一、Spring Boot 入门
1、Spring Boot 简介
- 简化Spring应用开发的一个框架;
- 整个Spring技术栈的一个大整合;
- J2EE开发的一站式解决方案;
2、微服务
2014,martin fowler提出
-
微服务:架构风格(服务微化)
-
一个应用应该是一组小型服务;可以通过HTTP的方式进行互通;
单体应用:ALL IN ONE
微服务:每一个功能元素最终都是一个可独立替换和独立升级的软件单元;
详细参照微服务文档:https://martinfowler.com/articles/microservices.html#MicroservicesAndSoa
3、Spring Boot HelloWorld
环境准备:
- 这里以 SpringBoot 1.5.9.RELEASE版本为例。
MAVEN设置:
- 给maven 的settings.xml配置文件的profiles标签添加
<profile>
<id>jdk‐1.8</id>
<activation>
<activeByDefault>true</activeByDefault>
<jdk>1.8</jdk>
</activation>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
</properties>
</profile>
基本功能:
- 浏览器发送hello请求,服务器接受请求并处理,响应Hello World字符串;
1、创建一个maven工程
2、导入spring boot相关的依赖
<?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>top.onefine</groupId>
<artifactId>springboot_maven</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<!-- 父项目:真正管理springboot应用里的所有依赖版本
也称为springboot的版本仲裁中心,即以后导入依赖默认不需要指明版本号
但若没有在dependencies里面管理的依赖自然需要声明版本号
-->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
</parent>
<dependencies>
<!-- 启动器
spring-boot-starter:spring-boot场景启动器,帮我们导入了web模块正常运行所依赖的组件;
Spring Boot将所有的功能场景都抽取出来,做成一个个的starters(启动器)
只需要在项目里面引入这些starter 相关场景的所有依赖都会导入进来。要用什么功能就导入什么场景的启动器
-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<!-- 引入此插件可以将应用打包成一个可执行的jar包 -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3、编写一个主程序:启动Spring Boot应用
package top.onefine;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication // 标注一个主程序,用来说明这是一个springboot应用
public class HelloWorldMainApplication {
//
public static void main(String[] args) {
// 启动springboot应用程序
SpringApplication.run(HelloWorldMainApplication.class, args);
}
}
4、编写相关的Controller或Service
package top.onefine.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class HelloController {
@ResponseBody
@RequestMapping("/hello")
public String hello() {
return "Hello SpringBoot";
}
}
或者:
package top.onefine.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
//@ResponseBody // 作用在类上表示这个类的所有方法返回的数据直接写给浏览器,和作用在单独的方法上效果一致
//@Controller
@RestController // = @ResponseBody + @Controller
public class HelloController {
// @ResponseBody // 作用在方法上表示这个方法返回的数据直接写给浏览器(如果是对象还能转为json数据)
@RequestMapping("/hello")
public String hello() {
return "hello world quick!";
}
}
5、运行主程序测试
执行main方法,浏览器中输入127.0.0.1:8080/hello
:
6、简化部署
<!-- 引入此插件可以将应用打包成一个可执行的jar包; -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
将这个应用打成jar包:Maven -> 项目名称 -> Lifecycle -> package
找到jar包导出位置:项目名称/target/项目名-版本号.jar
直接使用java -jar
的命令进行执行:
# 查看指定端口被占用情况
D:\projects\java\study_springboot\springboot_maven\target>netstat -ano|findstr "8080"
TCP 0.0.0.0:8080 0.0.0.0:0 LISTENING 9392
TCP [::]:8080 [::]:0 LISTENING 9392
# 关闭进程号对应的进程
D:\projects\java\study_springboot\springboot_maven\target>taskkill -PID 9392 -F
成功: 已终止 PID 为 9392 的进程。
D:\projects\java\study_springboot\springboot_maven\target>java -jar springboot_maven-1.0-SNAPSHOT.jar
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.9.RELEASE)
2020-05-23 11:01:58.183 INFO 10016 --- [ main] top.onefine.HelloWorldMainApplication : Starting HelloWorldMainApplication v1.0-SNAPSHOT on DESKTOP-LNTOAM6 with PID 10016 (D:\projects\java\study_springboot\springboot_maven\target\springboot_maven-1.0-SNAPSHOT.jar started by Lenovo in D:\projects\java\study_springboot\springboot_maven\target)
2020-05-23 11:01:58.187 INFO 10016 --- [ main] top.onefine.HelloWorldMainApplication : No active profile set, falling back to default profiles: default
2020-05-23 11:01:58.258 INFO 10016 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1698c449: startup date [Sat May 23 11:01:58 CST 2020]; root of context hierarchy
