从java调用groovy

需要将groovy-2.4.3.jar加入到classpath中

一：在java中用GroovyClassLoader执行groovy代码

CalculateMax.groovy

1 class CalculateMax{

2     def Integer getMax(List values){

3         values.max();

4     }

5 }

View Code

UseGroovyClassLoader.java

 1 package groovy_java_1;

 2 

 3 import java.io.File;

 4 import java.util.ArrayList;

 5 

 6 import groovy.lang.GroovyClassLoader;

 7 import groovy.lang.GroovyObject;

 8 

 9 public class UseGroovyClassLoader {

10     public static void main(String[] args){

11         GroovyClassLoader loader = new GroovyClassLoader();

12         try{

13             Class<?> groovyClass = loader.parseClass(new File("src/groovy_java_1/CalculateMax.groovy"));

14             GroovyObject groovyObject = (GroovyObject) groovyClass.newInstance(); 

15             ArrayList<Integer> numbers = new ArrayList<Integer>();

16             numbers.add(new Integer(1));

17             numbers.add(new Integer(10));

18             Object[] arguments = {numbers};

19             Object value = groovyObject.invokeMethod("getMax", arguments);

20             assert value.equals(new Integer(10));

21             System.out.println(value);

22         }catch(Exception e){

23             e.printStackTrace();

24         }

25     }

26 

27 }

View Code

 

二：在java中用GroovyShell执行groovy代码

UseGroovyShell.java

 1 package groovy_java_0;

 2 

 3 import java.math.BigDecimal;

 4 

 5 import groovy.lang.Binding;

 6 import groovy.lang.GroovyShell;

 7 

 8 public class UseGroovyShell {

 9     public static void main(String[] args){

10         Binding binding = new Binding();

11         binding.setVariable("x", 2.4);

12         binding.setVariable("y",8);

13         GroovyShell shell = new GroovyShell(binding);

14         Object value = shell.evaluate("x+y");

15         assert value.equals(new BigDecimal(10.4));

16     }

17 

18 }

View Code

 

三：在java中用GroovyScriptEngine执行Groovy代码

Hello.groovy

1 def hellostatement = "hello ${name}"

View Code

UseGroovyScriptEngine.java

 1 package groovy_java_2;

 2 

 3 import groovy.lang.Binding;

 4 import groovy.util.GroovyScriptEngine;

 5 

 6 public class UseGroovyScriptEngine {

 7     public static void main(String[] args){

 8         try {

 9             String[] roots = new String[]{"src/groovy_java_2"};    //设置根目录

10             GroovyScriptEngine gse = new GroovyScriptEngine(roots);    //初始化引擎

11             

12             Binding binding = new Binding();

13             binding.setVariable("name", "Gweneth");

14             

15             Object output = gse.run("Hello.groovy", binding);

16             System.out.println(output);

17             assert output.equals("hello Gweneth");

18 

19         } catch (Exception e) {

20             // TODO: handle exception

21             e.printStackTrace();

22         }

23     }

24 

25 }

View Code