag version, depending on the time in the selected bank.

Thus, they may also contradict the banks that you specified in pom.xml

I also deleted

 <dependency> <groupId>org.glassfish.jersey.media</groupId> <artifactId>jersey-media-json-jackson</artifactId> <version>2.24</version> </dependency> 

from pom.xml

Answer 3

For Jersey version 2.0x users who use the Application class instead of using web.xml, this works for me.

1. In ResourceConfig,

 @ApplicationPath("rest") public class JerseyApplication extends ResourceConfig { public JerseyApplication() { packages("com.example.rest"); register(JacksonFeature.class); } } 

Or, if you use the Application class,

 public class MyApplication extends Application { public Set<Class<?>> getClasses() { final Set<Class<?>> classes = new HashSet<Class<?>>(); . . classes.add(JacksonFeature.class); return classes; } } 

2. In pom.xml add this dependency,

 <dependency> <groupId>org.glassfish.jersey.media</groupId> <artifactId>jersey-media-json-jackson</artifactId> <version>2.26</version> </dependency> 

3. Make sure you have annotations on getters and setters. In my case, the @JsonIgnore annotation only worked when I used it on the getter and setter of this class variable.