7 种提升 SpringBoot 吞吐量神技！

2022-04-12 16:58:58

来源：https://xhcom.blog.csdn.net/article/details/88046026

一、异步执行

实现方式二种：

1. 使用异步注解@aysnc、启动类：添加@EnableAsync注解

2. JDK 8本身有一个非常好用的Future类——CompletableFuture

@AllArgsConstructorpublic class AskThread implements Runnable{    private CompletableFuture<Integer> re = null;
    public void run() {        int myRe = ;        try {            myRe = re.get() * re.get();        } catch (Exception e) {            e.printStackTrace();        }        System.out.println(myRe);    }
    public static void main(String[] args) throws InterruptedException {        final CompletableFuture<Integer> future = new CompletableFuture<>();        new Thread(new AskThread(future)).start();        //模拟长时间的计算过程        Thread.sleep(1000);        //告知完成结果        future.complete(60);    }}

在该示例中，启动一个线程，此时AskThread对象还没有拿到它需要的数据，执行到 myRe = re.get() * re.get()会阻塞。我们用休眠1秒来模拟一个长时间的计算过程，并将计算结果告诉future执行结果，AskThread线程将会继续执行。

public class Calc {    public static Integer calc(Integer para) {        try {            //模拟一个长时间的执行            Thread.sleep(1000);        } catch (InterruptedException e) {            e.printStackTrace();        }        return para * para;    }
    public static void main(String[] args) throws ExecutionException, InterruptedException {        final CompletableFuture<Void> future = CompletableFuture.supplyAsync(() -> calc(50))                .thenApply((i) -> Integer.toString(i))                .thenApply((str) -> "\"" + str + "\"")                .thenAccept(System.out::println);        future.get();    }}

CompletableFuture.supplyAsync方法构造一个CompletableFuture实例，在supplyAsync()方法中，它会在一个新线程中，执行传入的参数。在这里它会执行calc()方法，这个方法可能是比较慢的，但这并不影响CompletableFuture实例的构造速度，supplyAsync()会立即返回。

而返回的CompletableFuture实例就可以作为这次调用的契约，在将来任何场合，用于获得终的计算结果。

supplyAsync用于提供返回值的情况，CompletableFuture还有一个不需要返回值的异步调用方法runAsync(Runnable runnable),一般我们在优化Controller时，使用这个方法比较多。这两个方法如果在不指定线程池的情况下，都是在ForkJoinPool.common线程池中执行，而这个线程池中的所有线程都是Daemon（守护）线程，所以，当主线程结束时，这些线程无论执行完毕都会退出系统。

核心代码：

CompletableFuture.runAsync(() ->   this.afterBetProcessor(betRequest,betDetailResult,appUser,id));

异步调用使用Callable来实现

@RestController  public class HelloController {
    private static final Logger logger = LoggerFactory.getLogger(HelloController.class);
    @Autowired      private HelloService hello;      @GetMapping("/helloworld")    public String helloWorldController() {        return hello.sayHello();    }      /**     * 异步调用restful     * 当controller返回值是Callable的时候，springmvc就会启动一个线程将Callable交给TaskExecutor去处理     * 然后DispatcherServlet还有所有的spring拦截器都退出主线程，然后把response保持打开的状态     * 当Callable执行结束之后，springmvc就会重新启动分配一个request请求，然后DispatcherServlet就重新     * 调用和处理Callable异步执行的返回结果， 然后返回视图     *     * @return     */      @GetMapping("/hello")    public Callable<String> helloController() {        logger.info(Thread.currentThread().getName() + " 进入helloController方法");        Callable<String> callable = new Callable<String>() {              @Override              public String call() throws Exception {                logger.info(Thread.currentThread().getName() + " 进入call方法");                String say = hello.sayHello();                logger.info(Thread.currentThread().getName() + " 从helloService方法返回");                return say;            }        };        logger.info(Thread.currentThread().getName() + " 从helloController方法返回");        return callable;    }}

