使用SSM框架搭建仿知乎问答社区
项目来源自国内知名刷题网站的项目,主要是给在校的学生一个更加真实的实战项目,非经验,有些东西不是自己独立在实践生产中写的东西只能说是一种经历,但是比起书本上的项目的话确实挺值的.
- 操作系统 : Ubuntu 17.04
- IDE ：IntelliJ IDEA 2017.1.3 x64 && Pycharm 2017.1.1
- JDK Version : JDK1.8 建议使用JDK1.7以上版本
- Python Version : Python 2.7
- Web容器 ： SpringBoot集成的默认容器-Tomcat
- 数据库 ：Mysql-5.7
- 依赖管理工具 : Maven 管理jar包真的很方便
- 版本控制: Git
Download Zip或者 git clone
git clone https://github.com/Sunybyjava/wenda.git使用IDEA创建的项目,配置好maven的相关配置,以及项目JDK版本,直接在主界面选择Open,然后找到项目所在路径,点击导入就可以了
在resources下自行配置邮件发送的一些账号信息文件mailSetting.properties,这里提供参考信息
##以下属性自行更改
mail.username[email protected] // 账号名字
mail.password[email protected] // 账号密码
mail.host=smtp.qq.com // 邮件服务器
mail.port=465 // 邮件端口
mail.protocol=smtps // 邮件协议
mail.defaultEncoding=utf8 // 编码数据库文件全部位于resources/sql目录下面,导入数据库后可以自行填充数据
/opt/jdk/1.8/bin/java -javaagent:/opt/idea-IU-171.4249.39/lib/idea_rt.jar=41203:/opt/idea-IU-171.4249.39/bin -Dfile.encoding=UTF-8 -classpath /opt/jdk/1.8/jre/lib/charsets.jar:/opt/jdk/1.8/jre/lib/deploy.jar:/opt/jdk/1.8/jre/lib/ext/cldrdata.jar:/opt/jdk/1.8/jre/lib/ext/dnsns.jar:/opt/jdk/1.8/jre/lib/ext/jaccess.jar:/opt/jdk/1.8/jre/lib/ext/jfxrt.jar:/opt/jdk/1.8/jre/lib/ext/localedata.jar:/opt/jdk/1.8/jre/lib/ext/nashorn.jar:/opt/jdk/1.8/jre/lib/ext/sunec.jar:/opt/jdk/1.8/jre/lib/ext/sunjce_provider.jar:/opt/jdk/1.8/jre/lib/ext/sunpkcs11.jar:/opt/jdk/1.8/jre/lib/ext/zipfs.jar:/opt/jdk/1.8/jre/lib/javaws.jar:/opt/jdk/1.8/jre/lib/jce.jar:/opt/jdk/1.8/jre/lib/jfr.jar:/opt/jdk/1.8/jre/lib/jfxswt.jar:/opt/jdk/1.8/jre/lib/jsse.jar:/opt/jdk/1.8/jre/lib/management-agent.jar:/opt/jdk/1.8/jre/lib/plugin.jar:/opt/jdk/1.8/jre/lib/resources.jar:/opt/jdk/1.8/jre/lib/rt.jar:/home/sunjianrong/IdeaProjects/wenda/target/classes:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-aop/1.3.6.RELEASE/spring-boot-starter-aop-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter/1.3.6.RELEASE/spring-boot-starter-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-logging/1.3.6.RELEASE/spring-boot-starter-logging-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/ch/qos/logback/logback-classic/1.1.7/logback-classic-1.1.7.jar:/home/sunjianrong/.m2/repository/ch/qos/logback/logback-core/1.1.7/logback-core-1.1.7.jar:/home/sunjianrong/.m2/repository/org/slf4j/slf4j-api/1.7.21/slf4j-api-1.7.21.jar:/home/sunjianrong/.m2/repository/org/slf4j/jcl-over-slf4j/1.7.21/jcl-over-slf4j-1.7.21.jar:/home/sunjianrong/.m2/repository/org/slf4j/jul-to-slf4j/1.7.21/jul-to-slf4j-1.7.21.jar:/home/sunjianrong/.m2/repository/org/slf4j/log4j-over-slf4j/1.7.21/log4j-over-slf4j-1.7.21.jar:/home/sunjianrong/.m2/repository/org/yaml/snakeyaml/1.16/snakeyaml-1.16.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-aop/4.2.7.RELEASE/spring-aop-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-beans/4.2.7.RELEASE/spring-beans-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/aspectj/aspectjweaver/1.8.9/aspectjweaver-1.8.9.jar:/home/sunjianrong/.m2/repository/org/mybatis/spring/boot/mybatis-spring-boot-starter/1.3.0/mybatis-spring-boot-starter-1.3.0.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-jdbc/1.3.6.RELEASE/spring-boot-starter-jdbc-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/tomcat-jdbc/8.0.36/tomcat-jdbc-8.0.36.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/tomcat-juli/8.0.36/tomcat-juli-8.0.36.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-jdbc/4.2.7.RELEASE/spring-jdbc-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-tx/4.2.7.RELEASE/spring-tx-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/mybatis/spring/boot/mybatis-spring-boot-autoconfigure/1.3.0/mybatis-spring-boot-autoconfigure-1.3.0.jar:/home/sunjianrong/.m2/repository/org/mybatis/mybatis/3.4.4/mybatis-3.4.4.jar:/home/sunjianrong/.m2/repository/org/mybatis/mybatis-spring/1.3.1/mybatis-spring-1.3.1.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-web/1.3.6.RELEASE/spring-boot-starter-web-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/1.3.6.RELEASE/spring-boot-starter-tomcat-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.0.36/tomcat-embed-core-8.0.36.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/8.0.36/tomcat-embed-el-8.0.36.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/embed/tomcat-embed-logging-juli/8.0.36/tomcat-embed-logging-juli-8.0.36.jar:/home/sunjianrong/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/8.0.36/tomcat-embed-websocket-8.0.36.