I am having an issue after switching to Java 11 and adding modules to a Spring Boot application that acts as a REST API. I am not getting any errors when running the application and it shuts down after initialization with exit code 0. The Tomcat embedded server does not start, nor the dispatch server, which would prevent the application from closing and listen for incoming requests.
To me it looks like it does not start the embedded container because the modularization is preventing the Spring Boot Autoconfigure to find some Conditional Beans to initiate the REST server.
There is no error. It acts like if you run the application without a controller, it will shutdown without errors since there is no server to block it. I have listed the beans in the context and the HelloController is there, but like I said I can not find any beans that should exist for a running server, like web.servlet.DispatcherServlet.
I have tried searching for this, but unfortunately the fact that the term module existed long before Java 9 with a different meaning, makes it hard to find any answer. I apologize if somewhere deep in SO this question was already posted.
Even the basic example I can not make it work
Application.java
#SpringBootApplication()
public class SchoolsApplication {
public static void main(String[] args) {
SpringApplication.run(SchoolsApplication.class, args);
}
}
HelloController.java
#RestController
public class HelloController {
#GetMapping("hello")
public String hello(){
return "hello";
}
}
module-info.java
module controllers {
requires spring.boot;
requires spring.boot.autoconfigure;
requires spring.context;
requires spring.beans;
requires spring.web;
requires com.fasterxml.jackson.databind;
opens package.controllers to spring.core;
}
I am using Spring 2.3.4.RELEASE and I am in fact using JDK14, but target is Java 11.
I have tried to play with the required modules (i.e. spring.webmvc, tomcat.embedded.core) or search for the exact Spring beans to include, but with no success.
EDIT
When adding explicitly requires org.apache.tomcat.embed.core; the server starts and crashes with the error
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory]: Factory method 'tomcatServletWebServerFactory' threw exception
...
java.util.ServiceConfigurationError: org.apache.juli.logging.Log: module org.apache.tomcat.embed.core does not declare `uses`
The Tomcat version is 9.0.38
I managed to pinpoint the error to the Tomcat embedded server. The version used by spring-web-starter is tomcat-embed-core:9.0.38 . The issue was fixed in tomcat-embed-core:9.0.39 with
open module org.apache.tomcat.embed.core {
...
uses org.apache.juli.logging.Log;
}
So I resolved this through maven dependency management.
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>9.0.39</version>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>9.0.39</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
I am in the process of creating a Java REST application, using Spring-boot. I have successfully loaded the example here and I have tried to convert the JAR file to the WAR file as presented on the Spring-boot site. I've modified my pom.xml file, adding:
<!-- other pom.xml conf -->
<packaging>war</packaging>
<dependencies>
<!-- Spring -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
Then I've modified the Application.java class to initialize the servlet (this is for what Spring-boot uses to replace the web.xml file):
public class Application extends SpringBootServletInitializer {
// public static void main(String[] args) {
// new SpringApplicationBuilder(Application.class).run(args);
// }
#Bean
public ServletRegistrationBean jerseyServlet() {
ServletRegistrationBean registration = new ServletRegistrationBean(new ServletContainer(), "/*");
registration.addInitParameter(ServletProperties.JAXRS_APPLICATION_CLASS, JerseyInitialization.class.getName());
return registration;
}
#Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(Application.class);
}
}
I got my .WAR file generated, but when I deploy it on Tomcat the services are returning 404. The Tomcat logs aren't showing any errors either.
So I am not sure what it might be the problem. If you have any idea please, do share. Thanks!
Update:
Initially it wasn't working because beside the SpringBootApplication annotation to the Application class I was having other annotations too. Took those out and now Tomcat logs are showing this error.
SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
java.lang.IllegalStateException: Cannot initialize context because there is already a root application context present - check whether you have multiple ContextLoader* definitions in your web.xml!
I am not sure what other ContextLoader is there.
UpdateToUpdate:
Okay, after updating the jars to the latest version, using the annotation #SpringBootApplication for Application.java class, the application starts but when I am calling one of the services I receive:
java.lang.ClassNotFoundException: org.glassfish.jersey.process.internal.RequestExecutorFactory
A google search said that I should add the jersey-common and jersey-core jars, I did, but it didn't fix it. It looks like the RequestExecutorFactory.class is not packaged in the jersey-common-2.19.jar for some reason.
why do you have so many annotation in your Application class here ?
#SpringBootApplication should be sufficient to enable automatic configuration.
Try removing the others.
And put back the main method.
I think you mixed two configuration tw create a war : pre 3.0 and post 3.0 servlet container (as per the Spring Boot documentation)
EDIT :
I've found this question related to your problem.
Jersey is loading a Spring ApplicationContext. See this line of log : Spring WebApplicationInitializers detected on classpath: [com.jersey.Application#148ac084, org.glassfish.jersey.server.spring.SpringWebApplicationInitializer#7807c6d3]
Would it be possible for you to update your Spring Boot version ?
At least 1.20 so you will be able to use the spring-boot-starter-jersey. It will be a lot more easier to integrate Spring and Jersey.
