We Keep Coding

hibernate jpa metamodel generator: "Problem with Filer: Attempt to recreate a file for type"

I need to generate JPA metamodel types but I can not get rid of the mentioned filer problem. I'm using maven and have simply added this dependency in my pom.xml which triggers the annotation processor automatically:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-jpamodelgen-jakarta</artifactId>
<version>5.5.7.Final</version>
<scope>provided</scope>
</dependency>

I made some further investigations regarding the filer problem and here is what I found out (if you are in a hurry to find out about the solution of the filer problem just jump to the bottom of this answer).
Using the following dependencies in maven triggers automatic generation of jpa static metamodel when running "mvn compile":
<dependencies>
<dependency>
<groupId>jakarta.persistence</groupId>
<artifactId>jakarta.persistence-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-jpamodelgen-jakarta</artifactId>
<scope>provided</scope>
<version>5.6.12.Final</version>
</dependency>
</dependencies>
BTW: There's really nothing else to be done for jpa static metamodel generation.
But make sure to look at the right location for the generated code. You will find it under target/generated-sources/annotations.
The filer problem occurs, if you have (a copy of) jpa static metamodel source code in your "usual" source code directory, e.g. src/main/java. You can solve this if you delete the files in the source code directory.
If your IDE now complains about unresolvable types named *_, just add target/generated-sources/annotations as source code folder in the IDE's build path.
Cheers!

Mockito cannot find defined class while running a test

I am having trouble with mockito dependencies.I wrote a sample test and when I ran it I got this exception
java.lang.NoClassDefFoundError: javassist/NotFoundException
at org.powermock.core.transformers.TestClassTransformerBuilder$RemovesTestMethodAnnotation.fromMethods(TestClassTransformerBuilder.java:62)
at org.powermock.tests.utils.impl.AbstractCommonTestSuiteChunkerImpl.createDefaultMockLoader(AbstractCommonTestSuiteChunkerImpl.java:126)
....
the full Exception can be viewed at : https://pastebin.com/xWqUX0Wc
and the
test code - https://pastebin.com/pbWLc27B
My dependencies are the following:
mockito-all-1.9.5.jar
powermock-api-mockito-1.6.3.jar
powermock-api-support-1.4.9.jar
powermock-core-2.0.4.jar
powermock-module-junit-1.7.4.jar
powermock-module-junit-common-1.7.4.jar
powermock-reflect-2.0.4.jar
powermock-test-utils-1.5.3.jar
Where can be the problem?I guess something is wrong with the version of the jars.What version of the jars would you suggest to use ?

Your are missing JavaAssist jar download below jars and add them into your projects or add them in maven pom.xml file.
<javaassist.version>3.20.0-GA</javaassist.version>
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>${javaassist.version}</version>
<scope>compile</scope>
</dependency>

No FileSystem for scheme:hdfs and Class org.apache.hadoop.DistributedFileSystem not found

I want to upload a file to HDFS. I compiled my code using following jars as dependencies:
hadoop-auth-2.6.1.jar,
hadoop-common-2.6.1.jar and
hadoop-hdfs-2.6.1.jar,
My code:
I compiled it with Ant. But, it gave me this error: No FileSystem for scheme:hdfs.
Then I changed the code and compiled again:
But now I got another error: Class org.apache.hdfs.DistributedFileSystem not found.
What's wrong? And what should I do?

DistributedFileSystem is part of hadoop-core.
To fix this problem, you need to include hadoop-core-1.2.1.jar also (Note: I am using Maven for building):
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
Overall, I am using following Maven dependencies:
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.7.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-core</artifactId>
<version>2.7.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>

While getting Hadoop Filesystem object like below
FileSystem fs = FileSystem.get(hdfsUrl,configuration);
If you get following error :
"No FileSystem for scheme:hdfs"
You can resolve it by setting following 2 properties on configuration.
configuration.set("fs.hdfs.impl","org.apache.hadoop.hdfs.DistributedFileSystem");
configuration.set("fs.file.impl", "org.apache.hadoop.fs.LocalFileSystem");
Now, you may get new error like below :
java.lang.ClassNotFoundException: Class org.apache.hadoop.hdfs.DistributedFileSystem not found
Hadoop-common.jar uses Thread.currentThread.getContextClassLoader() and configuration.getClassLoader to load classes.
So, if you set your classLoader by using
Thread.currentThread.setContextClassLoader(yourClassLoader);
configuration.setClassLoader(yourClassLoader);
you will be able to load required class from other hadoop jars (e.g. hadoop-hdfs)
Let me know if you need more help. And don't forget to upvote if you find this bit useful.

