Having issues running java project through command line - maven

I am completely new to using maven. I have created a maven project and exported it to eclipse. Maven automatically created the src/test/java and src/main/java.
I created a java script and successfully ran it in eclipse. But when I try running it through command line, I got an error that says:
cannot find or load main class.
When I checked my project directory, there were two classfile paths: classes and test-classes. The script I was running is the one in 'test-classes' but it is not the main class. But the path to the main class executes successfully but that is not where my script is located.
The command I was using for the main classfile is:
java -cp target/Test-1.0-SNAPSHOT.jar com.mycompany.App.
The command for the test classfile is :
java -cp target/Test-1.0-SNAPSHOT.jar com.mycompany.AppTest.
This second command gives me the error I mentioned.
Please how do I get around this issue?

By convention, everything in src/test/java is supposed to be for testing only. That is, you should place only your test classes in this directory. Maven will run them before building the final JAR, but it will NOT include them in it.
If you absolutely need a JAR with your test classes, have a look at How to create a jar containing test classes.

Related

Error: Unable to access jarfile build/libs/gs-spring-boot-0.1.0.jar?

I follow the instructions in https://spring.io/guides/gs/spring-boot/#scratch, but when it says to run:
./gradlew build && java -jar build/libs/gs-spring-boot-0.1.0.jar
the build fails with the above error.
There is message before the failure that says:
Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0.
See https://docs.gradle.org/4.8.1/userguide/command_line_interface.html#sec:command_line_warnings
but everyone online says that's just a warning.
The build doesn't appear to create or download build/libs/gs-spring-boot-0.1.0.jar.
Currently completely blocked on first attempt to use Gradle.
I just had this problem.
The tutorial is in error in what you need to run. It should be
$ gradlew build && java -jar build/libs/gs-rest-service-0.1.0.jar
I think that they updated the code, but forgot to update the tutorial.
I had the same issue when build a simple project with Maven on Intellij IDEA. (Ubuntu 18.04.2).
Just typed terminal (in project directory):
$ sudo mvn package
$ java -jar ./target/(your-project-name)-(<version> at pom.xml).jar
For example my project name is hello-world-spring and version name in pom.xml is <version>0.0.1-SNAPSHOT</version>, I have to type:
$ sudo mvn package
$ java -jar ./target/hello-world-spring-0.0.1-SNAPSHOT.jar
Maybe this method can work for gradle as well.
Please check the path of the jar file build/libs/gs-spring-boot-0.1.0.jar. For your case, the jar might be in a different folder. If your code is in a module in the main project, then the jar will be in the build folder of the module.
If you git clone the repo, then the tutorial works. If you "To start from scratch, move on to Build with Gradle.", then the tutorial doesn't work. There are missing setup steps.
I got the same issue and I changed the command to java -jar target/rest-service-0.0.1-SNAPSHOT.jar (I checked the .jar file in target folder and found that the file name was incorrect).
Parent folder of my project was having spaces in it's name, i changed it to the underscore and it worked.
Looked at the command line as it was in the official guide:
./gradlew clean build && java -jar build/libs/gs-actuator-service-0.1.0.jar
First, the above command line has two parts:
(1) ./gradlew clean build //Use gradle wrapper to build
(2) java -jar build/libs/gs-actuator-service-0.1.0.jar //To run an application packaged as a JAR file
Now, one might run into issues with one part or both parts. Separating them and running just on thing at a time helped troubleshoot.
(1) didn't work for my Windows, I did the following instead and that built the application successfully.
.\gradlew.bat clean build
Now moving to (2) java -jar build/libs/gs-actuator-service-0.1.0.jar
It literally means that "Run a jar file that is called gs-actuator-service-0.1.0.jar under this directory/path: build/libs/" Again, for Windows, this translates to build\libs\ , and there's one more thing that may catch you: The jar file name can be slightly different depending on how it was actually named by the configuration in initial/setting.gradle:
rootProject.name = 'actuator-service'
Note that the official guide changed it from 'gs-actuator-service' to 'actuator-service' in their sample code but hasn't updated the tutorial accordingly. But now you know where the jar file name comes from, that doesn't matter anymore, and you have the choice to rename it however you want.
Having all the factors adjusted, below is what eventually worked in my case:
java -jar build\libs\actuator-service-0.0.1-SNAPSHOT.jar
or
java -jar C:\MyWorkspace\Spring\gs-actuator-service\initial\build\libs\actuator-service-0.0.1-SNAPSHOT.jar //with fully qualified path
If you are curious where does "-0.0.1-SNAPSHOT" come from, here it is:
in build.gradle
version = '0.0.1-SNAPSHOT'
Again, you have the choice to modify it however you want. For example, if I changed it to 0.0.2-SNAPSHOT, the command line should be adjusted accordingly
java -jar build\libs\actuator-service-0.0.2-SNAPSHOT.jar
Reference: https://docs.oracle.com/javase/tutorial/deployment/jar/basicsindex.html
Because you are trying to execute .jar file that doesn't exist. After building the project go to ./build/libs and check the name of freshly built .jar file and then in your project directory run:
./gradlew build && java -jar build/libs/name-of-your-jar-file.jar
or you can set version property to empty string in your build.gradle file
version = ''
after that:
./gradlew build && java -jar build/libs/your-project-name.jar
For Windows, these commands solved the problem: "Error: Unable to access jarfile springboot.jar":
cd target
java -jar springboot-0.0.1-SNAPSHOT.jar
run ./mvnw package
Now a folder named target is created and you can see a jar file inside it.
then execute java -jar target/<jarfilename>