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-validation/1.3.6.RELEASE/spring-boot-starter-validation-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/hibernate/hibernate-validator/5.2.4.Final/hibernate-validator-5.2.4.Final.jar:/home/sunjianrong/.m2/repository/javax/validation/validation-api/1.1.0.Final/validation-api-1.1.0.Final.jar:/home/sunjianrong/.m2/repository/org/jboss/logging/jboss-logging/3.3.0.Final/jboss-logging-3.3.0.Final.jar:/home/sunjianrong/.m2/repository/com/fasterxml/classmate/1.1.0/classmate-1.1.0.jar:/home/sunjianrong/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.6.7/jackson-databind-2.6.7.jar:/home/sunjianrong/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.6.7/jackson-annotations-2.6.7.jar:/home/sunjianrong/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.6.7/jackson-core-2.6.7.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-web/4.2.7.RELEASE/spring-web-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-context/4.2.7.RELEASE/spring-context-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-webmvc/4.2.7.RELEASE/spring-webmvc-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-expression/4.2.7.RELEASE/spring-expression-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-starter-velocity/1.3.6.RELEASE/spring-boot-starter-velocity-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/commons-beanutils/commons-beanutils/1.9.2/commons-beanutils-1.9.2.jar:/home/sunjianrong/.m2/repository/commons-collections/commons-collections/3.2.2/commons-collections-3.2.2.jar:/home/sunjianrong/.m2/repository/commons-digester/commons-digester/2.1/commons-digester-2.1.jar:/home/sunjianrong/.m2/repository/org/apache/velocity/velocity/1.7/velocity-1.7.jar:/home/sunjianrong/.m2/repository/commons-lang/commons-lang/2.4/commons-lang-2.4.jar:/home/sunjianrong/.m2/repository/org/apache/velocity/velocity-tools/2.0/velocity-tools-2.0.jar:/home/sunjianrong/.m2/repository/commons-chain/commons-chain/1.1/commons-chain-1.1.jar:/home/sunjianrong/.m2/repository/commons-validator/commons-validator/1.3.1/commons-validator-1.3.1.jar:/home/sunjianrong/.m2/repository/dom4j/dom4j/1.1/dom4j-1.1.jar:/home/sunjianrong/.m2/repository/oro/oro/2.0.8/oro-2.0.8.jar:/home/sunjianrong/.m2/repository/sslext/sslext/1.2-0/sslext-1.2-0.jar:/home/sunjianrong/.m2/repository/org/apache/struts/struts-core/1.3.8/struts-core-1.3.8.jar:/home/sunjianrong/.m2/repository/antlr/antlr/2.7.7/antlr-2.7.7.jar:/home/sunjianrong/.m2/repository/org/apache/struts/struts-taglib/1.3.8/struts-taglib-1.3.8.jar:/home/sunjianrong/.m2/repository/org/apache/struts/struts-tiles/1.3.8/struts-tiles-1.3.8.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-context-support/4.2.7.RELEASE/spring-context-support-4.2.7.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-devtools/1.3.6.RELEASE/spring-boot-devtools-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot/1.3.6.RELEASE/spring-boot-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/1.3.6.RELEASE/spring-boot-autoconfigure-1.3.6.RELEASE.jar:/home/sunjianrong/.m2/repository/mysql/mysql-connector-java/5.1.39/mysql-connector-java-5.1.39.jar:/home/sunjianrong/.m2/repository/org/springframework/spring-core/4.2.7.RELEASE/spring-core-4.2.7.RELEASE.jar com.suny.WendaApplication
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.3.6.RELEASE)
2017-09-01 12:00:31.780 INFO 29101 --- [ restartedMain] com.suny.WendaApplication : Starting WendaApplication on sunjianrong-CW65S with PID 29101 (/home/sunjianrong/IdeaProjects/wenda/target/classes started by sunjianrong in /home/sunjianrong/IdeaProjects/wenda)
2017-09-01 12:00:31.785 INFO 29101 --- [ restartedMain] com.suny.WendaApplication : No active profile set, falling back to default profiles: default
2017-09-01 12:00:31.857 INFO 29101 --- [ restartedMain] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1e4f0276: startup date [Fri Sep 01 12:00:31 CST 2017]; root of context hierarchy
2017-09-01 12:00:33.307 ERROR 29101 --- [ restartedMain] o.s.boot.SpringApplication : Application startup failed
java.lang.IllegalStateException: Cannot load configuration class: org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration
