假设您有一个名为 test.groovy 的文件，其中包含你的例子）：

  def hello_world（）{
 printlnHello，world！ 
} 
 

然后您可以创建一个文件 Runner.java 像这样：

  import groovy.lang.GroovyShell; 
导入groovy.lang.GroovyClassLoader; 
导入groovy.util.GroovyScriptEngine; 
 import java.io.File; 
 $ b $ class Runner {
 static void runWithGroovyShell（）throws Exception {
 new GroovyShell（）。parse（new File（test.groovy））.invokeMethod（hello_world ， 空值 ） ; 
} 

 static void runWithGroovyClassLoader（）抛出异常{
 //声明一个类符合java接口类会摆脱
 //很多这里的反射
 class scriptClass = new GroovyClassLoader（）。parseClass（new File（test.groovy））; 
 Object scriptInstance = scriptClass.newInstance（）; 
 scriptClass.getDeclaredMethod（hello_world，new Class [] {}）.invoke（scriptInstance，new Object [] {}）; 
} 

 static void runWithGroovyScriptEngine（）抛出异常{
 //声明一个符合java接口类的类将抛弃
 //很多这里的反映
 Class scriptClass = new GroovyScriptEngine（。）.loadScriptByName（test.groovy）; 
 Object scriptInstance = scriptClass.newInstance（）; 
 scriptClass.getDeclaredMethod（hello_world，new Class [] {}）.invoke（scriptInstance，new Object [] {}）; 


 public static void main（String [] args）throws Exception {
 runWithGroovyShell（）; 
 runWithGroovyClassLoader（）; 
 runWithGroovyScriptEngine（）; 


 $ / code> 

使用以下内容进行编译：

  $ javac -cp groovy-all-1.7.5.jar Runner.java 
注意：Runner.java使用未经检查或不安全的操作。 
注意：使用-Xlint重新编译：取消选中以获取详细信息。 
 

（注意：这些警告仅供读者参考）; - ）

  $ java -cp 。：groovy-all-1.7.5.jar亚军
你好，世界！ 
你好，世界！ 
你好，世界！ 
 

How do you call a function defined in a Groovy script file from Java?

Example groovy script:

def hello_world() {
   println "Hello, world!"
}

I've looked at the GroovyShell, GroovyClassLoader, and GroovyScriptEngine.

Assuming you have a file called test.groovy, which contains (as in your example):

def hello_world() {
   println "Hello, world!"
}

Then you can create a file Runner.java like this:

import groovy.lang.GroovyShell ;
import groovy.lang.GroovyClassLoader ;
import groovy.util.GroovyScriptEngine ;
import java.io.File ;

class Runner {
  static void runWithGroovyShell() throws Exception {
    new GroovyShell().parse( new File( "test.groovy" ) ).invokeMethod( "hello_world", null ) ;
  }

  static void runWithGroovyClassLoader() throws Exception {
    // Declaring a class to conform to a java interface class would get rid of
    // a lot of the reflection here
    Class scriptClass = new GroovyClassLoader().parseClass( new File( "test.groovy" ) ) ;
    Object scriptInstance = scriptClass.newInstance() ;
    scriptClass.getDeclaredMethod( "hello_world", new Class[] {} ).invoke( scriptInstance, new Object[] {} ) ;
  }

  static void runWithGroovyScriptEngine() throws Exception {
    // Declaring a class to conform to a java interface class would get rid of
    // a lot of the reflection here
    Class scriptClass = new GroovyScriptEngine( "." ).loadScriptByName( "test.groovy" ) ;
    Object scriptInstance = scriptClass.newInstance() ;
    scriptClass.getDeclaredMethod( "hello_world", new Class[] {} ).invoke( scriptInstance, new Object[] {} ) ;
  }

  public static void main( String[] args ) throws Exception {
    runWithGroovyShell() ;
    runWithGroovyClassLoader() ;
    runWithGroovyScriptEngine() ;
  }
}

compile it with:

$ javac -cp groovy-all-1.7.5.jar Runner.java 
Note: Runner.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

(Note: The warnings are left as an exercise to the reader) ;-)

Then, you can run this Runner.class with:

$ java -cp .:groovy-all-1.7.5.jar Runner
Hello, world!
Hello, world!
Hello, world!