I have a serializable class (CardGame) that I'm working with in Eclipse, and had originally put it in a package (x.cardlib). I renamed the package to y.cards.models using Eclipse's refactoring utility (now that I know how to properly name a package).
I wrote a new class (CardGameDatabase) that downloads and converts serialized CardGames from a database, and wrote a new JUnit test case (CardGameDatabaseTest) for it later on. I tried to run my test case, and received the following error:
java.lang.ClassNotFoundException: x.cardlib.CardGame
at y.cards.database.CardGameDatabase.getGame(CardGameDatabase.java:28)
at y.tests.CardGameDatabaseTest.test(CardGameDatabaseTest.java:13)
I figured that I must still have a reference to the old package in my code, so I did a project-wide search for any and all references to the old package (e.g. "import x.cardlib.CardGame"). I didn't find any.
I then deleted all compiled code and ran Eclipse's cleanup utility, thinking that maybe an old reference existed in previously compiled code. I'm still receiving the error.
(Hm, I figured it out while writing, in fact. I'll post the answer shortly in case anyone else has had a problem like this.)
Answer: I had stored the CardGame in my database before I refactored my code. Upon downloading the object from the database, it was still called x.cardlib.CardGame in the database. In short, renaming the package broke my serialization, leading to a ClassNotFoundException.
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I've been using Eclipse for a while and I'm having trouble understanding what's going on with my first project in IntelliJ. I've read the documentation, and searched other questions, but I still can't seem to grasp it. I think there is something wrong with my project structure. This is what my structure currently looks like;
I'm trying to run the JavaForLoop class, but whenever I do, compilation fails because I have errors in the StringMethods class of the strings package. My question is why would that prevent compilation if the two classes are in separate packages? Neither class uses the other, and they both have the appropriate package declaration statements. With a similar structure in Eclipse, this would work. Should I be using a different project structure?
By default IDEA adds Build Configuration which is executed before launch and includes following steps (taken from here):
Compiling source code in the source path of a module and placing results to the output path.
Compiling source code in the test path of a module and placing results to the test output path.
Creating copies of the resource files in the output path.
Reporting problems in the Messages tool window.
check if it's your case in Edit Configuration screen and if so, remove it.
To use a class from a different package you must declare a import statement to the class.
In your JavaForLoop.java add the import before the class statement (and after package declaration where its the case)
//package ...
import strings.StringMethods;
//public class JavaForLoop { and the rest of the code
Intellij uses regular javac, which will fail to compile if you have errors anywhere in the code.
Eclipse has it's own compiler, that allows to compile and even run code that has compilation errors, causing a runtime exception if any part of the code that has errors is run. This allows you to run parts of the code that work even if other pieces of code are failing.
The simple solution is to resolve your compilation errors. You can also use the eclipse compiler with Intellij, but I've never done this so I can't comment on how well it works.
I'm currently getting this error:
java.lang.NoSuchMethodError: org.json.JSONObject.keySet()Ljava/util/Set;
at ee.ut.cs.Parser.accessLint(Parser.java:39)
I have tried cleaning the project to no awail.
I suspect I have an error in the src/plugin/parse-htmlraw/build.xml while creating the jar file but I'm not certain. I understand that this error is because the function does not exist at runtime, but the object is created which means that the class is there, just not that function. I decompiled the .class file in created jar and it has the necessary functions.
Code is available at https://github.com/jaansusi/WCAGgrader
Q: What is wrong with the build that produces this error?
The problem is that even if I put the necessary class files in the jar I create, they are not linked correctly and the class that's called in the jar can't locate functions inside the other classes. The class object JSONObject is created but the functions inside the JSONObject class can't be found.
If you do not find the problematic version, there is a possibility you get it (especially if you are using Spring) from the following dependency -
<artifactId>android-json</artifactId>
<groupId>com.vaadin.external.google</groupId>
excluding it worked for me,
An easy way of analyzing dependencies is the maven-helper plugin in Intellij, see here
Check for the version you have used.
There might be a case where 2 different versions are being used which in turn causes this error.
To their own maven local repository com\Google\code\gson\gson, see if there are two or more version about json, will have to do is to delete the old, and remember to look at any other place in the project is introduced into the old version of the dependence, if any, change the old version of the dependence to the new version is perfectly solved this problem
I'm looking to store Java libraries inside my Oracle database. Note that this is the first time I'm doing that. That library is pd4ml. It is made up of two jars, which contains the compiled classes.
pd4ml.jar
ss_css2.jar (required by pd4ml.jar)
As loading them with Toad did not work (Toad said they were loaded successfully, but did they not show up anywhere) I went command line (loadjava) and managed to load ss_css2.jar successfully. All its classes were loaded and compiled.