at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:416) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:263) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:284) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:130) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:678) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:520) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:760) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:360) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:306) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
at com.suny.WendaApplication.main(WendaApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.3.6.RELEASE.jar:1.3.6.RELEASE]
Caused by: java.lang.IllegalStateException: Unable to load cache item
at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:79) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:116) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:291) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:480) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:337) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:135) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:107) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:406) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
... 17 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/springframework/beans/factory/ObjectProvider
at java.lang.Class.getDeclaredConstructors0(Native Method) ~[na:1.8.0_91]
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) ~[na:1.8.0_91]
at java.lang.Class.getDeclaredConstructors(Class.java:2020) ~[na:1.8.0_91]
at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:566) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanFactoryAwareGeneratorStrategy.generate(ConfigurationClassEnhancer.java:249) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:329) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:492) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:93) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:91) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_91]
at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61) ~[spring-core-4.2.7.RELEASE.jar:4.2.7.RELEASE]
... 25 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.beans.factory.ObjectProvider
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_91]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_91]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_91]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_91]
... 39 common frames omitted
2017-09-01 12:00:33.311 INFO 29101 --- [ restartedMain] .b.l.ClasspathLoggingApplicationListener : Application failed to start with classpath: [file:/home/sunjianrong/IdeaProjects/wenda/target/classes/]
Process finished with exit code 0
解决办法:我这里是更换了SpringBoot版本后正常运行
-
- 注释 COMMENT后使用单引号'
- 字段,表名需要括起来就是用反单引号`,也就是数字键1旁边的键位
sql> INSERT INTO question (id, title, content, user_id, created_date, comment_count)
VALUES (
NULL, "如何看待知乎的行为", '无法看待', 10000, CURRENT_TIMESTAMP(), 55)
[2017-09-02 23:40:08] [HY000][1366] Incorrect string value: '\xE5\xA6\x82\xE4\xBD\x95...' for column 'title' at row 1
[2017-09-02 23:40:08] [HY000][1366] Incorrect string value: '\xE6\x97\xA0\xE6\xB3\x95...' for column 'content' at row 1
[2017-09-02 23:40:08] [HY000][1366] Incorrect string value: '\xE5\xA6\x82\xE4\xBD\x95...' for column 'title' at row 1
解决办法: 看起来就是应该是中文才插不进去,然后我想起课程里面的sq代码是没有指定字符集的,而是默认的字符集,首先先选择需要更改编码的数据,然后使用mysql的查看字符集指令:
`show variables like 'character%';
我这边跑出来的是一下的结果
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
我们可以看到character_set_server的编码是latin1,然后我们先修改编码,使用
set character_set_server =utf8更改character_set_server的编码,然后查看结果
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
可以看到这里是已经更改好了的,然后我继续插入数据,还是失败了,只有手动删表,然后再建表的时候自己设置下编码,根据资料里面的SQL脚本为
CREATE TABLE `question` (
`id` INT NOT NULL AUTO_INCREMENT,
`title` VARCHAR(255) NOT NULL,
`content` TEXT NULL,
`user_id` INT NOT NULL,
`created_date` DATETIME NOT NULL,
`comment_count` INT NOT NULL,
PRIMARY KEY (`id`),
INDEX `date_index` (`created_date` ASC)
)我这里需改为下面的之后再重新插入是没用问题的
CREATE TABLE `question` (
`id` INT NOT NULL AUTO_INCREMENT,
`title` VARCHAR(255) NOT NULL,
`content` TEXT NULL,
`user_id` INT NOT NULL,
`created_date` DATETIME NOT NULL,
`comment_count` INT NOT NULL,
PRIMARY KEY (`id`),
INDEX `date_index` (`created_date` ASC)
)
ENGINE = InnoDB
DEFAULT CHARSET = UTF8 COMMENT '问题表';增加的内容为:
- ENGINE = InnoDB:数据库引擎,InnoDB是支持事物,外键关联,行级锁的
- DEFAULT CHARSET = UTF8:手动设置数据库编码,不适用默认编码
An invalid form control with name='' is not focusable.
