Java program does not run and throws an error about classes - java

So I want to run my just compiled Start.class file that I compiled from Start.java. The problem is that it will throw this error:
java Start
Exception in thread "main" java.lang.NoClassDefFoundError: Start (wrong name: files/Start)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
I have written the program in Eclipse and I want to run it from a Terminal. What is the problem here?
New error:
java files.Start http://mirror.symnds.com/software/Apache/tomcat/tomcat-7/v7.0.53/bin/apache-tomcat-7.0.53.zip
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/io/IOUtils
at files.Start.main(Start.java:93)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.io.IOUtils
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 1 more

Please have a look at How to Compile and Run Java Code from a Command Line where you will get the information about the class path and how to add dependent jars in class path.
Here is the details from above link.
Task
Lets say we have a fairly standard java project that consists of three top level folders:
/bin - empty folder that will contain compiled .class files
/lib - contains third party .jar files
/src - contains .java source files`
Our task would be to compile and launch the project from its root folder. We will use Windows OS as example (on Unix systems the only difference would be path separation symbol - ":" instead of ";").
Compiling Java Code
The first step is compiling plain text .java sources into Java Virtual Machine byte code (.class files). This is done with javac utility that comes with JDK.
Assuming we are at the application root folder trying to compile Application.java file from com.example package that uses lib1.jar and lib2.jar libraries from lib folder to a destination bin folder, compilation command should have the following format:
javac -d bin -sourcepath src -cp lib/lib1.jar;lib/lib2.jar src/com/example/Application.java

Related

Running a program after compiling it with javac

I have a source file named Plane.java. I am trying to compile and run the program in terminal, but i can't!
I am compiling it with:
javac Plane.java
So, I am getting with ls my classes
CargoBay.class
CleaningEmployee.class
Employee.class
EquipmentComponent.class
MaintenanceEmployee.class
PassengerComponent.class
Plane.class
Plane.java
PlaneComponent.class
PrivateComponent.class
SecurityEmployee.class
Now, I have no idea how to run it! I am trying with java Plane, but I keep getting errors. Any ideas ?
(errors: after java Plane)
Exception in thread "main" java.lang.NoClassDefFoundError: Plane (wrong name: plane/Plane)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
The program runs just fine in netbeans
Compile your class by
javac -d . Plane.java
This will create a plane directory at current location and put your classes into that directory then run your program using
java plane.Plane
Your classes are probably in a package named plane. The compiler creates a directory with the package name. What you have to do is go up one level from there
and call:
java plane.Plane
Other options would be to set the CLASSPATH environment variable or use the -cp option of the java command.

How to use classpath in ubuntu terminal for executing java class?

I tried to execute CreateTextFileTest.class file with classpath in the terminal as the following:
java -classpath ..:"/home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17/unit17/creatingtextfile" CreateTextFileTest
My class files in this directory : /home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17/unit17/creatingtextfile .
I have 3 classes in the directory: AccountRecord.class , CreateTextFile.class, and CreateTextFileTest.class
But, when I executed the CreateTextFileTest from the terminal with the code above, an error occured like that:
Exception in thread "main" java.lang.NoClassDefFoundError: CreateTextFileTest (**wrong name**: unit17/creatingtextfile/CreateTextFileTest)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
As far as I understand because CreateTextFileTest.java uses two different classes, executing fails. How to handle this situation? How to run my java project? How to use classpath in this situation? Am I using wrongly?
The error message states that the package name declared in your compiled class doesn't match what the JVM was expecting given your classpath setup. The classpath should point to the directory from which your packages start, not the directory actually containing your .class files. Given your error message I believe that this should work:
java -classpath ..:"/home/fatih/NetBeansProjects/Unit17 - CreatingTextFile/src/unit17" unit17.creatingtextfile.CreateTextFileTest
Given the duplicate unit17 in your path I get the impression there's something else mixed up here. You'll get a better answer on Stack Overflow...

