JAX RS MessageBodyWriter not found for media type=application/json

Question

I am creating Rest client using JAX RS Jersey 2. The client works but only in my IDE (IntellIJ IDEA), when I build it with Maven, using maven-assembly-plugin and run the jar it doesn't work anymore.

I get MessageBodyWriter not found for media type=application/json error.

I have tried adding more dependencies that people suggested in other posts but I don't think a dependency is a problem since it runs in the IDE.

Here is the code that throws the exception

return client.target(uri)
        .request(MediaType.APPLICATION_JSON)
        .post(Entity.entity(transactions.get(0), MediaType.APPLICATION_JSON));

After debugging, when I replace transactions.get(0) with an empty string "", it works.

Here is the pom.xml for maven

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>11</source>
                <target>11</target>
            </configuration>
        </plugin>
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>SequencerControllers</mainClass>
                    </manifest>
                </archive>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
            </configuration>
        </plugin>
    </plugins>
</build>
<dependencies>
    <dependency>
        <groupId>com.sparkjava</groupId>
        <artifactId>spark-core</artifactId>
        <version>2.8.0</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-client</artifactId>
        <version>2.25.1</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-json-jackson</artifactId>
        <version>2.25.1</version>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.8.0</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.7.21</version>
    </dependency>
</dependencies>

Am i missing something? Really bothers me that it runs in the IDE but not when built with Maven since I build it with dependencies.

mentallurg mentallurg · Accepted Answer · 2019-10-22T20:07:22

Check if you have class com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider in your resulting JAR. If not, add following dependency:

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-json-provider</artifactId>
    <version>2.10.0</version>
</dependency>

JAX RS MessageBodyWriter not found for media type=application/json

1 Answers