1.验证码工具类1.新建包utils2.新建VerifyCodeUtil类packagecn.coralcloud.ims.utils;importjavax.imageio.ImageIO;importjava.awt.*;importjava.awt.geom.AffineTransform;importjava.awt.image.BufferedImage;importjava.io.File;importjava.io.FileOutputStream;importjava.io.IOException;importjava.io.OutputStream;importjava.util.Arrays;importjava.util.Random;/***@authorc-geff*/publicclassVerifyCodeUtil{/***使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符*/privatestaticfinalStringVERIFY_CODES="23456789ABCDEFGHJKLMNPQRSTUVWXYZ";privatestaticRandomrandom=newRandom();/***使用系统默认字符源生成验证码*@paramverifySize验证码长度*@return*/publicstaticStringgenerateVerifyCode(intverifySize){returngenerateVerifyCode(verifySize,VERIFY_CODES);}/***使用指定源生成验证码*@paramverifySize验证码长度*@paramsources验证码字符源*@return*/publicstaticStringgenerateVerifyCode(intverifySize,Stringsources){if(sources==null||sources.length()==0){sources=VERIFY_CODES;}intcodesLen=sources.length();Randomrand=newRandom(System.currentTimeMillis());StringBuilderverifyCode=newStringBuilder(verifySize);for(inti=0;i<verifySize;i++){verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));}returnverifyCode.toString();}/***生成随机验证码文件,并返回验证码值*@paramw*@paramh*@paramoutputFile*@paramverifySize*@return*@throwsIOException*/publicstaticStringoutputVerifyImage(intw,inth,FileoutputFile,intverifySize)throwsIOException{StringverifyCode=generateVerifyCode(verifySize);outputImage(w,h,outputFile,verifyCode);returnverifyCode;}/***输出随机验证码图片流,并返回验证码值*@paramw*@paramh*@paramos*@paramverifySize*@return*@throwsIOException*/publicstaticStringoutputVerifyImage(intw,inth,OutputStreamos,intverifySize)throwsIOException{StringverifyCode=generateVerifyCode(verifySize);outputImage(w,h,os,verifyCode);returnverifyCode;}/***生成指定验证码图像文件*@paramw*@paramh*@paramoutputFile*@paramcode*@throwsIOException*/publicstaticvoidoutputImage(intw,inth,FileoutputFile,Stringcode)throwsIOException{if(outputFile==null){return;}Filedir=outputFile.getParentFile();if(!dir.exists()){dir.mkdirs();}try{outputFile.createNewFile();FileOutputStreamfos=newFileOutputStream(outputFile);outputImage(w,h,fos,code);fos.close();}catch(IOExceptione){throwe;}}/***输出指定验证码图片流*@paramw*@paramh*@paramos*@paramcode*@throwsIOException*/publicstaticvoidoutputImage(intw,inth,OutputStreamos,Stringcode)throwsIOException{intverifySize=code.length();BufferedImageimage=newBufferedImage(w,h,BufferedImage.TYPE_INT_RGB);Randomrand=newRandom();Graphics2Dg2=image.createGraphics();g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);Color[]colors=newColor[5];Color[]colorSpaces=newColor[]{Color.WHITE,Color.CYAN,Color.GRAY,Color.LIGHT_GRAY,Color.MAGENTA,Color.ORANGE,Color.PINK,Color.YELLOW};float[]fractions=newfloat[colors.length];for(inti=0;i<colors.length;i++){colors[i]=colorSpaces[rand.nextInt(colorSpaces.length)];fractions[i]=rand.nextFloat();}Arrays.sort(fractions);//设置边框色g2.setColor(Color.GRAY);g2.fillRect(0,0,w,h);Colorc=getRandColor(200,250);//设置背景色g2.setColor(c);g2.fillRect(0,2,w,h-4);//绘制干扰线Randomrandom=newRandom();//设置线条的颜色g2.setColor(getRandColor(160,200));intloop=20;for(inti=0;i<loop;i++){intx=random.nextInt(w-1);inty=random.nextInt(h-1);intxl=random.nextInt(6)+1;intyl=random.nextInt(12)+1;g2.drawLine(x,y,x+xl+40,y+yl+20);}//添加噪点//噪声率floatyawpRate=0.05f;intarea=(int)(yawpRate*w*h);for(inti=0;i<area;i++){intx=random.nextInt(w);inty=random.nextInt(h);intrgb=getRandomIntColor();image.setRGB(x,y,rgb);}//使图片扭曲shear(g2,w,h,c);g2.setColor(getRandColor(100,160));intfontSize=h-4;Fontfont=newFont("Algerian",Font.ITALIC,fontSize);g2.setFont(font);char[]chars=code.toCharArray();for(inti=0;i<verifySize;i++