Java program executes in eclipse but not in terminal

I am using Eclipse with Eclipse Maven Plugin (m2e).
My java program compiles and run correctly from eclipse interface but I am unable to compile and run it from terminal.
My Eclipse Setting:
I am using two third party APIs, for which in eclipse build path I added
"/home/syed/workspace/FirstMaven/target/resources/fuse-jna-master/build/classes" (as external class folder)
"/home/syed/workspace/FirstMaven/target/resources/apache-jena-2.11.1/lib" (as external jars)
Package:
package org.organization.upesh.FirstMaven;
My Project path:
syed#ubuntu:~/workspace/FirstMaven$
Source Code Directory Path:
syed#ubuntu:~/workspace/FirstMaven/src/main/java/org/organization/upesh/FirstMaven$
Classes Directory:
syed#ubuntu:~/workspace/FirstMaven/target/classes/org/organization/upesh/FirstMaven$
When I try to execute myProgram via below command
syed#ubuntu:~/workspace/FirstMaven/target/classes$ java org.organization.upesh.FirstMaven.myProgram
it gives me these errors:
Exception in thread "main" java.lang.NoClassDefFoundError: net/fusejna/util/FuseFilesystemAdapterFull
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
Caused by: java.lang.ClassNotFoundException: net.fusejna.util.FuseFilesystemAdapterFull
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 13 more
But my test program that do not use the third party API runs correctly via:
syed#ubuntu:~/workspace/FirstMaven/target/classes$ java org.organization.upesh.FirstMaven.test
I think myProgram is not executing because of the two APIs (class folder and jar folder) that I am using.
I have added path of class and jar folders of the APIs to /etc/environment (given below) and rested my computer, but still the same error
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/home/syed/workspace/FirstMaven/target/resources/apache-jena-2.11.1/lib:/home/syed/workspace/FirstMaven/target/resources/fuse-jna-master/build/classes"
Please guide me how to run my program correctly
JVM does not get libraries from PATH. It uses special environment variable CLASSPATH that can contain a list of directories or jar files separated by colon on Unix or semicolon on Windows.
So, just define CLASSPATH and put references to all your libraries there.
Aleternatively (and IMHO better) use command line switch -classpath (or its alias -cp) when running java:
java -cp mylib1.jar:mylib2.jar com.mycompany.Main

Run DiscardServer of Netty 4.0 from downloaded source directory

I am trying to run the DiscardServer module of a Maven compiled program called Netty, which I have downloaded as source code. I'm using a GNU/Linux command line terminal to try and follow the instructions in the manual http://netty.io/wiki/user-guide-for-4.x.html.
I'm assuming I should run DiscardServer in directory example/src/main/java, but when I move to that directory and type
$ java -cp "~/norbert/netty-master/all/target/netty-all-5.0.0.Alpha1-SNAPSHOT.jar:~/norbert/netty-master/all/target/netty-all-5.0.0.Alpha1-SNAPSHOT-sources.jar" io.netty.example.discard.DiscardServer
the response is "Error: Could not find or load main class io.netty.example.discard.DiscardServer"
I know the class can be run from a source directory somehow, because
$ java io.netty.example.discard.DiscardServer
produces
Exception in thread "main" java.lang.NoClassDefFoundError: io/netty/channel/EventLoopGroup
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2442)
at java.lang.Class.getMethod0(Class.java:2685)
at java.lang.Class.getMethod(Class.java:1620)
at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:492)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:484)
Caused by: java.lang.ClassNotFoundException: io.netty.channel.EventLoopGroup
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
... 6 more
Having downloaded the binary version netty-4.0.13.Final in addition, I was able to start the discard server in directory netty-4.0.13.Final/jar as follows:
$ java -cp "netty-example-4.0.13.Final.jar:netty-transport-4.0.13.Final.jar:netty-common-4.0.13.Final.jar:netty-buffer-4.0.13.Final.jar" io.netty.example.discard.DiscardServer
How can I run the DiscardServer from directory example/src/main/java or the relevant source directory, though? Thanks, any help would be appreciated.
inside the example folder, you should run:
mvn install
then
mvn exec:java -Dexec.mainClass="io.netty.example.discard.DiscardServer"

Can't run .class files from CMD

I am unable to run .class files from CMD, and I can't seem to find a way to get around the error messages. My environment variable is set to C:\program files (x86)\java\jdk1.7.0_45\bin, both java and javac are version 1.7.0_45 and I am running the code in the local directory:
C:\Java\hfjavafinalsamples\chap01> javac PhraseOMatic.java
C:\Java\hfjavafinalsamples\chap01> java -classpath . PhraseOMatic
Exception in thread "main" java.lang.NoClassDefFoundError: PhraseOMatic (wrong n
ame: chap01/PhraseOMatic)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:14
2)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
C:\Java\hfjavafinalsamples\chap01>
The fully qualified name of the class is chap01.PhraseOMatic, because its simple name is PhraseOMatic, and its package is chap01.
The java command expects a fully qualified name. Based on its classpath and on this fully qualified name, it will look for the .class file. So, if your classpath is '.' and the fully qualified name is chap01.PhraseOMatic, it will look for ./chap01/PhraseOMatic. So that won't work, since you're already inside the chap01 folder package.
The classpath should thus be .., or (better) you should be in the hfjavafinalsamples folder to run your application:
C:\Java\hfjavafinalsamples> java -classpath . chap01.PhraseOMatic
Also, you should not put the source files (.java) and the compiled files (.class) in the same folder tree. Create an src folder containing the source tree, and a classes file containing the compiled classes tree. and use the -d classes option of javac to compile the classes to the classes folder.

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