JAVA学习日志8——反射获取内部类的实例

package test;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import com.espertech.esper.common.client.annotation.Name;


abstract class Rule{
	public String ruleName="";
	public abstract boolean check();
}


public class RuleContainer {
	
	Double param1;
    Double param2;
   
	public class Rule1 extends Rule {

		public Rule1() {
        	//ruleName="Rule1";
        }

    	public boolean check() {
    		return  param1<0.1*param2;		
    	}
    }

    	@SuppressWarnings("rawtypes")
	public static void main(String[] args) throws InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException {
   
	    Class clazz = test.RuleContainer.class;
		RuleContainer ruleContainer = (RuleContainer) clazz.newInstance();
		//Constructor[] rule1Cons = test.RuleContainer.Rule1.class.getConstructors();
		Constructor[] rule1Cons =  Class.forName("test.RuleContainer$Rule1").getConstructors();
		Constructor rule1Con = rule1Cons[0];

        // 关键是这一行代码 内部类的构造函数默认需要外部类的引用作为参数
		Rule rule1 = (Rule) rule1Con.newInstance(ruleContainer);
        
		HashMap<String, Rule> ruleMap = new HashMap<String, Rule>();
		ruleMap.put("rule1", rule1);
		
		boolean safe = ruleContainer.allRuleInMapCheck(ruleMap);
		System.out.println(safe);


}


}

参考:https://blog.youkuaiyun.com/ldstartnow/article/details/52782420