netty-socketio服务器中的java.lang.NoSuchMethodError

Question

I'm trying to start netty-socketio server, and I can't trace origins of this exception. I have marked in stacktrace place where it may lead to the answer, so if anyone could provide explanation on this it will be much appreciated.

public class SocketIoServer {
    private Configuration cnf = new Configuration();
    private SocketIOServer server;

    public SocketIoServer() {

        Configuration config = new Configuration();
        config.setHostname("localhost");
        config.setPort(8081);

        server = new SocketIOServer(config);
        server.start();
    }
}

When I initialize socket an Exception gets thrown. Here's context:

Exception in thread "main" java.lang.IllegalArgumentException: 

java.lang.reflect.InvocationTargetException
    at com.corundumstudio.socketio.Configuration.<init>(Configuration.java:112)
    at com.corundumstudio.socketio.SocketIOServer.<init>(SocketIOServer.java:66)
    at SocketIoServer.<init>(SocketIoServer.java:17)
    at Server.main(Server.java:19)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.corundumstudio.socketio.Configuration.<init>(Configuration.java:109)
    ... 8 more

This line in particular

Caused by: java.lang.NoSuchMethodError: 
com.fasterxml.jackson.databind.module.SimpleModule.setSerializerModifier(Lcom/fasterxml/jackson/databind/ser/BeanSerializerModifier;)Lcom/fasterxml/jackson/databind/module/SimpleModule;
    at com.corundumstudio.socketio.protocol.JacksonJsonSupport.init(JacksonJsonSupport.java:316)
    at com.corundumstudio.socketio.protocol.JacksonJsonSupport.<init>(JacksonJsonSupport.java:311)
    at com.corundumstudio.socketio.protocol.JacksonJsonSupport.<init>(JacksonJsonSupport.java:304)
    ... 13 more

Answer 1

You have obviously a conflict of version of jackson-databind in your project, indeed the class com.corundumstudio.socketio.protocol.JacksonJsonSupport relies on the method SimpleModule#setSerializerModifier(BeanSerializerModifier mod) which has been added since the version 2.2 so as it cannot find this method, it means that you have a version of jackson-databind older than 2.2 in your classpath such that the method cannot be found.

Check all the jars that you have in your classpath and make sure that you have only one version of jackson-databind corresponding to the version expected by netty-socketio . For example assuming that you use the version 1.7.12 of netty-socketio , the expected version of jackson-databind is 2.7.4 as you can see here .