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Java getClass().getClassLoader().getResource(path) fails inside Maven shaded .jar

When running my project directly with java, I can confirm that a particular method is able to fetch a resource via getClass().getClassLoader().getResource(path), where path is docs/info.md and there exists a file at src/main/resources/docs/info.md
After the project is packaged with Maven into the final executable .jar, I can confirm that the path docs/info.md has been included via jar tf myproject.jar
However, when that .jar is executed, the same getClass().getClassLoader().getResource(path) returns null.
Here's myproject.pom:
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<!-- io.outright.myproject [parent] -->
<parent>
<groupId>io.outright</groupId>
<artifactId>myproject</artifactId>
<version>1.0-SNAPSHOT</version>
</parent>
<!-- io.outright.myproject -->
<groupId>io.outright.myproject</groupId>
<artifactId>hub</artifactId>
<version>1.0-SNAPSHOT</version>
<name>hub</name>
<!-- props -->
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<!-- deps -->
<dependencies>
<!-- ....removed for readability.... -->
</dependencies>
<!-- build -->
<build>
<resources>
<resource>
<directory>${basedir}/src/main/resources</directory>
<includes>
<include>**/*</include>
</includes>
</resource>
</resources>
<plugins>
<!-- Integration tests -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.19</version>
<executions>
<execution>
<id>integration-test</id>
<phase>integration-test</phase>
<goals>
<goal>integration-test</goal>
</goals>
</execution>
<execution>
<id>verify</id>
<phase>verify</phase>
<goals>
<goal>verify</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<inherited>true</inherited>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
</configuration>
</plugin>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<!--<classpathPrefix>lib/</classpathPrefix>-->
<mainClass>io.outright.myproject.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.4.3</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<artifactSet>
<excludes>
<exclude>junit:junit</exclude>
<!--<exclude>log4j:log4j:jar:</exclude>-->
</excludes>
</artifactSet>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

Use getResourceAsStream instead of getResource. getResource returns the URL of file, not the file itself. Then write the InputStream to a file, and use that file.
ClassLoader classLoader = getClass().getClassLoader();
if (classLoader.getResourceAsStream(filePath) == null) {
// throw error
}
InputStream inputStream = classLoader.getResourceAsStream(filePath);
// write input stream to a file
I faced the same issue. This might help: Get directory path of maven plugin in its own Mojo

How to create a fat jar?

With SpringBoot, you have the #SpringBootApplication annotation, but what is the equivalent with the neat Java Spark framework?
IntelliJ creates a Maven project and I added the spark dependency, but running the install goal, I get a 5 KB jar with no manifest. Not an executable jar.
The pom.xml created thus far is as follows:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>sparkdemo</groupId>
<artifactId>sparkdemo</artifactId>
<version>1.0 </version>
<packaging>jar</packaging>
<name>sparkdemo</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.sparkjava</groupId>
<artifactId>spark-core</artifactId>
<version>2.5.4</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<optimize>true</optimize>
<debug>true</debug>
</configuration>
</plugin>
</plugins>
</build>
</project>
Would appreciate any suggestions....Thanks!

What you need here is an executable jar that will not only contain your classes, but also classes from all your dependencies.
For that you can use the Maven Assembly Plugin.
See the sample code below.
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>org.sample.App</mainClass> // specify your main class here
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
[...]
</project>
Then, run mvn package and the executable jar should be located in the folder target (with a name like ProjectName-1.0-SNAPSHOT-jar-with-dependencies.jar).

Looks like you are looking for maven assembly plugin
Add this in the plugin section and run mvn package
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>assemble-all</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>

How to avoid the generation of default jar when specifying a final name?

