Develop Reference

Using getResource() throws nullpointer exception. How should I fix? [duplicate]

Hello I'm using a configuration file from src/main/resources in my java application. I'm reading it in my Class like this :
new BufferedReader(new FileReader(new File("src/main/resources/config.txt")));
So now I'm building this with maven using mvn assembly:assembly. Here is the bit for that in my pom.xml :
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.3</version>
<configuration>
<finalName>TestSuite</finalName>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.some.package.Test</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
So when I run my app I get this error :
src\main\resources\config.txt (The system cannot find the path specified)
But when I right click on my assembled jar I can see it inside, anyone knows what I'm doing wrong?

Resources from src/main/resources will be put onto the root of the classpath, so you'll need to get the resource as:
new BufferedReader(new InputStreamReader(getClass().getResourceAsStream("/config.txt")));
You can verify by looking at the JAR/WAR file produced by maven as you'll find config.txt in the root of your archive.

FileReader reads from files on the file system.
Perhaps you intended to use something like this to load a file from the class path
// this will look in src/main/resources before building and myjar.jar! after building.
InputStream is = MyClass.class.getClassloader()
.getResourceAsStream("config.txt");
Or you could extract the file from the jar before reading it.

The resources you put in src/main/resources will be copied during the build process to target/classes which can be accessed using:
...this.getClass().getResourceAsStream("/config.txt");

Once after we build the jar will have the resource files under BOOT-INF/classes or target/classes folder, which is in classpath, use the below method and pass the file under the src/main/resources as method call getAbsolutePath("certs/uat_staging_private.ppk"), even we can place this method in Utility class and the calling Thread instance will be taken to load the ClassLoader to get the resource from class path.
public String getAbsolutePath(String fileName) throws IOException {
return Thread.currentThread().getContextClassLoader().getResource(fileName).getFile();
}
we can add the below tag to tag in pom.xml to include these resource files to build target/classes folder
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.ppk</include>
</includes>
</resource>
</resources>

I think assembly plugin puts the file on class path. The location will be different in in the JAR than you see on disk. Unpack the resulting JAR and look where the file is located there.

You can replace the src/main/resources/ directly by classpath:
So for your example you will replace this line:
new BufferedReader(new FileReader(new File("src/main/resources/config.txt")));
By this line:
new BufferedReader(new FileReader(new File("classpath:config.txt")));

File not found exception, only when including the code as a maven dependency

I have written this project which has a bunch of config files in config/ folder, which are necessary for running:
https://github.com/danyaljj/jwnl-prime/
The code is working fine under mvn test in my computer and CI.
But after packaging it and adding it as a maven dependency to another project, the function calls give me error
java.io.FileNotFoundException: config/file_properties.xml (No such file or directory)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)
at net.didion.jwnl.TestDefaults.getInputStream(TestDefaults.java:63)
at net.didion.jwnl.JWNL.initialize(JWNL.java:92)
Any idea why I am getting this weird behavior?
Update:
after extracting the jar file, it turns out that the config files are not included in the jar:
Update2: After adding the suggestion by ? the config files get included in the jar file:
But still getting the same error: config/file_properties.xml (No such file or directory)

If you have project structure other than standard format you need to update pom.xml as well. If you need to include the config for build you need to add that in build section like
Refer link enter link description here
<build>
<extensions>
<extension>
<groupId>org.apache.maven.wagon</groupId>
<artifactId>wagon-ssh</artifactId>
<version>2.4</version>
</extension>
</extensions>
<resources>
<resource>
<directory>config</directory>
<includes>
<include>**/**</include>
</includes>
</resource>
</resources>
</build>

First, verify that the configuration files are actually being packaged into the jar. I would view it in an archive viewer or unpack it and see what's in it.
Secondly, you can't directly load a file from a jar using standard file opening methods. You'll have to use something like
Class.getResourceAsStream()
See here for some more suggestions:
How do I access a config file inside the jar?

