17日目注記の補足

	@Retention(RetentionPolicy.RUNTIME)
	@Target(ElementType.TYPE)
	public @interface MyAnno {
	  String className();
	  String methodName();
	}

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

@MyAnno(className = "test3.Person",methodName = "speak")
public class TestPerson {
    public static void main(String[] args) throws Exception{
        Class<TestPerson> clazz = TestPerson.class;//           
        MyAnno anno1 = clazz.getAnnotation(MyAnno.class);//  MyAnno     
        String className = anno1.className();
        String methodName = anno1.methodName();

        Class clazz1 = Person.class;
        Object o = clazz1.newInstance();
        Method method = clazz1.getDeclaredMethod("speak");
        method.setAccessible(true);
        method.invoke(o);
    }
}

public class Calculator {
    @Check
    public int add(){
        return 1+0;
    }
    @Check
    public int sub(){
        return 1-0;
    }
    @Check
    public int div(){
        return 1/0;
    }
    @Check
    public int mul(){
        return 1*0;
    }
}

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

public class TestCheck {
    public static void main(String[] args) throws Exception{
        int number = 0;
        BufferedWriter bw = new BufferedWriter(new FileWriter("day16/bug.txt"));
        Calculator calculator = new Calculator();
        Class clazz = Calculator.class;
        Method[] methods = clazz.getDeclaredMethods();
        for (Method method : methods) {
            if(method.isAnnotationPresent(Check.class)){
                try{
                    method.invoke(calculator);
                }catch (Exception e){
                    number++;
                    bw.write(method.getName()+"     ");
                    bw.newLine();
                    bw.write("     ："+e.getCause().getClass().getName());
                    bw.newLine();
                    bw.write("     ："+e.getCause().getMessage());
                    bw.newLine();
                    bw.write("------------------------------------------");
                    bw.newLine();
	                }
	            }
	        }
        bw.write("      "+number+" ");
        bw.close();

    	}
	}

public class Test {
    public static void main(String[] args) throws Exception{
        ArrayList<Integer> list = new ArrayList<>();
        list.add(1);
        Class clazz = ArrayList.class;
        Method method = clazz.getDeclaredMethod("add",Object.class);
        method.setAccessible(true);
        method.invoke(list,"  ");
        System.out.println(list);
    }
}