We Keep Coding

Spring Webflux change from Netty to Tomcat embedded server

I have changed the pom to switch from Netty to Tomcat as below, but now I get : java.lang.IllegalStateException: No suitable default ClientHttpConnector found, why is that? With Netty before the change was all good.
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.5</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.fer</groupId>
<artifactId>DemoReactive</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>DemoReactive</name>
<description>Demo project for Reactive</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<exclusions>
<exclusion>
<artifactId>spring-boot-starter-reactor-netty</artifactId>
<groupId>org.springframework.boot</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

Netty is optimal for Webflux. Don't replace it. The basic principle of operation of the two systems is different. If you want to use Tomcat, use the spring-boot-starter-web dependency, not webflux.
Spring webFlux differrences when Netty vs Tomcat is used under the hood
Spring Web MVC vs Spring WebFlux. Blocking and Non-blocking
Non-blocking programming requires a different approach because you must not block any thread. But you can use a blocker mechanism it just be wrapped.
https://projectreactor.io/docs/core/release/reference/#faq.wrap-blocking
If you want to program like with spring-boot-starter-web pack, not as "stream". I recommend using the Kotlin language with Coroutine, which is two-way compatible with ProjectReactor and Java.
And you can't use thread-based data like Tomcat because more processes can use one thread so there may be thread data that another process can override.
https://projectreactor.io/docs/core/release/reference/#context

I believe this is how you would do something equivalent, note the difference in exclusion:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>my-webflux-app</artifactId>
<version>1.0.0</version>
<properties>
<java.version>11</java.version>
<spring-boot.version>2.3.3.RELEASE</spring-boot.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<exclusions>
<exclusion>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

Why my springboot application ended up like this?

Here is the screenshot for the running result, the program ends immediately after running
enter image description here
And below is my pom.xml
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.0</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>Meituan</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Meituan</name>
<description>Meituan</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.20</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.76</version>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.23</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Can somebody help?

In common the JVM will ends when Main Thred finished the work and no non-daemon threads. It hard to say what you have now in your code. But I can see that there are no web-server (like embedded tomcat) and guess there are no tasks (for Main thread or any non-daemon thread). It is expected behavior for current project.
There are 2 ways (depend what you want to get)
Start web server
Create task which will do anything.

Could not initialize Eureka servlet context

I'm upgrading my actual project to spring boot 2.5.2.
I had a config server, a zuul gateway and a discovery server.
Now I saw that spring cloud has an embedded gateway in my discovery server which I want to use. So I have at the end only the config server and discovery server (which includes my gateway)
But I get the following stack trace from the discovery server:
08-07-2021 14:03:46.449 [Thread-11] INFO c.n.e.r.PeerAwareInstanceRegistryImpl.openForTraffic - Got 1 instances from neighboring DS node
08-07-2021 14:03:46.449 [Thread-11] INFO c.n.e.r.PeerAwareInstanceRegistryImpl.openForTraffic - Renew threshold is: 1
08-07-2021 14:03:46.449 [Thread-11] INFO c.n.e.r.PeerAwareInstanceRegistryImpl.openForTraffic - Changing status to UP
08-07-2021 14:03:46.467 [Thread-11] ERROR o.s.c.n.e.s.EurekaServerBootstrap.contextInitialized - Cannot bootstrap eureka server :
java.lang.NullPointerException: null
at org.springframework.cloud.netflix.eureka.server.EurekaServerBootstrap.contextInitialized(EurekaServerBootstrap.java:73)
at org.springframework.cloud.netflix.eureka.server.EurekaServerInitializerConfiguration.lambda$start$0(EurekaServerInitializerConfiguration.java:68)
at java.lang.Thread.run(Thread.java:748)
08-07-2021 14:03:46.468 [Thread-11] ERROR o.s.c.n.e.s.EurekaServerInitializerConfiguration.lambda$start$0 - Could not initialize Eureka servlet context
java.lang.RuntimeException: Cannot bootstrap eureka server :
at org.springframework.cloud.netflix.eureka.server.EurekaServerBootstrap.contextInitialized(EurekaServerBootstrap.java:77)
at org.springframework.cloud.netflix.eureka.server.EurekaServerInitializerConfiguration.lambda$start$0(EurekaServerInitializerConfiguration.java:68)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException: null
at org.springframework.cloud.netflix.eureka.server.EurekaServerBootstrap.contextInitialized(EurekaServerBootstrap.java:73)
... 2 common frames omitted
Here is my code:
Config server:
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.geminiald</groupId>
<artifactId>config-service</artifactId>
<version>2.1.0</version>
<name>config-service</name>
<description>Configuration service</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>2020.0.3</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml
spring:
cloud:
config:
server:
native:
search-locations: classpath:/shared
profiles:
active: native
security:
user:
password: configPassword
server:
port: 8081
shared/discovery-service.yml
server:
port: 8082
logging:
level:
org:
hibernate:
SQL: DEBUG
type:
descriptor:
sql:
BasicBinder: TRACE
Discovery server
pom.xml
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.2</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.geminiald</groupId>
<artifactId>discovery-service</artifactId>
<version>2.1.0</version>
<name>discovery-service</name>
<description>Discovery service</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>2020.0.3</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
</dependency>
<dependency>
<groupId>com.github.ben-manes.caffeine</groupId>
<artifactId>caffeine</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Main
#SpringBootApplication
#EnableEurekaServer
public class DiscoveryServiceApplication {
public static void main(String[] args) {
SpringApplication.run(DiscoveryServiceApplication.class, args);
}
}
GatewayDiscoveryConfiguration
#Configuration
#EnableDiscoveryClient
public class GatewayDiscoveryConfiguration {
#Bean
public DiscoveryClientRouteDefinitionLocator
discoveryClientRouteLocator(ReactiveDiscoveryClient discoveryClient, DiscoveryLocatorProperties locatorProperties) {
return new DiscoveryClientRouteDefinitionLocator(discoveryClient, locatorProperties);
}
}
It would be very appreciated if someone could help me.
Thanks in advance!