2020-05-23 11:01:59.736 INFO 10016 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2020-05-23 11:01:59.754 INFO 10016 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-05-23 11:01:59.757 INFO 10016 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.23
2020-05-23 11:01:59.870 INFO 10016 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2020-05-23 11:01:59.870 INFO 10016 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1615 ms
2020-05-23 11:01:59.983 INFO 10016 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2020-05-23 11:01:59.987 INFO 10016 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2020-05-23 11:01:59.987 INFO 10016 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2020-05-23 11:01:59.987 INFO 10016 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2020-05-23 11:01:59.987 INFO 10016 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2020-05-23 11:02:00.294 INFO 10016 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1698c449: startup date [Sat May 23 11:01:58 CST 2020]; root of context hierarchy
2020-05-23 11:02:00.415 INFO 10016 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello]}" onto public java.lang.String top.onefine.controller.HelloController.hello()
2020-05-23 11:02:00.421 INFO 10016 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2020-05-23 11:02:00.422 INFO 10016 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2020-05-23 11:02:00.468 INFO 10016 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-05-23 11:02:00.469 INFO 10016 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-05-23 11:02:00.527 INFO 10016 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-05-23 11:02:00.651 INFO 10016 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2020-05-23 11:02:00.732 INFO 10016 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2020-05-23 11:02:00.740 INFO 10016 --- [ main] top.onefine.HelloWorldMainApplication : Started HelloWorldMainApplication in 2.904 seconds (JVM running for 3.238)
4、主程序类、主入口类探究
@SpringBootApplication // 标注一个主程序,用来说明这是一个springboot应用
public class HelloWorldMainApplication {
//
public static void main(String[] args) {
// 启动springboot应用程序
SpringApplication.run(HelloWorldMainApplication.class, args);
}
}
@SpringBootApplication
:Spring Boot应用标注在某个类上说明这个类是SpringBoot的主配置类,SpringBoot就应该运行这个类的main方法来启动SpringBoot应用;这个注解源码如下:
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = {
@Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
@Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {
// ...
}
解释:
@SpringBootConfiguration
:Spring Boot的配置类;标注在某个类上,表示这是一个Spring Boot的配置类;
@Configuration
:配置类上来标注这个注解;
- 配置类(和配置文件一样的作用);
- 配置类也是容器中的一个组件:
@Component
@EnableAutoConfiguration
:开启自动配置功能;
以前我们需要配置的东西,现在Spring Boot帮我们自动配置;@EnableAutoConfiguration
告诉SpringBoot开启自
动配置功能,这样自动配置才能生效;@EnableAutoConfiguration源码如下:
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@AutoConfigurationPackage
@Import(EnableAutoConfigurationImportSelector.class)
public @interface EnableAutoConfiguration {
// ...
}
解释:
@AutoConfigurationPackage
:自动配置包
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@Import(AutoConfigurationPackages.Registrar.class)
public @interface AutoConfigurationPackage {
}
@Import(AutoConfigurationPackages.Registrar.class)
:
- Spring的底层注解
@Import
,给容器中导入一个组件; - 导入的组件由
AutoConfigurationPackages.Registrar.class
将主配置类(@SpringBootApplication
标注的类)的所在包及下面所有子包里面的所有组件扫描到Spring容器;
@Import(EnableAutoConfigurationImportSelector.class)
:给容器中导入组件EnableAutoConfigurationImportSelector
- EnableAutoConfigurationImportSelector:导入哪些组件的选择器;
- 将所有需要导入的组件以全类名的方式返回,这些组件就会被添加到容器中;
- 会给容器中导入非常多的自动配置类(
xxxAutoConfiguration
