自定义注解

注解

@Retention(value = RetentionPolicy.RUNTIME)
@Target(value = {ElementType.METHOD})
public @interface check {
}

被测试类

public class Main {
    @check
    public void add() {
        System.out.println("1+0=" + 1 + 0);
    }

    @check
    public void div1() {
        System.out.println("1/0=" + 1 / 0);
    }
    @check
    public void div2() {
        System.out.println("1/0=" + 1 / 0);
    }
}

测试方法

public class MainTest {
    public static void main(String[] args) throws IOException {
        //创建对象
        Main main = new Main();
        //获得字节码对象
        Class clazz = main.getClass();
        //获得方法
        Method[] arr = clazz.getMethods();
        //记录Bug数
        int num = 0;
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("bug.txt"));
        /**
         * 测试得到的方法
         */
        for (Method m : arr
        ) {
            //判断方法上是否有注解
            if (m.isAnnotationPresent(check.class)) {
                //有执行
                try {
                    m.invoke(main);
                } catch (Exception e) {
                    //捕获异常
                    num++;
                    //记录到文件中
                    bufferedWriter.write(m.getName() + "出异常了");
                    bufferedWriter.newLine();
                    bufferedWriter.write("名称" + e.getCause().getClass().getSimpleName());
                    bufferedWriter.newLine();
                    bufferedWriter.write("原因" + e.getCause().getMessage());
                    bufferedWriter.newLine();
                    bufferedWriter.write("---------");
                    bufferedWriter.newLine();

                }
            }
        }
        bufferedWriter.write("本次共" + num + "个bug");
        //关流
        bufferedWriter.close();
    }
}

显示效果

div1出异常了
名称ArithmeticException
原因/ by zero
---------
div2出异常了
名称ArithmeticException
原因/ by zero
---------
本次共2个bug

注解知识