java-retrying's Introduction

java-retrying

java重试, 支持同步/异步, 简单灵活可配, 不依赖第三方库.

基于guava-retrying改造, 增加了异步重试, 同时去掉了第三方依赖, 使用方法基本一致.

名称	JDK	第三方依赖	同步重试	异步重试
guava-retrying	大于等于6	guava,findbugs	Y	N
java-retrying	大于等于8	无	Y	Y

Quickstart

依赖

<dependency>
    <groupId>com.github.lowzj</groupId>
    <artifactId>java-retrying</artifactId>
    <version>1.2</version>
</dependency>

同步重试

Retryer<Integer> retryer = RetryerBuilder.<Integer>newBuilder()
    .withWaitStrategy(WaitStrategies.fixedWait(100L, TimeUnit.MILLISECONDS))
    .retryIfResult(num -> num != 5)
    .retryIfExceptionOfType(RuntimeException.class)
    .withStopStrategy(StopStrategies.stopAfterAttempt(7))
    .build();

try {
    retryer.call(noRuntimeExceptionAfter(4));
} catch (ExecutionException | RetryException e) {
    e.printStackTrace();
}

异步重试

AsyncRetryer<Integer> asyncRetryer = RetryerBuilder.<Integer>newBuilder()
    .withWaitStrategy(WaitStrategies.fixedWait(100L, TimeUnit.MILLISECONDS))
    .retryIfResult(num -> num != 4)
    .retryIfExceptionOfType(RuntimeException.class)
    .withStopStrategy(StopStrategies.stopAfterAttempt(7))
    .withExecutor(ExecutorsUtil.scheduledExecutorService("example", 1))
    .buildAsyncRetryer();

CompletableFuture<Integer> future = asyncRetryer.call(noRuntimeExceptionAfter(3));

// get the result asynchronously
future.whenComplete((result, error) -> System.out.println(result));

// or get the result synchronously
try {
    System.out.println(future.get());
} catch (InterruptedException | ExecutionException e) {
    e.printStackTrace();
}

其中函数noRuntimeExceptionAfter如下:

private Callable<Integer> noRuntimeExceptionAfter(final int attemptNumber) {
    return new Callable<Integer>() {
        private int count = 0;
        @Override
        public Integer call() throws Exception {
            if (count++ < attemptNumber) {
                throw new RuntimeException("count[" + (count - 1) + "] < attemptNumber[" + attemptNumber + "]");
            }
            return count;
        }
    };
}