){AffineTransformaffine=newAffineTransform();affine.setToRotation(Math.PI/4*rand.nextDouble()*(rand.nextBoolean()?1:-1),(w/verifySize)*i+fontSize/2,h/2);g2.setTransform(affine);g2.drawChars(chars,i,1,((w-10)/verifySize)*i+5,h/2+fontSize/2-10);}g2.dispose();ImageIO.write(image,"jpg",os);}privatestaticfinalIntegerCOLOR_MAX_INT=255;privatestaticColorgetRandColor(intfc,intbc){if(fc>COLOR_MAX_INT){fc=COLOR_MAX_INT;}if(bc>COLOR_MAX_INT){bc=COLOR_MAX_INT;}intr=fc+random.nextInt(bc-fc);intg=fc+random.nextInt(bc-fc);intb=fc+random.nextInt(bc-fc);returnnewColor(r,g,b);}privatestaticintgetRandomIntColor(){int[]rgb=getRandomRgb();intcolor=0;for(intc:rgb){color=color<<8;color=color|c;}returncolor;}privatestaticint[]getRandomRgb(){int[]rgb=newint[3];intloop=3;for(inti=0;i<loop;i++){rgb[i]=random.nextInt(255);}returnrgb;}privatestaticvoidshear(Graphicsg,intw1,inth1,Colorcolor){shearx(g,w1,h1,color);sheary(g,w1,h1,color);}privatestaticvoidshearx(Graphicsg,intw1,inth1,Colorcolor){intperiod=random.nextInt(2);booleanborderGap=true;intframes=1;intphase=random.nextInt(2);for(inti=0;i<h1;i++){doubled=(double)(period>>1)*Math.sin((double)i/(double)period+(6.2831853071795862D*(double)phase)/(double)frames);g.copyArea(0,i,w1,1,(int)d,0);if(borderGap){g.setColor(color);g.drawLine((int)d,i,0,i);g.drawLine((int)d+w1,i,w1,i);}}}privatestaticvoidsheary(Graphicsg,intw1,inth1,Colorcolor){intperiod=random.nextInt(40)+10;booleanborderGap=true;intframes=20;intphase=7;for(inti=0;i<w1;i++){doubled=(double)(period>>1)*Math.sin((double)i/(double)period+(6.2831853071795862D*(double)phase)/(double)frames);g.copyArea(i,0,1,h1,0,(int)d);if(borderGap){g.setColor(color);g.drawLine(i,(int)d,i,0);g.drawLine(i,(int)d+h1,i,h1);}}}}2.UserController新增验证码接口2.1新增captcha方法@GetMapping("/captcha")publicvoidcaptcha(HttpServletResponseresponse,HttpSessionsession){Stringcode=VerifyCodeUtil.generateVerifyCode(4);session.setAttribute(SessionKey.ADMIN_CAPTCHA_KEY,code);try{VerifyCodeUtil.outputImage(150,50,response.getOutputStream(),code);}catch(IOExceptione){e.printStackTrace();}}2.2修改login方法,增加验证下方为最终的登录验证方法:@PostMapping("/login")publicModelAndViewlogin(Stringemail,Stringpassword,Stringcaptcha,HttpSessionsession){StringsessionCaptcha=(String)session.getAttribute(SessionKey.ADMIN_CAPTCHA_KEY);ModelAndViewview=newModelAndView();view.setViewName("user/login");//将email和password写回到页面,使得登录失败时输入的账号密码不会丢失view.addObject("email",email);view.addObject("password",password);if(StringUtils.isEmpty(captcha)||!Objects.equals(captcha,sessionCaptcha)){view.addObject("errmsg","验证码错误!");returnview;}Useruser=userService.login(email,password);if(user!=null){session.setAttribute(SessionKey.ADMIN_USER_KEY,user);view.setViewName("redirect:/index");returnview;}view.addObject("errmsg","用户名或密码错误!");returnview;}注:此处将Session的Key值通过一个常量类SessionKey保存2.3SessionKey类在utils包下新建SessionKey类packagecn.coralcloud.ims.utils;/***@authorc-geff*@nameSessionKey*@description*@date2020-11-0410:12*/publicclassSessionKey{publicstaticfinalStringADMIN_USER_KEY="AdminUserKey";publicstaticfinalStringADMIN_CAPTCHA_KEY="AdminLoginCaptchaCode";}3.