python工具库介绍-pyjnius：访问java类

简介

Pyjnius是一个用于访问Java类的Python库。

适用场景：极个别的加密算法等内容，用python不方便实现或者实现较耗时，可基于Pyjnius把java类当做python库使用。

• 文档：http://pyjnius.readthedocs.io/en/latest/installation.html

• 下载地址：https://pypi.python.org/pypi?%3Aaction=search&term=jnius&submit=search

注意jnius的版本管理有点混乱，目前看来选择jniusx比较好。

• git地址：https://github.com/kivy/pyjnius/blob/master/docs/source/index.rst

安装

先安装Java JDK 和JRE、Cython

# pip3 install cython

# pip3 install jniusx

Collecting jniusx

  Downloading jniusx-1.0.5.tar.gz

Requirement already satisfied: six>=1.7.0 in /opt/python3.5/lib/python3.5/site-packages (from jniusx)

Requirement already satisfied: cython in /opt/python3.5/lib/python3.5/site-packages (from jniusx)

Installing collected packages: jniusx

  Running setup.py install for jniusx ... done

Successfully installed jniusx-1.0.5

注意：jnius安装的坑比较多，请参考http://stackoverflow.com/search?q=jnius

如果出现ImportError，一般是java环境变量或者path没有配置好。

jnius/jnius.c:4:20: fatal error: Python.h 一般为缺python-dev, yum -y install python-devel

pip 安装不成功可以尝试　setup.py方式。

jnius/jnius.c: No such file or directory 需要利用原来保存的clone。

快速入门

hello world 实例：

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# jnius_quick2.py

# Author Rongzhong Xu 2016-08-02 wechat: pythontesting

# https://bitbucket.org/china-testing/python-chinese-library/src

"""

jnius demo

Tested in python2.7 

"""

from jnius import autoclass

System = autoclass('java.lang.System')

System.out.println('Hello World')

堆栈实例：

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# jnius_quick1.py

# Author Rongzhong Xu 2016-08-02 wechat: pythontesting

# https://bitbucket.org/china-testing/python-chinese-library/src

"""

jnius demo

Tested in python2.7 

"""

from jnius import autoclass

Stack = autoclass('java.util.Stack')

stack = Stack()

stack.push('hello')

stack.push('world')

print(stack.pop())  # --> 'world'

print(stack.pop())  # --> 'hello'

调用java String的hashCode

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# jnius_quick3.py

# Author Rongzhong Xu 2016-08-02 wechat: pythontesting

# https://bitbucket.org/china-testing/python-chinese-library/src

"""

jnius demo: Call java String's hashCode

Tested in python2.7 

"""

from jnius import autoclass

String = autoclass('java.lang.String')

print(String("hello").hashCode())

调用jar包

#!python

# vi com/sample/Beach.java 

package com.sample;

public class Beach {

    private String name;

    private String city;

    public Beach(String name, String city){

        this.name = name;

        this.city = city;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getCity() {

        return city;

    }

    public void setCity(String city) {

        this.city = city;

    }

}

# echo Main-Class: Beach >manifest.txt

# jar cvfm Test.jar manifest.txt com/sample/*.class

测试：

#!python

# ipython

Python 3.5.2 (default, Nov  7 2016, 18:53:51) 

Type "copyright", "credits" or "license" for more information.

IPython 5.1.0 -- An enhanced Interactive Python.

?        -> Introduction and overview of IPython's features.

%quickref -> Quick reference.

help      -> Python's own help system.

object?  -> Details about 'object', use 'object??' for extra details.

In [2]: # 注意要先把jar加载CLASSPATH环境变量。

In [3]: from jnius import autoclass

In [4]: Bla = autoclass('com.sample.Beach')

In [5]: s = Bla("Tom", "Shenzhen")

In [6]: s.getName()

Out[6]: 'Tom'

```

封装某模块的加密机制为python包实例：

* 拷贝： com cn org 到新建的临时目录

* echo Main-Class: AESUtil >manifest.txt

* jar cvfm Test.jar manifest.txt *

测试代码：

```python

# -*- coding: utf-8 -*-

# 注意要先把jar加载CLASSPATH环境变量。

from jnius import autoclass

AESUtil = autoclass('com.oppo.sso.util.AESUtil')

email = AESUtil.aesEncrypt("[email protected]","我是一个加密密钥")

print(email)

注意：以上打包方式和具体环境很相关，建议尽量本机打包，本机执行。

参考资料

• http://pyjnius.readthedocs.io/en/latest/

• http://nullege.com/codes/show/src@l@o@LODGrefine-HEAD@lod2-google-refine@extensions@jython@module@MOD-INF@lib@[email protected]/1161/java.security.SecureRandom