Hot swap available by maven wrapper (mvnw)? - spring

I added spring boot dev tool dependency in current Spring boot application, but when running the application by mvnw spring-boot:run It seems not recognized the change made in Java
I do use Eclipse to make the code change and enable automatically build. and refresh my code. So i think the latest .class file should be under /target directory
So does mvnw supports hot swap at all?

Related

Spring boot application as a shipable standalone jar

So I created a spring boot application. And I simply like to run it as a program from a Main class. No need for web controller access.
It runs great in my Intellij.
But how do I ship it as a jar?
It depends on your project structure. If you use maven just run "maven install" and find your jar in your local repository.
When you have it, run "java -jar your.jar"

mvn spring-boot:run vs java -jar

I know it may sound silly question but I am unable to understand the difference between mvn spring-boot:run and java -jar (.jar file generated with mvn install)
I have a spring boot application with jsp pages in /src/main/resources/META-INF/resources/WEB-INF/. If I use mvn spring-boot:run these pages are served. But If I use java -jar these pages are not found by application.
The application that I am working on is at https://github.com/ArslanAnjum/angularSpringApi
UPDATE:
It works with spring boot 1.4.2.RELEASE while I intend to use the latest version i.e., 1.5.8.RELEASE.
UPDATE:
Well I solved the problem by putting jsps in src/main/webapp/WEB-INF/views/ and changing packaging type to war and then running this war using java -jar target/myapp.war and its working fine now.
Short answer: spring-boot:run is a java -jar command on steroïd running as part of your Maven build, ensuring all required parameters are passed to your app (such as resources). spring-boot:run will also ensure that your project is compiled by executing test-compile lifecycle goals prior to running your app.
Long answer:
When you run java -jar, you launch a new JVM instance with all the parameters you passed to this JVM. For example, using the Spring doc example
java -Xdebug -Xrunjdwp:server=y, \
transport=dt_socket, address=8000, suspend=
-jar target/myproject-0.0.1-SNAPSHOT.jar
You will launch a brand new JVM with the given parameters. You need to make sure to include everything needed, such as classpath elements, application parameters, JVM options, etc. on the command line.
When you run mvn spring-boot:run, you launch a Maven build that will:
Run the test-compile lifecycle goals, by default it will be resources:resources, compiler:compile, resources:testResources, compiler:testCompile goals of the Maven Resources and Compiler plugin.
Launch your application with a bunch of parameters that will depend on the
Spring Boot Maven Plugin configuration you defined in your project (your pom.xml, parents and settings, command line, etc.). This includes among other things:
A lot of classpath elements: your target/classes folder which may contain resources and libraries required by your app, your Maven dependencies, etc.
Whether to fork your JVM or not (whether to create a brand new JVM to run your app or re-use the JVM of the Maven build), see fork and agent parameter of the plugin
As per:
I have a spring boot application with jsp pages in
/src/main/resources/META-INF/resources/WEB-INF/. If I use mvn
spring-boot:run these pages are served. But If I use java -jar these
pages are not found by application.
It's because the mvn spring:boot command will make sure your target/classes folder is present in the Classpath when your app is running. After compilation, this folder will contain target/classes/META-INF/resources/WEB-INF among other things. Your app will then be able to find META-INF/resources/WEB-INF and load them when asked. When you ran java -jar command, this folder was probably not on the classpath, your app was then not able to find your resources. (these resources were copied from the src/main/resources folder during the resources:resources goal)
To have a similar result with your java -jar command, you must include your resources on the classpath such as javar -jar myapp.jar -cp $CLASSPATH;/path/to/my/project/target/classes/
Have you tried creating a jar file using mvn package instead of mvn install when you are running jar file using java -jar? package will create a jar/war as per your POM file whereas install will install generated jar file to the local repository for other dependencies if present.

Use of spring-boot-maven-plugin

While creating a spring boot project I define property in pom.xml as <packaging>war</packaging> with which I can create a war and thereafter deploy the war into server maybe tomcat or WAS.
But I came across a plugin named spring-boot-maven-plugin whose documentation states that it's use is to package executable jar or war archives and run an application in-place.
My query is why do we need this at all ?
If my packaging can tell me what to create and then can deploy it to run, what is the used of this plugin.
I am trying to understand a new project so wanted to be sure that every line makes sense
The maven plugin will create an "executable" archive. In the case of the war packaging, you would be able to execute your app with java -jar my-app.war. If you intend to deploy your Spring Boot application in an existing Servlet container, then this plugin is, indeed, not necessary.
The maven plugin does more things like running your app from the shell or creating build information.
Check the documentation
The Spring Boot Maven Plugin provides Spring Boot support in Apache Maven, letting you package executable jar or war archives and run an application “in-place”.
Refer this - https://www.javaguides.net/2019/02/use-of-spring-boot-maven-plugin-with.html

Maven JBOSS application deployment

I followed this tutorial http://www.mastertheboss.com/jboss-maven/jboss-maven-example-building-a-java-ee-6-application/ in order to have a simple web application to better understand Java EE and JBOSS. I set up the example project (by archetype) and compiled it.
However, I am stuck after running mvn compile. I want to deploy my application as a war file to my JBOSS webroot directory (in my case /usr/share/jboss-as/standalone/deployments/).
I think mvn package and mvn install must be executed. Where can I specify that I want a war file and that it should be copied to my deployment location on JBOSS?
Obviously, I can use the jboss maven plugin http://docs.jboss.org/jbossas/7/plugins/maven/latest/, which is addressed via console
jboss-as:deploy
Configuration is read from the POM file.

How do I deploy a maven created webapp to tomcat

So I was following http://www.mkyong.com/jsf2/jsf-2-0-hello-world-example/ for a simple tutorial on how to use maven and jsf. I created a maven project by running mvn archetype:generate -Dfilter=org.apache:maven-archetype-webapp in my command prompt. Then I continued with the tutorial, I wound up creating all necessary files, but then when I got to the end, I realized I did have a server created. So I created one real quick, but when it came to the point of adding files to the server (from the add or remove dialog box), no projects or files showed up. I am not on my computer where the project is located so I can't copy/paste the .pom file in, but it looks practically exactly like the pom in the tutorial (only difference is groupId, artifact, ect.) No additional plugins, dependencies, or configs.
Do you want to deploy the webapp within Eclipse to Tomcat? Or as some sort of automatic/continuous deployment?
Within Eclipse you often need to add the Dynamic Web project and JSF facets to your project so Eclipse recognizes the project as deployment capable. If you are using m2eclipse make sure to install the m2eclipse wtp add on so this is done automatically.
If you want to add auto-deployment to the pom.xml I recommend using the maven cargo plugin: http://cargo.codehaus.org/Maven2+plugin - it supports the major containers.
For tomcat you need to modify the tomcat-users.xml to allow auto-deployment and leave the tomcat-manager application in place. If you have startet tomcat and pointing your browser to http://localhost:8080/manager/html/list it should either tell you to login or what to add to that file.
The configured user is then used in the configuration to deploy the war file via the tomcat-manager using the mvn cargo:deploy goal. The configuration has to be added to the pom.xml using war as packaging, not to the parent-pom.xml

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