修改login.ftl3.1引入jquery下载jqeury文件jquery.min.js在/static/js文件夹下新建jquery文件夹,将jquery.min.js复制到文件夹下修改login.ftl文件,最终login.ftl内容为下:<!doctypehtml><htmllang="en"xmlns:th="http://www.thymeleaf.org"><head><metacharset="UTF-8"><metaname="viewport"content="width=device-width,user-scalable=no,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0"><metahttp-equiv="X-UA-Compatible"content="ie=edge"><linktype="text/css"rel="stylesheet"href="/static/css/main.css"><linktype="text/css"rel="stylesheet"href="/static/css/login.css"><scriptsrc="/static/js/jquery/jquery.min.js"type="application/javascript"></script><title>用户登录</title></head><body><divclass="login-container"><formaction="/user/login"method="post"><div><h3>用户登录</h3></div><divclass="ims-form-item"><labelclass="ims-form-label"for="email">登录邮箱</label><inputclass="ims-form-input"id="email"autocomplete="off"th:value="${email}"placeholder="请输入邮箱"type="text"name="email"></div><divclass="ims-form-item"><labelclass="ims-form-label"for="password">登录密码</label><inputclass="ims-form-input"id="password"autocomplete="new-password"th:value="${password}"placeholder="请输入密码"type="password"name="password"></div><divclass="ims-form-item"><labelclass="ims-form-label"for="captcha">图片验证</label><inputclass="ims-form-input"id="captcha"type="text"placeholder="请输入图片验证码"name="captcha"><imgsrc="/user/captcha"class="captcha"alt="图片验证码"></div><pclass="errormsg"th:if="${errmsg}!=null"th:text="${errmsg}"></p><div><buttontype="submit"class="ims-button">登录</button></div></form></div></body><scripttype="application/javascript">$(document).ready(function(){$('img.captcha').click(function(){$(this).attr("src","/user/captcha?_="+newDate().getTime())})})</script></html>注,login.ftl变更如下:1.head新增引入jquery.min.js2.input新增读取前面保存的email和password3.新增图片验证码输入框及图片4.新建图片点击监听事件,更换图片验证码4.修改样式login.css#captcha{width:100px;border-top-right-radius:0;border-bottom-right-radius:0;}.captcha{width:1px;flex:1;height:42px;cursor:pointer;border-top-right-radius:4px;border-bottom-right-radius:4px;}5.最终效果
一、Sharding-jdbc简介Sharding-jdbc是开源的数据库操作中间件；定位为轻量级Java框架，在Java的JDBC层提供的额外服务。它使用客户端直连数据库，以jar包形式提供服务，无需额外部署和依赖，可理解为增强版的JDBC驱动，完全兼容JDBC和各种ORM框架。官方文档地址：https://shardingsphere.apache.org/document/current/cn/overview/本文demo实现了分库分表功能。作者能力有限，如有错误，欢迎各位在评论中指出。不胜感激！二、项目结构首先创建一个一般的Springboot项目，项目采用三层架构，结构图如下：项目目录结构图POM.xml文件如下：<?xmlversion="1.0"encoding="UTF-8"?><projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.6.RELEASE</version><relativePath/><!--lookupparentfromrepository--></parent><groupId>com.macky</groupId><artifactId>spring-boot-shardingjdbc</artifactId><version>0.0.1-SNAPSHOT</version><name>spring-boot-shardingjdbc</name><description>Demoprojectforspring-boot-shardingjdbc</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!--mysql--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><!--Mybatis-Plus--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.1.1</version></dependency><!--shardingspherestart--><!--forspringboot--><dependency><groupId>io.shardingsphere</groupId><artifactId>sharding-jdbc-spring-boot-starter</artifactId><version>3.1.0</version></dependency><!--forspringnamespace--><dependency><groupId>io.shardingsphere</groupId><artifactId>sharding-jdbc-spring-namespace</artifactId><version>3.1.0</version></dependency><!--shardingsphereend--><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>实体类以书本为例packagecom.macky.springbootshardingjdbc.entity;importcom.baomidou.mybatisplus.annotation.TableName;importcom.baomidou.mybatisplus.extension.activerecord.Model;importgroovy.transform.EqualsAndHashCode;importlombok.Data;importlombok.experimental.Accessors;/***@authorMacky*@TitleclassBook*@Description:书籍是实体类*@date2019/7/1315:23*/@Data@EqualsAndHashCode(callSuper=true)@Accessors(chain=true)@TableName("book")publicclassBookextendsModel<Book>{privateintid;privateStringname;privateintcount;}开放保存和查询两个接口，代码如下：packagecom.macky.springbootshardingjdbc.controller;importcom.macky.springbootshardingjdbc.entity.Book;importcom.macky.springbootshardingjdbc.service.BookService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.