原来的代码
把原来的构造方法注入修改成以下的代码就可以正常注入,
@Component
public class PassportInterceptor implements HandlerInterceptor {
@Autowired
private LoginTicketDAO loginTicketDAO;
@Autowired
private UserDAO userDAO;
@Autowired
private HostHolder hostHolder;在mapper中的写法是这样,注意看from跟where前面是没有空格的
@Select({"select", SELECT_FIELDS + "from " + TABLE_NAME + "where ticket=#{ticket}"})控制台报错出来的语句
### SQL: select id user_id, expired, status, ticketfrom login_ticketwhere ticket=?
不是我们预想的那样,于是把mapper中的语句改成下面这样就不报错了
@Select({"select", SELECT_FIELDS + " from " + TABLE_NAME + " where ticket=#{ticket}"})-
报错信息:
[42000][1055] Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'tt.from_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
这个报错嘻嘻中提取关键词就是最后那个组合的单词sql_mode=only_full_group_by,直接去网上找答案吧!反正我也没碰过这个错误,首先看看MYSQL官方文档里面写的东西,这里就是说在版本5.7默认的模式就有这几个,看到了我们出错的关键词,然后就是在MySQL 5.7.5的时候默认添加了ONLY_FULL_GROUP_BY and STRICT_TRANS_TABLES两个模式,探究其中的原理的话很多博客文档都有详细的解释
参考链接接:
[MYSQL官方关于sql-mode文档](https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html)
[CSDN某博主比较详细的解释](http://blog.csdn.net/allen_tsang/article/details/54892046)
[stackoverflow上关于disable-only-full-group-by的帖子](https://stackoverflow.com/questions/23921117/disable-only-full-group-by)
- 报错的SQL代码:
SELECT
from_id,
to_id,
content,
has_read,
conversation_id,
create_date,
count(id) AS id
FROM
(SELECT *
FROM message
WHERE from_id = 10000 OR to_id = 10000
ORDER BY id DESC) tt
GROUP BY conversation_id- 登录数据库控制台查看模式
SELECT @@global.sql_mode如果你确定关闭这个模式不会对你的项目造成问题的话,你可以选择关闭ONLY_FULL_GROUP_BY限制,请注意关闭后的风险!!!
set sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'; Exception in thread "Thread-4" org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 465;
nested exception is:
java.net.ConnectException: Connection refused. Failed messages: javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 465;
nested exception is:
java.net.ConnectException: Connection refused; message exception details (1) are:
Failed message 1:
javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 465;
nested exception is:
java.net.ConnectException: Connection refused
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1961)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:654)
at javax.mail.Service.connect(Service.java:295)
at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:501)
at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:421)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:345)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
at com.suny.utils.MailSender.sendWithHTMLTemplate(MailSender.java:55)
at com.suny.async.handler.LoginExceptionHandler.doHandle(LoginExceptionHandler.java:33)
at com.suny.async.EventConsumer$1.run(EventConsumer.java:78)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:321)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:237)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1927)
... 10 more
看这个就直接去看邮件服务器信息是否错误,我的是配置的信息错误
Exception in thread "Thread-4" org.springframework.mail.MailAuthenticationException: Authentication failed; nested exception is javax.mail.AuthenticationFailedException: 535 Error: ÇëʹÓÃÊÚȨÂëµÇ¼¡£ÏêÇéÇë¿´: http://service.mail.qq.com/cgi-bin/help?subtype=1&&id=28&&no=1001256
at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:424)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:345)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
at com.suny.utils.MailSender.sendWithHTMLTemplate(MailSender.java:55)
at com.suny.async.handler.LoginExceptionHandler.doHandle(LoginExceptionHandler.java:33)
at com.suny.async.EventConsumer$1.run(EventConsumer.java:78)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.mail.AuthenticationFailedException: 535 Error: ÇëʹÓÃÊÚȨÂëµÇ¼¡£ÏêÇéÇë¿´: http://service.mail.qq.com/cgi-bin/help?subtype=1&&id=28&&no=1001256
