1.建基础包/文件夹2.application.propertis编写application.propertis基础配置和数据库连接3.index.ftl注:在index.ftl页面可以输入感叹号!,然后按tab键一键生成HTML代码4.IndexController.java5.启动服务启动服务,后再浏览器输入http://localhost:8080,是否能成功访问:
下载与ES对应的版本：官网地址解压修改$KIBANA_HOME/config/kibana.yml文件启动Kibana：sudo$KIBANA_HOME/bin/kibana浏览器输入host:5601能正常打开页面即可KAAE插件安装KAAE为Kibana的插件，主要用来监控和报警，用户可以根据需求配置相应的监控条件，达到某个条件会发出报警消息，同时KAAE也提供有报告Report功能，能够将查询到的结果生成图表发送到指定邮箱。安装：$KIBANA_HOME/bin/kibana-pulgininstallhttps://github.com/sirensolutions/sentinl/releases/download/tag-6.2.3-3/sentinl-v6.2.4.zip配置kibana.yml文件，在最后加上：重启Kibana后，浏览器输入：http://ip:5601出现以下界面说明插件安装成功可以在页面上按照需求配置监听报警
Vue+SpringBoot实现WebSocket通信服务端在SpringBoot项目中添加ServerEndpointExporterBean的方法@BeanpublicServerEndpointExporterexporter(){returnnewServerEndpointExporter();}创建WebSocket客户端管理类:WebSocketComponent.javapackagecn.coralcloud.blog.web.component;importcom.alibaba.fastjson.JSON;importorg.springframework.stereotype.Component;importjavax.websocket.*;importjavax.websocket.server.ServerEndpoint;importjava.io.IOException;importjava.util.Objects;importjava.util.concurrent.CopyOnWriteArraySet;/**@authorgeff@nameWebSocketComponent@description@date2019-12-1814:22/@ServerEndpoint(value="/websocket")@ComponentpublicclassWebSocketComponent{/**静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。/privatestaticintonlineCount=0;/**concurrent包的线程安全Set，用来存放每个客户端对应的CumWebSocket对象。/privatestaticCopyOnWriteArraySetwebSocketSet=newCopyOnWriteArraySet<>();/**与某个客户端的连接会话，需要通过它来给客户端发送数据/privateSessionsession;/**连接建立成功调用的方法@paramsessionsession/@OnOpenpublicvoidonOpen(Sessionsession){this.session=session;//加入set中webSocketSet.add(this);//添加在线人数addOnlineCount();System.out.println("新连接接入。当前在线人数为："+getOnlineCount());}/**连接关闭调用的方法/@OnClosepublicvoidonClose(){//从set中删除webSocketSet.remove(this);//在线数减1subOnlineCount();System.out.println("有连接关闭。当前在线人数为："+getOnlineCount());}/**收到客户端消息后调用@parammessagemessage@paramsessionsession/@OnMessagepublicvoidonMessage(Stringmessage,Sessionsession){System.out.println("客户端发送的消息："+message);sendAll(JSON.toJSONString(messageDTO),session.getId());}/**群发@parammessagemessage/privatestaticvoidsendAll(Stringmessage,StringsessionId){webSocketSet.forEach(item->{if(!item.session.getId().equals(sessionId)){//群发try{item.sendMessage(message);}catch(IOExceptione){e.printStackTrace();}}});}/**发生错误时调用@paramsessionsession@paramerrorerror/@OnErrorpublicvoidonError(Sessionsession,Throwableerror){System.out.println("----websocket-------有异常啦");error.printStackTrace();}/**减少在线人数/privatevoidsubOnlineCount(){WebSocketComponent.onlineCount--;}/**添加在线人数/privatevoidaddOnlineCount(){WebSocketComponent.onlineCount++;}/**当前在线人数@returnint/publicstaticsynchronizedintgetOnlineCount(){returnonlineCount;}/**发送信息@parammessagemessagethrowsIOException/publicvoidsendMessage(Stringmessage)throwsIOException{//获取session远程基本连接发送文本消息this.session.getBasicRemote().sendText(message);//this.session.getAsyncRemote().sendText(message);}@Overridepublicbooleanequals(Objecto){if(this==o){returntrue;}if(o==null||getClass()!=o.getClass()){returnfalse;}WebSocketComponentthat=(WebSocketComponent)o;returnObjects.equals(session,that.session);}@OverridepublicinthashCode(){returnObjects.hash(session);}}@ServerEndpoint注解标识当前WebSocket服务端endpoint地址,本文实际前端访问的ws地址为:ws://localhost:8080/websocket。