I have a project in Eclipse that currently has no ANT build file, but is about to have one created (to facilitate building jars). I'd like to write the build file so that it would work for both. I was just going to write the full build in ANT but I noticed this line in an IBM Help doc.
The Java builder runs the internal
Eclipse Java compiler which in turn is
responsible for indexing your source
so that searching, refactoring and
many other features are available.
Thus it is not possible to replace the
internal Eclipse Java compiler by
using a project builder. You can
disable the Java builder and you can
control when the Java Builder runs
with respect to the project builders
that you define.
Do I need to write the ANT file so that it conditionally compiles (javac) only outside Eclipse? Are there other things I need to do to make ANT and Eclipse play nicely together?
There are maybe more sophisticated approaches, but here's what works for me. Just set up your Java project in Eclipse to output classes to the same dir as your Ant buildfile does. Let Eclipse compile your project using normal Java compiler.
During typical development, you will probably be changing Java source files and wanting to see that they compile. The Eclipse Java compiler will take care of this. Less frequently you will need to rebuild jars. Ant will take care of that. You can kick off the Ant build when you need to from the command line or from Eclipse.
Related
I want to use CDT parser in a project. The project would be a command-line, stand-alone project, i.e., not an Eclipse plugin.
All solutions that I've seen requires using a IWorkspace. But, I want to use the CDT parser on single files outside eclipse. Is there any way to do that?
It depends what you mean by "without Eclipse".
CDT's code is built on top of the Eclipse Platform, so you're going to need to be running an application that includes the Eclipse Platform. However, there's no reason that application can't be a command-line application. These are called "headless" applications in the Eclipse community, and you can find many tutorials for making one (here's one).
Requiring an IWorkspace shouldn't be a problem. You can e.g. create a workspace and a project in a temporary folder, and copy the code to be analyzed there.
If, for some reason, you really want to use just CDT's parser in an application that doesn't include the Eclipse Platform, you can probably copy the parser code from CDT, and replace any dependencies it has on the Eclipse Platform with your own implementations. However, this is likely to be a more labour-intensive approach, and I wouldn't recommend it.
Part of a project I'm on has a GUI app that is built with Netbeans using the GUI design tools that come in that IDE.
But this is only part of a bigger project, and needs to be built in an environment that does not have Netbeans installed (it happens to be a Gradle-based build on Jenkins). I've gotten builds to (seemingly) work, but keep running into inexplicable run-time errors (i.e., dependencies appear to be met with identical jars on the classpath and so on, but attempts to read resources from the project jar fail.).
From googling around, it looks like this might have something to do with compiling .form files and then including some dependency for the resulting java. (though, the Netbeans build does not add any jars above what our gradle build adds).
So the question is... can this even be done? or does a proper build simply rely on some hidden build-time mojo that's going on in Netbeans?
Yes, you can compile the classes without NetBeans. Just be sure you do not any NetBeans library, like AbsoluteLayout. The .form files are for NetBeans showing you components with Matisse, but all the generated code will be in the .java file.
This question is not limited to lex and yacc, but how can I add a custom script compiler as part of a project? For example, I have the following files in the project:
grammar.y
grammar.l
test.script
The binary 'script_compiler' will be generated using grammar.y and grammar.l compiled by lex, yacc and g++. And then I want to use that generated script_compiler to compile test.script to generate CompiledScript.java. This file should be compiled along with the rest of the java files in the project. This setting is possible with XCode or make, but is it also possible with Eclipse alone? If not, how about together with Maven plugin?
(I might setup the script compiler as a separate project, but it would be nice if they can be put in the same project so that changes to the grammar files can be applied immediately)
Thanks in advance for your help!
You can add a custom "Builder" from the project properties dialog. This can be an ant script (with an optional target) or any other script or executable.
There are also maven plugins for ant and other scripting languages
If you just want to run an external program in Maven this is what you want: http://mojo.codehaus.org/exec-maven-plugin/ -- you can then run Maven targets from your IDE or command line and it should do the right thing either way.
To integrate with the normal compilation bind the plugin to the "generate-sources" phase and add the location where the Java files are generated to the "sourceRoot" option of the exec plugin. That way the compiler will pick them up.
Ideally you generate the code into a folder "target/generated-sources/MY_SCRIPT_NAME". That is the standard location for generated sources in the Maven world and e.g. IntelliJ IDEA will pick up source files inside of that location. Note that this doesn't work if the files are directly in "target/generated-sources".
The other option is to write your own Maven plugin, which is actually quite easy as well. See e.g. https://github.com/peterbecker/maven-code-generator
I'm trying to convert a Netbeans 6.9.1 project into a scripted build (without netbeans). Of course, it fails (or I wouldn't be asking for help).
In the failure it says that the org.apache.commons.httpclient package does not exist. (Of course, it worked when we ran the build in Netbeans).
Now I know exactly where the commons-httpclient.jar file is located in my project structure, but I can't seem to tell it to the compiler via the ant build files and the netbeans property files.
Perhaps related to this is when I ran "ant -v" to build my software, it said,
Property lib.mystuff.classpath has not been set. This variable is important, I guess, because
the file nbproject/project.properties uses lib.mystuff.classpath in its definition of javac.classpath, which of course tells the Java compiler where to find the JARs.
So...when moving a Netbeans project to a netbeans-independent scripted build, how can the build script set these properties? Also, how can I ensure that the jar file gets included in the ant build?
I appreciate any help I can get, as I am a Java newbie.
UPDATE AFTER ACCEPTING ANSWER FROM vkraemer:
There are a few best practices for build scripts for production software:
Put everything needed for a build under a single directory tree. (Netbeans = fail)
Put everything in source code control. (I did that)
The first line of the build script should clear all environment variables.
The next section of the build script should explicitly set all environment variables to values which are known to work.
The next part of the build should be able to execute using command-line programs such as javac, ant, cc, etc, and must not depend on firing up an IDE such as Eclipse or Netbeans.
It is a shame that Netbeans makes this hard.
I did a quick look in a Java Application project and found the following...
javac.classpath = ${libs.MyStuff.classpath}
libs.MyStuff.classpath is defined in %HOME%/.netbeans/6.9.1/build.properties.
You may be able to get by doing the following...
ant -Dlibs.MyStuff.classpath=c:\a\b\c.jar
You would need to do more if you have multiple jar files in the MyStuff library that you created in NetBeans.
I need to batch a compilation with a special JRE which has been "customized".
Eclipse is able to compile the classes with this JRE, but I need to make a build script outside of Eclipse.
What is the method used by Eclipse to generate the .class files without a JDK?
Eclipse comes with its own compiler for the following reasons:
Incremental compilation (can compile just the changed parts of the project which can mean more than the amount of files you just saved, for example, when you changed some global)
The Eclipse compiler can create a class file even when the code contains errors. This allows to run the project even though not everything compiles.
The compiler provides Eclipse with an AST so it can do all kinds of fancy stuff (like the outline, show you all the places where the variable under the cursor is used, etc) at no extra cost (i.e. it doesn't have to run the compiler and another parser).
I believe Eclipse comes with internal compilers, and you can choose the compatibility to Java 1.3 through 1.6 (check the Preferences menu, under Java->Compiler). So Eclipse doesn't need an external JDK to compile, because it comes with it is self-sufficient.
If you want to create a build script outside of Eclipse, you're gonna need an external compiler, like the one that comes with the real JDK.
For the case one is interested: Eclipse's compiler is part of JDT core.
Eclipse was originally created by IBM. Eclipse has its own built-in Java compiler which is based on IBM's Java compiler, Jikes.