):作用就是给容器中导入这个场景需要的所有组件,并配置好这些组件;
- 有了自动配置类,免去了我们手动编写配置注入功能组件等的工作;
SpringFactoriesLoader.loadFactoryNames(EnableAutoConfiguration.class,classLoader)
:Spring Boot在启动的时候从类路径下的META-INF/spring.factories
中获取EnableAutoConfiguration
指定的值,将这些值作为自动配置类导入到容器中,自动配置类就生效,帮我们进行自动配置工作;以前我们需要自己配置的东西,自动配置类都帮我们;J2EE的整体整合解决方案和自动配置都在spring-boot-autoconfigure-1.5.9.RELEASE.jar
中做好了。
5、resources文件夹中目录结构
- static:保存所有的静态资源; js、css、images;
- templates:保存所有的模板页面;Spring Boot默认jar包使用嵌入式的Tomcat,默认不支持JSP页面;可以使用模板引擎(freemarker、thymeleaf);
- application.properties:Spring Boot应用的配置文件;可以修改一些默认设置;
二、配置文件
SpringBoot使用一个全局的配置文件,配置文件名是固定的;
- application.properties
- application.yml
配置文件的作用:由于SpringBoot在底层都给我们自动配置好大多数配置,配置文件用于修改SpringBoot自动配置的这些默认值;
YAML(YAML Ain’t Markup Language)
- YAML A Markup Language:是一个标记语言
- YAML isn’t Markup Language:不是一个标记语言;
标记语言
- 以前的配置文件;大多都使用的是 xxxx.xml文件;
- YAML:以数据为中心,比json、xml等更适合做配置文件;
YAML:配置例子
server:
port: 8081
对应XML形式:
<server>
<port>8081</port>
</server>
对应properties形式:
server.port=8081
1、YAML语法:
1.1、基本语法
k:(空格)v
:表示一对键值对(空格必须有);
- 以空格的缩进来控制层级关系;只要是左对齐的一列数据,都是同一个层级的
server:
port: 8081
path: /hello
- 属性和值也是大小写敏感;
1.2、值的写法
字面量:普通的值(数字,字符串,布尔)
k: v
:字面直接来写;- 字符串默认不用加上单引号或者双引号;
""
:双引号;不会转义字符串里面的特殊字符;特殊字符会作为本身想表示的意思
name: "zhangsan \n lisi"
:输出;zhangsan 换行 lisi''
:单引号;会转义特殊字符,特殊字符最终只是一个普通的字符串数据
name: ‘zhangsan \n lisi’
:输出;zhangsan \n lisi
对象、Map(属性和值)(键值对):
-
k: v
:在下一行来写对象的属性和值的关系;注意缩进! -
对象还是k: v的方式
friends:
lastName: zhangsan
age: 20
- 行内写法:
friends: {lastName: zhangsan,age: 18}
数组(List、Set):
- 用
- 值
表示数组中的一个元素
pets:
‐ cat
‐ dog
‐ pig
- 行内写法
pets: [cat,dog,pig]
2、配置文件值注入
配置文件src\main\resources\application.yml
:
server:
port: 8090
person:
lastName: one fine中文
age: 18
boss: false
birth: 1996/3/1
map: {k1: v1, k2: 12}
list:
- li si
- wang wu
dog:
name: 小狗
age: 2
javaBean:
package top.onefine.bean;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.List;
import java.util.Map;
/**
* 将配置文件中配置的每一个属性的值映射到这个组件中
*
* @ ConfigurationProperties
* 告诉springboot将本类中的所有属性和配置文件中相关的配置进行绑定
* prefix = "person"
* 配置文件中哪个下面的所有属性进行一一映射
*
* 注意:只有当这个组件是容器中的组件,才能使用容器提供的@ ConfigurationProperties功能
* @ Component 将组件加入到容器中
*/
@Getter
@Setter
@ToString
@Component
@ConfigurationProperties(prefix = "person")
public class Person {
private String lastName;
private Integer age;
private Boolean boss;
private Date birth;
private Map<String, Object> map;
private List<Object> list;
private Dog dog;
}
package top.onefine.bean;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
@Getter
@Setter
@ToString
public class Dog {
private String name;
private String age;
}
我们可以导入配置文件处理器,以后编写配置就有提示了:
<!‐‐导入配置文件处理器,配置文件进行绑定就会有提示‐‐>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring‐boot‐configuration‐processor</artifactId>
<optional>true</optional>
</dependency>
测试类:
package top.onefine;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import top.onefine.bean.Person;
/**
* springboot单元测试
*
*/
@SpringBootTest
class SpringbootQuickApplicationTests {
@Autowired
private Person person;
@Test
void contextLoads() {
System.out.println(person);
}
}
结果:
Person(lastName=one fine中文, age=18, boss=false, birth=Fri Mar 01 00:00:00 CST 1996, map={k1=v1, k2=12}, list=[li si, wang wu], dog=Dog(name=小狗, age=2))
附:完整pom.xml(这里使用springboot 2.3.0.RELEASE):
<?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 https://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>2.3.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>top.onefine</groupId>
<artifactId>springboot_quick</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot_quick</name>
