springboot 是 springmvc 的升级,对于编码、配置、部署和监控,更加简单
微服务
微服务是一个新兴的软件架构,就是把一个大型的单个应用程序和服务拆分为数十个的支持微服务。一个微服务的策略可以让工作变得更为简便,它可扩展单个组件而不是整个的应用程序堆栈,从而满足服务等级协议。
spring 为 微服务提供了一整套的组件-springclound , spirngboot 就是该基础。
第一个springboot程序
这里使用的开发软件是intellij idea,和eclipse差不太多,界面更炫酷,功能更强大;android studio就是基于intellij 开发的,我之前使用过android studio,它俩界面几乎一样。
intellij idea官网:http://www.jetbrains.com/idea/
配置好 maven, tomcat, jdk 就可以使用了
maven配置的中央仓库阿里云镜像,这个地址下载 jar 包的速度,谁用谁知道!
setting.xml
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. . <mirrors> <mirror> <id>alimaven</id> <name>aliyun maven</name> <url>http: //maven.aliyun.com/nexus/content/groups/public/</url> <mirrorof>central</mirrorof> </mirror> </mirrors> . . |
使用idea创建springboot项目
我的idea版本:intellij idea 2016.3.1
项目结构为:
项目默认的 maven pom.xml文件
pom.xml
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<?xml version= "1.0" encoding= "utf-8" ?> <project xmlns= "http://maven.apache.org/pom/4.0.0" xmlns:xsi= "http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation= "http://maven.apache.org/pom/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" > <modelversion> 4.0 . 0 </modelversion> <groupid>com.jxust</groupid> <artifactid>spirngbootdemo</artifactid> <version> 0.0 . 1 -snapshot</version> <packaging>jar</packaging> <name>spirngbootdemo</name> <description>demo project for spring boot</description> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version> 1.4 . 2 .release</version> <relativepath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceencoding>utf- 8 </project.build.sourceencoding> <project.reporting.outputencoding>utf- 8 </project.reporting.outputencoding> <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> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> </plugins> </build> </project> |
运行spirngbootdemoapplication的main方法,就能开始运行。
其他启动方式,请看视频教程 http://www.imooc.com/learn/767\
控制台输出:
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"c:\program files\java\jdk1.8.0_91\bin\java" .... . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | ' _| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: spring boot :: (v1. 4.2 .release) 2016 - 12 - 16 14 : 56 : 52.083 info 15872 --- [ main] o.s.j.e.a.annotationmbeanexporter : registering beans for jmx exposure on startup 2016 - 12 - 16 14 : 56 : 52.215 info 15872 --- [ main] s.b.c.e.t.tomcatembeddedservletcontainer : tomcat started on port(s): 8080 (http) 2016 - 12 - 16 14 : 56 : 52.255 info 15872 --- [ main] com.jxust.spirngbootdemoapplication : started spirngbootdemoapplication in 7.795 seconds (jvm running for 9.177 ) |
从这里可以看到 tomcat 的端口号,因为还没有自定义controller,所以还没有视图,下面来创建一个输出hello springboot!的视图。
创建一个hellocontroller,位于controller包下
hellocontroller.java
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package com.jxust.controller; import org.springframework.web.bind.annotation.getmapping; import org.springframework.web.bind.annotation.restcontroller; /** * created by peng * time: 2016/12/16 15:45 */ @restcontroller public class hellocontroller { @requestmapping ( "/hello" ) public string say(){ return "hello springboot!" ; } } |
@restcontroller spring4 之后新加的注解,原来返回json需要@responsebody配合@controller,现在一个顶俩
在浏览器中输入http://localhost:8080/hello就能输出hello springboot!这句话。
自定义属性配置
用到的是application.properties这个文件
配置端口号和访问前缀
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application.properties server.port= 8081 server.context-path=/springboot |
除了使用.properties格式的文件,还可以使用.yml格式的配置文件(推荐),更加简便
application.yml
把原来的application.properties文件删除
注意格式,空格不能少
获取配置文件中的属性值
我们也可以在配置文件中,配置数据,在 controller 中获取,比如:
application.yml
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server: port: 8081 context-path: /springboot name: 小胖 |
hellocontroller 获取配置文件中的值
hellocontroller.java
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.... @restcontroller public class hellocontroller { @value ( "${name}" ) private string name; @requestmapping (value = "/hello" ,method = requestmethod.get) public string say(){ return name; } } |
返回的为name的值
配置文件中值配置方式的多样化
配置文件的值可以是多个,也可以是组合,如:
application.yml
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name: 小胖 age: 22 或者 name: 小胖 age: 22 content: "name: ${name},age: ${age}" 或者 server: port: 8081 context-path: /springboot person: name: 小胖 age: 22 |
前两种配置获取值的方式都是一样的,但是对于这种方式,person 有相应的两个属性,需要这样处理
personproperties.java