We are using maven profile to build a jar specific to tomcat.
<profile>
<id>TOMCAT</id>
<build>
<plugins>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<id>default-jar</id>
<phase>package</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<finalName>${project.artifactId}-tomcat-${project.version}</finalName>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-core</artifactId>
<version>5.7.0</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.apache.geronimo.specs</groupId>
<artifactId>geronimo-j2ee-management_1.1_spec</artifactId>
<version>1.0.1</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.jboss.javaee</groupId>
<artifactId>jboss-jms-api</artifactId>
<version>1.1.0.GA</version>
</dependency>
</dependencies>
</profile>
My expectation is to create a single jar with name acme-tomcat-0.0.1-SNAPSHOT.jar but on building the project, maven is generating another one (a default one) acme-0.0.1-SNAPSHOT.jar. How can we avoid the generation of the second one (acme-0.0.1-SNAPSHOT.jar)?
Thanks

I've only used Maven a few times to build projects, and I've generated WARs for Tomcat instead of JARs, but the process should be similar.
My build looks like this:
<build>
<finalName>sb</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
The header at the top goes like this:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.majisto.socialbusiness</groupId>
<artifactId>socialbusiness</artifactId>
<version>0.0.2</version>
<packaging>war</packaging>
<name>socialbusiness</name>
I imagine if you switch the packaging row to JAR you should get one JAR file out of it. The finalName in the build determines the filename and I think where you have it might be the confusing part to Maven. Let me know if you have any other questions. Maven made working with Spring so much easier. Are you using "maven package" in the CLI?

By changing the build section in the profile section from
<build>
<plugins>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<id>default-jar</id>
<phase>package</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<finalName>${project.artifactId}-tomcat-${project.version}</finalName>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
to
<build>
<finalName>${project.artifactId}-tomcat-${project.version}</finalName>
</build>
helped me to solve this issue

Copy all dependencies jars from child projects into parent project directory

I'm trying to build a Maven parent project script which incorporates a 3rd party project (with all its dependencies) and another couple of projects of mine.
I'd like to copy all dependencies (I mean ALL dependencies, including jars requested by other dependencies which in turn are requested by one of my child project) to a parent project directory, e.g. "lib", so that I can just run java with a wildcard classpath:
java -cp "lib/*" package.blah.blah.Main
I tried with various methods using the maven-dependency-plugin such as copy-dependencies, but all I can point Maven to is my own child projects, not their dependencies (I mean in the parent project pom).
This is the parent project pom I've been writing:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<properties>
<server.version>7.0.2</server.version>
<ext.version>1.0-alpha3-SNAPSHOT</ext.version>
</properties>
<modelVersion>4.0.0</modelVersion>
<groupId>org.kontalk</groupId>
<artifactId>tigase-kontalk</artifactId>
<version>devel</version>
<packaging>pom</packaging>
<modules>
<module>../tigase-server/modules/master</module>
<module>../tigase-extension</module>
</modules>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-artifact</id>
<phase>package</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>org.kontalk</groupId>
<artifactId>tigase-server</artifactId>
<version>${server.version}</version>
<type>jar</type>
</artifactItem>
<artifactItem>
<groupId>org.kontalk</groupId>
<artifactId>tigase-extension</artifactId>
<version>${ext.version}</version>
<type>jar</type>
</artifactItem>
</artifactItems>
<outputDirectory>bin</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.kontalk</groupId>
<artifactId>tigase-server</artifactId>
<version>${server.version}</version>
</dependency>
<dependency>
<groupId>org.kontalk</groupId>
<artifactId>tigase-extension</artifactId>
<version>${ext.version}</version>
</dependency>
</dependencies>
</dependencyManagement>
</project>
It will copy just the two direct child project jars in the bin directory, but nothing else.
I'm thinking of doing a manual copy (as in a Maven copy) to brutally copy all jars from my child projects' target/dependency directories, but it just seems... brutal.
If it can't be done with the existing Maven software, I can even be content with using maven exec directly (which, I hope, should set up classpath automatically, right?)
EDIT: I'd like to modify the child projects poms as little as possible, especially the 3rd party one.