<description>Demo project for Spring Boot</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.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<!-- springboot进行单元测试的模块 -->
<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>
<!-- 配置文件处理器,导入后配置文件进行绑定时就会有提示 -->
<!--
https://docs.spring.io/spring-boot/docs/2.3.0.RELEASE/reference/html/appendix-configuration-metadata.html#configuration-metadata-annotation-processor
-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3、properties形式
server.port=8091
person.last-name=one中文
#[email protected]
person.age=18
person.birth=1996/3/1
person.boss=false
person.map.k1=v1
person.map.k2=v2
person.list=a,b,c
person.dog.name=dog
person.dog.age=15
properties配置文件在idea中默认utf-8可能会乱码,更改idea设置:
4、@Value
获取值
package top.onefine.bean;
import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Data
@Component
//@ConfigurationProperties(prefix = "person")
public class Person {
/**
* <bean class="Person">
* <property name="lastName" value="字面量/${key}从环境变量、配置文件中获取值/{SpEL}"></property>
* <bean/>
*/
@Value(value = "${person.last-name}") // ${key}从环境变量、配置文件中获取值
private String lastName;
@Value("#{9 * 2}") // spring表达式语言:{SpEL}
private Integer age;
@Value("true") // 字面量
private Boolean boss;
private Date birth;
private Map<String, Object> map;
private List<Object> list;
private Dog dog;
}
运行测试:
@Value
获取值和@ConfigurationProperties
获取值比较:
@ConfigurationProperties |
@Value |
|
---|---|---|
功能 | 批量注入配置文件中的属性 | 一个个指定 |
松散绑定(松散语法) | 支持 | 不支持 |
SpEL | 不支持 | 支持 |
JSR303数据校验 | 支持 | 不支持 |
复杂类型封装 | 支持 | 不支持 |
松散绑定
JSR303数据校验
maven中导入座标:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.3.6.Final</version>
</dependency>
package top.onefine.bean;
import lombok.Data;
import org.hibernate.validator.constraints.Email;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Data
@Component
@Validated // 数据校验
@ConfigurationProperties(prefix = "person")
public class Person {
// @Value(value = "${person.last-name}") // ${key}从环境变量、配置文件中获取值
@Email // 数据校验:lastName必须是邮箱格式
private String lastName;
// @Value("#{9 * 2}") // spring表达式语言:{SpEL}
private Integer age;
// @Value("true") // 字面量
private Boolean boss;
private Date birth;
private Map<String, Object> map;
private List<Object> list;
private Dog dog;
}
执行:
关于复杂类型封装
package top.onefine.bean;
import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Data
@Component
//@ConfigurationProperties(prefix = "person")
public class Person {
@Value(value = "${person.last-name}") // ${key}从环境变量、配置文件中获取值
private String lastName;
@Value("#{9 * 2}") // spring表达式语言:{SpEL}
private Integer age;
@Value("true") // 字面量
private Boolean boss;
private Date birth;
@Value("${person.dog.name}")
private Map<String, Object> map;
private List<Object> list;
private Dog dog;
}
总结:
- 配置文件yml还是properties他们都能获取到值;
- 若只是在某个业务逻辑中需要获取一下配置文件中的某项值,使用
@Value
; - 若专门编写了一个javaBean来和配置文件进行映射,我们就直接使用
@ConfigurationProperties
;
某个业务逻辑举例:
package top.onefine.controller;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HiDemo {
@Value("${person.last-name}")
private String name;
@RequestMapping("/sayHi")
public String sayHello() {
return "hello " + name;
}
}
@PropertySource
&@ImportResource
&@Bean
@ConfigurationProperties(prefix = "person")
默认从全局配置文件中获取值。
@PropertySource
:加载指定的配置文件;
配置文件person.properties:
person.last-name=fine配置
person.age=18
person.birth=1996/3/1
person.boss=false
person.map.k1=v1
person.map.k2=v2
person.list=a,b,c
person.dog.name=小狗
person.dog.age=15
package top.onefine.bean;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Data
@Component
@ConfigurationProperties(prefix = "person") // 默认从全局配置文件中获取值
@PropertySource(value = {"classpath:person.properties"}) // 修改加载指定配置文件位置,不从全局配置文件中加载值
public class Person {
private String lastName;