至此，服务端工作完成。页面VUE端<template><el-cardv-loading="loading"element-loading-spinner="el-icon-loading":body-style="{padding:'5px',backgroundColor:'#eee'}"class="socket-box"shadow="hover"><divclass="socket-box__content":style="{height:(boxHeight-125)+'px'}"id="socket-content"><divv-if="hasMore"@click="loadMore"class="load-more"><span>加载更多</span></div><divv-elsestyle="width:100%;text-align:center;font-size:12px">没有更多了</div><divclass="item"v-for="minmessages":class="checkMe(m)?'sender':''"><divclass="slide"><divclass="avatar":style="{background:m.background}">{{m.name.substring(0,1)}}</div><divclass="meta"><divclass="name">{{m.name}}</div><divclass="date">{{m.createTime|datetime}}</div></div></div><p>{{m.content}}</p></div></div><divclass="socket-box__footer"><el-form@submit.native.prevent><el-form-item><el-inputtype="textarea"resize="none":rows="3":disabled="!connect":placeholder="connect?'输入内容...':'当前连接断开,请刷新重试!'":clearable="true"v-model="message"@keydown.native.enter="submitMsgForm"></el-input></el-form-item><el-form-item><el-button@click="sendMsg(message)":disabled="!connect"style="width:100%"type="primary"size="small">发送(Enter)</el-button></el-form-item></el-form></div></el-card></template><script>import{GET}from"@/api";exportdefault{name:"Chatroom",data(){return{messages:[],message:'',//boxHeight:document.documentElement.clientHeight-85,hasMore:true,pager:{pageNo:1,pageSize:10,total:0},loading:false,connect:false}},props:{boxHeight:{type:Number,required:true}},methods:{submitMsgForm(event){if(event.shiftKey){return;}event.preventDefault();this.sendMsg(this.message)},checkMe(message){letuser=localStorage.getItem("socketUser");if(user){user=JSON.parse(user);returnuser.uid===message.uid}else{returnfalse;}},initWebSocket:function(){this.websock=newWebSocket(`ws://localhost:8080/websocket`);this.websock.onopen=this.websocketonopen;this.websock.onerror=this.websocketonerror;this.websock.onmessage=this.websocketonmessage;this.websock.onclose=this.websocketclose;constthat=this;that.loading=true;GET({url:'/api/personal/web/message/socketData?pageNo=1',callback:res=>{if(res.code===200){that.messages=res.data.messages;that.hasMore=res.data.messages.length===that.pager.pageSize;that.$nextTick(function(){document.getElementById("socket-content").scroll({top:document.getElementById("socket-content").scrollHeight,left:0,behavior:'smooth'})})}that.loading=false}})},sendMsg(data){if(/^\s*$/.test(data)){this.message='';return;}//发送时传入JSON(UID,昵称,内容)constlocal=localStorage.getItem("socketUser");if(local){constl=JSON.parse(local);this.send(l,data)}else{//弹框this.$prompt('首次发表,请输入昵称','提示',{confirmButtonText:'确定',cancelButtonText:'取消',}).then(({value})=>{//随机生成UIDconstuid=this.randomVideoUuid(32,16);constform={uid:uid,name:value,background:`rgb(${Math.random()*255},${Math.random()*255},${Math.random()*255})`};localStorage.setItem("socketUser",JSON.stringify(form));this.send(form,data)}).catch(()=>{this.$message({type:'info',message:'取消输入'});});}},send(obj,data){obj.content=data;obj.createTime=newDate().getTime();this.websock.send(JSON.stringify(obj));this.message='';this.messages.push(obj);this.