If you want to build a simply runnable jar file with maven then you can use this config:
<profiles>
<profile>
<id>dist</id>
<activation>
<activeByDefault>false</activeByDefault>
</activation>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<finalName>yourJarName</finalName>
<appendAssemblyId>false</appendAssemblyId>
<archive>
<manifest>
<mainClass>your.MainClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>dist</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
then you can build it using mvn clean package -Pdist
edit: then you can run it with java -jar target/yourJarName.jar

I ended up using copy-dependencies. This is the main project pom:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.8</version>
<executions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.basedir}/jars</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>2.4.3</version>
<executions>
<execution>
<id>copy-resources</id>
<phase>install</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<outputDirectory>jars</outputDirectory>
<resources>
<resource>
<directory>../tigase-extension/target/lib</directory>
<excludes>
<exclude>junit*</exclude>
</excludes>
</resource>
<resource>
<directory>../tigase-server/target/lib</directory>
<excludes>
<exclude>junit*</exclude>
</excludes>
</resource>
<resource>
<directory>../tigase-extension/target</directory>
<includes>
<include>tigase-extension-*.jar</include>
</includes>
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
In the submodules I've added to the same plugin this code:
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
Basically, the submodules copy their dependency jars into target/lib, then the main project copies those jars into its own jars folder.
It has some project-specific filenames and other hard-coded things, but still I think this is the best option if I want to use only Maven-provided tools. Probably a new Maven plugin would have been optimal, but I don't really have the time.

Avoid Maven profiles to generate duplicated jars

I'm new to Maven and I'm trying to configure Maven to generate 2 jars: one for development and one for production. The only difference between them is a config.properties file that have the database connection different so I thought I could use Maven profiles.
To my surprise I can't generate both files at once. When using profiles, each time you build you have to select the profile and a jar (in my case) will be created using the profile. The thing is that it will create 2 exactly equals jars, one without a classifier and one with the classifier (like myjar.jar and myjar-prod.jar) so if I want to generate the dev and the prod jar I have to create 4 jars (running first Maven with one profile and after that with another profile)
Why is this? Doesn't make any sense to me... but ok...
My question is:
Is there a way I could avoid the two jars from being generated? I mean, I want to have different profiles, and I have accepted (with grief) to execute multiple times the build process (one for each profile), could I avoid to have each time 2 jars and have only one without the classifier?
This is my pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.p2p.</groupId>
<artifactId>LoadACHFiles</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>MyProject</name>
<url>http://maven.apache.org</url>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<excludes>
<exclude>config-*.properties</exclude>
</excludes>
</resource>
</resources>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>org.jasypt</groupId>
<artifactId>jasypt</artifactId>
<version>1.9.0</version>
<type>jar</type>
</dependency>
</dependencies>
<profiles>
<profile>
<id>prod</id>
<build>
<plugins>
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>test</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<!--<delete file="${project.build.outputDirectory}/config.properties"/>-->
<copy file="src/main/resources/config-prod.properties"
tofile="${project.build.outputDirectory}/config.properties"/>
</tasks>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.13</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<classifier>prod</classifier>
<source>1.6</source>
<target>1.6</target>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>

If you are okay with having classified jars, you may do what you want without profiles, so you may have jars for all environments with a single build command. The key is to understand how Maven filtering works.
This is expanding on an answer I provided to a similar question. Start with that setup. Then:
Create config.properties in your src/main/resources, containing properties your app needs.
my.database.url=${database.url}
my.database.user=${database.user}
my.database.pw=${database.pw}
Now, create prod.properties and dev.properties in ${basedir}/src/main/filters holding appropriate values for each environment.
database.url=URL-for-dev
database.user=user-for-dev
database.pw=pw-for-dev
When you run mvn clean package, Maven will copy the contents of /src/main/resources, including config.properties, doing property replacement during the copy. Because there are multiple executions of both resources and jar plugins, Maven will create separate classified jar files. Each will contain a config.properties file, holding the correct properties for the environment. The filters will not end up in the built jars.

I made it removing the maven jar plugin in the profile section. Changed this:
<profile>
<id>prod</id>
<build>
<plugins>
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>test</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<!--<delete file="${project.build.outputDirectory}/config.properties"/>-->
<copy file="src/main/resources/config-prod.properties"
tofile="${project.build.outputDirectory}/config.properties"/>
</tasks>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.13</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<classifier>prod</classifier>
<source>1.6</source>
<target>1.6</target>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
For this:
<profile>
<id>prod</id>
<build>
<plugins>
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>test</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<!--<delete file="${project.build.outputDirectory}/config.properties"/>-->
<copy file="src/main/resources/config-prod.properties"
tofile="${project.build.outputDirectory}/config.properties"/>
</tasks>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.13</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>
</profile>