private Integer age;
private Boolean boss;
private Date birth;
private Map<String, Object> map;
private List<Object> list;
private Dog dog;
}
注:加载顺序为application.properties->application.yml->person.properties
@ImportResource
:导入Spring的配置文件,让配置文件里面的内容生效;
- Spring Boot里面没有Spring的配置文件,我们自己编写的配置文件,也不能自动识别;想使用Spring的配置文件加载进来生效:使用
@ImportResource
标注在一个配置类上:
src\main\java\top\onefine\service\HelloService.java:
package top.onefine.service;
public class HelloService {
}
spring的配置文件beans.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="helloService" class="top.onefine.service.HelloService" />
</beans>
@package top.onefine;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;
@ImportResource(locations = {"classpath:beans.xml"}) // 导入Spring的配置文件让其生效
@SpringBootApplication
public class SpringbootQuickApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootQuickApplication.class, args);
}
}
测试类:
package top.onefine;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
/**
* springboot单元测试
*
*/
@SpringBootTest
class SpringbootQuickApplicationTests {
@Autowired
ApplicationContext ioc; // IOC容器
@Test
void contextLoads() {
boolean b = ioc.containsBean("helloService");
System.out.println(b ? "存在" : "不存在");
}
}
SpringBoot推荐给容器中添加组件的方式:使用全注解的方式,不要编写这里的配置文件beans.xml和启动器上的@ImportResource
注解
1、配置类@Configuration
—替代—>Spring配置文件 bean.xml
2、使用@Bean给容器中添加组件
package top.onefine.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import top.onefine.service.HelloService;
@Configuration // 标明这是一个配置类,替代spring的配置文件如刚才的beans.xml
public class MyAppConfig {
// 刚才的配置文件使用<bean></bean>标签来添加组件
//
// 将方法的返回值添加到容器中,容器中组件默认的id就是方法名
@Bean
public HelloService helloService() {
return new HelloService();
}
}
5、配置文件占位符
占位符获取之前配置的值,如果没有可以是用:
指定默认值
${random.value}
${random.int}
${random.long}
${random.int(10)}
${random.int[1024,65536]}
// ...
举例:
server.port=8091
# 随机数
person.last-name=one中文${random.uuid}
#person.last-name=onefine@qq.com
person.age=${random.int}
person.birth=1996/3/1
person.boss=false
# 获取不存在的值
person.map.k1=${one}
# 不存在则设置默认值v2
person.map.k2=${one:v2}
person.list=a,b,c
# 引用值
person.dog.name=${person.last-name}的小狗
person.dog.age=15
执行测试文件:
package top.onefine;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import top.onefine.bean.Person;
@SpringBootTest
class SpringbootQuickApplicationTests {
@Autowired
private Person person;
@Test
void contextLoads() {
System.out.println(person);
}
}
结果:
6、Profile
Profile是Spring对不同环境提供不同配置功能的支持,可以通过激活、指定参数等方式快速切换环境。
6.1、多Profile文件
在编写主配置文件的时候,文件名可以是 application-{profile}.properties/yml
application-dev.properties
application-prod.properties
默认使用application.properties的配置
6.2、激活指定profile方式
1、在配置文件(src\main\resources\application.properties
)中指定
server.port=8081
# 激活开发环境
#spring.profiles.active=dev
# 激活生产环境
spring.profiles.active=prod
2、命令行:
java -jar springboot_quick-0.0.1-SNAPSHOT.jar --spring.profiles.active=dev
可以直接在测试的时候,配置传入命令行参数
3、虚拟机参数:
# jvm参数
-Dspring.profiles.active=dev
6.3、yml支持多文档块方式
使用---
分隔文档块
# 文档块1
server:
port: 8081
servlet:
context-path: /boot
## 配置项目的访问路径
## 激活开发环境
#spring:
# profiles:
# active: dev
## 激活生产环境
spring:
profiles:
active: prod
---
# 文档块2
server:
port: 8082
## 指定环境:开发环境
spring:
profiles: dev
---
# 文档块3
server:
port: 8083
## 指定环境:生产环境
spring:
profiles: prod
7、配置文件加载位置
springboot 启动会扫描以下位置的application.properties或者application.yml文件作为Spring boot的默认配置文件:
file:./config/
:file表示当前项目文件路径,在项目名/
file:./
classpath:/config/
:classpath表示当前项目类路径,在项目名/src/main/resources/
classpath:/
以上是优先级由高到低的顺序排列,所有位置的文件都会被加载,高优先级的配置会覆盖低优先级的配置;
SpringBoot会从这四个位置全部加载主配置文件,互补配置;
我们还可以通过spring.config.location