The second library, pd4ml.jar, was also loaded, but several classes won't compile. I ran ojvmtc to try to resolve references. I got the following message:
The following classes could not be found:
javax/servlet/http/HttpServletResponseWrapper
org/zefer/pd4ml/npdf/parser/c
The first one, if my understanding is correct, should be part of the JRE that is built-in 11g r2. Browsing the sys schema, it does not appear to exist.
The second one is part of the jar library. Now I'm not exactly sure of the structure of compiled Java, I've never had to look into it before, but I have several .class files inside org/zefer/pd4ml/npdf/parser/, these being: c$_b, c$_c.... to c$_g. There is none that is only c.
The library works well on my local machine when passing command line arguments or running it from Eclipse, so it should work. There is no specific error message that shows up when trying to compile them in Toad. I have a feeling it's a dependencies/classpath issue.
Any hints on how I should ensure that classes contained in pd4ml.jar can properly access those in ss_css2.jar , or any potential causes to investigate? Perhaps a way to get detailed error messages from the Java code?
The strange class names like c$_b, c$_c.... to c$_g are result of JAR file obfuscation. The obfuscation impacts only non-public classes, so it should not harm.
As I see, in your particular case javax/servlet/http/HttpServletResponseWrapper class is missing (and probably few more) - the classes can be found in servlet-api.jar. Just take the file from any J2EE (or Tomcat) distribution and add the file to your project/application.
In usual scenarios the servlet-api classes are required only when WebApp-specific PD4ML methods are called. And the methods are called only when pd4ml.jar is a part of a web application (that means servlet-api.jar is among the application resources).
As I see now, Oracle database Java sub-system scans for all referenced resources (even if they are not needed in a scenario) and panic if anything is missing.
I am working on moving code from R2007a to R2013a. I am getting a java.lang.NoClassDefFoundError during my run in R2013a which does not appear in R2007a. It occurs when I call.
feval('get',fname,jevent);
Where fname is a product.ProxyField object for an Object Filter and jevent is a product.format.java.internal.JavaEvent.
The class is in a jar file on the path and is being accessed by another class in the same jar file. The stack trace does not leave the realm of the product if that helps.
I do not have access to the original code for the jar file. I do have access to code derived from that original code and both classes are in the same package. I'm guessing this has something to do with differences in the java version but I'm not sure what to do since I don't have the original code to recompile.
Unfortunately I can't provide actual source or full detail but a google search only yielded results for MATLAB startup issues. Any thoughts?
Seems like the difference between R2007a and R2013a is that the first uses 1.5 jre and second uses 1.6 jre. It would be easier to help you if you provided the stack trace showing the exception. Sometimes classes get moved around in between jvm versions, so having the actual missing classes would help in determining if the missing class is a class that was just moved around to a different package. You could take the missing class, google it adding the same exception message as you put above and seeing who else ran into similar issues.
I have a class which extends OrmliteSqliteOpenHelper in order to provide a persistence module for an Android application. The problem is, whenever I access this class from the test project in Eclipse, it throws a NoClassDefFound Exception. The source code appears to be fine as the package is imported and Eclipse has no highlighting to indicate anything will go wrong, but it does.
Here's the kicker: not only does everything else in the project work fine when accessed from the test project, but when I move this file into the test project voila it works perfectly! The issue is that it needs to be in the actual project in order for other components to make calls to it. Has anyone ever encountered this error or have any idea where I might be going wrong?
The class path is set correctly as all the other classes work and the test project always has the main project added to its class path. I also tried moving the OrmliteSqliteOpenHelper object to an inner class: this allowed the outer class to be visible and touched but as soon as it tried to instantiate the inner class the same error occurs. Also, if I copy this file into both projects in the same package, an error occurs stating "class ref in pre-verified class resolved to unexpected implementation" whenever something in the main project tries to access this class. Clearly, there is some difference in the way the class is being compiled/handled between the two projects.
I'm quite stumped :/ Thanks a ton for any assistance!
Well friends, I seem to have hacked together a solution for this issue:
I linked the entire 'src' folder from the main project into the one for the test project. Now, when it goes searching for the particular package my file is located in, it finds the file in its own source tree first. Hooray!
Why does this work? I haven't a clue, perhaps someone could enlighten us to that fact.
Does it work? For now...
There is how I fix the problem:
Remove OrmLite from Build Path of the test project.
Export them from the main project.