小编zon*_*ang的帖子

我有这样的代码:

List<Listing> Listings = new ArrayList<>();
Listings.add(listing1);
Listings.add(listing2);
...
...
...

Listing listing= listings.stream()
                .filter(l -> l.getVin() == 456)
                .findFirst();

我的问题是过滤过程的时间复杂度是多少？如果它是O(n),我的直觉是将它转换为HashSet,就像数据结构一样,这样时间复杂度就可以变成O(1),是否有一种优雅的方式来实现流？

当我尝试对 Spring Boot 服务进行休息调用时遇到了这个异常。是什么导致这个异常？

信息

 Handler dispatch failed; nested exception is java.lang.NoSuchMethodError: org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.getResponseStatus()Lorg/springframework/http/HttpStatus;

描述

 The server encountered an unexpected condition that prevented it from fulfilling the request.

例外

org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.NoSuchMethodError: org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.getResponseStatus()Lorg/springframework/http/HttpStatus;
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:978)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

根本原因

java.lang.NoSuchMethodError: org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.getResponseStatus()Lorg/springframework/http/HttpStatus;
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.setResponseStatus(ServletInvocableHandlerMethod.java:128)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:98)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

pom.xml

<?xml version="1.0" …

我正在使用融合平台，zookeeper 处于活动状态并进行状态查找。但是当我尝试使用 confluent 启动 kafka 时，它显示 zookeeper 已关闭。

$ sudo service zookeeper status
Redirecting to /bin/systemctl status  zookeeper.service
? zookeeper.service - Zookeeper
   Loaded: loaded (/etc/systemd/system/zookeeper.service; disabled; vendor preset: disabled)
   Active: active (running) since Tue 2017-08-08 17:25:34 PDT; 16h ago
     Docs: http://kafka.apache.org/documentation.html
  Process: 3774 ExecStop=/var/www/confluent/bin/zookeeper-server-stop (code=exited, status=1/FAILURE)
 Main PID: 3785 (java)
   CGroup: /system.slice/zookeeper.service
           ??3785 java -Xmx512M -Xms512M -server -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+DisableExplicitGC -Djava.awt.headless=true -Xloggc:/var/log...

 zookeeper[3785]: [2017-08-08 17:26:09,005] INFO Processed session termination for sessionid: 0x15dc460fd0c0000 (org.apache.zooke...Processor)
 zookeeper[3785]: [2017-08-08 17:26:39,000] INFO Expiring session …

假设我在数据结构中有一些整数.当我在数据结构中插入新数字时,我希望获得新插入元素与数据结构中已有的任何其他元素之间的最小差异.我应该使用什么数据结构和算法？AO(n)解决方案是微不足道的,我想要更好.谢谢.

如果我有一个大约3000个字符的文本.我想搜索具有某些特征的字符串,例如字符串[*].

也就是说,我想[a]和[bc]来自

sjfhshdkfjhskdhfksdf[a]sfdsgfsdf[bc]

我知道有一种称为KMP的算法可以保证通过文本进行线性时间搜索操作,但是在这里我没有找到固定的字符串,也许我必须在某个地方使用一些正则表达式.

我怎么能比O(n ^ 2)更好地做到这一点？如果我使用java,是否有任何光库？