*;importjava.util.List;/***@authorMacky*@TitleclassBookController*@Description:TODO*@date2019/7/1220:53*/@RestControllerpublicclassBookController{@AutowiredBookServicebookService;@RequestMapping(value="/book",method=RequestMethod.GET)publicList<Book>getItems(){returnbookService.getBookList();}@RequestMapping(value="/book",method=RequestMethod.POST)publicBooleansaveItem(Bookbook){returnbookService.save(book);}}BookServiceImpl.javapackagecom.macky.springbootshardingjdbc.service.impl;importcom.baomidou.mybatisplus.core.toolkit.Wrappers;importcom.baomidou.mybatisplus.extension.service.impl.ServiceImpl;importcom.macky.springbootshardingjdbc.entity.Book;importcom.macky.springbootshardingjdbc.mapper.BookMapper;importcom.macky.springbootshardingjdbc.service.BookService;importorg.springframework.stereotype.Service;importjava.util.List;/***@authorMacky*@TitleclassBookServiceImpl*@Description:TODO*@date2019/7/1220:47*/@ServicepublicclassBookServiceImplextendsServiceImpl<BookMapper,Book>implementsBookService{@OverridepublicList<Book>getBookList(){returnbaseMapper.selectList(Wrappers.<Book>lambdaQuery());}@Overridepublicbooleansave(Bookbook){returnsuper.save(book);}}BookMapper.javapackagecom.macky.springbootshardingjdbc.mapper;importcom.baomidou.mybatisplus.core.mapper.BaseMapper;importcom.macky.springbootshardingjdbc.entity.Book;/***@authorMacky*@TitleclassBookMapper*@Description:TODO*@date2019/7/1220:46*/publicinterfaceBookMapperextendsBaseMapper<Book>{}创建数据库表，DDL语句如下:#创建数据库表数据CREATEDATABASEIFNOTEXISTS`db0`;USE`db0`;DROPTABLEIFEXISTS`book_0`;CREATETABLE`book_0`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;DROPTABLEIFEXISTS`book_1`;CREATETABLE`book_1`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;CREATEDATABASEIFNOTEXISTS`db1`;USE`db1`;DROPTABLEIFEXISTS`book_0`;CREATETABLE`book_0`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;DROPTABLEIFEXISTS`book_1`;CREATETABLE`book_1`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;CREATEDATABASEIFNOTEXISTS`db2`;USE`db2`;DROPTABLEIFEXISTS`book_0`;CREATETABLE`book_0`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;DROPTABLEIFEXISTS`book_1`;CREATETABLE`book_1`(`id`INT(11)NOTNULL,`name`VARCHAR(255)DEFAULTNULL,`count`INT(11)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=INNODBDEFAULTCHARSET=utf8mb4;配置分库分表策略application.properties：#数据源db0,db1,db2sharding.jdbc.datasource.names=db0,db1,db2#第一个数据库sharding.jdbc.datasource.db0.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db0.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db0.jdbc-url=jdbc:mysql://localhost:3306/db0?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db0.username=rootsharding.jdbc.datasource.db0.password=Aa123456#第二个数据库sharding.jdbc.datasource.db1.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db1.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db1.jdbc-url=jdbc:mysql://localhost:3306/db1?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db1.username=rootsharding.jdbc.datasource.db1.password=Aa123456#第三个数据库sharding.jdbc.datasource.db2.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db2.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db2.jdbc-url=jdbc:mysql://localhost:3306/db2?