How to use Jython in java

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What is Jython

Jython is a pure Java implementation of Python. She seamlessly combines Java classes with Python, enabling users to write software that runs on Java virtual machines in the syntax of the Python language. Its features are: compared with similar Java programs, Jython greatly reduces the amount of programming code. Jython has both an interpreter and a compiler so that it can test program code without compiling.

Second, use step 1. Introduce dependency

The code is as follows (example):

Org.python jython-standalone 2.7.0 2. Call code / / function: find the corresponding encrypted data from word. The encryption algorithm is hash.md5_crypt / / original data List word = new ArrayList (); word.add ("123"); word.add ("456"); / / encrypted data List cryptWord = new ArrayList (); cryptWord.add ("$1 $KP074k5L$GkgfZVwByM0FQt4l.KLoh/") CryptWord.add ("$1 $zTxoz1fL$HKSbEyNFHGkLgAHZUTjmz."); String pythonFilePath = "jython_test.py"; String pythonFileMethod = "verify"; PythonInterpreter interpreter = new PythonInterpreter (); ClassPathResource resource = new ClassPathResource (pythonFilePath); InputStream inputStream = resource.getInputStream (); interpreter.execfile (inputStream); PyFunction verify = interpreter.get (pythonFileMethod, PyFunction.class) / / call PyObject pyObject = verify.__call__ (new PyList (word), new PyList (cryptWord)); List result = (List) pyObject.__tojava__ (List.class); System.out.println (result); interpreter.close ()

Output result:

['word:456, crypt_word:1 11KP074k5L' GkgfZVwByM0FQt4l.KLoh, 'word:123, crypt_word:1 11zTxoz1fL' HKSbEyNFHGkLgAHZUTjmz.']

2.python script from passlib.hash import md5_cryptdef verify (word,crypt_word): result= [] for crypt_w in crypt_word: for w in word: if md5_crypt.verify (wPowerCryptExw): item = 'word: {}, crypt_word: {}' .format (wmai cryptfolw) result.append (item) break return result III, question 1. Error report: ImportError: No module named passlib

The error indicates that the passlib library is not installed, then you need to import the passlib library before you can use from passlib.hash import md5_crypt

Can be installed on linux through the pip install passlib command

Windows: for example, you can use spyder to perform a pip install passlib installation

If you still report an error after installation, it may be because the library installation path is not in path, so you need to introduce the installation path in the script, for example:

Import syssys.path.append ('D:\ tools\ Anaconda\ lib\ site-packages')

Or introduce it through code:

Interpreter.exec ("import sys"); interpreter.exec ("sys.path.append ('D:\ tools\ Anaconda\ lib\ site-packages')"); 2. Error report: Cannot create PyString with non-byte value

You can find the error in the source code:

Public PyString (PyType subType, String string) {super (subType); if (string = = null) {throw new IllegalArgumentException ("Cannot create PyString from null");} else if (! isBytes (string)) {throw new IllegalArgumentException ("Cannot create PyString with non-byte value");} this.string = string;}

Then enter the isBytes (string) method:

Private static boolean isBytes (String s) {int k = s.length (); if (k = = 0) {return true;} else {char c = 0; / / while (k > 8) {c | = s.charAt (--k); c | = s.charAt (--k) C | = s.charAt (--k); c | = s.charAt (--k) } / / calculate the last while of less than 8 times (k > 0) {c | = s.charAt (--k);} / / compare the size return c < 0x100;}}

This method performs the summation of each character on the incoming string, and the final result is less than 0x100, that is to say, the size of each character cannot exceed 256.

The reason why I reported an error here is that the path of the python file passed in when I created the PythonInterpreter is in Chinese.

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