I have the same problem, when I compile my Java code into a executable jar and run the compiled jar. Always some error "Not found" (e.g. in your case no FileSystem...), which means some hadoop jar is not included in the compilation.
The solution is add the correct dependencies in the Maven/Gradle or add (all) the jars.
In my case, the hdfs is from the class org.apache.hadoop.hdfs.DistributedFileSystem from the jar: hadoop-hdfs-client-3.2.1.jar.
The relevant jars which have been used can be found in the log file (if you successfully run the program and have the log file). In my example is the following:
You can simply add all the jars (from the installed hadoop folder). They should be in the folder of common/hdfs/ ... under the folder: hadoop 3.2.1/share/hadoop. There are possible other jars which are used but not shown in the log. To be safe, just include all the jars. You can run hdfs classpath in the terminal to find the location of all the jars.
Once all the jars have been added, in your java code, you may also need to set the hadoop configuration
Configuration hadoopConfiguration = new Configuration();
hadoopConfiguration.addResource(new Path(CoreSiteXMLStr));
hadoopConfiguration.set("fs.hdfs.impl", "org.apache.hadoop.hdfs.DistributedFileSystem");

Why is Maven not resolving all dependencies for commons-configuration?

Summary
When trying XMLConfiguration configuration = new XMLConfiguration("config/config.xml"); with only commons-configuration 1.10 I need to add more depencies (namely commons-collections not newer than 3.2.1) to my maven setup. Why is that so and why doesn't maven simply resolve all needed dependencies?
Details
I am trying to get commons-configuration to work. First I wanted to use the latest version, 2.0-alpha2, which didn't work well at all since I was unable to configure Maven to download the correct ressources - but that is another story.
After I found out that version 1.10 is in fact "one point ten" (not "one point one zero") and thus the latest version of commons-configuration 1 (and covered by the tutorials), I decided to give it a try instead.
For my maven dependencies (integrated in eclipse) I used:
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.10</version>
</dependency>
However, when trying out this example:
package main;
import java.util.Iterator;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;
public class ConfigurationTest {
public static void main(String... args) {
try {
XMLConfiguration configuration =
new XMLConfiguration("config/config.xml");
Iterator<String> iterator = configuration.getKeys();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
} catch (ConfigurationException e) {
e.printStackTrace();
}
}
}
with the following config.xml:
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<configuration>
<property>value</property>
<nestedproperty>
<arrayvalue>0,1,2,3,4</arrayvalue>
<property>anothervalue</property>
</nestedproperty>
</configuration>
I got the error:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/collections/CollectionUtils
at org.apache.commons.configuration.XMLConfiguration.constructHierarchy(XMLConfiguration.java:640)
at org.apache.commons.configuration.XMLConfiguration.initProperties(XMLConfiguration.java:596)
at org.apache.commons.configuration.XMLConfiguration.load(XMLConfiguration.java:1009)
at org.apache.commons.configuration.XMLConfiguration.load(XMLConfiguration.java:972)
at org.apache.commons.configuration.XMLConfiguration$XMLFileConfigurationDelegate.load(XMLConfiguration.java:1647)
at org.apache.commons.configuration.AbstractFileConfiguration.load(AbstractFileConfiguration.java:324)
at org.apache.commons.configuration.AbstractFileConfiguration.load(AbstractFileConfiguration.java:261)
at org.apache.commons.configuration.AbstractFileConfiguration.load(AbstractFileConfiguration.java:238)
at org.apache.commons.configuration.AbstractHierarchicalFileConfiguration.load(AbstractHierarchicalFileConfiguration.java:184)
at org.apache.commons.configuration.AbstractHierarchicalFileConfiguration.<init>(AbstractHierarchicalFileConfiguration.java:95)
at org.apache.commons.configuration.XMLConfiguration.<init>(XMLConfiguration.java:261)
at main.ConfigurationTest.main(ConfigurationTest.java:12)
I first hoped they (not me, of course) just screwed up some maven dependencies and since I wouldn't bother which version to use anyway anymore (I didn't get 2.0 to work, remember?) I decided to go down to version 1.9 by replacing the maven dependency with:
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.9</version>
</dependency>
That solved the problem pretty well, the test case is running:
property
nestedproperty.arrayvalue
nestedproperty.property
But when I tried to implement a similar example to the one referenced in Very simple Apache-commons configuration example throws NoClassDefFoundError and its follow-up question I got the exact same error which is referenced there - but the solution, importing org.apache.commons.beanutils.PropertyUtils is not working as I am missing the beanutils. So basically by downgrading I just switched from the error of missing the collections to missing beanutils.
There is a dependency overview where you can see which dependencies are used when you do what. I was a bit suprised to learn that version 1.10 now used other dependencies (namely the CollectionUtils) than 1.9 did in the constructor call. Since there were dependency problems in 1.10 as well as in 1.9 I just sticked to the newer version.
I found the CollectionUtils located in the following artifact (as I was pointed there by its maven repository):
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>4.0</version>
</dependency>
Sadly that one (not obvious to me at first) doesn't define the class CollectionUtils in the package collections, but in the package collections4. It was hinted at this problem on the dependency overview, but they only mentioned possible problems with earlier versions... I appeared to be at a point of not thinking much about it anymore but simply changed the dependency to:
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.2.1</version>
</dependency>
I got everything to work (more or less, but the Exceptions I get now are not anymore depending on missing class definitions) after using these dependencies:
<dependencies>
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.10</version>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.2.1</version>
</dependency>
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.9.2</version>
</dependency>
</dependencies>
Why do I have to add the dependencies myself? I thought the whole point in using maven is to avoid having to do such things and in terms of javadocs and source files it does a pretty good job.
By now I am convinced that the dependencies are not included in the hierarchy by design (is that so?), probably to avoid overhead. However is there a way to either simply get all dependencies at once or even better to get all dependencies I need? And why is it designed this way?

