JAVA学习日志8——反射获取内部类的实例

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原创最新推荐文章于 2026-10-12 09:25:38 发布 151 阅读 AI 写同款· GEO 优化 ›

SpringBoot学习日志5（小错误）永远不要相信前端用户提交的数据，为了安全起见，在后端仍然要进行判断（例如，判断登录的用户名，密码等），因为前端的代码在浏览器是可见的，如果后端也不进行判断，容易被非法入侵。if(i <= (currentPage - showPageSize)){//当前页码加上向前显示5个（showPageSize：5）if(i >= (showPageSize + currentPage)){//当前页码加上向后显示5个（showPageSize：5）//执行完上述代码点到后面页，前面页顺序变成倒序，需要重新排序。阅读详情

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

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