Java classes fails - java

I have a project that fails in one class, i think that the project cant find the classes. Help please, i dont know how to solve it. Why are happen this?
The type javax.ws.rs.ext.RuntimeDelegate$HeaderDelegate cannot be resolved. It is indirectly referenced from required .class files
It is failing in the declaration of the package.

Try adding the below dependency to your pom.xml -
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.0</version>
</dependency>

Related

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!

Twitter4j: Cannot use StatusListener cannot be resolved

I'm struggling with Twitter4j. I am using a Maven project with the following Twitter4j dependency:
<dependency>
<groupId>org.twitter4j</groupId>
<artifactId>twitter4j-core</artifactId>
<version>[4.0,)</version>
</dependency>
However every time I try and declare a StatusListener, I get Cannot resolve symbol 'StatusListener' even though I'm importing import twitter4j.*;.
Anyone know why this might happen when I can use pretty much all other features of Twitter4j?
I needed to add
<dependency>
<groupId>org.twitter4j</groupId>
<artifactId>twitter4j-stream</artifactId>
<version>[4.0,)</version>
</dependency>
As a dependency to my pom.xml. Turns out the Streaming API and all related classes are in a different part of the Twitter4J ecosystem.
As twitter4j lib contains the core, async, example, and a stream part. You should try to include all these but mainly the stream dependency contains the status listener method. I hope it solves your problem.

The type com.google.protobuf.GeneratedMessageV3$Builder cannot be resolved. It is indirectly referenced from required .class files

I have been doing my project and all the sudden eclipse started to give this error saying
The type com.google.protobuf.GeneratedMessageV3$Builder cannot be resolved.
It is indirectly referenced from required .class files where we declare the package. I have tried adding com.google.protobuf-2.4.0.jar to build path but it did not work. Please help and here's the screenshot.
com.mysql.cj.x.protobuf.MysqlxSql.StmtExecute is not on the classpath so remove this import
If you are expecting Protobuf generated files to be available, then ensure that you have added the Protobuf library to your project.
Gradle example:
implementation group: 'com.google.protobuf', name: 'protobuf-java', version: googleProtobufVersion
Maven example:
<dependency>
<groupId>com.google.protobuf</groupId>
<artifactId>protobuf-java</artifactId>
<version>${googleProtobufVersion}</version>
</dependency>
Not sure if this helps at such a later date. But i also faced something similar.
I found that I imported this by mistake
import com.mysql.cj.x.protobuf.MysqlxDatatypes.Array;
After removing this line, it works fine.
In your case you need to remove the import
com.mysql.cj.x.protobuf.MysqlxSql.StmtExecute
Replace it with the relevant import.
This is due to the missing dependency of gRPC protobuf. Add this dependency to your pom.xml and this should solve your problem.
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-protobuf</artifactId>
<version>1.16.1</version>
</dependency>
Lastly, do maven -> project update

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

Error generating report with JDK8

Using Netbeans IDE 8.0.2 and JDK8, when I try to generate a PDF report i get this error:
The type java.lang.CharSequence cannot be resolved. It is indirectly referenced from required .class filesvalue = ((java.lang.String)field_type.getValue()).contentEquals("XML"); //$JR_EXPR_ID=26$
This error occurs everytime I use this expression $F{type}.contentEquals("XML") or even the .equals expression.
With JDK6 it doesn't happen.
I've searched the web and I find a fix for this but for ecliplse in this url: https://community.jaspersoft.com/jasperreports-server/issues/3498
My dependencies are:
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>5.6.0</version>
</dependency>
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports-fonts</artifactId>
<version>5.6.1</version>
</dependency>
Well i didnt find a perfect solution for this, although to walktrough this issue I used .endsWith() instead of .equals. Works in this situation.

Categories