You can find an example here (Spring Boot official examples).
Or you have to exclude the org.glassfish.jersey.server.spring.SpringWebApplicationInitializer of initializers
i've troubles getting my application to tomcat 8. I'm using websocket and spring 4 but i don't want to use the spring internal STOMP mechanism so i've decided to follow this tutorial and implemented my websocket routines my way.
I'm developing since a couple of weeks now and tested it always with jetty (maven jetty plugin) and everything works fine. But now i want to deploy my application to our production server running tomcat 8.0.15 on java 8 and CentOS but it's not working.
Here is the sourcecode:
#WebListener
public class MyApplication implements ServletContextListener {
private final static String SERVER_CONTAINER_ATTRIBUTE = "javax.websocket.server.ServerContainer";
#Override
public void contextInitialized(ServletContextEvent sce) {
ServletContext container = sce.getServletContext();
final ServerContainer serverContainer = (ServerContainer) container.getAttribute(SERVER_CONTAINER_ATTRIBUTE);
try {
serverContainer.addEndpoint(new MyEndpointConfig(MyEndpoint.class, "/wstest"));
} catch (DeploymentException e) {
e.printStackTrace();
}
}
}
And here's the error:
java.lang.ClassCastException: org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server.ServerContainer
at my.package.contextInitialized(MyApplication.java:23)
Line 23 is where i do the cast to ServerContainer.
I guess that "container.getAttribute(SERVER_CONTAINER_ATTRIBUTE)" returns null and therefore the cast fails, but why??
It's all working fine with Jetty 9.2.3. I've tested it also with a local tomcat 8 installed (newest 8.0.18) and the latest JDK 8 on Windows 7 and same behaviour.
Do you have any ideas how to fix this?
Thank you very very much!
Appleman1234 is pointing to a very useful bug report. See Iyad Elian comment:
FYI, I found why the exception happens javax.websocket-api like javax.servlet-api needs to be excluded at runtime in tomcat. jetty prefers application classloader to it's own however so it's not a problem.
<dependency>
<groupId>javax.websocket</groupId>
<artifactId>javax.websocket-api</artifactId>
<version>1.0</version>
<scope>provided</scope>
</dependency>
And that's exactly why it was not working on tomcat but on jetty. I've just added
<scope>provided</scope>
and now it's working fine. Thanks to Appleman1234!
I have a simple Spring Boot application that gets messages from a JMS queue and saves some data to a log file, but does not need a web server. Is there any way of starting Spring Boot without the web server?
if you want to run Spring Boot 1.x without a servlet container, but with one on the classpath (e.g. for tests), use the following, as described in the spring boot documentation:
#Configuration
#EnableAutoConfiguration
public class MyClass {
public static void main(String[] args) throws JAXBException {
SpringApplication app = new SpringApplication(MyClass.class);
app.setWebEnvironment(false); //<<<<<<<<<
ConfigurableApplicationContext ctx = app.run(args);
}
}
also, I just stumbled across this property:
spring.main.web-environment=false
Spring Boot 2.x, 3.x
Application Properties
spring.main.web-application-type=NONE
# REACTIVE, SERVLET
or SpringApplicationBuilder
#SpringBootApplication
public class MyApplication {
public static void main(String[] args) {
new SpringApplicationBuilder(MyApplication.class)
.web(WebApplicationType.NONE) // .REACTIVE, .SERVLET
.run(args);
}
}
Where WebApplicationType:
NONE - The application should not run as a web application and should not start an embedded web server.
REACTIVE - The application should run as a reactive web application and should start an embedded reactive web server.
SERVLET - The application should run as a servlet-based web application and should start an embedded servlet web server.
You can create something like this:
#SpringBootApplication
public class Application {
public static void main(String[] args) {
new SpringApplicationBuilder(Application.class).web(false).run(args);
}
}
And
#Component
public class CommandLiner implements CommandLineRunner {
#Override
public void run(String... args) throws Exception {
// Put your logic here
}
}
The dependency is still there though but not used.
Spring boot will not include embedded tomcat if you don't have Tomcat dependencies on the classpath.
You can view this fact yourself at the class EmbeddedServletContainerAutoConfiguration whose source you can find here.
The meat of the code is the use of the #ConditionalOnClass annotation on the class EmbeddedTomcat
Also, for more information check out this and this guide and this part of the documentation
The simplest solution. in your application.properties file. add the following property as mentioned by a previous answer:
spring.main.web-environment=false
For version 2.0.0 of Spring boot starter, use the following property :
spring.main.web-application-type=none
For documentation on all properties use this link : https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html
Use this code.
