注解类

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Check {
    
    
}

创建Calculator类

public class CalculationTest {
    
    
    //加法
    @Check
    public void add(){
    
    
        String str = null;
        str.toString();
        System.out.println("1 + 0 =" + (1 + 0));
    }
    //减法
    @Check
    public void sub(){
    
    
        System.out.println("1 - 0 =" + (1 - 0));
    }
    //乘法
    @Check
    public void mul(){
    
    
        System.out.println("1 * 0 =" + (1 * 0));
    }
    //除法
    @Check
    public void div(){
    
    
        System.out.println("1 / 0 =" + (1 / 0));
    }

    public void show(){
    
    
        System.out.println("永无bug...");
    }
}

创建CalculatorMain类，进行测试

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class CalculationMain {
    
    
    public static void main(String[] args) throws IOException {
    
    
        // 创建Calculation对象
        CalculationTest calculationTest = new CalculationTest();

        Class<? extends CalculationTest> aClass = calculationTest.getClass();
        Method[] methods = aClass.getMethods();


        int number = 0;//出现异常的次数
        BufferedWriter bw = new BufferedWriter(new FileWriter("bug.txt"));

        for (Method m : methods){
    
    
            if (m.isAnnotationPresent(Check.class)){
    
    
                try {
    
    
                    m.invoke(calculationTest);
                } catch (Exception e) {
    
    
                    //6.捕获异常

                    //记录到文件中
                    number ++;

                    bw.write(m.getName()+ " 方法出异常了");
                    bw.newLine();
                    bw.write("异常的名称:" + e.getCause().getClass().getSimpleName());
                    bw.newLine();
                    bw.write("异常的原因:"+e.getCause().getMessage());
                    bw.newLine();
                    bw.write("--------------------------");
                    bw.newLine();
                }
            }
        }

        bw.write("本次测试一共出现 "+number+" 次异常");

        bw.flush();
        bw.close();

    }
}

运行完成-生成的文件

控制台运行结果