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package com.jxust; import org.springframework.boot.context.properties.configurationproperties; import org.springframework.stereotype.component; /** * created by peng * time: 2016/12/16 16:34 */ @component @configurationproperties (prefix = "person" ) public class personproperties { private string name; private integer age; public string getname() { return name; } public void setname(string name) { this .name = name; } public integer getage() { return age; } public void setage(integer age) { this .age = age; } } |
alt+insert快捷键提示生成 getter and setter
pom.xml需要加入下面的依赖,处理警告
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<dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-configuration-processor</artifactid> <optional> true </optional> </dependency> |
hellocontroller.java
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package com.jxust.controller; import com.jxust.personproperties; import org.springframework.beans.factory.annotation.autowired; import org.springframework.web.bind.annotation.requestmapping; import org.springframework.web.bind.annotation.requestmethod; import org.springframework.web.bind.annotation.restcontroller; /** * created by peng * time: 2016/12/15 20:55 */ @restcontroller public class hellocontroller { @autowired private personproperties personproperties; @requestmapping (value = "/hello" ,method = requestmethod.get) public string say(){ return personproperties.getname()+personproperties.getage(); } } |
关于配置文件application.yml的多套配置
类似 il8n 文件国际化的配置方式i18n_en_us.properties和i18n_zh_cn.properties
这样能解决,需要频繁修改配置的尴尬
由application.yml配置文件决定使用那套配置文件。
application.yml
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spring: profiles: active: a |
application-a.yml
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server: port: 8081 context-path: /springboot person: name: 小雷 age: 21 |
application-b.yml
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server: port: 8081 context-path: /springboot person: name: 小胖 age: 22 |
springboot增删改查实例
完整的项目结构
controller的使用
controller的使用
@controller chu处理http请求
@restcontroller spring4 之后新加的注解,原来返回json需要@responsebody配合@controller
@requestmapping 配置url映射
对于 rest 风格的请求
对于 controller 中的方法上的注解
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@requestmapping (value = “/hello”,method = requestmethod.get) @requestmapping (value = “/hello”,method = requestmethod.post) @requestmapping (value = “/hello”,method = requestmethod.delete) @requestmapping (value = “/hello”,method = requestmethod.put) |
springboot 对上面的注解进行了简化
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@getmapping (value = “/girls”) @postmapping (value = “/girls”) @putmapping (value = “/girls/{id}”) @deletemapping (value = “/girls/{id}”) |
浏览器需要发送不同方式的请求,可以安装httprequester插件,火狐浏览器可以直接搜索该组件安装。
spring-data-jpa
jpa全称java persistence api.jpa通过jdk 5.0注解或xml描述对象-关系表的映射关系,并将运行期的实体对象持久化到数据库中。
hibernate3.2+、toplink 10.1.3以及openjpa都提供了jpa的实现。
利用jpa创建mysql数据库
pom.xml加入jpa和mysql的依赖
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<dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-data-jpa</artifactid> </dependency> <dependency> <groupid>mysql</groupid> <artifactid>mysql-connector-java</artifactid> </dependency> |
配置jpa和数据库
application.yml
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spring: profiles: active: a datasource: driver- class -name: com.mysql.jdbc.driver url: jdbc:mysql: //127.0.0.1:3306/db_person username: root password: root jpa: hibernate: ddl-auto: update show-sql: true |
格式很重要
需要自己手动去创建 db_person 数据库
创建与数据表对应的实体类person
person.java
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package com.jxust.entity; import javax.persistence.entity; import javax.persistence.generatedvalue; import javax.persistence.id; /** * created by peng * time: 2016/12/16 17:56 */ @entity public class person { @id @generatedvalue private integer id; private string name; private integer age; //必须要有构造函数 public person() { } public integer getid() { return id; } public void setid(integer id) { this .id = id; } public string getname() { return name; } public void setname(string name) { this .name = name; } public integer getage() { return age; } public void setage(integer age) { this .age = age; } } |
运行项目后,查看数据库,会自动创建表 person
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mysql> use db_person; database changed mysql> desc person; +-------+--------------+------+-----+---------+----------------+ | field | type | null | key | default | extra | +-------+--------------+------+-----+---------+----------------+ | id | int ( 11 ) | no | pri | null | auto_increment | | age | int ( 11 ) | yes | | null | | | name | varchar( 255 ) | yes | | null | | +-------+--------------+------+-----+---------+----------------+ 3 rows in set ( 0.09 sec) |
接下来就可以进行person表的增删改查了
