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Reading .qm translation files with Java

I'm trying to read a .qm translation files with Java.
.qm files are binary files. I don't have access to the .ts files.
And I don't find much info on these .qm files.
How are they structured ?
Regards,

There's no documentation that I know of, but if you look at QTranslator::load you should be able to follow the format of the QM file.
You will probably need to reimplement QTranslator in Java, as you need not only the ability to load the files, but also to extract and apply translations in Qt fashion.

As per request of OP:
You could use those files by using the Qt libraries and JNI. By using the translator in a c++ dll you can translate strings easily. However, you cannot extract the files or list the contained translations. But if all you need is the actual translation, this solution should work.
I cannot give a real example, because I only now how it works in theory, I haven't tried it, because it's not trivial. But if you are eager to try it out, the general idea would be:
Create a C++ dll and build it against QtCore. The easiest way is to download Qt from their website qt.io. You can for example create a default library project with QtCreator. Note: Besides Qt5Core.dll, Qt requires other libraries to correctly run. They are all included in the installation, but once you deploy your application, those of course have to be includes as well.
Include JNI to the C++ project and link against it. if you're new to this, here is a nice tutorial: Java Programming Tutorial
Create your wrapper methods. Methods in cpp you can call from java that take java strings, convert them to QString, translate them with QTranslator and convert them back.
Load the library in Java and execute those methods
Important:
First, I don't know how java handles dll dependencies. If you encounter errors while loading the dll, it's probably because dependencies of your dll are not present. Second, Qt typically requires a QCoreApplication running in the main thread for most of it's operations. I tested the translator without such an app, and it worked. So apparently for translations only the app is not required. However, depending on what you do in your dll, I think this is important to know.
If you need more details, feel free to ask.

How do I embed a Java compiler&runner into a JVM-based program?

I want user to be able to input a snippet of code with a class or function implemented in Java and the program should run this code, without referring to external tools like javac or saving class files to fisk.
In Clojure it is clear, as there is read and eval. Can it be done for a plain Java code, possibly with some third party jar?
The code is expected to be some variables, some loops, some mathematical functions and maybe some calls to the framework that is running it.

How do I use Jython to script Java programs

I am working on a project, which will introduce programmable computers to Minecraft, similar to ComputerCraft, except using Python as opposed to lua.
I am aware of Jython, so thought it would be suitable to check if I could use that for my project, however couldn't find enough information (on their website and with a few searches) to be certain.
I am aware of the topic discussing using Java from within Jython, however this is not how I want my project to work. Those that have used Computercraft, know that you have only the libraries that Computercraft provides you, whereas the topic linked above has full access to.. well everything. In my use case, everything isn't possible. I also don't want from pycomputers.api import Colors, I want the 'colors' api to be used like colors.red.
Hopefully the above is possible, within Jython, if not I would love to know another Python interpreter (that can be used from Java), to make my project with.

According to the docs if you want to embed the Jython into a java application then you have to invoke it with the PythonInterpreter class. It's pretty strait forward from there, just note that the overloads that provide a filename argument are for the name of the main executable file (this information is normally available through the sys module in regular old CPython).
Now in order to expose bindings in java to python (say to control the minecraft world), we need to add the jar files to sys.path as is described here, and if you want to control the sys.path value from within java then use
PythonInterpreter pi = new PythonInterpreter();
pi.getSystemState().path.append(new PyString("path/to/java/modules.jar"));
Note that the packages inside the jar files cannot be organized in the reverse url style. Instead, follow the instructions on package naming. Particularly make note of Naming Python Modules and Packages and if you follow the guidelines in Proper Python Naming then you will get the results you desire.
Finally we execute the code with
String source = ...;
pi.execute(pi.compile(source));

Simple and effective way to call Python from Java

I have a couple of python scripts whose methods I'd like to access from Java. These functions take a string as a parameter and also return a string. What would be a simple and effective way to do that?
My python codes don't run under jython. With jython, I get loads of errors for simple things like:
'with' will become a reserved keyword in Python 2.6
However, I am able to create .so objects using cython. Could that be used from Java?

You will need to wrap the functions in a command line executable that outputs the desired result. Then you can use ProcessBuilder to call the script and get the output.

Java library for text/string processing simular to unix/linux utilities

I'm a java programmer. I use bash scripts a lot for text processing.
Utilities like grep,sed,awk,tr,wc,find, along with piping between commands gives such a powerful combination.
However bash programming lacks portability, testability and the more elegant programming constructs that exist in Java. It also makes it harder to integrate into our other Java products.
I was wondering if anyone knows of any Java text processing libraries out there which might offer what I'm looking for.
It would be so cool to be able to write:
Text.createFromFile("blah.txt).grep("-v","ERROR.*").sed("s/ERROR/blah/g").awk("print $1").writeTo("output.txt")
This might be pie-in-in-the-sky stuff. But thought I'd put the question out there anyway.

Unix4j implements some basic unix commands, mainly focussing on text-processing (with support for piping between commands): http://www.unix4j.org
Example (Ben's example, but without awk as this is not currently supported):
Unix4j.fromStrings("1:here is no error", "2:ERRORS everywhere", "3:another ERROR", "4:nothing").toFile("blah.txt");
Unix4j.fromFile("blah.txt").grep(Grep.Options.v, "ERROR.*").sed("s/ERROR/blah/g").toFile("output.txt");
Unix4j.fromFile("output.txt").toStdOut();
>>>
1:here is no error
4:nothing
Note:
the author of the question is involved in the unix4j project

Believe it or not, but I used embedded Ant for many of those tasks.
Update
Ant has Java api's that allow it to be called from Java projects. This is embedded mode. This is a reference to And Api 1.6.1. Distribution should include docs as well.
To use it, you would create new task object, set appropriate parameters and execute it just as you would in build.xml but via Java Api. Than you can run your task.
Something like
ReplaceRegExp regexp = new ReplaceRegExp();
regexp.setMatch("bla");
regexp.setFile(new File("inputFile"));
regexp.execute();
You may need to set up some other stuff as well.
Not sure if it solves your problem, but Ant has a lot of code to do things. Just search through docs.