at com.sun.mail.smtp.SMTPTransport$Authenticator.authenticate(SMTPTransport.java:826)
at com.sun.mail.smtp.SMTPTransport.authenticate(SMTPTransport.java:761)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:685)
at javax.mail.Service.connect(Service.java:295)
at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:501)
at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:421)
... 6 more
Exception in thread "Thread-4" org.springframework.mail.MailSendException: Failed messages: com.sun.mail.smtp.SMTPSendFailedException: 501 mail from address must be same as authorization user
;
nested exception is:
com.sun.mail.smtp.SMTPSenderFailedException: 501 mail from address must be same as authorization user
; message exception details (1) are:
Failed message 1:
com.sun.mail.smtp.SMTPSendFailedException: 501 mail from address must be same as authorization user
;
nested exception is:
com.sun.mail.smtp.SMTPSenderFailedException: 501 mail from address must be same as authorization user
at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:2108)
at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1609)
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1117)
at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:448)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:345)
at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
at com.suny.utils.MailSender.sendWithHTMLTemplate(MailSender.java:55)
at com.suny.async.handler.LoginExceptionHandler.doHandle(LoginExceptionHandler.java:33)
at com.suny.async.EventConsumer$1.run(EventConsumer.java:78)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.sun.mail.smtp.SMTPSenderFailedException: 501 mail from address must be same as authorization user
at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1616)
原因:邮件来源地址必须跟你发送邮件的地址是一模一样的,否则报错
public boolean sendWithHTMLTemplate(String to, String subject,
String template, Map<String, Object> model) {
try {
String nick = MimeUtility.encodeText("邮件通知");
// 下面这个邮箱地址必须跟发送邮件的地址一模一样,否则报错
InternetAddress from = new InternetAddress(nick + "<[email protected]>");
MimeMessage mimeMessage = mailSender.createMimeMessage();
MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage);
String result = VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, template, "UTF-8", model);
mimeMessageHelper.setTo(to);
mimeMessageHelper.setFrom(from);
mimeMessageHelper.setSubject(subject);
mimeMessageHelper.setText(result, true);
mailSender.send(mimeMessage);
return true;
} catch (UnsupportedEncodingException e) {
logger.error("发送邮件失败", e.getMessage());
return false;
} catch (javax.mail.MessagingException e) {
logger.error("消息发送异常", e.getMessage());
return false;
}
}解决方法:当然是把配置文件中的发件邮箱地址跟InternetAddress()方法中传入的邮箱地址一致即可
在这个项目中还是学到了挺多的知识点,很感谢叶神的辛苦付出,总结起来项目基本的模型写好以后含有的知识点还是非常的多的,然后我自己也在慢慢地想完善这个项目,总结出一些刚学习到的一些新的知识点,包括但不限于技巧,框架,技术点,语法等
-
这个模板引擎还是第一次接触,第一次看到这个还是在《深入分析JAVAWEB内幕》里面看到的,当时看到这个词是介绍淘宝里面应该是在使用或者是早起使用了它,以前自己也只是带学习性用过一下
FreeMarker，然后网上也出现了许多的模板引擎,我的理解就是大多数模板引擎的出现是为了使用户界面与业务数据进行分离,jsp在用户访问量大的时候容易出现解析时间久,用户体验性不好等等原因,使用起来其实还是挺方便的,至于性能的话我也没有去测试
-
貌似最近
Spring Boot挺火的,还跟微服务,SpringCould等高大上名词的扯上了关系.总结起来就是Spring的发展导致便携性非常高,然后各种配置文件很繁琐,于是又回到了注解的开发,大幅度减少无关于业务的代码量.这个倒确实有点体会,各种Spring的配置文件手动编写起来很是麻烦.总结出特点就是:- 创建独立的Spring应用程序
- 嵌入的Tomcat，无需部署WAR文件
- 简化Maven配置
- 自动配置Spring
- 提供生产就绪型功能，如指标，健康检查和外部配置
- 绝对没有代码生成和对XML没有要求配置
在IDEA中生成一个SpringBoot工程还是挺方便的,填入跟选择相对应的值直接一步步就可以了
还有一种方法就是在Spring官网生成好一个工程再导入IDEA中:
-
-
引入了
ticket的概念,在用户登录之后会后台自动产生一个ticket,然后放入数据库中,ticket具有时效性的,通过保存的过期时间跟当前服务器时间进行对比,如果过期了就需要重新登录,如果没有过期就会直接是登录状态,这里的ticket在服务器发送给客户端后保存在Cookie中
-
在进行登录注册的时候保存当前用户访问的网址,在登录或者注册完成后直接跳回操作的网址,提升用户的体验性
-
正如大多数网站发表言论都是需要经过审查的,而在我们的局域网里面,更是是要经过无数次的审查,然后方案有一下几种:
- 把敏感词删除
- 把敏感词替换为指定的字符串
这里并不是使用replace()方法或者使用正则表达式进行逐个查找然后进行替换,而是采用更加优良的算法-前缀树
- 根节点不包含字符,除根节点外每一个节点都只包含一个字符