来改变默认的配置文件位置:项目打包好以后,我们可以使用命令行参数的形式,启动项目的时候来指定配置文件的新位置;指定配置文件和默认加载的这些配置文件共同起作用形成互补配置;
java -jar springboot_quick-0.0.1-SNAPSHOT.jar --spring.config.location=G:/application.properties
8、外部配置加载顺序
SpringBoot也可以从以下位置加载配置,优先级从高到低,且高优先级的配置覆盖低优先级的配置,所有的配置会形成互补配置:
- 1.命令行参数
- 所有的配置都可以在命令行上进行指定
java -jar springboot_quick-0.0.1-SNAPSHOT.jar --server.port=8087 --server.context-path=/abc
- 多个配置用空格分开,格式为:
--配置项=值
- 2.来自
java:comp/env
的JNDI属性 - 3.Java系统属性(System.getProperties())
- 4.操作系统环境变量
- 5.RandomValuePropertySource配置的random.*属性值
由jar包外向jar包内进行寻找,优先加载带profile:
- 6.jar包外部的application-{profile}.properties或application.yml(带spring.profile)配置文件
- 7.jar包内部的application-{profile}.properties或application.yml(带spring.profile)配置文件
注:
jar包外部是指和jar同一级目录
jar包内部是指项目打包前项目内的配置文件
再来加载不带profile:
- 8.jar包外部的application.properties或application.yml(不带spring.profile)配置文件
- 9.jar包内部的application.properties或application.yml(不带spring.profile)配置文件
- 10.@Configuration注解类上的@PropertySource
- 11.通过SpringApplication.setDefaultProperties指定的默认属性
以上仅列出常用的配置加载来源,所有支持的配置加载来源,详参考官方文档!
9、自动配置原理
配置文件到底能写什么?怎么写?自动配置原理;
配置文件能配置的属性参照:官方文档
9.1、自动配置原理:
1)、SpringBoot启动的时候加载主配置类,开启了自动配置功能 @EnableAutoConfiguration
2)、@EnableAutoConfiguration
作用:
- 利用
EnableAutoConfigurationImportSelector
给spring容器中导入一些组件 - 可以查看
selectImports()
方法的内容:List configurations = getCandidateConfigurations(annotationMetadata, attributes);
获取候选的配置。
SpringFactoriesLoader.loadFactoryNames()
// 扫描所有jar包类路径下 META‐INF/spring.factories 文件
// 把扫描到的这些文件的内容包装成properties对象
// 从properties中获取到EnableAutoConfiguration.class类(类名)对应的值,然后把他们添加在容器中
// 将类路径下 `META-INF/spring.factories` 里面配置的所有`EnableAutoConfiguration`的值加入到了容器中:
# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\
org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\
org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\
org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\
org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\
org.springframework.boot.autoconfigure.cloud.CloudAutoConfiguration,\
org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\
org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\
org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\
org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.ldap.LdapDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\
org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration,\
org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\
org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\
org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\
org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\
org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\
org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\
org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\
org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\
org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\
org.springframework.boot.autoconfigure.mobile.DeviceResolverAutoConfiguration,\
org.springframework.boot.autoconfigure.mobile.DeviceDelegatingViewResolverAutoConfiguration,\
org.springframework.boot.autoconfigure.mobile.SitePreferenceAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\
org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\
org.springframework.boot.autoconfigure.reactor.ReactorAutoConfiguration,\
org.springframework.boot.autoconfigure.security.SecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.SecurityFilterAutoConfiguration,\
org.springframework.boot.autoconfigure.security.FallbackWebSecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.OAuth2AutoConfiguration,\
org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\