异步调用的方式 WebAsyncTask

@RestController  public class HelloController {
    private static final Logger logger = LoggerFactory.getLogger(HelloController.class);
    @Autowired      private HelloService hello;          /**     * 带超时时间的异步请求 通过WebAsyncTask自定义客户端超时间     *     * @return     */      @GetMapping("/world")    public WebAsyncTask<String> worldController() {        logger.info(Thread.currentThread().getName() + " 进入helloController方法");          // 3s钟没返回，则认为超时        WebAsyncTask<String> webAsyncTask = new WebAsyncTask<>(3000, new Callable<String>() {              @Override              public String call() throws Exception {                logger.info(Thread.currentThread().getName() + " 进入call方法");                String say = hello.sayHello();                logger.info(Thread.currentThread().getName() + " 从helloService方法返回");                return say;            }        });        logger.info(Thread.currentThread().getName() + " 从helloController方法返回");          webAsyncTask.onCompletion(new Runnable() {              @Override              public void run() {                logger.info(Thread.currentThread().getName() + " 执行完毕");            }        });          webAsyncTask.onTimeout(new Callable<String>() {              @Override              public String call() throws Exception {                logger.info(Thread.currentThread().getName() + " onTimeout");                // 超时的时候，直接抛异常，让外层统一处理超时异常                throw new TimeoutException("调用超时");            }        });        return webAsyncTask;    }      /**     * 异步调用，异常处理，详细的处理流程见MyExceptionHandler类     *     * @return     */      @GetMapping("/exception")    public WebAsyncTask<String> exceptionController() {        logger.info(Thread.currentThread().getName() + " 进入helloController方法");        Callable<String> callable = new Callable<String>() {              @Override              public String call() throws Exception {                logger.info(Thread.currentThread().getName() + " 进入call方法");                throw new TimeoutException("调用超时!");            }        };        logger.info(Thread.currentThread().getName() + " 从helloController方法返回");        return new WebAsyncTask<>(20000, callable);    }}

二、增加内嵌Tomcat的大连接数

@Configurationpublic class TomcatConfig {    @Bean    public ConfigurableServletWebServerFactory webServerFactory() {        TomcatServletWebServerFactory tomcatFactory = new TomcatServletWebServerFactory();        tomcatFactory.addConnectorCustomizers(new MyTomcatConnectorCustomizer());        tomcatFactory.setPort(8005);        tomcatFactory.setContextPath("/api-g");        return tomcatFactory;    }    class MyTomcatConnectorCustomizer implements TomcatConnectorCustomizer {        public void customize(Connector connector) {            Http11NioProtocol protocol = (Http11NioProtocol) connector.getProtocolHandler();            //设置大连接数            protocol.setMaxConnections(20000);            //设置大线程数            protocol.setMaxThreads(2000);            protocol.setConnectionTimeout(30000);        }    }}

三、使用@ComponentScan()定位扫包比@SpringBootApplication扫包更快

四、默认tomcat容器改为Undertow（Jboss下的服务器，Tomcat吞吐量5000，Undertow吞吐量8000）

<exclusions>  <exclusion>     <groupId>org.springframework.boot</groupId>     <artifactId>spring-boot-starter-tomcat</artifactId>  </exclusion></exclusions>

改为:

<dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-undertow</artifactId></dependency>

五、使用 BufferedWriter 进行缓冲

六、Deferred方式实现异步调用

@RestControllerpublic class AsyncDeferredController {    private final Logger logger = LoggerFactory.getLogger(this.getClass());    private final LongTimeTask taskService;
    @Autowired    public AsyncDeferredController(LongTimeTask taskService) {        this.taskService = taskService;    }
    @GetMapping("/deferred")    public DeferredResult<String> executeSlowTask() {        logger.info(Thread.currentThread().getName() + "进入executeSlowTask方法");        DeferredResult<String> deferredResult = new DeferredResult<>();        // 调用长时间执行任务        taskService.execute(deferredResult);        // 当长时间任务中使用deferred.setResult("world");这个方法时，会从长时间任务中返回，继续controller里面的流程        logger.info(Thread.currentThread().getName() + "从executeSlowTask方法返回");        // 超时的回调方法        deferredResult.onTimeout(new Runnable(){     @Override   public void run() {    logger.info(Thread.currentThread().getName() + " onTimeout");    // 返回超时信息    deferredResult.setErrorResult("time out!");   }  });        // 处理完成的回调方法，无论是超时还是处理成功，都会进入这个回调方法        deferredResult.onCompletion(new Runnable(){
   @Override   public void run() {    logger.info(Thread.currentThread().getName() + " onCompletion");   }  });        return deferredResult;    }}

七、异步调用可以使用AsyncHandlerInterceptor进行拦截

@Componentpublic class MyAsyncHandlerInterceptor implements AsyncHandlerInterceptor {  private static final Logger logger = LoggerFactory.getLogger(MyAsyncHandlerInterceptor.class);  @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)   throws Exception {  return true; }  @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,   ModelAndView modelAndView) throws Exception {// HandlerMethod handlerMethod = (HandlerMethod) handler;  logger.info(Thread.currentThread().getName()+ "服务调用完成，返回结果给客户端"); }  @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)   throws Exception {  if(null != ex){   System.out.println("发生异常:"+ex.getMessage());  } }  @Override public void afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler)   throws Exception {    // 拦截之后，重新写回数据，将原来的hello world换成如下字符串  String resp = "my name is chhliu!";  response.setContentLength(resp.length());  response.getOutputStream().write(resp.getBytes());    logger.info(Thread.currentThread().getName() + " 进入afterConcurrentHandlingStarted方法"); }}