Java Code Examples: Common Logic Processing

Contents

1. 1. Multiple attempts to get the result

Multiple attempts to get the result

public class LogicProcessingUtils {
    /**
     * @param maxTryTimes
     * @param successPredicate
     * @param function
     * @param params           parameter object
     * @param <T>              function return type
     * @param <P>              function parameter type
     * @return
     */
    public static <T, P> T tryToGetResult(int maxTryTimes,
                                          Predicate<T> successPredicate,
                                          Function<P, T> function,
                                          P param) {
        int tryTimes = 0;
        T t = null;
        while (tryTimes < maxTryTimes) {
            t = function.apply(param);
            // System.out.println(t);
            if (successPredicate.test(t)) {
                break;
            }
            tryTimes++;
        }
        return t;
    }

    public static <T> T tryToGetResult(int maxTryTimes,
                                          Predicate<T> successPredicate,
                                          Supplier<T> supplier) {
        int tryTimes = 0;
        T t = null;
        while (tryTimes < maxTryTimes) {
            t = supplier.get();
            // System.out.println(t);
            if (successPredicate.test(t)) {
                break;
            }
            tryTimes++;
        }
        return t;
    }
}

public class MyTest {
    public static void main(String[] args) {
        MyTest myTest = new MyTest();
        int maxTryTimes = 3;
        ObjectNode result = LogicProcessingUtils.tryToGetResult(
                maxTryTimes,
                jsonNode -> jsonNode.get("code").asInt() == 200,
                myTest::getResult,
                0);
        System.out.println(result);
    }

    public ObjectNode getResult(Object param)  {
        System.out.println("param: " + param);
        ThreadLocalRandom random = ThreadLocalRandom.current();
        int randomNumber = random.nextInt(10);
        System.out.println("random number: " + randomNumber);
        String jsonStr = "{\"code\":500,\"data\":%d,\"msg\":\"请求失败\"}";
        ObjectMapper objectMapper = new ObjectMapper();
        try {
            return (ObjectNode) objectMapper.readTree(String.format(jsonStr, randomNumber));
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }
}