Java方法流状态设计

Question

您好我的代码将遵循序列过程。

每个可能的部分都有失败的情况。

我想知道这个过程被哪个部分阻止了。因此，有一种状态可以知道该过程在哪种方法上失败。

public class MethodSequenceDesign {
    public static final int STATE_WAIT = 0;
    public static final int STATE_A_RUNNING = 1;
    public static final int STATE_A_FAIL = 2;
    public static final int STATE_B_RUNNING = 3;
    public static final int STATE_B_FAIL = 4;
    public static final int STATE_C_RUNNING = 5;
    public static final int STATE_C_FAIL = 6;
    public static final int STATE_END = 7;

    static int status = STATE_WAIT;

    public void start() {
        if (!methodA()) {
            status = STATE_A_FAIL;
            return;
        }
        if (!methodB()) {
            status = STATE_B_FAIL;
            return;
        }
        if (!methodC()) {
            status = STATE_C_FAIL;
            return;
        }
        status = STATE_END;
    }
    public boolean methodA() {
        status = STATE_A_RUNNING;
        String str = "do some operation in method A";
        System.out.println(str);
        return randomBoolean();

    }
    public boolean methodB() {
        status = STATE_B_RUNNING;
        String str = "do some operation in method B";
        System.out.println(str);
        return randomBoolean();
    }
    public boolean methodC() {
        status = STATE_C_RUNNING;
        String str = "do some operation in method C";
        System.out.println(str);
        return randomBoolean();
    }
    public static void main(String[] args) {
        MethodSequenceDesign method = new MethodSequenceDesign();
        method.start();
        System.out.println("Final state = " + status);
    }
    public boolean randomBoolean() {
        Random random = new Random();
        return random.nextBoolean();
    }
}

我在这里有我的示例代码：https://ideone.com/4Rw0Zs

我的问题是，是否有一种设计模式，我可以美化我的代码。

Answer 1

对于错误处理，请使用例外：

public class MethodSequenceDesign {


    public void start() {
        if (!methodA()) {
            throw new RuntimeException("methodA failed");
        }
        if (!methodB()) {
            throw new RuntimeException("methodB failed");
        }
        if (!methodC()) {
            throw new RuntimeException("methodC failed");
        }
    }
    public boolean methodA() {
        String str = "do some operation in method A";
        System.out.println(str);
        return randomBoolean();

    }
    public boolean methodB() {
        String str = "do some operation in method B";
        System.out.println(str);
        return randomBoolean();
    }
    public boolean methodC() {
        String str = "do some operation in method C";
        System.out.println(str);
        return randomBoolean();
    }
    public static void main(String[] args) {
        MethodSequenceDesign method = new MethodSequenceDesign();
        try{
            method.start();
        } catch (Exception e) {
            e.printStacktrace();
        }
    }
    public boolean randomBoolean() {
        Random random = new Random();
        return random.nextBoolean();
    }
}

Answer 2

州，https://en.m.wikipedia.org/wiki/State_pattern，可能是你在这里寻找的。

编辑

针对您的特定问题的一个解决方案可能是将方法实现为实现接口的lambda表达式，该接口将您添加到集合类，然后循环遍历集合并执行每个集合，直到所有已执行或返回失败状态。