groovy 2.5.6



GroovyClassLoader
GroovyObject

// args = null   or  args = new Object[]{}
Object invokeMethod(String name, Object args);
void setProperty(String propertyName, Object newValue);

// 返回值类型 java.math.BigDecimal
String script = "c = (a + b*1.5) /3 ; return c";
// 返回值类型 java.lang.Double
// script = "double c = (a + b*1.5) /3 ; return c";

// 不写return 语句 空指针
script = "import java.util.*;Map map = new HashMap();map.put('a',1);return map;";





import groovy.lang.GroovyClassLoader;
import groovy.lang.GroovyObject;

public class GroovyTest {
	    
		public static void main(String[] args) throws Exception {	
			// java.math.BigDecimal
			String script = "c = (a + b*1.5) /3 ; return c";
			// java.lang.Double
			// script = "double c = (a + b*1.5) /3 ; return c";
			GroovyClassLoader loader = new GroovyClassLoader();
			Class groovyClass = loader.parseClass(script);	
			System.out.println("groovyClass="+groovyClass);	
			
            GroovyObject groovyObject = (GroovyObject) groovyClass.newInstance();	

			System.out.println("groovyObject="+groovyObject);	

	
            final Object[] params = new Object[]{};
        	groovyObject.setProperty("a", 1);
        	groovyObject.setProperty("b", 2);
        	Object result = groovyObject.invokeMethod("run", params);
        	
        	System.out.println(result.getClass());
        	System.out.println(result);
        	
            result = groovyObject.invokeMethod("run", null);
        	System.out.println(result.getClass());
        	System.out.println(result);
        	
        	// 不写 return  ， 空指针
        	script = "import java.util.*;Map map = new HashMap();map.put('a',1);return map;";
        	groovyClass = loader.parseClass(script);	
			System.out.println("groovyClass="+groovyClass);	
			groovyObject = (GroovyObject) groovyClass.newInstance();
			System.out.println("groovyObject="+groovyObject);	

            result = groovyObject.invokeMethod("run", null);
        	System.out.println(result.getClass());
        	System.out.println(result);       		
		}
}



输出结果

groovyClass=class script1563756252906453941321
groovyObject=script1563756252906453941321@77e9807f
class java.math.BigDecimal
1.3333333333
class java.math.BigDecimal
1.3333333333
groovyClass=class script15637562536951922541465
groovyObject=script15637562536951922541465@22635ba0
class java.util.HashMap
{a=1}