SpringApplication application = new SpringApplication(DemoApplication.class);
application.setWebApplicationType(WebApplicationType.NONE);
application.run(args);
For Spring boot v2.1.3.RELEASE, just add the follow properties into application.propertes:
spring.main.web-application-type=none
If you need web functionality in your application (like org.springframework.web.client.RestTemplate for REST calls) but you don't want to start a TOMCAT server, just exclude it in the POM:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
Through program :
ConfigurableApplicationContext ctx = new SpringApplicationBuilder(YourApplicationMain.class)
.web(WebApplicationType.NONE)
.run(args);
Through application.properties file :
spring.main.web-environment=false
Through application.yml file :
spring:
main:
web-environment:false
Spring boot has many starters, some starters have an embedded web server, some don't. The following have the embedded web server:
spring-boot-starter-web
spring-boot-starter-data-jpa
spring-boot-starter-jetty
spring-boot-starter-tomcat
spring-boot-starter-jdbc
spring-boot-starter-data-rest
...
Pick the one that meets your requirements and that does not have server support.
I only need to make restful json api request in my spring application, so the starter I need is
spring-boot-starter-json
which provide RestTemplate and jackson for me to use.
You can use the spring-boot-starter dependency. This will not have the web stuff.
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
If you want to use one of the "Getting Started" templates from spring.io site, but you don't need any of the servlet-related stuff that comes with the "default" ("gs/spring-boot") template, you can try the scheduling-tasks template (whose pom* contains spring-boot-starter etc) instead:
https://spring.io/guides/gs/scheduling-tasks/
That gives you Spring Boot, and the app runs as a standalone (no servlets or spring-webmvc etc are included in the pom). Which is what you wanted (though you may need to add some JMS-specific stuff, as someone else points out already).
[* I'm using Maven, but assume that a Gradle build will work similarly].
Remove folowing dependancy on your pom file will work for me
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
For Kotling here is what I used lately:
// src/main/com.blabla/ShellApplication.kt
/**
* Main entry point for the shell application.
*/
#SpringBootApplication
public class ShellApplication : CommandLineRunner {
companion object {
#JvmStatic
fun main(args: Array<String>) {
val application = SpringApplication(ShellApplication::class.java)
application.webApplicationType = WebApplicationType.NONE
application.run(*args);
}
}
override fun run(vararg args: String?) {}
}
// src/main/com.blabla/command/CustomCommand.kt
#ShellComponent
public class CustomCommand {
private val logger = KotlinLogging.logger {}
#ShellMethod("Import, create and update data from CSV")
public fun importCsv(#ShellOption() file: String) {
logger.info("Hi")
}
}
And everything boot normally ending up with a shell with my custom command available.
In Spring boot, Spring Web dependency provides an embedded Apache Tomcat web server. If you remove spring-boot-starter-web dependency in the pom.xml then it doesn't provide an embedded web server.
remove the following dependency
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
From my experience on spring boot > 2.5 ,
if you plan to build the application as a jar file, in my opinion the solution of spring.main.web-application-type=NONE should not be widely accepted and used, since it has only a limited scope of benefits.
For asking to have spring boot without the web server, it means that you have from Spring either the dependency spring-boot-starter-web to build a spring web application or the dependency spring-boot-starter-jersey to build a jax-rs web application. Those dependencies pack inside the spring-boot-starter-tomcat which will then bring the dependency of tomcat-embed-core which is the actual tomcat server. This library is packed automatically inside and is of size ~3.3 MB. Even if you disable the server with the aforementioned property, you will still deliver your application jar file, containing the tomcat server inside.
So the con of just using the aforementioned property is that the deliverable jar file will be some MB larger in size without any actual need.
So if you want to have spring boot without the web server just don't use the dependencies spring-boot-starter-jersey or spring-boot-starter-web since if you build your application as a jar file there is no reason to have those dependencies and not have an embedded server delivered.
if you plan to build the application as a war file, you should also not use the above property.
In this case you will just need in your .pom the following configurations
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web or (spring-boot-starter-jersey)</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>pick the version that the server that already runs in production supports</version>
<scope>provided</scope>
</dependency>
</dependencies>
Exceptional cases
The property spring.main.web-application-type=NONE should be in my opinion used for some exceptional cases like if we build some web library that needs the above dependencies but is not to be used like a web application, or we have some complex type of testing that needs those libraries although the application does not need any server to run. This type of usages are however rare.
Similar to #nayun oh answer above, but for older versions of Spring, use this code:
SpringApplication application = new SpringApplication(DemoApplication.class);
application.setApplicationContextClass(AnnotationConfigApplicationContext.class);
application.run(args);
I am attempting to run some unit tests on my spring web app using Maven. The app installs and runs fine without tests.
I receive this error in my surefire test report :
java.lang.NoClassDefFoundError: javax/servlet/ServletException
The test itself looks like this :
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations={"file:C:/myProjects/myWebapp/src/main/webapp/WEB-INF/applicationContext-test.xml"})
#Transactional
public class MyTest {
...
Previously I was receiving this error, however I removed any reference to the security package from test app context. And got this latest error.
Both problems are caused by my classpath not being set correctly ? The maven dependencies do not seem to be included when testing ? How can I change this, or what else am I missing ?
Try this.
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>test</scope>
</dependency>
Your servlet container will have this but some of your tests must need it. You may need to adjust the version.
The scope is important. You don't want to bundle this jar into your war but you want it available to your tests.