If it helps anybody at all.
The context was null hence NPE was fixed for me by adding tomcat-embed-core.jar into the classpath.

application dosen't read config server spring cloud

Im try to create a simple project with 2 application ( a simple rest app and a config-server app )
My config-server project is ok, because if I got http://localhost:9091/form-create/container I can see all vars from form-create.properties
but my application form-create is not getting properties from config-server
here is my bootstrap.properties in form-create project
spring.application.name=form-create
spring.cloud.config.uri=http://localhost:9091
spring.cloud.config.fail-fast=true
pom.xml in form-create project
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.2</version>
<relativePath />
</parent>
<groupId>com.formcloud</groupId>
<artifactId>ms-form-create</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>ms-form-create</name>
<description>Microservice to manage form creation</description>
<properties>
<java.version>11</java.version>
<spring-cloud.version>2020.0.3</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Main class
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class MsFormCreateApplication {
public static void main(String[] args) {
SpringApplication.run(MsFormCreateApplication.class, args);
}
}
What am I doing wrong? if I start my form-create application is starting on 8080 port and not getting properties from config server.

I think you should try to check two things:
Your maven dependencies. It looks like you've put them wrong, namely, if you're running cloud config client, why do you have a dependency for spring-cloud-config-server?
For Web and cloud config client the following list is sufficient:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
When you start the config server, are you sure that it indeed reads the configuration from the repository you've configured (git, file system, whatever)?
In general it exposes REST API so you can curl the server to get the information even without starting the spring boot application
Try that and make sure that it works as expected. For example, read this part of tutorial. Note that you might have put the configuration for different profile or different branch, cloud config server can handle that, but you'll have to specify profile for example in the bootstrap.properties.

EnableConfigServer cannot be resolved to a type

I want to connect my spring cloud config server by adding #EnableConfigServer but getting error that EnableConfigServer cannot be resolved to a type. Already check the application.properties, name, git repository path and i also already try to clean the project still gettin same error.I cant view localhost:8888/limits-service/default.Please help me
This my pom.xml
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.samazlan.microservices</groupId>
<artifactId>spring-cloud-config-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-cloud-config-server</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.SR1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>

For me, the problem was resolved after changing the starter dependency
from
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-**starter-config**</artifactId>
</dependency>
to
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-**config-server**</artifactId>
</dependency>

You can try, as in here, to clean your local .m2 maven cache.
(rename it, to force maven to re-create a new m2 folder).
See if the dependencies are imported then.