If we analyse commons-configuration's POM we see that the commons-collections dependency is optional:
<dependencies>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.2.1</version>
<optional>true</optional>
</dependency>
...
Furthermore, from the Maven docs:
If a user wants to use functionality related to an optional
dependency, they will have to redeclare that optional dependency in
their own project.

This issue is explained on the Runtime dependencies page of the Commons Configuration website.
Quoting from that page:
A lot of dependencies are declared in the Maven POM. These are all needed during compile time. On runtime however you only need to add the dependencies to your classpath that are required by the parts of the Commons Configuration package you are using. The following table helps you to determine which dependencies you have to include based on the components you intend to use.
The other answers explain why this works from a Maven perspective. This answer is intended to provide a defence, of sorts, to the Commons Configuration folks. They did at least warn you!
In cases where the dependencies are on other Apache Commons components, they've taken the time to test with a variety of versions and have posted information on compatibility at the bottom of that page.

Maven tries to resolve all necessary dependencies for a library you're using in your pom. Well sometimes you have some dependencies which are only necessary for some specific features and you don't want to force the user of your dependency to download it if he doesn't use it. Then you're declaring your dependency as optional. This happened with commons-collections within commons-configuration. See commons-configuration-pom here

NoSuchMethod error getting a gdata service

I get the following error:
Exception in thread "main" java.lang.NoSuchMethodError: com.google.common.collect.ImmutableSet.of([Ljava/lang/Object;)Lcom/google/common/collect/ImmutableSet;
at com.google.gdata.wireformats.AltFormat$Builder.setAcceptableTypes(AltFormat.java:399)
at com.google.gdata.wireformats.AltFormat$Builder.setAcceptableXmlTypes(AltFormat.java:387)
at com.google.gdata.wireformats.AltFormat.<clinit>(AltFormat.java:49)
at com.google.gdata.client.Service.<clinit>(Service.java:558)
at testproject.TestProject.run(TestProject.java:22)
at testproject.TestProject.main(TestProject.java:31)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)
This comes from the following code:
package testproject;
import com.google.gdata.client.youtube.YouTubeService;
import com.google.gdata.util.*;
import java.util.logging.*;
public class TestProject {
public static void main(String[] args) {
try {
YouTubeService service = new YouTubeService("Test", "developerKey");
service.setUserCredentials("root#gmail.com", "pa$$word");
} catch (AuthenticationException ex) {
Logger.getLogger(TestProject.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
At first, I included every library in http://code.google.com/p/gdata-java-client/downloads/list and also imported much more than I needed to.
I've since removed the libraries I deemed unnecessary (thanks thinksteep). So the libraries I'm currently including are the following libraries:
mail.jar
activation.jar
ant.jar
gdata-core-1.0.jar
gdata-media-1.0.jar
guava-11.0.1.jar
gdata-youtube-2.0.jar
gdata-youtube-met-2.0.jar
(There are probably a few libraries there which are not necessary... But I'm at my whit's end...)
I'm just trying to test getting a YouTube service so I can get things going on this project, but no dice. Oh, and I've also included this library: http://code.google.com/p/guava-libraries because before I was getting a NoClassDefFound error and including that library seemed to solve it. Thank you in advance for the help!
Oh, and I also followed every step exactly (or at least I think so) in the gdata getting started guide. My test build was successful by the end... Thanks again!