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db2.username=rootsharding.jdbc.datasource.db2.password=Aa123456#水平拆分的数据库（表）配置分库+分表策略行表达式分片策略#分库策略sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=idsharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=db$->{id%3}#分表策略其中book为逻辑表分表主要取决于id行sharding.jdbc.config.sharding.tables.book.actual-data-nodes=db$->{0..2}.book_$->{0..2}sharding.jdbc.config.sharding.tables.book.table-strategy.inline.sharding-column=count#分片算法表达式sharding.jdbc.config.sharding.tables.book.table-strategy.inline.algorithm-expression=book_$->{count%3}#主键UUID18位数如果是分布式还要进行一个设置防止主键重复#sharding.jdbc.config.sharding.tables.user.key-generator-column-name=id#打印执行的数据库以及语句sharding.jdbc.config.props..sql.show=truespring.main.allow-bean-definition-overriding=true#读写分离sharding.jdbc.datasource.dsmaster=接口测试使用postman示例：GET请求------>http://localhost:8080/bookPOST请求：------->http://localhost:8080/book?id=1&name=java编程思想&count=8demo的github地址：https://github.com/Macky-He/spring-boot--shardingsphere-examples如各位觉得有帮助的话，还请给个star鼓励鼓励博主，谢谢！三、总结分库分表实现按照官方文档做一个demo是第一步，如需深入还需要研究源码，研究架构，研究思想；此文仅作为入门demo搭建指南，如需深入理解，还请移步至官方文档。参考资料1.官方文档：https://shardingsphere.apache.org/document/current/cn/manual/sharding-jdbc/usage/sharding/
1.项目介绍本项目基础架构为:SpringBoot+Thymleaf+Mybatis整合SpringBoot版本:2.3.52.创建项目（打开IDEA,选择File->New->Project,在弹出的对话框中选择SpringInitializr）3.设置项目基础信息4.选择项目基础依赖5.设置项目保存路径6.创建完成等待项目依赖下载完成,则项目框架到此全部搭建完成7.pom.xml最终项目的pom.xml:<?xmlversion="1.0"encoding="UTF-8"?><projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.3.5.RELEASE</version><relativePath/><!--lookupparentfromrepository--></parent><groupId>cn.coralcloud</groupId><artifactId>ims</artifactId><version>0.0.1-SNAPSHOT</version><name>ims</name><description>DemoprojectforSpringBoot</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-thymeleaf</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.3</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><optional>true</optional></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope><exclusions><exclusion><groupId>org.junit.vintage</groupId><artifactId>junit-vintage-engine</artifactId></exclusion></exclusions></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
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.@Component,@Service,@Controller,@Repository是spring注解，注解后可以被spring框架所扫描并注入到spring容器来进行管理2.@Component是通用注解，其他三个注解是这个注解的拓展，并且具有了特定的功能3.如果想使用自定义的组件注解，那么只要在你定义的新注解中加上@Component即可:4.@Repository注解在持久层中，具有将数据库操作抛出的原生异常翻译转化为spring的持久层异常的功能。5.@Controller层是spring-mvc的注解，具有将请求进行转发，重定向的功能。6.@Service层是业务逻辑层注解，这个注解只是标注该类处于业务逻辑层。7.用这些注解对应用进行分层之后，就能将请求处理，义务逻辑处理，数据库操作处理分离出来，为代码解耦，也方便了以后项目的维护和开发。
1.、@RequestParam与@RequestPart主要用来接收文件,两者都能用于后端接收文件2.@RequestPart这个注解用在multipart/form-data表单提交请求的方法上。支持的请求方法的方式MultipartFile，属于Spring的MultipartResolver类。这个请求是通过http协议传输的。3.@RequestParam也同样支持multipart/form-data请求。当请求方法的请求参数类型是String类型的时候。4.@RequestParam适用于name-valueString类型的请求域，@RequestPart适用于复杂的请求域（像JSON，XML）5.@RequestPart注解会生成临时文件，而@RequestParam则不会生成临时文件，效率上ReqeustParam会比RequestPart快一些
下载破解文件JetbrainsIdesCrack-3.4.jar将下载的文件复制到WebStorm安装文件夹下的bin文件夹下(在桌面上WebStorm快捷方式上右键【打开文件所在的位置】可直接进入)双击打开WebStorm进入激活页面,点选【Evaluateforfree】试用30天,进入应用界面在菜单【Help】->【EditcustomVMoptions..】点击打开配置文件.在配置文件最下方加入一行:-javaagent:D:\software\WebStorm2019.1.3\bin\JetbrainsIdesCrack-3.4.jar这里的文件路径具体指向到刚才复制的破解文件路径下在菜单【Help】->【Register...】点击打开激活页面,选择【licenseserver】激活方式,在下面输入框中填写:https://fls.jetbrains-agent.com点击【Activate】激活后,重启WebStorm生效.
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:
采集节点主要安装Filebeat组件即可，Filebeat可以很简单运行在Windows/Linux操作系统上，不需要其余环境。下载Filebeat压缩包:https://www.elastic.co/downloads/past-releases/filebeat-6-2-4根据操作系统选择对应的版本下载解压修改目录下filebeat.yml文件，具体配置下图：上图为filebeat的输入端配置，指定监听文件上图为filebeat的输出端配置，指定输出到本机的Logstash中Filebeat启动（cd$FILEBEAT_HOME）：./filebeat-e-cfilebeat.yml后台启动可使用nohup命令nohup./filebeat-e-cfilebeat.yml-d"publish">logs/filebeat.log2>&1&
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)。
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