$nextTick(function(){document.getElementById("socket-content").scroll({top:document.getElementById("socket-content").scrollHeight,left:0,behavior:'smooth'})})},loadMore(){this.loading=true;constthat=this;if(this.hasMore){this.pager.pageNo+=1;GET({url:'/api/personal/web/message/socketData?pageNo='+this.pager.pageNo,callback:res=>{if(res.code===200){that.messages=[...res.data.messages,...that.messages];that.hasMore=res.data.messages.length>=that.pager.pageSize;}that.loading=false;}})}},websocketonopen:function(e){console.log("WebSocket连接成功",e);this.connect=true;},websocketonerror:function(e){console.log("WebSocket连接发生错误");this.connect=false;},websocketonmessage:function(e){constda=JSON.parse(e.data);this.messages.push(da);this.$nextTick(function(){document.getElementById("socket-content").scroll({top:document.getElementById("socket-content").scrollHeight,left:0,behavior:'smooth'})})},websocketclose:function(e){console.log("connectionclosed("+e.code+")");},randomVideoUuid(len,radix){letchars='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');letuuid=[];radix=radix||chars.length;if(len){for(leti=0;i<len;i++)uuid[i]=chars[0|Math.random()*radix];}else{letr;uuid[8]=uuid[13]=uuid[18]=uuid[23]='-';uuid[14]='4';for(leti=0;i<36;i++){if(!uuid[i]){r=0|Math.random()*16;uuid[i]=chars[(i===19)?(r&0x3)|0x8:r];}}}returnuuid.join('');},},mounted(){this.initWebSocket();}}</script>本段代码为简单的Vue实现的网页聊天室代码,其中@/api为自己简单封装的JS函数,用户初次进入页面时会生成一个随机UID保存到localStorage中,在mounted周期中初始化websocket连接。本聊天室最终效果地址：https://web.coralcloud.cn/blog/message
一、安装Redis1.下载Rediswgethttp://download.redis.io/releases/redis-4.0.6.tar.gz2.解压tar-zxvfredis-4.0.6.tar.gz3.yum安装gccyuminstall-ygcc4.编译安装rediscdredis-4.0.6makeMALLOC=libccdsrc&&makeinstall二、启动Redis1.在/etc目录下新建redis目录mkdir-p/etc/redis2.将/usr/local/redis-4.0.6/redis.conf文件复制一份到/etc/redis目录下，并命名为6379.confcp/usr/local/redis-4.0.6/redis.conf/etc/redis/6379.conf3.将redis的启动脚本复制一份放到/etc/init.d目录下cp/usr/local/redis-4.0.6/utils/redis_init_script/etc/init.d/redisd4.设置redis开机自启动cd/etc/init.dchkconfigredisdonserviceredisddoesnotsupportchkconfig看结果是redisd不支持chkconfig,编辑redisd文件,加入如下注释:#chkconfig:23459010#description:Redisisapersistentkey-valuedatabasechkconfigredisdon启动redis:serviceredisdstart停止redis:serviceredisdstop
1.新建数据库表ims-learn.user2.Model包下新建User类注:因为之前初始化项目时添加了lombok依赖,所以model类可以不用写setter/getter,直接使用@Data注解替代3.编写UserDao接口类4.UserMapper.xml<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTDMapper3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="cn.coralcloud.ims.dao.UserDao"><resultMapid="userResultMap"type="User"><idproperty="id"column="id"/><resultproperty="createTime"column="create_time"/><resultproperty="updateTime"column="update_time"/></resultMap><selectid="login"resultMap="userResultMap">select*fromuserwhereemail=#{email}andpassword=#{password}</select></mapper>5.mybatis.xml编写mybatis基础配置,新建resources/mybatis/mybatis.xml<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEconfigurationPUBLIC"-//mybatis.org//DTDConfig3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><settings><settingname="logImpl"value="STDOUT_LOGGING"/><settingname="lazyLoadingEnabled"value="true"/><settingname="aggressiveLazyLoading