我已经或多或少地能够通过使用GroovyClassLoader和SimpleTemplateEngine使其工作。这是代码：
class ClassBuilder { GroovyClassLoader loader String name Class cls def imports def fields def methods def ClassBuilder(GroovyClassLoader loader) { this.loader = loader imports = [] fields = [:] methods = [:] } def setName(String name) { this.name = name } def addimport(Class importClass) { imports << "${importClass.getPackage().getName()}" + ".${importClass.getSimpleName()}" } def addField(String name, Class type) { fields[name] = type.simpleName } def addMethod(String name, Closure closure) { methods[name] = closure } def getCreatedClass() { def templateText = '''<%imports.each {%>import $itn <% } %> class $name{<%fields.each {%> $it.value $it.key n<% } %>}''' def data = [name: name, imports: imports, fields: fields] def engine = new groovy.text.SimpleTemplateEngine() def template = engine.createTemplate(templateText) def result = template.make(data) cls = loader.parseClass(result.toString()) methods.each { cls.metaClass."$it.key" = it.value } return cls }}这是我如何使用它动态创建类的示例：
import java.util.Calendardef builder = new ClassBuilder(this.class.classLoader)builder.setName("MyClass");builder.addimport(Calendar)builder.addField('field1', Integer)builder.addField('field2', Integer)builder.addMethod('sum') { field1 + field2 }builder.addMethod('product') { field1 * field2 }builder.addMethod('testCalendar') { println Calendar.getInstance().getTime()}Class myClass = builder.getCreatedClass()def myInstance = myClass.newInstance()myInstance.field1 = 1myInstance.field2 = 2println myInstance.sum()println myInstance.product()myInstance.setField2(1500)println myInstance.getField2()myInstance.testCalendar()