- 从根节点到某一节点,路径上经过的字符连接起来,为该节点对应的字符串
- 每个节点的所有子节点包含的字符都不相同
在当今互联网这种上网人群多,访问量大的情况下,异步编程提供了一个非堵塞的,基于事件驱动的编程模型.这种编程方式可以充分利用计算机的多核来同时执行并行任务,提高资源的利用效率.应用场景在我了解的也不多,可以想象应用场景是很广泛的.举个很简单的例子,我们在网站注册新的社交账号的话,严格一点的网站都是会有验证邮箱地址的邮件.这个就是一个异步的事件,你不可能说直接把邮件验证的流程嵌套在业务逻辑里面.应该是把这个事件发送给一个队列里面,然后队列专门处理这种事件.在一个网站中有各种各样的事情需要进行处理
简单设计流程:
- 1.首先定义一个定义一个枚举类型的
EventType类,这里面列举各种各样将会出现的事件 - 2.再定义一个事件模型
EventModel类,里面包含的是一个事件所应该具有的一些属性.例如事件类型,操作者的ID,操作的实体类型,操作的实体ID,操作的实体拥有者等等 - 3.再定义一个接口
EventHandler,里面写上几个抽象的方法,具体的实现由继承的类进行实现 - 4.定义一个事件生产者
EventProducer,这里就是用来生产各种各样的事件,如异常登录或者是注册邮件等等.本项目中这里就是把事件送到Redis中进行储存 - 5.定义一个事件消费者
EventConsumer,这里就是需要继承InitializingBean跟ApplicationContextAware.继承InitializingBean是可以定义bean的初始化方式,继承InitializingBean是为了可以通过这个上下文对象得到我们想获取的bean.然后在这个类里面使用多线程一直去Redis里面读取出事件,然后进行处理 - 6.再继承
EventHandler在方法里面写自己的实现
按照步骤来的代码示例:
EventType类
public enum EventType {
LIKE(0),
COMMENT(1),
LOGIN(2),
MAIL(3),
FOLLOW(4),
UNFOLLOW(5);
private int value;
EventType(int value) {
this.value = value;
}
public int getValue() {
return value;
}
}
EventModel类
public class EventModel {
private EventType type;
private int actorId;
private int entityType;
private int entityId;
private int entityOwnerId;
private Map<String, String> exts = new HashMap<>();
public EventModel() {
}
public EventModel setExt(String key, String value) {
exts.put(key, value);
return this;
}
public EventModel(EventType type) {
this.type = type;
}
public String getExt(String key) {
return exts.get(key);
}
public EventType getType() {
return type;
}
public EventModel setType(EventType type) {
this.type = type;
return this;
}
public int getActorId() {
return actorId;
}
public EventModel setActorId(int actorId) {
this.actorId = actorId;
return this;
}
public int getEntityType() {
return entityType;
}
public EventModel setEntityType(int entityType) {
this.entityType = entityType;
return this;
}
public int getEntityId() {
return entityId;
}
public EventModel setEntityId(int entityId) {
this.entityId = entityId;
return this;
}
public int getEntityOwnerId() {
return entityOwnerId;
}
public EventModel setEntityOwnerId(int entityOwnerId) {
this.entityOwnerId = entityOwnerId;
return this;
}
public Map<String, String> getExts() {
return exts;
}
public EventModel setExts(Map<String, String> exts) {
this.exts = exts;
return this;
}
}
EventHandler接口
public interface EventHandler {
void doHandle(EventModel model);
List<EventType> getSupportEventTypes();
}
EventProducer类
public class EventProducer {
private final JedisAdapter jedisAdapter;
@Autowired
public EventProducer(JedisAdapter jedisAdapter) {
this.jedisAdapter = jedisAdapter;
}
public boolean fireEvent(EventModel eventModel) {
try {
String json = JSONObject.toJSONString(eventModel);
String key = RedisKeyUtil.getEventQueueKey();
jedisAdapter.lpush(key, json);
return true;
} catch (Exception e) {
return false;
}
}
}EventConsumer类
public class EventConsumer implements InitializingBean, ApplicationContextAware {
private static Logger logger = LoggerFactory.getLogger(EventConsumer.class);
private Map<EventType, List<EventHandler>> config = new HashMap<>();
private ApplicationContext applicationContext;
private final JedisAdapter jedisAdapter;
@Autowired
public EventConsumer(JedisAdapter jedisAdapter) {
this.jedisAdapter = jedisAdapter;
}
@Override
public void afterPropertiesSet() throws Exception {
Map<String, EventHandler> beans = applicationContext.getBeansOfType(EventHandler.class);
if (beans != null) {
for (Map.Entry<String, EventHandler> entry : beans.entrySet()) {
List<EventType> eventTypes = entry.getValue().getSupportEventTypes();
for (EventType type : eventTypes) {
if (!config.containsKey(type)) {
config.put(type, new ArrayList<>());
}
config.get(type).add(entry.getValue());
}
}
}
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