Onejar and resource loading

I have a maven project which I would like to package in an executable jar.
It's using quite a few dependencies, like spring and so on.
It was suggested in a few posts to use OneJar, to avoid a lot of headaches.
This is what I have currently in my pom.xml:
<plugin>
<groupId>org.dstovall</groupId>
<artifactId>onejar-maven-plugin</artifactId>
<version>1.4.4</version>
<executions>
<execution>
<configuration>
<mainClass>com.cool.project.Application</mainClass>
<onejarVersion>0.97</onejarVersion>
<attachToBuild>true</attachToBuild>
<classifier>coolproject</classifier>
</configuration>
<goals>
<goal>one-jar</goal>
</goals>
</execution>
</executions>
</plugin>
In my Spring configuration one of the classes needs to pass the a resource (src/main/resources/coolfile.bin) path to an external library (jsch) method:
String resource = ConfigurationClass.class.getClassLoader().getResource("coolfile.bin").getFile();
jsch.addIdentity(resource);
When I run Application.java from the IDE (eclipse), the entire application loads successfully.
Although when I run mvn clean install, the onejar jar is built under the target folder, but when I try to run it with java -jar coolproject.one-jar.jar the following error is displayed:
...
Caused by: java.io.FileNotFoundException: file:/target/coolproject.one-jar.jar!/main/coolproject.jar!/coolfile.bin (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:97)
at com.jcraft.jsch.IdentityFile.newInstance(IdentityFile.java:83
If I inspect coolproject.one-jar.jar, I can find the coolproject.jar under the main folder, and if I inspect that, I can see coolfile.bin in its root.
So in theory the resource should be found? What am I missing?

Turns out that FileInputStream would not find the path specified by resource.
Luckily jsch provides another method where you can pass the byte array of the file rather than its location:
jsch.addIdentity("coolfile.bin", toByteArray(ConfigurationClass.class.getResourceAsStream("/coolfile.bin")), null, null);

Add classpath to netbeans maven project

I have a java project which uses .properties files for configuration. On the server, when launching, I set the classpath to include a folder which contains all the properties files. On my local machine, I'd like to point to a different folder.
I'm looking to add to the classpath, ideally for all projects, but adding it to each project is also fine. I've tried changing the Run > VM Options to include classpath, but with that change it can't find the main class, and I get java.lang.NoClassDefFoundError. I've also tried changing nbactions.xml directly to set the classpath to -classpath ~\MyFolder\;%classpath, but this has the same problem.
To add to the difficulty, the server is running linux while my local machine is running Windows.

I stuck with topic-starter issue also for a long time. My goal - put config files for debug purpose in project root and extend classpath to ${basedir}, so this code:
String appConfigLocation = System.getProperty("config.location");
if (appConfigLocation == null) {
logger.error("System property 'config.location' is not set...");
System.exit(1);
}
InputStream appConfigStream = Main.class.getClassLoader().getResourceAsStream(appConfigLocation);
if (appConfigStream == null) {
logger.error("Can't find resource {} in classpath, fix 'config.location'...", appConfigLocation);
System.exit(1);
}
Properties appProps = new Properties();
try {
appProps.load(appConfigStream);
} catch (IOException ex) {
System.out.println("IO error during loading of {}...", appConfigLocation);
System.exit(1);
}
read configs from ${basedir}. I like that instead of putting them to src/main/resources.
Check sources of ExecMojo.java for v1.2.1 http://grepcode.com/file/repo1.maven.org/maven2/org.codehaus.mojo/exec-maven-plugin/1.2.1/org/codehaus/mojo/exec/ExecMojo.java?av=f :
if ( CLASSPATH_TOKEN.equals( args[i] ) ) {
commandArguments.add( computeClasspathString( null ) );
}
and and v1.3.2 http://grepcode.com/file/repo1.maven.org/maven2/org.codehaus.mojo/exec-maven-plugin/1.3.2/org/codehaus/mojo/exec/ExecMojo.java?av=f:
if ( args[i].contains( CLASSPATH_TOKEN ) ) {
commandArguments.add( args[i].replace( CLASSPATH_TOKEN,
computeClasspathString( null ) ) );
}
So update NB config Execute goals to new version:
process-classes org.codehaus.mojo:exec-maven-plugin:1.3.2:exec
and use complex -classpath args in exec.argsparams:
exec.args=-classpath %classpath:.:"${basedir}" \
-Dconfig.location=app.properties \
-Dlogback.configurationFile=logback.xml \
${packageClassName}
Fix any action you need to have such behavior:
See also:
http://wiki.netbeans.org/FaqEnvVarsDuringRun
http://wiki.netbeans.org/FaqSysPropsDuringRun