创建控制器personcontroller.java
首先创建一个接口personrepository,位于dao包下,personcontroller调用该接口继承自jparepository的方法,来实现和数据库交互
这个personrepository接口的功能,与ssm框架中 dao 层接口功能有异曲同工之妙;在ssm框架中,service层通过该接口,间接执行mybatis数据库映射文件(.xml)里的相应sql语句,执行数据库增删改查的操作。(mapper自动实现dao接口)
personrepository.java
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package com.jxust.dao; import com.jxust.entity.person; import org.springframework.data.jpa.repository.jparepository; /** * created by peng * time: 2016/12/16 18:07 */ public interface personrepository extends jparepository<person,integer> { } |
personcontroller.java
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package com.jxust.controller; import com.jxust.dao.personrepository; import com.jxust.entity.person; import org.springframework.beans.factory.annotation.autowired; import org.springframework.web.bind.annotation.getmapping; import org.springframework.web.bind.annotation.restcontroller; import java.util.list; /** * created by peng * time: 2016/12/16 18:04 */ @restcontroller public class personcontroller { @autowired personrepository personrepository; @getmapping (value = "/person" ) private list<person> personlist() { return personrepository.findall(); } } |
在数据库中添加两条数据
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mysql> select * from person; +----+------+--------+ | id | age | name | +----+------+--------+ | 1 | 23 | 夏洛 | | 2 | 21 | 马冬梅 | +----+------+--------+ 2 rows in set ( 0.04 sec) |
启动项目执行请求 http://localhost:8081/springboot/person
控制台输出的sql语句:
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hibernate: select person0_.id as id1_0_, person0_.age as age2_0_, person0_.name as name3_0_ from person person0_ |
其他增删改查的方法
personcontroller.java
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.... /** * 添加一个人员 * * @param name * @param age * @return */ @postmapping (value = "/person" ) public person personadd( @requestparam ( "name" ) string name, @requestparam ( "age" ) integer age) { person person = new person(); person.setname(name); person.setage(age); return personrepository.save(person); } /** * 查询一个人员 * * @param id * @return */ @getmapping (value = "/person/{id}" ) public person personfindone( @pathvariable ( "id" ) integer id) { return personrepository.findone(id); } /** * 删除一个人员 * * @param id */ @deletemapping (value = "/person/{id}" ) public void persondelete( @pathvariable ( "id" ) integer id) { personrepository.delete(id); } /** * 更新一个人员 * * @param id * @param name * @param age * @return */ @putmapping (value = "/person/{id}" ) public person personupdate( @pathvariable ( "id" ) integer id, @requestparam ( "name" ) string name, @requestparam ( "age" ) integer age) { person person = new person(); person.setid(id); person.setname(name); person.setage(age); return personrepository.save(person); } |
对应的请求方式为:
查询一个用户:
添加一个用户
删除一个用户(无返回值)
更新一个用户
那么根据年龄查询,可不可以呢。答案是此刻还不行
从控制台的语句可以看出,sql 语句都是根据id来查询的
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hibernate: select person0_.id as id1_0_0_, person0_.age as age2_0_0_, person0_.name as name3_0_0_ from person person0_ where person0_.id=? |
根据年龄查询
在personrepository增加一个方法findbyage(integer age)
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public interface personrepository extends jparepository<person,integer> { /** * 通过年龄来查询 * 方法名固定findbyage * @param age * @return */ public list<person> findbyage(integer age); } |
在personcontroller中加入相应的查询方法
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.... /** * 通过年龄来查询 * @param age * @return */ @getmapping (value = "/person/age/{age}" ) public list<person> personlistbyage( @pathvariable ( "age" ) integer age) { return personrepository.findbyage(age); } |
输入请求http://localhost:8081/springboot/person/age/23,查询年龄为23的人员
控制台输出sql语句:
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hibernate: select person0_.id as id1_0_, person0_.age as age2_0_, person0_.name as name3_0_ from person person0_ where person0_.age=? |
事务管理
两条 sql 语句同时在一个方法中执行,为了防止一个 sql 语句执行成功而另一个 sql 语句执行失败,引入了事务管理,需要在方法上加 @transactional事务注解
事务确保了数据库数据的完整性和一致性
personservice.java
在personcontroll
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package com.jxust.service; import com.jxust.dao.personrepository; import com.jxust.entity.person; import org.springframework.beans.factory.annotation.autowired; import org.springframework.stereotype.service; import javax.transaction.transactional; /** * created by peng * time: 2016/12/16 19:30 */ @service public class personservice { @autowired private personrepository personrepository; /** * 事务管理测试 * 两条数据同时成功,或者同时不成功 * 保证数据库数据的完整性和一致性 */ @transactional public void inserttwo(){ person persona = new person(); persona.setname( "秋雅" ); persona.setage( 19 ); personrepository.save(persona); system.out.print( 1 / 0 ); person personb = new person(); personb.setname( "梦特娇" ); personb.setage( 25 ); personrepository.save(personb); } } |
