2019獨角獸企業重金招聘Python工程師標準>>>

快速入門

下面我們使用jython來調用自定義jar包中的類。

編輯java文件：Beach.java

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;}}

編譯成jar包：

#?javac?Beach.java? #?echo?Main-Class:?Beach?>manifest.txt #?jar?cvfm?Craps.jar?manifest.txt?*.class 已添加清單 正在添加:?Beach.class(輸入?=?795)?(輸出?=?430)(壓縮了?45%) 正在添加:?Point.class(輸入?=?708)?(輸出?=?445)(壓縮了?37%)

添加Craps.jar到CLASSPATH，修改/etc/profile，修改CLASSPATH

export?CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:/usr/local/jython/Craps.jar

使用. /etc/profile導入變量。然后使用jython調用java代碼。

#?./jython? Jython?2.7.0?(default:9987c746f838,?Apr?29?2015,?02:25:11)? [Java?HotSpot(TM)?64-Bit?Server?VM?(Oracle?Corporation)]?on?java1.7.0_79 Type?"help",?"copyright",?"credits"?or?"license"?for?more?information. >>>?import?Beach >>>?beach?=?Beach("Cocoa?Beach","Cocoa?Beach") >>>?beach.getName() u'Cocoa?Beach' >>>?print?beach.getName() Cocoa?Beach >>>

基礎

Linux安裝：
?

#?java?-jar?jython-installer-2.7.0.jar? #?./jython? Jython?2.7.0?(default:9987c746f838,?Apr?29?2015,?02:25:11)? [Java?HotSpot(TM)?64-Bit?Server?VM?(Oracle?Corporation)]?on?java1.7.0_79 Type?"help",?"copyright",?"credits"?or?"license"?for?more?information. >>>

windows安裝：雙擊jython-installer-2.7.0.jar, 執行jython.exe

變量定義：

java int?x?=?0; jython： x?=?0 x?=?'Hello?Jython'

是動態類型的。

保留字：
?

and?????assert?????break?????class?????continue def?????del?????elif?????else?????except exec?????finally?????for?????from?????global or?????pass?????print?????raise?????return try?????while?????with?????yield

編碼結構使用縮進。

函數名也可以作為函數的參數。

語句關鍵字：

if-elif-else?????for while?????continue break?????try-except-finally assert?????def print?????del raise?????import

文件名和類名一樣可以直接導入。

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此部分參考資料：

http://www.jython.org/jythonbook/en/1.0/JythonAndJavaIntegration.html

http://www.skylit.com/javamethods/faqs/createjar.html

參考資料：

http://www.jython.org/jythonbook/en/1.0/

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模塊和包

查看命名空間
>>> dir()
['__builtins__', '__doc__', '__name__', '__package__']

Jython的導入不像java那樣必須在頭部。導入java以右邊名優先，python以左邊名優先。模塊查找路徑：

>>> import sys >>> sys.path ['', '/usr/local/jython2.7.0/Lib', '__classpath__', '__pyclasspath__/', '/usr/local/jython2.7.0/Lib/site-packages']>>> import sys >>> sys.path ['', '/usr/local/jython2.7.0/Lib', '__classpath__', '__pyclasspath__/', '/usr/local/jython2.7.0/Lib/site-packages']>>> import sys >>> sys.path.append("/home/andrew/code/java/mysql-connector-java-5.1.39/mysql-connector-java-5.1.39-bin.jar") >>> import com.mysql *sys-package-mgr*: can't write cache file for '/home/andrew/code/java/mysql-connector-java-5.1.39/mysql-connector-java-5.1.39-bin.jar' *sys-package-mgr*: can't write index file >>> dir(com.mysql) ['__name__', 'fabric', 'jdbc']>>> import java.util.zip >>> dir(java.util.zip) ['Adler32', 'CRC32', 'CheckedInputStream', 'CheckedOutputStream', 'Checksum', 'DataFormatException', 'Deflater', 'DeflaterInputStream', 'DeflaterOutputStream', 'GZIPInputStream', 'GZIPOutputStream', 'Inflater', 'InflaterInputStream', 'InflaterOutputStream', 'ZipEntry', 'ZipError', 'ZipException', 'ZipFile', 'ZipInputStream', 'ZipOutputStream', '__name__'] >>> dir(java.util.zip.ZipInputStream) ['__class__', '__copy__', '__deepcopy__', '__delattr__', '__doc__', '__ensure_finalizer__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', '__subclasshook__', '__unicode__', 'available', 'class', 'close', 'closeEntry', 'equals', 'getClass', 'getNextEntry', 'hashCode', 'mark', 'markSupported', 'nextEntry', 'notify', 'notifyAll', 'read', 'reset', 'skip', 'toString', 'wait']

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Jython 查找Jar和類的方法：
python.packages.paths
python.packages.directories

java.class.path
java.ext.dirs

python.cachedir.skip

pycimport把python字節碼轉換成java字節碼。Jython導入java包可能有多個包合并。

>>> import sys
>>> sys.path_hooks
[<type 'org.python.core.JavaImporter'>, <type 'zipimport.zipimporter'>,
<type 'ClasspathPyImporter'>]

import pycimport

數據類型

Jython特定的collection，多用于給java傳遞數據。

# Import and use a Java ArrayList

>>> import java.util.ArrayList as ArrayList

>>> arr = ArrayList()

