Good evening Stack Overflow!
I started learning Java quite a few days ago, but not using an IDE once my computer is a bit slow. So, I decided to use Sublime Text, and compile things using ant on the cmd, since it seems to be the most reasonable thing to do.
Today I started ( at least tried ) to follow along a series of LWJGL tutorials (which are really cool), from ThinMatrix, but I can't manage to solve an error which I get every time I try to compile the 'project'.
This is the structure of my project:
LWJGL
src
com
game
test
MainGameLoop.java
renderEngine
DisplayManager.java
build.xml
And ladies and gentlemen... the build.xml (following Ant's official HelloWorld tutorial):
<project name="LWJGL" basedir="." default="main">
<property name="src.dir" value="src"/>
<property name="build.dir" value="build"/>
<property name="classes.dir" value="${build.dir}/classes"/>
<property name="lib.dir" value="lib"/>
<property name="jar.dir" value="${build.dir}/jar"/>
<property name="main-class" value="com.game.test.MainGameLoop"/>
<path id="classpath">
<fileset dir="${lib.dir}" includes="**/*.jar" />
</path>
<target name="clean">
<delete dir="${build.dir}"/>
</target>
<target name="compile">
<mkdir dir="${classes.dir}"/>
<javac srcdir="${src.dir}" destdir="${classes.dir}" includeantruntime="false" classpathref="classpath" />
</target>
<target name="jar" depends="compile">
<mkdir dir="${jar.dir}"/>
<jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}">
<manifest>
<attribute name="Main-Class" value="${main-class}"/>
</manifest>
</jar>
</target>
<target name="run" depends="jar">
<java jar="${jar.dir}/${ant.project.name}.jar" fork="true">
<jvmarg value="-Djava.library.path=lib/natives-win" />
</java>
</target>
<target name="clean-build" depends="clean,jar"/>
<target name="main" depends="clean,run"/>
Every time I run ant on the command line, inside the root folder of my project, I get this:
[java] Error: Could not find or load main class com.game.test.MainGameLoop
[java] Java Result: 1
I'm struggling to understand what is the root problem of this, I kinda sexually abused Google Search trying to find an answer on Java forums, Blogs, and even here...
I don't usually like populating Stack Overflow with noob questions, but I have to admit I don't know what to do.
Thanks in advance!
Your code depends on libraries. You have successfully added the libraries in the classpath to compile your code, and have thus successfully created an executable jar files containing your classes. But these classes depend on libraries to run. And when running the jar file, you don't secify anywhere that Java should look for classes in libraries in addition to your jar file.
See Generate manifest class-path from <classpath> in Ant for how to add a Class-Path entry to the manifest of your executbale jar file. Beware: the paths of the libraries must be relatie to the path of the jar.
Ant is a bit outdated. If I were you, I'd try using gradle, which has a neat application plugin doing all that for you, and much more.
I finally managed to solve this problem that I was struggling with by the help from a good friend of mine. There are two tricky points:
First, when specifying the "Main-Class" in the manifest section, just use the following format "packageName.className", and there is no need to specify the "build" or "source" folders!
Second, try and zip all the jar files that your "jar" file is going to depend on using "zipgroupfileset"
This image shows how I have commented out the "Class-Path" attribute that I would use for addressing the dependencies of the project, and have replaced it with the "zipgroupfileset". I hope that help you as well.
Small thing that can cause this issue is using uppercase letters in file extension. For example you can't use MainGameLoop.Java, The correct extension should be all lowercase like below.
MainGameLoop.java
Please check that first.
Related
I have create RESTful web service based on the JAX-RS and used Jersey embedded web server. My ant script compiles code successfully while it gives me error ClassNotFoundException when I run my main class. So after doing research I came up with solution & here it goes java build ant file with external jar files . What I did was created a bundled jar file try to execute that & it works perfectly fine. I want to know the reason behind :
why this solution works ?
Why I should combine all jar file ?
Is it similar to war file which we create following J2EE architecture otherwise war will not be extracted by server ( say TOMCAT ) & in my case jar file for Jersey embedded HTTP server?
