No goals have been specified for this build

When we started a maven project without setting the run goal then the Maven build will get failed and generate the below error "No goals have been specified for this build. You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>:<plugin-artifact-id>[:<plugin-version>]:<goal>. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy. -> [Help 1]". 

In this case, we have to set the maven goal e.g. clean install to successfully build and run the project or application. 

Resolution

If you are running using IDE then please set the command line as mentioned below and restart the build. To set the command line with IntelliJ, please go to Run >> Edit Configurations >> Select your project >> Select Parameters tab from left >> put clean install in command line field.

Now rerun the maven build.

Error while running the Maven project.

[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.882 s
[INFO] Finished at: 2021-06-09T07:28:32+05:30
[INFO] ------------------------------------------------------------------------
[ERROR] No goals have been specified for this build. You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>:<plugin-artifact-id>[:<plugin-version>]:<goal>. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy. -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/NoGoalSpecifiedException

Process finished with exit code 1

Diamond operator is not supported in source

While running a Java project with IntelliJ, we might face an error stating "diamond operator is not supported in -source 1.5", which means we are trying to run the project on a lower version of Java which is developed on a higher version.

Error statement 

java: diamond operator is not supported in -source 1.5

  (use -source 7 or higher to enable diamond operator)

Solution/Apply the following fix

Go to File option from menu >> Project Structure >> Project Settings >> Modules. Here in Module, we need to use the higher version of language level under the Source tab 

Hope this helps you!

Cast an object to Integer in Java

We could cast an object that have integer value into an integer using below Java code.

int value = Integer.parseInt(object.toString());