I am having an error while trying to use Jsonb / JsonbBuilder in a JakartaEE maven project.

Error StackTrace

java.lang.RuntimeException: jakarta/json/bind/JsonbBuilder
    at org.apache.tomcat.websocket.pojo.PojoMessageHandlerBase.handlePojoMethodException(PojoMessageHandlerBase.java:119)
    at org.apache.tomcat.websocket.pojo.PojoMessageHandlerWholeBase.onMessage(PojoMessageHandlerWholeBase.java:107)
    at org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:415)
    at org.apache.tomcat.websocket.server.WsFrameServer.sendMessageText(WsFrameServer.java:129)
    at org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:515)
    at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:301)
    at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:133)
    at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:85)
    at org.apache.tomcat.websocket.server.WsFrameServer.doOnDataAvailable(WsFrameServer.java:183)
    at org.apache.tomcat.websocket.server.WsFrameServer.notifyDataAvailable(WsFrameServer.java:162)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.upgradeDispatch(WsHttpUpgradeHandler.java:157)
    at org.apache.coyote.http11.upgrade.UpgradeProcessorInternal.dispatch(UpgradeProcessorInternal.java:60)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:59)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1762)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.NoClassDefFoundError: jakarta/json/bind/JsonbBuilder
    at com.example.websockets.WebChat.onMessage(WebChat.java:21)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
    at java.base/java.lang.reflect.Method.invoke(Method.java:577)
    at org.apache.tomcat.websocket.pojo.PojoMessageHandlerWholeBase.onMessage(PojoMessageHandlerWholeBase.java:105)
    ... 18 more
Caused by: java.lang.ClassNotFoundException: jakarta.json.bind.JsonbBuilder
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1449)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1257)
    ... 22 more

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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>websockets</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>websockets</name>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.target>18</maven.compiler.target>
        <maven.compiler.source>18</maven.compiler.source>
    </properties>

    <dependencies>


        <dependency>
            <groupId>jakarta.platform</groupId>
            <artifactId>jakarta.jakartaee-api</artifactId>
            <version>9.1.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.3.2</version>
            </plugin>
        </plugins>
    </build>
</project>

The method throwing the error and the class imports

@OnMessage
public void onMessage(Session session, String text) {

    try(Jsonb jsonb = JsonbBuilder.create()) {
        Message message = jsonb.fromJson(text, Message.class);
        System.out.println("Message received: "   message);

        if(message.getType().equals("join")){
            session.getUserProperties().put("name", message.getUserName());
            session.getUserProperties().put("active", true);
            Message info = new Message(message.getUserName(), "join", message.getUserName()   " has joined the chat");
            Message updateUserList = new Message(message.getUserName(), "users", getUserNames(session));

            sendAll(session , info);
            sendAll(session , updateUserList);
        } else if(message.getType().equals("chat")){
            sendAll(session, message);
        }
    }catch (Exception e){
        throw new RuntimeException(e);
    }
}

It looks like your post is mostly code; please add some more details.

import jakarta.json.Json;
import jakarta.json.bind.Jsonb;
import jakarta.json.bind.JsonbBuilder;
import jakarta.websocket.OnClose;
import jakarta.websocket.OnError;
import jakarta.websocket.OnMessage;
import jakarta.websocket.Session;
import jakarta.websocket.server.ServerEndpoint;

import java.util.stream.Collectors;

The error is shown when I try to use JsonbBuilder And I do have jakarta/json/bind/JsonbBuilder in maven dependencies.

CodePudding user response：

Tomcat doesn't include an implementation of the Json Binding specification. You can either include an implementation or switch to other application server that fully implements the Jakarta specification.

<dependency>
  <groupId>org.eclipse</groupId>
  <artifactId>yasson</artifactId>
  <version>2.0.4</version>
</dependency>
<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>jakarta.json</artifactId>
    <version>2.0.1</version>
</dependency>

CodePudding user response：

Changing to TomEE fixed the error.