EDIT:
Here is my ant build.xml file
<property name="lib.dir" value="${user.dir}/lib"/>
<property name="build.dir" value="${user.dir}/build"/>
<property name="build.lib.dir" value="${build.dir}/lib"/>
<property name="build.classes.dir" value="${build.dir}/classes"/>
<property name="src.dir" value="${user.dir}/src/main/java"/>
<property name="main.class" value="com.assignment.ConsoleServer"/>
<path id="classpath">
<fileset dir="${lib.dir}" includes="**/*.jar"/>
</path>
<target name="clean">
<delete dir="${build.dir}"/>
</target>
<target name="init" depends="clean">
<!-- Create the build directory structure used by compile -->
<mkdir dir="${build.dir}"/>
<mkdir dir="${build.classes.dir}"/>
</target>
<target name="copy_jars" depends="init" >
<copy todir="${build.lib.dir}" >
<fileset dir="${lib.dir}">
<include name="**/*.jar" />
</fileset>
</copy>
</target>
<target name="compile" depends="copy_jars">
<javac srcdir="${src.dir}" destdir="${build.classes.dir}" classpathref="classpath" includeantruntime="false"/>
</target>
<target name="jar" depends="compile">
<jar destfile="${build.dir}/${ant.project.name}.jar" basedir="${build.classes.dir}">
<manifest>
<attribute name="Main-Class" value="${main.class}"/>
</manifest>
<zipgroupfileset dir="${lib.dir}" includes="*.jar"/>
</jar>
</target>
<target name="run" depends="jar">
<java fork="true" classname="${main.class}">
<classpath>
<path refid="classpath"/>
<path location="${build.dir}/${ant.project.name}.jar"/>
</classpath>
</java>
</target>
Here is my folder structure
P.S. I am not java expert so pardon me if this question is stupid.
Why this solution works?
In your particular case, you probably didn't include all of the necessary dependencies in your deployment in your previous. (It is not clear from your question how you were originally doing the deployment.)
Now you have put all of the application and dependent class files, etc into one JAR file, and presumably you are deploying / running that file. It works because now it has everything that it needs to run ... which it didn't before.
Why I should combine all jar file?
In your case I suspect that it was not strictly necessary. There was probably a way to "deploy" all of the dependencies without combining them into a single JAR file.
However, there is one case where a "uber-jar" has advantages. That is when the JAR is intended to be an "executable" JAR, and you want to be able to distribute / install it as a single file. (And executable JAR
file can refer to external JARs, etc, but the way that you have to do
it is "fragile".)
Is it similar to war file ... ?
Sort of, though a WAR file contains JAR files ... and typically other kinds of resources that the web-container understands.
The solution works because you packed all you service classes and depending libraries in one jar. That jar and everything inside will be in the class path and visible to your execution virtual machines class loader.
If you leave your depending libraries out your Jersey Web server needs to have them on it's class path, then you wouldn't get ClassNotFoundExcpetion
You shouldn't pack web application in single jar. You should crate war file where you dependencies will be placed inside WEB-INF/lib. You would easily then deploy that war on any application server. Switching to Maven instead of Ant can help a lot.
EDIT: After you added more details to description and ant
If you don't want to use fat-jar you can either
modify your antjava task to specify classpath that will reference
all external libraries (basically telling ant how to build
-classpath parameter for java -jar command
even better, modify your javac ant task by making complete Manifest file that specifies Class-Path correctly, take a better
look at the solution (at the bottom) of the answer you linked (java build ant file with external jar files)
For completness reference on Manifest here
I am currently developing a Java project in order to perform automatic screenshots of my Android application, however, when performing the uiautomator command:
adb shell uiautomator runtest AutoScreenshot.jar -c test.ScreenshotRoutine
I am getting the following error:
INSTRUMENTATION_RESULT: shortMsg=java.lang.RuntimeException
INSTRUMENTATION_RESULT: longMsg=Didn't find class "test.ScreenshotRoutine" on pa
th: DexPathList[[zip file "/system/framework/android.test.runner.jar", zip file
"/system/framework/uiautomator.jar", zip file "/data/local/tmp/AutoSc
reenshot.jar"],nativeLibraryDirectories=[/system/lib]]
INSTRUMENTATION_CODE: 0
I have already searched everywhere and lost around 1 day around this issue. It seems that the answers around these kind of questions are over 1 year old and none of the solutions have worked for me.
