springboot quartz 任务监控阻塞 springboot请求阻塞

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代码探险家 2024-04-03 14:03:58

文章标签 resttemplate get请求 resttemplate get请求参数 resttemplate post请求 文章分类 运维

springboot quartz 任务监控阻塞 springboot请求阻塞_resttemplate get请求参数

【SpringBoot WEB 系列】AsyncRestTemplate 之异步非阻塞网络请求介绍篇

AsyncRestTemplate 发起异步网络请求，由 Spring4.0 引入，但是在 5.0 就被表上了删除注解，官方推荐使用基于 React 的 WebClient 来代替。

虽然官方已经不推荐使用AsyncRestTemplate，但是如果你的 web 项目，并不想引入 react 相关的包，使用AsyncRestTemplate来实现异步网络请求也不失为一个选择，本文将主要介绍它的基本使用姿势

I. 项目环境

本文创建的实例工程采用SpringBoot 2.2.1.RELEASE + maven 3.5.3 + idea进行开发

1. pom 依赖

具体的 SpringBoot 项目工程创建就不赘述了，对于 pom 文件中，需要重点关注下面两个依赖类

<dependencies>
    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-webartifactId>
    dependency>
dependencies>

<dependencies>
    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-webartifactId>
    dependency>
dependencies>

请注意我们并没有引入 react 相关的包，所以是没法直接使用 webclient 的

简单的配置一下 logback 的日志输出(非必要条件), application.yml文件内容如下

logging:
  pattern:
    console: (%msg%n%n){blue}

logging:
  pattern:
    console: (%msg%n%n){blue}

2. 测试接口

编写几个简单的用于测试的 REST 接口

@GetMapping(path = "atimeout")
public String aTimeOut(HttpServletRequest request) throws InterruptedException {
    Thread.sleep(3_000L);
    return "time out!" + JSON.toJSONString(request.getParameterMap());
}

@GetMapping(path = "4xx")
public String _4xx(HttpServletRequest request, HttpServletResponse response) {
    response.setStatus(401);
    return "return 401 : " + JSON.toJSONString(request.getParameterMap());
}

@GetMapping(path = "atimeout")
public String aTimeOut(HttpServletRequest request) throws InterruptedException {
    Thread.sleep(3_000L);
    return "time out!" + JSON.toJSONString(request.getParameterMap());
}

@GetMapping(path = "4xx")
public String _4xx(HttpServletRequest request, HttpServletResponse response) {
    response.setStatus(401);
    return "return 401 : " + JSON.toJSONString(request.getParameterMap());
}

II. 使用说明

从接口声明上来看，AsyncRestTemplate 与 RestTemplate 的使用姿势没有什么区别，如典型的 GET/POST 接口声明如下

// GET
@Override
public  ListenableFuture> getForEntity(String url, Class responseType, Object... uriVariables) throws RestClientException@Overridepublic  ListenableFuture> getForEntity(String url, Class responseType,
  Map uriVariables) throws RestClientException@Overridepublic  ListenableFuture> getForEntity(URI url, Class responseType)throws RestClientException//POST@Overridepublic  ListenableFuture> postForEntity(String url, @Nullable HttpEntity> request,
  Class responseType, Object... uriVariables) throws RestClientException@Overridepublic  ListenableFuture> postForEntity(String url, @Nullable HttpEntity> request,
  Class responseType, Map uriVariables) throws RestClientException@Overridepublic  ListenableFuture> postForEntity(URI url,@Nullable HttpEntity> request, Class responseType) throws RestClientException
// GET
@Override
public  ListenableFuture> getForEntity(String url, Class responseType, Object... uriVariables) throws RestClientException@Overridepublic  ListenableFuture> getForEntity(String url, Class responseType,
  Map uriVariables) throws RestClientException@Overridepublic  ListenableFuture> getForEntity(URI url, Class responseType)throws RestClientException//POST@Overridepublic  ListenableFuture> postForEntity(String url, @Nullable HttpEntity> request,
  Class responseType, Object... uriVariables) throws RestClientException@Overridepublic  ListenableFuture> postForEntity(String url, @Nullable HttpEntity> request,
  Class responseType, Map uriVariables) throws RestClientException@Overridepublic  ListenableFuture> postForEntity(URI url,@Nullable HttpEntity> request, Class responseType) throws RestClientException

1. 使用姿势

GET/POST 的访问姿势就不再赘述，有兴趣的小伙伴可以查看 RestTemplate 的使用博文：【WEB 系列】RestTemplate 基础用法小结

注意到不同的点在于返回的对象，RestTemplate是直接返回实体；而AsyncRestTemplate返回的则是ListenerableFuture包装的结果，这个类属于 Spring 自定义对象，继承自 Future 体系，而 Future 是我们并发编程中用于获取异步结果的一个接口

ListenerableFuture的最大特点在于它可以绑定执行完成的监听器，就不需要通过 get 来阻塞获取结果了，一个简单的使用姿势如下, 分别演示正常返回，异常返回的回调 case(两者都不会阻塞主线程的执行哦)

AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate();

long start = System.currentTimeMillis();
ListenableFuture> response =
        asyncRestTemplate.getForEntity("http://127.0.0.1:8080/atimeout?name=一灰灰&age=20", String.class);
response.addCallback(new ListenableFutureCallback>() {@Overridepublic void onFailure(Throwable throwable) {
        log.info("1. Async get error! cost: {}, e: {}", System.currentTimeMillis() - start, throwable);
    }@Overridepublic void onSuccess(ResponseEntity stringResponseEntity) {
        String ans = stringResponseEntity.getBody();
        log.info("1. success get: {}, cost: {}", ans, System.currentTimeMillis() - start);
    }
});
response = asyncRestTemplate.getForEntity("http://127.0.0.1:8080/4xx?name=一灰灰&age=20", String.class);
response.addCallback(new ListenableFutureCallback>() {@Overridepublic void onFailure(Throwable ex) {
        log.info("2. Async get error! cost: {}, e: {}", System.currentTimeMillis() - start, ex);
    }@Overridepublic void onSuccess(ResponseEntity result) {
        log.info("2. success get: {}, cost: {}", result, System.currentTimeMillis() - start);
    }
});
log.info("do something else!!!");
AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate();

long start = System.currentTimeMillis();
ListenableFuture> response =
        asyncRestTemplate.getForEntity("http://127.0.0.1:8080/atimeout?name=一灰灰&age=20", String.class);
response.addCallback(new ListenableFutureCallback>() {@Overridepublic void onFailure(Throwable throwable) {
        log.info("1. Async get error! cost: {}, e: {}", System.currentTimeMillis() - start, throwable);
    }@Overridepublic void onSuccess(ResponseEntity stringResponseEntity) {
        String ans = stringResponseEntity.getBody();
        log.info("1. success get: {}, cost: {}", ans, System.currentTimeMillis() - start);
    }
});
response = asyncRestTemplate.getForEntity("http://127.0.0.1:8080/4xx?name=一灰灰&age=20", String.class);
response.addCallback(new ListenableFutureCallback>() {@Overridepublic void onFailure(Throwable ex) {
        log.info("2. Async get error! cost: {}, e: {}", System.currentTimeMillis() - start, ex);
    }@Overridepublic void onSuccess(ResponseEntity result) {
        log.info("2. success get: {}, cost: {}", result, System.currentTimeMillis() - start);
    }
});
log.info("do something else!!!");

请注意下面的动图，主线程的do something else!!!文案会优先输出，并不会被阻塞；然后就是返回结果之后的回调，因为第一个 case 访问的 rest 服务有个 sleep，所以输出也会有一个明显的滞后

2. Guava 方式的异步请求

除了上面说到的 AsyncRestTemplate 来实现异步访问，我们也可以借助 Gauva 配合RestTemplate来实现类似的效果，下面作为扩展知识点，给出一个等效的使用说明

public void guava() {
    ExecutorService executorService = Executors.newFixedThreadPool(1);
    // 基于jdk线程池，创建支持异步回调的线程池
    ListeningExecutorService listeningExecutorService = MoreExecutors.listeningDecorator(executorService);

    long start = System.currentTimeMillis();
    // 具体的异步访问任务
    com.google.common.util.concurrent.ListenableFuture> ans =
            listeningExecutorService.submit(new Callable>() {@Overridepublic HttpEntity call() throws Exception {
                    RestTemplate restTemplate = new RestTemplate();return restTemplate
                            .getForEntity("http://127.0.0.1:8080/atimeout?name=一灰灰&age=19", String.class);
                }
            });// 完成之后，在指定的线程池(第三个参数)中回调
    Futures.addCallback(ans, new com.google.common.util.concurrent.FutureCallback>() {@Overridepublic void onSuccess(@Nullable HttpEntity stringHttpEntity) {
            log.info("guava call back res: {}, cost: {}", stringHttpEntity.getBody(),
                    System.currentTimeMillis() - start);
        }@Overridepublic void onFailure(Throwable throwable) {
            log.info("guava call back failed cost:{}, e: {}", System.currentTimeMillis() - start, throwable);
        }
    }, Executors.newFixedThreadPool(1));
    log.info("do something other in guava!");
    listeningExecutorService.shutdown();
}
public void guava() {
    ExecutorService executorService = Executors.newFixedThreadPool(1);
    // 基于jdk线程池，创建支持异步回调的线程池
    ListeningExecutorService listeningExecutorService = MoreExecutors.listeningDecorator(executorService);

    long start = System.currentTimeMillis();
    // 具体的异步访问任务
    com.google.common.util.concurrent.ListenableFuture> ans =
            listeningExecutorService.submit(new Callable>() {@Overridepublic HttpEntity call() throws Exception {
                    RestTemplate restTemplate = new RestTemplate();return restTemplate
                            .getForEntity("http://127.0.0.1:8080/atimeout?name=一灰灰&age=19", String.class);
                }
            });// 完成之后，在指定的线程池(第三个参数)中回调
    Futures.addCallback(ans, new com.google.common.util.concurrent.FutureCallback>() {@Overridepublic void onSuccess(@Nullable HttpEntity stringHttpEntity) {
            log.info("guava call back res: {}, cost: {}", stringHttpEntity.getBody(),
                    System.currentTimeMillis() - start);
        }@Overridepublic void onFailure(Throwable throwable) {
            log.info("guava call back failed cost:{}, e: {}", System.currentTimeMillis() - start, throwable);
        }
    }, Executors.newFixedThreadPool(1));
    log.info("do something other in guava!");
    listeningExecutorService.shutdown();
}

看到这里自然而然会有一个疑问，异步任务完成的回调，是怎么实现呢？

欢迎各位小伙伴评论给出看法