Hi I had a similar need to give NetBeans7.4 a classpath to a jar with a driver outwith Maven dependencies e.g. c:\Program Files\Java\jdk1.7.0_25\db\lib\derby.jar in a Java Maven project called MyProject.
As you were thinking with the Run > VM Options, I would suggest the following:
1) right-click on MyProject to open project Properties
2) in 'Project Properties' pop-up, select 'Actions'
3) locate 'Run pproject' among the 'Actions' and select it
4) edit in 'Set Properties' text box entering
exec.args=-cp %classpath;.;"c:\Program Files\Java\jdk1.7.0_25\db\lib\derby.jar" biz.letsweb.derbyconnect.App
exec.executable=java
exec.workingdir=c:\Users\Tomasz\Documents\NetBeansProjects\DerbyConnect\target\classes
Alternatively edit nbactions.xml analogically. Once I did this, I could simply run the project inside NetBeans by pressing green arrow.

what about having the properties included as ? and those you use locally only have in a 's and activate that profile on local machine?

This is how I've been adding classpath to many of my projects
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.nitinsurana.policereports.GUI</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>

An outside the box solution I ended up using for my similar case in NetBeans 7.3.1:
Adding files to java classpath at runtime
private static void addSoftwareLibrary(File file) throws Exception {
Method method = URLClassLoader.class.getDeclaredMethod("addURL", new Class[]{URL.class});
method.setAccessible(true);
method.invoke(ClassLoader.getSystemClassLoader(), new Object[]{file.toURI().toURL()});
}
This gives me a hacky way to add files to my classpath at run time via program arguments. Related notes I compiled while researching:
To include a dependency for compilation only, not runtime set:
Dependency Scope
<dependency><scope>provided</scope>...</dependency>
To exclude a dependency from the shaded jar, set: Exclude
<exclude>groupId:artifactId[[:type]:classifier]</exclude>
To copy resources to the target directory from outside the typical source directory: Copy Resources
<project>
...
<build>
<plugins>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>2.7</version>
<executions>
<execution>
<id>copy-resources</id>
<!-- here the phase you need -->
<phase>validate</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<outputDirectory>target/extra-resources</outputDirectory>
<resources>
<resource>
<directory>extra-resources</directory>
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
...
</build>
...
</project>
Note that the base path for directory is the project home. The linked post has <filtering>true</filtering> which can cause "invalid mark" in Netbeans 7.3.1.

Resource from src/main/resources not found after building with maven

Hello I'm using a configuration file from src/main/resources in my java application. I'm reading it in my Class like this :
new BufferedReader(new FileReader(new File("src/main/resources/config.txt")));
So now I'm building this with maven using mvn assembly:assembly. Here is the bit for that in my pom.xml :
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.3</version>
<configuration>
<finalName>TestSuite</finalName>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.some.package.Test</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
So when I run my app I get this error :
src\main\resources\config.txt (The system cannot find the path specified)
But when I right click on my assembled jar I can see it inside, anyone knows what I'm doing wrong?

Resources from src/main/resources will be put onto the root of the classpath, so you'll need to get the resource as:
new BufferedReader(new InputStreamReader(getClass().getResourceAsStream("/config.txt")));
You can verify by looking at the JAR/WAR file produced by maven as you'll find config.txt in the root of your archive.

FileReader reads from files on the file system.
Perhaps you intended to use something like this to load a file from the class path
// this will look in src/main/resources before building and myjar.jar! after building.
InputStream is = MyClass.class.getClassloader()
.getResourceAsStream("config.txt");
Or you could extract the file from the jar before reading it.

The resources you put in src/main/resources will be copied during the build process to target/classes which can be accessed using:
...this.getClass().getResourceAsStream("/config.txt");

Once after we build the jar will have the resource files under BOOT-INF/classes or target/classes folder, which is in classpath, use the below method and pass the file under the src/main/resources as method call getAbsolutePath("certs/uat_staging_private.ppk"), even we can place this method in Utility class and the calling Thread instance will be taken to load the ClassLoader to get the resource from class path.
public String getAbsolutePath(String fileName) throws IOException {
return Thread.currentThread().getContextClassLoader().getResource(fileName).getFile();
}
we can add the below tag to tag in pom.xml to include these resource files to build target/classes folder
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.ppk</include>
</includes>
</resource>
</resources>

I think assembly plugin puts the file on class path. The location will be different in in the JAR than you see on disk. Unpack the resulting JAR and look where the file is located there.

You can replace the src/main/resources/ directly by classpath:
So for your example you will replace this line:
new BufferedReader(new FileReader(new File("src/main/resources/config.txt")));
By this line:
new BufferedReader(new FileReader(new File("classpath:config.txt")));