What's the difference between the below two dependencies? Do i really need the first one to make a consumer or producer app?
<dependencies>
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.9.2</artifactId>
<version>0.8.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.8.2.1</version>
</dependency>
</dependencies>
My Producer works fine with just the first one , but the consumer needs the second one.
I had thought the "kafka-clients" artifact would work for both producer and consumer. But looks like "kafka.consumer.Consumer" comes from the other dependency. Why is there a difference?
Also, why is the first artifact named as kafka_2.9.2? i.e why is a version identifier in the name?
If you want to use the latest producer and consumer API then the correct Maven coordinates are:
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.9.0.0</version>
</dependency>
See the API documentation for more.
Related
It's not a huge problem but I'm curious where some extra stream consumers are coming from, and if that's a setting I can change.
I've got a very simple spring cloud stream consumer setup against a local Kafka broker. Here's the spring config
spring:
cloud:
stream:
bindings:
consumer-in-0:
destination: test-topic
group: test-group
And the consumer class itself:
#Bean
Consumer<Message<String>> consumer() {
return message -> System.out.println("Got it: " + message.getPayload());
}
When I run the app though, I can see 3 consumers created in the output. But when I check the consumer-group members in my local broker, it's always just one consumer, and it's always the second consumer created (i.e. with client id test-group-2)
Just for clarity, I'm using Spring Boot version 2.3.4.RELEASE and cloud dependencies version Hoxton.SR10.
And here's the dependencies in the pom:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-binder-kafka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
<dependencies>
Why am I getting 3 consumers? Why is the second one the only one that actually listens on the Kafka topic?
During start up, a temporary consumer is created to get information about the partitions provisioned for the topic.
The second consumer is the real consumer.
If you have the actuator (actually Micrometer) on the classpath the KafkaBinderMetrics creates another consumer so it can calculate the lag. It does not actually consume anything.
I am migrating existing Spring project into Spring boot.unable to run spring boot application its showing following error.
The error log says there is a conflict on tomcat-embed-core.
In eclipse Dependency hierarchy of porm.xml is given below
i exclude the maven architect ,and try to run the application its showing following error
porm.xml
<modelVersion>4.0.0</modelVersion>
<artifactId>MyService</artifactId>
<packaging>jar</packaging>
<properties>
<java.version>1.8</java.version>
<!-- 2.1.3.RELEASE -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<springframework.boot.version>2.1.7.RELEASE</springframework.boot.version>
</properties>
<name>MyService</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.sybase.jdbc3.jdbc</groupId>
<artifactId>jconn3</artifactId>
<version>${jconn3.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-juli</artifactId>
<version>${tomcat.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
<version>${tomcat.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
what was wrong in this porm.xml
Where is
${tomcat.version}
defined?
That version probably does not match the tomcat version that auto magically is included with spring boot items.
And thus the conflict.
Go here:
https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web/2.1.7.RELEASE
And start following the COMPILE dependencies, and you'll find the versions that are auto included with 2.1.7.RELEASE. and you have to alter the other includes that are overwriting the springboot auto include tomcat versions.
Again, follow the COMPILED dependency trail.
So below is what you should find by crawling the COMPILED dependency trail (from immediately above in my answer)
https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-tomcat/2.1.7.RELEASE
And you'll find you need to set
tomcat.version to
9.0.22
By defining tomcat.version as 8.x, you are breaking it.
Another way to put it
You have to go ~way~ back to springboot 1.5.2.RELEASE or 1.5.3.RELEASE
https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-tomcat/1.5.2.RELEASE
https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-tomcat/1.5.3.RELEASE
(Again, in the two above links, looked at the COMPILE dependencies)
To find a version of tomcat (that is auto included with springboot) that gets close to tomcat 8.5.x (where 8.5.x is the one you are attempting to use)
That's pretty old.
The principal you are missing is that springboot auto includes dependencies. And anything else you import has to play nice with everything springboot auto includes.
And your current value for tomcat.version is NOT playing nice with everything springboot 2.1.7.RELEASE is auto including.
And now that you've been through all of that. You'll find you'll make your life easier if you engage the springboot world more completely.
Alot of times, springboot will have a (sub)package that will bring in the thing you really desire.
spring-boot-starter-jdbc
https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jdbc/2.1.7.RELEASE
You would probably be better off bringing that package in, vs hand-picking ones. Aka, get rid of your "tomcat-jdbc" include and see if the spring-boot-starter-jdbc can give you what you want.
The curse/blessing of spring-boot is that it is its own universe. But if you engage, you probably want to play by its rules more often than not.
PS
It is pom.xml, not porm.xml
Try adding spring-boot-starter-tomcat as a dependency:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
Remove tomcat-juli and tomcat-jdbc dependencies. If you need JDBC support, add the corresponding starter:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
If you use JSP views, you will probably need the following dependencies as well:
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
Also, pay attention to your dependencies versions. Spring Boot's parent POM defines version management for many common artifacts so you don't need to set the <version></version> for these libraries. See https://docs.spring.io/spring-boot/docs/2.1.7.RELEASE/reference/htmlsingle/#appendix-dependency-versions
I excluded an artifact because it causes conflicts, namely the jsr311-api given below. Yet when I run the generated jar I'm still getting the java.lang.NoSuchMethodError error. I suspect that another dependency is also including this artifact. How can I find out which one? My dependency list is quite large. Which dependencies include the package javax.ws.rs.core?
