Java

Different ways of loading a file as an InputStream

There are subtle differences as to how the fileName you are passing is interpreted. 

Basically, you have 2 different methods: ClassLoader.getResourceAsStream() and Class.getResourceAsStream(). These two methods will locate the resource differently.

In Class.getResourceAsStream(path), the path is interpreted as a path local to the package of the class you are calling it from.

 For example calling, String.getResourceAsStream("myfile.txt") will look for a file in your classpath at the following location: "java/lang/myfile.txt". 

 If your path starts with a /, then it will be considered an absolute path, and will start searching from the root of the classpath. 

So calling String.getResourceAsStream("/myfile.txt") will look at the following location in your class path ./myfile.txt.

ClassLoader.getResourceAsStream(path) will consider all paths to be absolute paths. 

So calling String.getClassLoader().getResourceAsString("myfile.txt") and String.getClassLoader().getResourceAsString("/myfile.txt") will both look for a file 

in your classpath at the following location: ./myfile.txt.

Every mention of location in this post,  could be a location in your filesystem itself, or inside the corresponding jar file, depending on the Class and/or ClassLoader you are loading the resource from.

In  case, you are loading the class from an Application Server, so your should use 

Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName) 

instead of this.getClass().getClassLoader().getResourceAsStream(fileName). this.getClass().getResourceAsStream() will also work.

Regex

String emailRegEx =

 "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";

  last name : [a-zA-z]+([ '-][a-zA-Z]+)*

   phone : ^\\+?[0-9\\-]+\\*?$

Issue 

JDK 13 , using maven project , maven dependencies does not appear in class path 

Solution : add below to .classpath

<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">

    <attributes>

        <attribute name="maven.pomderived" value="true"/>

    </attributes>

</classpathentry>

Basic MAVEN commands

Spcifific test classes 

mvn test -Phmof,bamboo-app -Dmaven.surefire.debug -Dtest=com.dao.SectionDaoDBTest#createExtraData_OK

Run test in Debug

mvn -Dmaven.surefire.debug="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 -Xnoagent  -Djava.compiler=NONE"

will use 4 threads

mvn -T 4 install 

will use 1 thread per available CPU core

mvn -T 1C install 

mvn install -pl $moduleName -am

pl – makes Maven build only specified modules and not the whole project.

-am – makes Maven figure out what modules out target depends on and build them too.

-DdependencyLocationsEnabled=false to your MAVEN_OPTS variables. This addition will mean Maven will retain fewer outgoing connections throughout the build and maybe shave a few seconds off your build as well.

mvn spring-boot:run -Dspring.profiles.active=dev

mvn spring-boot:run  -Dspring.profiles.active=dev -Drun.profiles=dev

run specific tests 

mvn test -Dspring.profiles.active=dev -Dtest=com.api.v1.controller.InfoControllerTest#testGetInfoValidation4

run with multiple profiles 

mvn clean install -Psomedet,local-app,create-db -DskipTests