"value="false"/><settingname="lazyLoadTriggerMethods"value=""/></settings></configuration>6.UserService.java7.UserController.javapackagecn.coralcloud.ims.controller;importcn.coralcloud.ims.model.User;importcn.coralcloud.ims.service.UserService;importcom.sun.org.apache.xpath.internal.operations.Mod;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Controller;importorg.springframework.ui.Model;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.PostMapping;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.servlet.ModelAndView;importorg.springframework.web.servlet.View;importjavax.servlet.http.HttpSession;/***@authorc-geff*@nameUserController*@description*@date2020-11-0310:45*/@Controller@RequestMapping("/user")publicclassUserController{@AutowiredprivateUserServiceuserService;@PostMapping("/login")publicModelAndViewlogin(Stringemail,Stringpassword,HttpSessionsession){ModelAndViewview=newModelAndView();view.setViewName("user/login");Useruser=userService.login(email,password);if(user!=null){session.setAttribute("AdminUserKey",user);view.setViewName("redirect:/index");returnview;}view.addObject("errmsg","用户名或密码错误!");returnview;}@GetMapping("/login")publicStringlogin(){return"user/login";}}8.login.ftl9.IndexController改造10.index.ftl改造,展示用户登录后的用户名11.数据库添加一条用户数据,然后在/user/login页面登录测试
FastDFS服务器迁移1.1目标服务器安装FastDFS首先按照上一篇文章《FastDFS介绍和安装》搭建好新的FastDFS服务器(Tracker,Storage),先配置好不用启动1.2修改配置文件修改新的Storage配置文件/etc/fdfs/storage.conf将tracker_server的IP修改为旧的Tracker服务器IP1.3启动目标Storage进程,同步数据servicefdfs_storagedrestart查看同步进程,在旧tracker服务器执行：fdfs_monitor/etc/fdfs/client.conf可以看到同步状态:等待数据同步...ACTIVE标识表示数据已经同步完成数据同步完成后,停掉Storage服务servicefdfs_storagedstop1.4修改storage配置文件修改/etc/fdfs/storage.conf文件将tracker_server的IP修改为新的tracker服务器IP1.5修改.data_init_flag文件该文件所在位置为storage.conf文件中所配置的base_path路径后面的data路径下,如配置为/home/data/fastdfs/storage,则文件所在位置为/home/data/fastdfs/storage/data/下将文件中sync_src_server配置项留空，其它配置项不变sync_src_server=1.6启动进程启动新的storage服务器进程,启动新的tracker服务器进程,在新tracker服务器下fdfs_monitor/etc/fdfs/client.conf查看Storage状态
1.在使用mybatis的动态sql时，有时候遇到根据条件判断添加where后面的筛选条件的情况，会出现多余的AND或者OR：2.使用where关键字:2.1当第一个参数为空时,拼接后的sql为:select*fromtdwhereandphone=.......;2.2当所有的参数都为空时,拼接后的sql为:select*fromtdwhere.....,显然这样的sql不是完整的sql,执行时会报错.3.使用where标签时:3.1当第一个参数为空时,拼接后的sql为:select*fromtdwherephone=......(若语句的开头为AND或者OR时,where元素会将他们去除).3.2当所有的参数都为空时,拼接后的sql为:select*fromtd.(where元素只会在至少有一个子元素的条件返回SQL子句的情况下才去插入“WHERE”子句)。
1.新建CSS和JS文件2.新建静态资源配置类:ImsConfig.javapackagecn.coralcloud.ims.config;importorg.springframework.context.annotation.Configuration;importorg.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;importorg.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;/***@authorc-geff*@nameImsConfig*@description*@date2020-11-0315:28*/@ConfigurationpublicclassImsConfigextendsWebMvcConfigurerAdapter{@OverridepublicvoidaddResourceHandlers(ResourceHandlerRegistryregistry){registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");super.addResourceHandlers(registry);}}注:新建config包,然后新建ImsConfig类,继承自WebMvcConfigurerAdapter,实现了addResourceHandlers方法,该方法设置了访问/static/路径的文件时会映射到项目static文件夹下3.login.ftl修改,head添加CSS引入:4.login.ftl修改,页面布局修改:5.