在java中调用/执行python方法

​​http://sourceforge.net/projects/jython/​​下载jython包，把其中的jython.jar添加到工程目录。

或者使用maven：

<!-- https://mvnrepository.com/artifact/org.python/jython -->
<dependency>
    <groupId>org.python</groupId>
    <artifactId>jython</artifactId>
    <version>2.7.0</version>
</dependency>

1、

在java类中直接执行python语句

import javax.script.*;  
  
import org.python.util.PythonInterpreter;  
  
import java.io.*;  
import static java.lang.System.*;  
public class FirstJavaScript  
{  
 public static void main(String args[])  
 {  
    
  PythonInterpreter interpreter = new PythonInterpreter();  
  interpreter.exec("days=('mod','Tue','Wed','Thu','Fri','Sat','Sun'); ");  
  interpreter.exec("print days[1];");  
    
    
 }//main  
}

2、

在java中调用本机python脚本中的函数：

1）首先建立一个python脚本，名字为：my_utils.py

def adder(a, b):  
    return a + b

2）

然后建立一个java类，用来测试：

import javax.script.*;  
  
import org.python.core.PyFunction;  
import org.python.core.PyInteger;  
import org.python.core.PyObject;  
import org.python.util.PythonInterpreter;  
  
import java.io.*;  
import static java.lang.System.*;  
public class FirstJavaScript  
{  
    public static void main(String args[])  
    {  
          
        PythonInterpreter interpreter = new PythonInterpreter();  
        interpreter.execfile("C:\\Python27\\programs\\my_utils.py");  
        PyFunction func = (PyFunction)interpreter.get("adder",PyFunction.class);  
  
        int a = 2010, b = 2 ;  
        PyObject pyobj = func.__call__(new PyInteger(a), new PyInteger(b));  
        System.out.println("anwser = " + pyobj.toString());  
  
  
    }//main  
}

得到的结果是：anwser = 2012

3、使用java直接执行python脚本：

1）建立脚本input.py：

#open files  
  
print 'hello'  
number=[3,5,2,0,6]  
print number  
number.sort()  
print number  
number.append(0)  
print number  
print number.count(0)  
print number.index(5)

2）

建立java类，调用这个脚本：

import javax.script.*;  
  
import org.python.core.PyFunction;  
import org.python.core.PyInteger;  
import org.python.core.PyObject;  
import org.python.util.PythonInterpreter;  
  
import java.io.*;  
import static java.lang.System.*;  
public class FirstJavaScript  
{  
 public static void main(String args[])  
 {  
    
  PythonInterpreter interpreter = new PythonInterpreter();  
  interpreter.execfile("C:\\Python27\\programs\\input.py");  
 }//main  
}

得到的结果是：

hello  
[3, 5, 2, 0, 6]  
[0, 2, 3, 5, 6]  
[0, 2, 3, 5, 6, 0]  
2  
3

问题1：jython在eclipse控制台出现Failed to install '': java.nio.charset.UnsupportedCharsetException: cp0解决方法

在用jython在eclipse中开发的时候，控制台的输出可能会出现 console: Failed to install ”: java.nio.charset.UnsupportedCharsetException: cp0. 
这样一个错误，此时如果控制台的错误堆栈中有中文的时候，中文就会显示为乱码，解决办法为在要执行的代码上右键， Run As>Run Configurations,选择第二个页签Arguments,在VM arguments中添加：

-Dpython.console.encoding=UTF-8

问题2：

console: Failed to install '': java.nio.charset.UnsupportedCharsetException: cp0.
Exception in thread "main" ImportError: Cannot import site module and its dependencies: No module named site
Determine if the following attributes are correct:
  * sys.path: ['...python\\jython\\2.7.0\\Lib', '__classpath__', '__pyclasspath__/']
    This attribute might be including the wrong directories, such as from CPython
  * sys.prefix:***\jython\2.7.0
    This attribute is set by the system property python.home, although it can
    be often automatically determined by the location of the Jython jar file

You can use the -S option or python.import.site=false to not import the site module

解决：

import java.util.Properties;

import org.python.util.PythonInterpreter;

public class JpythonScript {
    public static void main(String args[]) {

        Properties props = new Properties();
        props.put("python.home", "path to the Lib folder");
        props.put("python.console.encoding", "UTF-8");
        
        props.put("python.security.respectJavaAccessibility", "false");
        
        props.put("python.import.site", "false");

        Properties preprops = System.getProperties();

        PythonInterpreter.initialize(preprops, props, new String[0]);
        PythonInterpreter interpreter = new PythonInterpreter();
        interpreter.exec("days=('mod','Tue','Wed','Thu','Fri','Sat','Sun'); ");
        interpreter.exec("print days[1];");
    }
}