problems running state machine examples

Congratulations on the spring state machine, I found it yesterday and have been trying it out, specifically the turnstile example running in STS. I found it very easy and intuitive to build a FSM.
Because spring shell doesn't work well in STS I tracked down the instructions to run the examples from the command line in the reference doc,
"java -jar
spring-statemachine-samples-turnstile-1.0.0.BUILD-SNAPSHOT.jar"
,
but running it got an error
"no main manifest attribute, in spring-statemachine-samples-turnstile-1.0.0.BUILD-SNAPSHOT.jar".
Although not even a novice in using gradle, I tried fixing this by adding this line to build.gradle in the jar section
"manifest.attributes['Main-Class'] = 'demo.turnstile.Application'"
(which doesn't handle the various sub-projects I know) but got this error
"NoClassDefFoundError: org/springframework/shell/Bootstrap".
If it is possible to run the samples from gradle, could you include them in the reference document? I tried running the samples using
gradle run
but it there was no interaction with the shell scripts.
Samples are designed to be run as executable jar and with shell so that you can interact without a need to recompile with every change. Your error indicates that you didn't build that sample jar as mentioned in docs.
./gradlew clean build -x test
This will automatically use spring boot plugin which will add the necessary jar manifest headers to jar meta info to make it a true executable jar. Essentially every every sample is a spring boot app.
Building SM sample projects in Windows Environment:
Open Command prompt (windows key + r -->cmd-->Enter), Change directory to project root folder spring-statemachine-master (Inside the Extracted folder).
Run gradlew install to get all spring dependencies copied to local machine.
Run gradlew clean build -x test to get the spring shell jars built. Courtesy Janne
These steps should ideally get all .jar built, look into \build\libs folder of respective sample project for jar files.
Run the like any other java jar file java -jar [jar-file-name.jar] (make sure to be change directory to jar file directory location).
One more thing where I was stuck was, How to give events to SM:
It's like this sm event EVENT_NAME_AS_DEFINED_IN_CLASS. Ref
E.g.: sm event RINSE --> to washer project

How do I run a java program in cmd?