编写对应的main.css文件,该文件为通用样式html,body{padding:0;margin:0;}.ims-form-label{font-size:15px;color:rgba(0,0,0,.7);width:100px;height:40px;line-height:40px;letter-spacing:3px;}.ims-form-input{height:40px;line-height:40px;flex:1;outline:0;padding:015px;border:1pxsolid#DCDFE6;border-radius:4px;}.ims-form-input:focus{border-color:#409EFF;}.ims-form-item{margin:15px0;width:100%;display:flex;}.ims-button{height:40px;line-height:40px;border-radius:4px;padding:030px;border:none;color:#FFFFFF;font-size:14px;background-color:#409EFF;cursor:pointer;margin:15px0;outline:0;}.ims-button:hover{background-color:#3888e0;}.ims-button:focus{background-color:rgba(64,158,255,0.81);}6.编写对应的login.css文件,该文件为登录页专用样式.login-container{display:flex;align-content:center;justify-content:center;text-align:center;-webkit-box-pack:center;-webkit-box-align:center;align-items:center;width:100vw;height:100vh;background-image:url("/static/images/login_bg.jpg");background-repeat:no-repeat;background-size:100%100%;}.login-containerform{width:350px;height:300px;background-color:rgba(255,255,255,.7);border-radius:5px;padding:10px20px;}.login-container.ims-button{width:100%}.errormsg{color:#ed2322;font-size:13px;margin-bottom:0;}7.static目录下新建文件夹images保存背景图片login_bg.jpglogin_bg.jpg
Centos安装ApacheHadoop2.7.7准备文件:hadoop-2.7.7.tar.gz一、安装JDK安装Hadoop之前需要保证JDK8成功安装java-version二、上传Hadoop压缩包上传成功后解压文件：tar-zxvfhadoop-2.7.7.tar.gz假设解压后的Hadoop目录为:/home/hadoop/hadoop-2.7.7注意配置HADOOP_HOME环境变量exportHADOOP_HOME=/home/hadoop/hadoop-2.7.7exportPATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin三、配置服务器免密登录$ssh-keygen-trsa-P''-f~/.ssh/id_rsa$cat~/.ssh/id_rsa.pub>>~/.ssh/authorized_keys$chmod0600~/.ssh/authorized_keys执行完成后:sshmaster命令则能够跳过输入密码阶段直接连接四、修改配置==配置文件所在位置:$HADOOP_HOME/etc/hadoop==core-size.xml<configuration><property><name>fs.defaultFS</name><value>hdfs://master:9000</value></property></configuration>hdfs-size.xml<configuration><property><name>dfs.replication</name><value>1</value></property></configuration>mapred-site.xml<configuration><property><name>mapreduce.framework.name</name><value>yarn</value></property><property><name>mapreduce.application.classpath</name><value>$HADOOP_MAPRED_HOME/share/hadoop/mapreduce/*:$HADOOP_MAPRED_HOME/share/hadoop/mapreduce/lib/*</value></property></configuration>yarn-site.xml<configuration><property><name>yarn.nodemanager.aux-services</name><value>mapreduce_shuffle</value></property><property><name>yarn.nodemanager.env-whitelist</name><value>JAVA_HOME,HADOOP_COMMON_HOME,HADOOP_HDFS_HOME,HADOOP_CONF_DIR,CLASSPATH_PREPEND_DISTCACHE,HADOOP_YARN_HOME,HADOOP_MAPRED_HOME</value></property></configuration>五、启动初始化HDFShdfsnamenode-format启动HDFSstart-dfs.sh启动YARNstart-yarn.sh启动成功后访问http://master:50070查看HDFS状态六、相关命令start-dfs.sh启动HDFS(namenode/datanode/SecondaryNamenode)stop-dfs.sh停止HDFSstart-yarn.sh启动Yarnstop-yarn.sh停止Yarnstart-all.sh启动HDFS和Yarnstop-all.sh停止HDFS和Yarn
1.@RestController注解相当于@ResponseBody＋@Controller合在一起的作用。2.如果只是使用@RestController注解Controller，则Controller中的方法无法返回jsp页面，或者html，配置的视图解析器InternalResourceViewResolver不起作用，返回的内容就是Return里的内容。3.如果需要返回到指定页面，则需要用@Controller配合视图解析器InternalResourceViewResolver才行。4.如果需要返回JSON，XML或自定义mediaType内容到页面，则需要在对应的方法上加上@ResponseBody注解。)
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