Adding more than required may cause issue too. java.lang.NoSuchMethodError error typically happens in case where runtime couldn't find required method with exact signature. Possible causes are:
1) There might be mulitple jars with same code, which may cause wrong class get loaded.
2) Incompatable version of jar, the jar you have in classpath might be older version/newer version.
Make sure none of those cases happening.

Issue with latest version of gdata still referencing older guava methods
Check Out
http://code.google.com/p/gdata-java-client/issues/detail?can=2&start=0&num=100&q=&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary&groupby=&sort=&id=344
Solution
I switched to guava-r07.jar located at
http://code.google.com/p/guava-libraries/downloads/detail?name=guava-r07.zip&can=4&q=
This got me past
ContactsService service = new ContactsService("");
Jar's in use:
Default Eclipse plugin jar's
gdata-base-1.0.jar
gdata-client-1.0.jar
gdata-contacts-3.0.jar
gdata-core-1.0.jar
gdata-media-1.0.jar
guava-r07.jar
Apache (servlet-api.jar)
JavaMail (mail.jar)
JavaBeans Activation Framework (activation.jar)

I dont know if its still relevant but i had the same exception
there is a problem with guava 11.02.jar (currently latest version)
when using guava-10.0.1 (can be found here) everything went well.

The Required library jars are as follows.
gdata-client-1.0.jar
gdata-core-1.0.jar
gdata-media-1.0.jar
gdata-youtube-2.0.jar
guava-11.0.2.jar
java-mail-1.4.4.jar
I am using the above mentioned library . Please make use of it ; because the ultimate aim is to get the YouTubeService Object. Check below for the code snippet.
package com.baba.test;
/*
* Author : Somanath Nanda
*/
import java.net.MalformedURLException;
import java.net.URL;
import com.google.gdata.client.youtube.YouTubeQuery;
import com.google.gdata.client.youtube.YouTubeService;
public class Test {
private static final String CLIENT_ID = "XXXXXXXX.XXXXX.XXX.XXX";
private static final String DEVELOPER_KEY = "*********************************88";
public static void main(String[] args) throws MalformedURLException {
YouTubeService service = new YouTubeService(CLIENT_ID,DEVELOPER_KEY);
System.out.println("Service : "+service);
}

If you're using a build tool, such as Maven, then you could simply do something similar to the following example from a portion of the dependencies section in my pom.xml:
<!-- The mail dependency is required BEFORE the javaee-api dependency.
The gdata dependency (YouTube API) requires the mail dependency. -->
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.gdata</groupId>
<artifactId>core</artifactId>
<version>1.47.1</version>
</dependency>

I have added googlecollection-exp.jar into my build path then the previous execption was gone.

Pay attention to this jar gdata-core-1.0.jar I have the same problem, and I realized I have problem with this jar gdata-core-1.0.jar, and I found from website the same jar gdata-core-1.0.jar, but the content is different. After I replaced the new gdata-core-1.0.jar, problem solved.
So it's tricky that the jar with the same name but their contents are not the same. you thought you have the jar, actually it's not the right one

It could be that some of your jars would be having dependency on google/guava jars and if they're not in build path or if multiple of them are there it might raise inconsistency hence the error. A quick solution could be add latest version of guava to your pom
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>24.0-jre</version>
</dependency>
Now check in dependency hierarchy if any of your Jar apart from guava is referring to any other older jar of guava/google-collections. If so then exclude it, something like this
<exclusions>
<exclusion>
<groupId>com.google.collections</groupId>
<artifactId>google-collections</artifactId>
</exclusion>
</exclusions>