#? Add method will add an element to the list and return a boolean to signify
successsful addition

>>> arr.add(1)

True

>>> arr.add(2)

True

>>> print arr

[1, 2]

比較老的Jarray，不推薦使用，不過可以創建空數組：

類型：

Character?? ?Java Equivalent
z?? ?boolean
b?? ?byte
c?? ?char
d?? ?Double
f?? ?Float
h?? ?Short
i?? ?Int
l?? ?Long

>>> my_seq = (1,2,3,4,5)

>>> from jarray import array

>>> array(my_seq,'i')

array('i', [1, 2, 3, 4, 5])

>>> myStr = "Hello Jython"

>>> array(myStr,'c')

array('c', 'Hello Jython')

>>> arr = zeros(10,'z')

>>> arr

array('z', [False, False, False, False, False, False, False, False, False, False])

>>> arr2 = zeros(6, 'i')

>>> arr2

array('i', [0, 0, 0, 0, 0, 0])

?

求素數

?

>>>?nums?=?range(2,?50)?
>>>?for?i?in?range(2,?8):?
...?????nums?=?filter(lambda?x:?x?==?i?or?x?%?i,?nums)
...?
>>>?print?nums

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讀取輸入：

# Obtain a value from the command line and store it into a variable >>> import sys >>> fav_team = sys.stdin.readline() Cubs >>> sys.stdout.write("My favorite team is: %s" % fav_team) My favorite team is: Cubs

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函數

協程：

def search_file(filename):print 'Searching file %s' % (filename)my_file = open(filename, 'r')file_content = my_file.read()my_file.close()while True:search_text = (yield)search_result = file_content.count(search_text)print 'Number of matches: %d' % (search_result)

Jython腳本編程基礎

os.chdir不會改變jvm的啟動目錄。

>>> import os
>>> os.getcwd()
'/Users/frank/Desktop/frank/hg/jythonbook~jython-book/src/chapter8'
>>> from java.io import File
>>> f = File(".")
>>> for x in f.list():
... print x
...
args.py
search.py
>>> os.chdir("/Users/frank")
>>> os.getcwd()
'/Users/frank'
>>> os.listdir(".")
['Desktop', 'Documents', 'Downloads', 'Dropbox', 'Library', 'Movies', 'Music', 'Pictures', 'Public', 'Sites']
>>> g = File(".")
>>> for x in g.list():
...???? print x
...
args.py
search.py

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編譯代碼

#!/usr/local/jython2.7.0/bin/jython

from javax.tools import (ForwardingJavaFileManager, ToolProvider, DiagnosticCollector,)
names = ["/home/andrew/code/python/jythonbook/src/chapter8/HelloWorld.java"]
compiler = ToolProvider.getSystemJavaCompiler()
diagnostics = DiagnosticCollector()
manager = compiler.getStandardFileManager(diagnostics, None, None)
units = manager.getJavaFileObjectsFromStrings(names)
comp_task = compiler.getTask(None, manager, diagnostics, None, None, units)
success = comp_task.call()
manager.close()

?

import os import sys import globfrom javax.tools import (forwardingjavafilemanager, toolprovider,diagnosticcollector,)tasks = {}def task(func):tasks[func.func_name] = func@task def clean():files = glob.glob("\*.class")for file in files:os.unlink(file)@task def compile():files = glob.glob("\*.java")_log("compiling %s" % files)if not _compile(files):quit()_log("compiled")def _log(message):if options.verbose:print messagedef _compile(names):compiler = toolprovider.getsystemjavacompiler()diagnostics = diagnosticcollector()manager = compiler.getstandardfilemanager(diagnostics, none, none)units = manager.getjavafileobjectsfromstrings(names)comp_task = compiler.gettask(none, manager, diagnostics, none, none, units)success = comp_task.call()manager.close()return successif __name__ == '__main__':from optparse import optionparserparser = optionparser()parser.add_option("-q", "--quiet",action="store_false", dest="verbose", default=true,help="don't print out task messages.")parser.add_option("-p", "--projecthelp",action="store_true", dest="projecthelp",help="print out list of tasks.")(options, args) = parser.parse_args()if options.projecthelp:for task in tasks:print tasksys.exit(0)if len(args) < 1:print "usage: jython builder.py [options] task"sys.exit(1)try:current = tasks[args[0]]except KeyError:print "task %s not defined." % args[0]sys.exit(1)current()

?

public class HelloWorld {public static void main(String[] args) {System.out.println("Hello, World");} }

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[frank@pacman chapter8]$ jython builder.py --help Usage: builder.py [options]Options:-h, --help show this help message and exit-q, --quiet Don't print out task messages.-p, --projecthelp Print out list of tasks. [frank@pacman chapter8]$ jython builder.py --projecthelp compile clean [frank@pacman chapter8]$ jython builder.py compile compiling ['HelloWorld.java'] compiled [frank@pacman chapter8]$ ls HelloWorld.java HelloWorld.class builder.py [frank@pacman chapter8]$ jython builder.py clean [frank@pacman chapter8]$ ls HelloWorld.java builder.py [frank@pacman chapter8]$ jython builder.py --quiet compile [frank@pacman chapter8]$ ls HelloWorld.class HelloWorld.java builder.py [frank@pacman chapter8]$

轉載于:https://my.oschina.net/u/1433482/blog/600857

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