<dependency>
<groupId>org.apache.axis2</groupId>
<artifactId>axis2-kernel</artifactId>
<version>1.7.3</version>
<exclusions>
<!-- Causes java.lang.NoSuchMethodError: javax.ws.rs.core.Response$Status$Family.familyOf(I)Ljavax/ws/rs/core/Response$Status$Family; -->
<exclusion>
<artifactId>jsr311-api</artifactId>
<groupId>javax.ws.rs</groupId>
</exclusion>
</exclusions>
</dependency>
Go to
http://search.maven.org/#advancedsearch%7Cgav
and use classname search to find
javax.ws.rs.core.Response
If you use a Nexus 2.x in your company, you can use classname search there as well.
If you want to find out where a given artifact (that you e.g. found by classnmae search) comes from, use dependency:tree in Maven.
In my case the mistake was that I had to manually add the javaee api and I set <scope>provided</scope> which was a mistake, fixing this solved the problem.
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope><!-- remove this -->
</dependency>
As far as i read top level depths should be chosen. But as you can see below second level is chosen. Am i missing something?
You're right, it should have worked as per the Dependency Mediation rules, but it doesn't, because of the constraints on the jersey-spring.pom (see here).
The constraint allows only versions 2.5.2 thru 3 of spring-core to be used with itself.
<spring25-release-version>[2.5.2,3)</spring25-release-version>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring25-release-version}</version>
<scope>compile</scope>
</dependency>
If you know for certain that 4.1.7.RELEASE of spring-core plays well with that 1.19 of jersey-spring, you can try "managing" the dependency and then use it normally like you did.
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
</dependencies>
</dependencyManagement>
Dependency management basically trumps all other means.
I would like to use the logback slf4j implementation in my application, but activemq-all is spoiling the classpath by including the log4j implementation classes. I'm not the only one facing that problem, as witnessed by for instance multiple SLF4J bindings Error with activemq-all-5.6.0.jar. According to that post I have to replace activemq-all by
org.apache.activemq:activemq-camel
org.apache.activemq:activemq-core
org.apache.activemq:activemq-console
org.apache.activemq:activemq-jaas
org.apache.activemq:activemq-optional
org.apache.activemq:kahadb
org.apache.geronimo.specs:geronimo-jms_1.1_spec
org.apache.geronimo.specs:geronimo-jta_1.0.1B_spec
org.apache.geronimo.specs:geronimo-j2ee-management_1.1_spec
org.apache.geronimo.specs:geronimo-annotation_1.0_spec.
The problem is that I don't have the complete maven dependencies (group id, artifact id, version) for these artifacts. Can someone provide me with a ready-to-use replacement for
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-all</artifactId>
<version>5.9.0</version>
</dependency>
You can use active mq core library. Please note that active mq is backward compatible for client.
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-core</artifactId>
<version>5.4.3</version>
<exclusions>
<exclusion>
<artifactId>org.slf4j</artifactId>
<groupId>slf4j-log4j12</groupId>
</exclusion>
<exclusion>
<artifactId>log4j</artifactId>
<groupId>log4j</groupId>
</exclusion>
</exclusions>
</dependency>
In a nutshell, you have already listed group id/artifact id separated by a colon for the artifact you found. Please note that these satisfy some usecase with ActiveMQ 5.6. For instance activemq-core is not really valid any more - use activemq-client and activemq-broker instead.
Currently, these artifact are bundled in activemq-all. But you may want to check out the pom.xml for your version of choice (this list might change over time). You probably won't need all of them unless you are about to embedd a broker with all transports, plugins and configurations within your applications.
<artifactSet>
<includes>
<include>${project.groupId}:activemq-client</include>
<include>${project.groupId}:activemq-openwire-legacy</include>
<include>${project.groupId}:activemq-camel</include>
<include>${project.groupId}:activemq-jaas</include>
<include>${project.groupId}:activemq-broker</include>
<include>${project.groupId}:activemq-console</include>
<include>${project.groupId}:activemq-shiro</include>
<include>${project.groupId}:activemq-spring</include>
<include>${project.groupId}:activemq-pool</include>
<include>${project.groupId}:activemq-jms-pool</include>
<include>${project.groupId}:activemq-amqp</include>
<include>${project.groupId}:activemq-http</include>
<include>${project.groupId}:activemq-mqtt</include>
<include>${project.groupId}:activemq-stomp</include>
<include>${project.groupId}:activemq-kahadb-store</include>
<include>${project.groupId}:activemq-leveldb-store</include>
<include>${project.groupId}:activemq-jdbc-store</include>
<include>org.apache.activemq.protobuf:activemq-protobuf</include>
<include>org.fusesource.hawtbuf:hawtbuf</include>
<include>org.jasypt:jasypt</include>
<include>org.apache.geronimo.specs:geronimo-jms_1.1_spec</include>
<include>org.apache.geronimo.specs:geronimo-jta_1.0.1B_spec</include>
<include>org.apache.geronimo.specs:geronimo-j2ee-management_1.1_spec</include>
<include>org.apache.geronimo.specs:geronimo-annotation_1.0_spec</include>
<include>org.slf4j:slf4j-api</include>
<include>org.slf4j:slf4j-log4j12</include>
<include>log4j:log4j</include>
</includes>
</artifactSet>
Ok, the version number for org.apache.activemq should simply be the release you want to use. For the geronimo specs, this is not so obvious.
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-jms_1.1_spec</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-j2ee-management_1.1_spec</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-annotation_1.0_spec</artifactId>
<version>1.1.1</version>
</dependency>
I was also facing this same issue with activemq-all API and I replaced this dependency with this below dependency and it worked for me.
<!-- https://mvnrepository.com/artifact/org.apache.activemq/activemq-spring -->
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-spring</artifactId>
<version>5.14.3</version>
</dependency>
Hope this can help others.