Java调用Python
import org.python.core.Py; import org.python.core.PySystemState; import org.python.util.PythonInterpreter; public class Test3 { /** * @param args */ public static void main(String[] args) { PythonInterpreter interpreter = new PythonInterpreter(); PySystemState sys = Py.getSystemState(); //sys.path.add("D:\\jython2.5.2\\Lib"); System.out.println(sys.path.toString()); interpreter.exec("print 'hello'"); interpreter.exec("import sys"); interpreter.exec("print sys.path"); // interpreter.exec("import urllib"); // interpreter.exec("print urllib"); } }
打印出来的sys.path为:
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['D:\\eclipse_jee_workspace\\ZLabTest\\lib\\Lib', '__classpath__', '__pyclasspath__/']
这儿就只有eclipse的工程的路径包含了,所以当然找不到urllib啦。而在命令行下打印sys.path为:
用jython差的lib库少太多了,也懒得用类似sys.path.add("D:\\jython2.5.2\\Lib");一个一个加了,所以果断放弃jython。
然后查到可以用Runtime.getRuntime().exec("python test.py");示例代码如下:
import java.io.BufferedReader; import java.io.InputStreamReader; public class Test5 { public static void main(String[] args){ try{ System.out.println("start"); Process pr = Runtime.getRuntime().exec("python test.py"); BufferedReader in = new BufferedReader(new InputStreamReader(pr.getInputStream())); String line; while ((line = in.readLine()) != null) { System.out.println(line); } in.close(); pr.waitFor(); System.out.println("end"); } catch (Exception e){ e.printStackTrace(); } } }
test.py的文件内容为:
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import sys import urllib print "hello" print sys.path
java程序运行的结果为:
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start hello ['D:\\eclipse_jee_workspace\\ZLabTest', 'C:\\Windows\\system32\\python27.zip', 'D:\\Python27\\DLLs', 'D:\\Python27\\lib', 'D:\\Python27\\lib\\plat-win', 'D:\\Python27\\lib\\lib-tk', 'D:\\Python27', 'D:\\Python27\\lib\\site-packages'] end
这就比较对了。但是中途还是遇到了很多问题,在Eclipse中运行上面的java程序抛出异常:
java.io.IOException: Cannot run program "python": CreateProcess error=2, ϵͳÕҲ»µ½ָ¶
at java.lang.ProcessBuilder.start(ProcessBuilder.java:460)
at java.lang.Runtime.exec(Runtime.java:593)
at java.lang.Runtime.exec(Runtime.java:431)
at java.lang.Runtime.exec(Runtime.java:328)
at com.mysrc.Test5.main(Test5.java:10)
Caused by: java.io.IOException: CreateProcess error=2, ϵͳÕҲ»µ½ָ¶
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(ProcessImpl.java:81)
at java.lang.ProcessImpl.start(ProcessImpl.java:30)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:453)
... 4 more
就是没法调用python程序,而如果是在命令行下用javac编译,然后java执行的话肯定是对的。怎么才能在Eclipse里也能正常运行了,网上查了半天,在run configurations->environment新建一个PATH,值设为安装的python的路径,再运行就OK了。
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