I have created a program in Java, but it is not taking the inputs correctly in edit-plus(compiler) so now I want it to run in cmd. My JSK file is at : C:\Program Files\Java\jdk1.7.0_21\bin and my Java file is at: C:\TurboC4\TC\java new programs
Please tell me the steps to run it in cmd.
On the command line use:
java -jar path/to/your/jar_file.jar
if you do not have a jar file, than you have to compile first your Java classes:
javac -g Foo.java
if you have just a single file (containing a static void main()) than you can simply run it with:
java path/to/your/compiled_class_file [<command line args>, ...]
Note: Run the command above without .class extension. i.e.
java Foo
if you want to generate a jar file from your compiled .class files run:
jar cf jar-file input-file(s)
However, I would recommend you to use a IDE that compiles, packs and runs your code for you automatically with one click. i.e. IntelliJ or Eclipse
If your class is not into a package and is compiled as java.class in C:\TurboC4\TC\:
cd C:\TurboC4\TC\
C:\Program Files\Java\jdk1.7.0_21\bin java
If you just want to run your single java class as a command line program, then the answer is in This question.
Example:
java my.class.HelloWorld
If you have compiled an entire java project into a JAR file, check this Stackoverflow question for the answer.
Example:
java -cp c:\location_of_jar\myjar.jar com.mypackage.myClass

Running a groovy script created in STS(Spring Tool Suite) using the command line

I have used the STS(Spring Tool Suite) to create a compiled groovy script which exists as a file on windows called Test.class. I am able to right click on the file in STS and execute it which works well.
However - I want to be able to execute the script on the windows command line, so far I have tried various ways but have not been successful. I have tried the following...
java -cp C:\Users\MyName\springsource\sts->
3.1.0.RELEASE\plugins\org.codehaus.grails.bundle_2.1.1\content\lib\
org.codehaus.groovy\groovy-all\jars\groovy-all-1.8.8.jar Test.class
But that does not work it gives me an error --> Error: Could not find or load main class Test.class
Any Pointers?
You are trying to run a test case, so you really ned to be launching junit and ass this test as the test to run.
The easiest thing to do is to download a distribution of groovy, unzip, and run:
groovy Test.groovy
Step 1
In STS(Spring Tool Suite) ,Create a Groovy Class e.g. Customer.groovy file. Specify a Package Name e.g. com.customer. In the main method put in code to validate the code is being called e.g. println ‘test’.
Step 2
Go to your command line (Windows use command prompt). Switch\cd to the ROOT directory of your project. Execute the command below.
Step 3
execute java -cp C:\Users\Profile\springsource\sts-3.1.0.RELEASE\plugins\org.codehaus.grails.bundle_2.1.1\content\lib\org.codehaus.groovy\groovy-all\jars\groovy-all-1.8.8.jar;. com.customer.Customer
The code should run.
V Important
If like me, you do not have a class and you only have a groovy script then in step#3 specify the Groovy script name without the suffix.
Test is naked? (without package name?) try this.
java -cp C:\Users\MyName\springsource\sts-> 3.1.0.RELEASE\plugins\org.codehaus.grails.bundle_2.1.1\content\lib\ org.codehaus.groovy\groovy-all\jars\groovy-all-1.8.8.jar;. package.Test
Pay attention to ;. and package name.

How run mahout in action example ReutersToSparseVectors?

I want run "ReutersToSparseVectors.java". I can compile and created JAR file without problem.
I compiled this file by below command:
javac -classpath hadoop-core-0.20.205.0.jar:lucene-core-3.6.0.jar:mahout-core-0.7.jar:mahout-math-0.7.jar ReutersToSparseVectors.java
created JAR file with below command:
jar cvf ReutersToSparseVectors.jar ReutersToSparseVectors.class
When I write java -jar ReutersToSparseVectors.jar to run, give me below error:
Failed to load Main-Class manifest attribute from
ReutersToSparseVectors.jar
Do you can help me to solve this problem?
IF this example can run with hadoop, please me that how i can run this with hadoop.
instead of using -jar option, then it's better to to run:
java -cp mahout-core.jar:... mia.clustering.ch09.ReutersToSparseVectors
or you can use mvn exec:java command, as described in README for examples...
mvn exec:java -Dexec.mainClass="mia.clustering.ch09.ReutersToSparseVectors"
Or you can run this file directly from your IDE (assuming, that you correctly imported Maven project).
P.S. your command isn't working, because to run with -jar switch, the .jar file should have special entry in manifest that describes that class should be started by default...
P.P.S. It's better to use book's examples with Mahout 0.7, as they were tested for it. You can use it with version 0.7 if you need, by then you need to take source code from mahout-0.7 branch of repository with examples (link is above)

Resources