while (true) {
String key = RedisKeyUtil.getEventQueueKey();
List<String> events = jedisAdapter.brpop(0, key);
for (String message : events) {
if (message.equals(key)) {
continue;
}
EventModel eventModel = JSON.parseObject(message, EventModel.class);
if (!config.containsKey(eventModel.getType())) {
logger.error("不能识别的事件");
continue;
}
for (EventHandler handler : config.get(eventModel.getType())) {
handler.doHandle(eventModel);
}
}
}
}
});
thread.start();
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}
*Handler继承类
public class LikeHandler implements EventHandler {
private final MessageService messageService;
private final UserService userService;
@Autowired
public LikeHandler(MessageService messageService, UserService userService) {
this.messageService = messageService;
this.userService = userService;
}
@Override
public void doHandle(EventModel model) {
Message message = new Message();
message.setFromId(WendaUtil.SYSTEM_USERID);
message.setToId(model.getEntityOwnerId());
message.setCreateDate(new Date());
User user = userService.getUser(model.getActorId());
message.setContent("用户" + user.getName() + "赞了你的评论,http://127.0.0.1:8080/question/" + model.getExt("questionId"));
// 这里的会话ID肯定是系统管理员跟通知用户之间的会话
message.setConversationId(WendaUtil.SYSTEM_USERID + "_" + model.getEntityOwnerId());
messageService.addMessage(message);
}
@Override
public List<EventType> getSupportEventTypes() {
return Arrays.asList(EventType.LIKE);
}
}在写事件处理的时候继承了Spring的InitializingBean接口,这个接口只有一个方法:
public interface InitializingBean {
/**
* Invoked by a BeanFactory after it has set all bean properties supplied
* (and satisfied BeanFactoryAware and ApplicationContextAware).
* <p>This method allows the bean instance to perform initialization only
* possible when all bean properties have been set and to throw an
* exception in the event of misconfiguration.
* @throws Exception in the event of misconfiguration (such
* as failure to set an essential property) or if initialization fails.
*/
void afterPropertiesSet() throws Exception;
}我们要对某个bean进行自定义的初始化的时候,我们就可以让bean继承这个接口,然后在里面写上我们的业务逻辑,在Spring初始化bean的时候就会检查bean是否继承了InitializingBean接口,然后再执行afterPropertiesSet()方法.这样使用虽然很方便,但是这个bean中的代码跟Spring耦合在一起了
邮件发送倒也是第一次接触,好像以前看张孝祥老师的是有个邮件发送的视频的,不过当时也不会写.这里还是引用的是官方的javax.mail包,然后是通过Spring进行调用,这样可以减少一些邮件发送的复杂度,毕竟很多时候这种固定套路的代码都是复制过来用的.
流程: - 定义一个发送邮件的配置文件,里面写好相关的配置,包括服务器信息,邮件协议,账号信息等等
- 定义一个bean实现`InitializingBean`,然后也是在`afterPropertiesSet()`方法中初始化一些属性,这里就是在方法里面读取配置文件初始化`JavaMailSenderImpl`的几个必要的属性,方便我们后来的使用
- 在bean中写一个方法
sendWithHTMLTemplate()用来发送邮件的,因为不可能每一个邮件都是一样的,这里是采用了Velocity进行生成邮件文本的 - 在需要调用发送邮件的地方调用
sendWithHTMLTemplate()发送邮件
示例代码:
+ MailSender类
public class MailSender implements InitializingBean {
private static Logger logger = LoggerFactory.getLogger(MailSender.class);
private JavaMailSenderImpl mailSender;
private final VelocityEngine velocityEngine;
private final MailSetting mailSetting;
@Autowired
public MailSender(VelocityEngine velocityEngine, MailSetting mailSetting) {
this.velocityEngine = velocityEngine;
this.mailSetting = mailSetting;
}
public boolean sendWithHTMLTemplate(String to, String subject,
String template, Map<String, Object> model) {
try {
String nick = MimeUtility.encodeText("牛客中级课程");
InternetAddress from = new InternetAddress(nick + "<[email protected]>");
MimeMessage mimeMessage = mailSender.createMimeMessage();
MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage);
String result = VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, template, "UTF-8", model);
mimeMessageHelper.setTo(to);
mimeMessageHelper.setFrom(from);
mimeMessageHelper.setSubject(subject);
mimeMessageHelper.setText(result, true);
mailSender.send(mimeMessage);
return true;
} catch (UnsupportedEncodingException e) {