I have followed the examples found here and here, and changed the project slightly and have the following project structure:
src
|- test
|- <class extending UiAutomatorTestCase>
|- interfaces
|- routines
|- utils
My ANT file for generating the JAR file is the following:
<?xml version="1.0" encoding="UTF-8"?>
<project name="AutoScreenshot.makejar" basedir=".">
<property name="src.dir" value="src"/>
<property name="libs.dir" value="libs"/>
<property name="root.dir" value="build"/>
<property name="jar.dir" value="${root.dir}/jar"/>
<property name="jar.file" value="${jar.dir}/AutoScreenshot.jar"/>
<property name="classes.dir" value="${root.dir}/classes"/>
<path id="jars-classpath">
<fileset dir="${libs.dir}">
<include name="*.jar"/>
</fileset>
</path>
<target name="clean">
<delete dir="${root.dir}"/>
</target>
<target name="compile">
<mkdir dir="${classes.dir}"/>
<mkdir dir="${jar.dir}"/>
<javac srcdir="${src.dir}" destdir="${classes.dir}" target="1.8" includeantruntime="false">
<classpath refid="jars-classpath"/>
</javac>
<jar jarfile="${jar.file}" basedir="${classes.dir}">
<fileset dir="${libs.dir}" includes="**/*.jar" />
<fileset dir="${classes.dir}" includes="**/*.class" />
</jar>
</target>
</project>
Inside my Java project, I have created a ´libs´ folder which holds:
android.jar;
junit.jar;
uiautomator.jar.
Am I missing something, where am I missing it?
If you need any other file you consider relevant, please feel free to ask.
UPDATE #1 - Add batch file content
Here is what I have in the batch file I've done in order to compile and upload the jar file
#echo off
echo CLEANING PROJECT
call ant clean
echo COMPILING JAR FILE
call ant compile
echo PUSHING JAR FILE TO DEVICE
call adb push "D:\Workspaces\...\build\jar\AutoScreenshot.jar" /data/local/tmp/
echo EXECUTING JAR FILE ON DEVICE
call adb shell uiautomator runtest /data/local/tmp/AutoScreenshot.jar -c test.ScreenshotRoutine#runRoutine -e lang en
Many thanks in advance.
I'm completely new to Ant and need to add a couple jars to my classpath, compile a couple .java files, and run a junit test, all in Ant. I've been looking at a few online tutorials and manuals, but can't seem to wrap my head around the entire xml writing process.
All the previously-written code resides in a single directory called XXX.
In XXX there are two jars I need to add to my classpath with export CLASSPATH=$CLASSPATH:jar1:jar2, two java files I compile with javac *.java, one of which contains several junit tests that I run with java org.junit.runner.JUnitCore Tests. The build.xml would reside in XXX as well (I believe).
So far I have the following for just compiling, although I think there's a lot missing.
<?xml version="1.0"?>
<project name="EtlAutomation" default="compile" basedir=".">
<property name="src" value="${basedir}"/>
<target name="compile">
<!-- Compile .java files -->
<javac srcdir="${src}" destdir="${src}"/>
</target>
</project>
What else do I need to add to compile *.java in the current directory? How can I run the export CLASSPATH command, and finally the junit commend?
I'm not asking for anyone to write my code, but it would be appreciated. If anyone knows a good beginner tutorial for a unix environment, that would be awesome. I'm a total beginner with ant so I'll take what I can get.
Here is a previous question addressing this. And this may work for you:
<project name="EtlAutomation" default="compile" basedir=".">
<property name="src" value="${basedir}"/>
<path id="compile.classpath">
<fileset dir="./">
<include name="*.jar"/>
</fileset>
</path>
<target name="compile" >
<javac destdir="${src}" srcdir="${src}">
<classpath refid="compile.classpath"/>
</javac>
</target>
<target name="run" depends="compile">
<junit>
<classpath refid="compile.classpath" />
<test name="TestExample" />
</junit>
</target>
</project>
I'm working on a small library for our in-company use, and have been heavily documenting it. Now I'm building my jar with the following code:
<project name="commonutils" default="compile" basedir=".">
<property name="src" location="src" />
<property name="build" location="buildDirecotry" />
<target name="compile">
<delete file="${ant.project.name}.jar" />
<mkdir dir="${build}"/>
<javac srcdir="${src}" destdir="${build}" debug="on" target="1.5">
<classpath>
<pathelement location="lib/build/server.zip" />
<pathelement path="${java.class.path}/"/>
</classpath>
</javac>
<jar basedir="${build}" destfile="${ant.project.name}.jar" />
<delete dir="${build}" />
</target>
</project>
Which works fine, it builds my jar file with all the src files in it, but when I include the jar file in another project I no-longer have any of my javadoc comments. Using JDDecompiler I cannot see the comments in the class file, although I'm not sure if its the java compiler that's stripping them or JD.