er中测试
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... @autowired private personservice personservice; ... /** * 事务测试 */ @postmapping ( "/person/two" ) public void persontwo(){ personservice.inserttwo(); } |
重新运行项目,执行请求 post方式http://localhost:8081/springboot/person/two
数据库并没有添加第一条数据,说明存在事务管理
完整的personcontroller.java、personrepository.java和pom.xml
personcontroller.java
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package com.jxust.controller; import com.jxust.dao.personrepository; import com.jxust.entity.person; import com.jxust.service.personservice; import org.springframework.beans.factory.annotation.autowired; import org.springframework.web.bind.annotation.*; import java.util.list; /** * created by peng * time: 2016/12/16 18:04 */ @restcontroller public class personcontroller { @autowired personrepository personrepository; @autowired private personservice personservice; /** * 查询所有人员列表 * * @return */ @getmapping (value = "/person" ) private list<person> personlist() { return personrepository.findall(); } /** * 添加一个人员 * * @param name * @param age * @return */ @postmapping (value = "/person" ) public person personadd( @requestparam ( "name" ) string name, @requestparam ( "age" ) integer age) { person person = new person(); person.setname(name); person.setage(age); return personrepository.save(person); } /** * 查询一个人员 * * @param id * @return */ @getmapping (value = "/person/{id}" ) public person personfindone( @pathvariable ( "id" ) integer id) { return personrepository.findone(id); } /** * 删除一个人员 * * @param id */ @deletemapping (value = "/person/{id}" ) public void persondelete( @pathvariable ( "id" ) integer id) { personrepository.delete(id); } /** * 更新一个人员 * * @param id * @param name * @param age * @return */ @putmapping (value = "/person/{id}" ) public person personupdate( @pathvariable ( "id" ) integer id, @requestparam ( "name" ) string name, @requestparam ( "age" ) integer age) { person person = new person(); person.setid(id); person.setname(name); person.setage(age); return personrepository.save(person); } /** * 通过年龄来查询 * @param age * @return */ @getmapping (value = "/person/age/{age}" ) public list<person> personlistbyage( @pathvariable ( "age" ) integer age) { return personrepository.findbyage(age); } /** * 事务测试 */ @postmapping ( "/person/two" ) public void persontwo(){ personservice.inserttwo(); } } |
personrepository.java
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package com.jxust.dao; import com.jxust.entity.person; import org.springframework.data.jpa.repository.jparepository; import java.util.list; /** * created by peng * time: 2016/12/16 18:07 */ public interface personrepository extends jparepository<person,integer> { /** * 通过年龄来查询 * 方法名固定 * @param age * @return */ public list<person> findbyage(integer age); } |
pom.xml
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<?xml version= "1.0" encoding= "utf-8" ?> <project xmlns= "http://maven.apache.org/pom/4.0.0" xmlns:xsi= "http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation= "http://maven.apache.org/pom/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" > <modelversion> 4.0 . 0 </modelversion> <groupid>com.jxust</groupid> <artifactid>spirngbootdemo</artifactid> <version> 0.0 . 1 -snapshot</version> <packaging>jar</packaging> <name>spirngbootdemo</name> <description>demo project for spring boot</description> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version> 1.4 . 2 .release</version> <relativepath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceencoding>utf- 8 </project.build.sourceencoding> <project.reporting.outputencoding>utf- 8 </project.reporting.outputencoding> <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> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-configuration-processor</artifactid> <optional> true </optional> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-data-jpa</artifactid> </dependency> <dependency> <groupid>mysql</groupid> <artifactid>mysql-connector-java</artifactid> </dependency> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> </plugins> </build> </project> |
总结
以上所述是小编给大家介绍的intellij idea springboot 数据库增删改查实例详解,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持!
原文链接:https://blog.phpsoho.com/2018/02/07/intellij-idea-springboot-数据库增删改查实例/