logger.error("发送邮件失败", e.getMessage());
return false;
} catch (javax.mail.MessagingException e) {
logger.error("消息发送异常", e.getMessage());
return false;
}
}
@Override
public void afterPropertiesSet() throws Exception {
mailSender = new JavaMailSenderImpl();
mailSender.setUsername(mailSetting.getUsername());
mailSender.setPassword(mailSetting.getPassword());
mailSender.setHost(mailSetting.getHost());
mailSender.setPort(mailSetting.getPort());
mailSender.setProtocol(mailSetting.getProtocol());
mailSender.setDefaultEncoding(mailSetting.getDefaultEncoding());
Session session = Session.getDefaultInstance(mailSender.getJavaMailProperties(), new Authenticator() {
// 身份认证
@Override
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(mailSender.getUsername(), mailSender.getPassword());
}
});
mailSender.setSession(session);
Properties javaProperties = new Properties();
javaProperties.put("mail.stmp.auth",true);
javaProperties.put("mail.stmp.starttls.enable",true);
mailSender.setJavaMailProperties(javaProperties);
}
}+ `mailSetting.properties`邮件配置文件信息
##一下属性自行更改
[email protected]
[email protected]
mail.host=smtp.qq.com
mail.port=465
mail.protocol=smtps
mail.defaultEncoding=utf8
-
以前只知道在关系型数据库里面是有事物的概念的,没想到在 Redis中也是有事物的概念的.很多时候一些重要的操作如果没有事物进行控制的话,会造成很多不必要的损失
在Redis事物要用到的两个命令:
-
MULTI命令
首先在事物开始的时候,先发送
MULTI命令给Redis,表示开始事物,然后再进行一些数据的操作. -
EXEC命令 在操作全部完成后发送
EXEC命令告诉Redis事物已经结束了,可以执行了
在事物中间执行的命令都是已经保存在Reids中,但是没有被执行,直到收到EXEC命令,然后才会以此开始以此执行服务器中保存的命令.当中只要有一次命令执行失败了的话,其他的指定命令也会被撤销.执行原则就是"要么全部被执行成功,要么全部不执行"
在Java中使用Jedis操作事物:
try {
Transaction tx = jedis.multi();
tx.zadd("test", 2, "1");
tx.zadd("demo", 3, "2");
List<Object> objs = tx.exec();
tx.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
}-
排序算法这东西我不熟悉,只能说是了解一下,确实有点难度....
- Hacker News
- StackOverflow
- IMDB
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顾名思义就是时间轴的意思,在sns网站中一般是要有互动的,然后就会有各种各样的个人时间轴时间或者是新鲜事.在大量用户会产生大量数据的情况下,对数据的储存我们需要合理地分配储存位置以及储存方式,让数据库性能最优化.
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数据储存方案:
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高热点数据放到Redis之类的非关系型数据库,便于高速读取
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用户言论等数据储存到关系型数据库,便于持久储存,安全性相对更高
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消息推送方案:
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这里我们采用推拉的模式,活跃用户直接推送消息,不活跃用户采用拉取的方式,合理利用服务器资源
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这里数据的读取采用Python进行爬取,主要是Python做一件事的代码量,前提是抛开别的因素.当我写第一个简单爬虫代码的时候我都惊讶到了,操作数据库短短两三行代码.非常的简洁,又有点自然语言的特点.
采用的是Pyspider框架,包管理器使用pip,IDE用IDEA的兄弟Pycharm
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这里介绍的是一个阿帕奇下的一个开源工具
apache2-utils,因为我是在Ubuntu系统下,直接从终端安装就好了
sudo apt-get install apache2-utils
然后直接在终端里面就可以打开,输入命令ab 后面带参数ab [options] [http[s]://]hostname[:port]/path 就可以开始进行测试了,你可以随便输入下,然后就会有帮助出来,跟着帮助做做例子就知道怎么用了,不过这里需要注意的是网址的填写,填写简短的网址的话肯定运行不了的,网址最后面那个要带到来,例如对鹅厂测试下:
ab -n 100 -c 100 http://qq.com/
This is ApacheBench, Version 2.3 <$Revision: 1706008 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking qq.com (be patient).....done
Server Software: squid/3.5.20
Server Hostname: qq.com
Server Port: 80
Document Path: /
Document Length: 160 bytes
Concurrency Level: 100
Time taken for tests: 0.107 seconds
Complete requests: 100
Failed requests: 0
Non-2xx responses: 100
Total transferred: 45222 bytes
HTML transferred: 16000 bytes
Requests per second: 930.95 [#/sec] (mean)
Time per request: 107.417 [ms] (mean)
Time per request: 1.074 [ms] (mean, across all concurrent requests)
Transfer rate: 411.13 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 14 23 6.7 21 32
Processing: 14 28 13.5 26 76
Waiting: 14 28 13.5 26 76
Total: 29 51 17.4 52 107
Percentage of the requests served within a certain time (ms)
50% 52
66% 61
75% 62
80% 63
90% 73
95% 87
98% 97
99% 107
100% 107 (longest request)