My question is: How can I build my jar file so that users who use the library will be able to see the javadoc in Eclipse.
If you include the source files in the jar (each class and java file in the same package-directory) it should work.
<target name="jar.noCompile.src">
<jar destfile="${ant.project.name}.jar">
<fileset dir="${build}"/>
<fileset dir="${src}" includes="**/*.java"/>
</jar>
</target>
AFAIK the documentation is an Eclipse feature. You have to configure it manually. In your build generate the documentation (usually into folder 'javadoc') and package it with the JAR. Once someone wants to use your library, he/she has to go into Java Build Path select libraries, add yours, click next to it to open the tree node and then double click on Javadoc location to configure it.
I have a bunch of .java files in a "src" folder that depend on three jars in a "lib" folder. I have the following build.xml file:
<?xml version="1.0"?>
<project name="MyProj" basedir=".">
<property name="src" value="src"/>
<property name="build" value="build"/>
<property name="lib" value="lib"/>
<path id="master-classpath">
<fileset dir="${lib}">
<include name="activemq-all-5.1-SNAPSHOT.jar"/>
<include name="geronimo-jms_1.1_spec-1.1.1.jar"/>
<include name="activemq-core-5.3.0.jar"/>
</fileset>
</path>
<javac destdir="${build}">
<src path="${src}"/>
<classpath refid="master-classpath"/>
</javac>
</project>
This compiles fine, but when I try and run I get
"java.lang.NoClassDefFoundError:
javax/jms/Destination"
This program runs and compiles fine when I include the jars in the buildpath using Eclipse, though.
EDIT: So I copied the jars into the folder that has the compiled classes. The class with the main method is NDriver.class. When I try:
java -classpath
./geronimo-jms_1.1_spec-1.1.1.jar:./activemq-core-5.3.0.jar:./activemq-all-5.1-SNAPSHOT.jar
NDriver
This gives:
Exception in thread "main"
java.lang.NoClassDefFoundError:
NDriver
I'd appreciate any help.
You need to put the jars used at compile time on the classpath when running the application. Sadly, you didn't provide any detail on how you are actually running it so its hard to provide more guidance.
UPDATE: The directory containing the compiled classes needs to be added to the classpath too. If you launch java from the directory containing the compiled classes, then you can use . to designate the current directory. Add it to the classpath as shown below to tell java to look for classes there too (I've added . right after activemq-all-5.1-SNAPSHOT.jar):
java -classpath ./geronimo-jms_1.1_spec-1.1.1.jar:./activemq-core-5.3.0.jar:./activemq-all-5.1-SNAPSHOT.jar:. NDriver
One way (slightly different variables than yours)
<path id="classpath">
<fileset dir="${lib.dir}" includes="**/*.jar"/>
</path>
<manifestclasspath property="manifest.classpath" jarfile="${jarfile}">
<classpath refid="classpath"/>
</manifestclasspath>
<target name="jar" depends="compile" description="create the jar">
<jar destfile="${jarfile}" basedir="${build.dir}">
<manifest>
<attribute name="Manifest-Version" value="${manifest-version}"/>
<attribute name="Created-By" value="${ant.java.version}"/>
<attribute name="Main-Class" value="${main-class}"/>
<attribute name="Class-Path" value="${manifest.classpath}"/>
</manifest>
</jar>
</target>
Of course here I'm assuming that you are creating a jar and running it (including the classpath there). Another option would be to have a run target which use the <java> tag and explicitly use the classpath there.
Are the library jars included in the classpath when you run the program? Eclipse automatically add these, but you need to specifying them when you run the program from the command line.
From my experience it seems Eclipse will often include classes and jars in the classpath without explicitly using the classpath declaration. Indeed it can sometimes be quite hard to remove classes from Eclipse's build (they have to be deleted or clean'ed).