org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\
org.springframework.boot.autoconfigure.social.SocialWebAutoConfiguration,\
org.springframework.boot.autoconfigure.social.FacebookAutoConfiguration,\
org.springframework.boot.autoconfigure.social.LinkedInAutoConfiguration,\
org.springframework.boot.autoconfigure.social.TwitterAutoConfiguration,\
org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\
org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\
org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\
org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration,\
org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration,\
org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.web.HttpEncodingAutoConfiguration,\
org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration,\
org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration,\
org.springframework.boot.autoconfigure.web.ServerPropertiesAutoConfiguration,\
org.springframework.boot.autoconfigure.web.WebClientAutoConfiguration,\
org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.WebSocketAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.WebSocketMessagingAutoConfiguration,\
org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration
// 每一个这样的 xxxAutoConfiguration类都是容器中的一个组件,都加入到容器中;用他们来做自动配置;
3)、每一个自动配置类进行自动配置功能;
4)、以HttpEncodingAutoConfiguration
(Http编码自动配置)为例解释自动配置原理:
@Configuration //表示这是一个配置类,和以前编写的配置文件一样,也可以给容器中添加组件
//启动指定类的ConfigurationProperties功能;将配置文件中对应的值和HttpEncodingProperties绑定起来;并把HttpEncodingProperties加入到ioc容器中
@EnableConfigurationProperties(HttpEncodingProperties.class)
//Spring底层@Conditional注解,根据不同的条件,如果满足指定的条件,整个配置类里面的配置就会生效; 判断当前应用是否是web应用,如果是,当前配置类生效
@ConditionalOnWebApplication
//判断当前项目有没有CharacterEncodingFilter这个类,这是SpringMVC中进行乱码解决的过滤器;
@ConditionalOnClass(CharacterEncodingFilter.class)
//判断配置文件中是否存在某个配置 spring.http.encoding.enabled;matchIfMissing 表示如果不存在,判断也是成立的,即默认配置。
@ConditionalOnProperty(prefix = "spring.http.encoding", value = "enabled", matchIfMissing = true)
//即使我们配置文件中不配置pring.http.encoding.enabled=true,也是默认生效的;
public class HttpEncodingAutoConfiguration {
//他已经和SpringBoot的配置文件映射了
private final HttpEncodingProperties properties;
//只有一个有参构造器的情况下,参数的值就会从容器中拿
public HttpEncodingAutoConfiguration(HttpEncodingProperties properties) {
this.properties = properties;
}
@Bean //给容器中添加一个组件,这个组件的某些值需要从properties中获取
@ConditionalOnMissingBean(CharacterEncodingFilter.class) //判断容器没有这个组件?
public CharacterEncodingFilter characterEncodingFilter() {
CharacterEncodingFilter filter = new OrderedCharacterEncodingFilter();
filter.setEncoding(this.properties.getCharset().name());
filter.setForceRequestEncoding(this.properties.shouldForce(Type.REQUEST));
filter.setForceResponseEncoding(this.properties.shouldForce(Type.RESPONSE));
return filter;
}
}
根据当前不同的条件判断,决定这个配置类是否生效。一但这个配置类生效,这个配置类就会给容器中添加各种组件;这些组件的属性是从对应的properties类中获取的,这些类里面的每一个属性又是和配置文件绑定的;
5)、所有在配置文件中能配置的属性都是在xxxxProperties
类中封装者‘,配置文件能配置什么就可以参照某个功能对应的这个属性类:
@ConfigurationProperties(prefix = "spring.http.encoding") //从配置文件中获取指定的值和bean的属性进行绑定
public class HttpEncodingProperties {
public static final Charset DEFAULT_CHARSET = Charset.forName("UTF‐8");
}
springboot精髓
1)、SpringBoot启动会加载大量的自动配置类
2)、我们看我们需要的功能有没有SpringBoot默认写好的自动配置类;
3)、我们再来看这个自动配置类中到底配置了哪些组件;(只要要用的组件有,就不需要再来配置了)
4)、给容器中自动配置类添加组件的时候,会从properties类中获取某些属性。我们就可以在配置文件中指定这些属性的值;
总结:
-
xxxxAutoConfigurartion:自动配置类,会给容器中添加组件;
-
xxxxProperties:封装配置文件中相关属性;
9.2、细节
1、@Conditional
派生注解
作用:必须是@Conditional
指定的条件成立,才给容器中添加组件,配置配里面的所有内容才生效;
自动配置类必须在一定的条件下才能生效:
@Conditional 扩展注解 |
作用(判断是否满足当前指定条件) |
---|---|
@ConditionalOnJava |
系统的java版本是否符合要求 |
@ConditionalOnBean |
容器中存在指定Bean; |
@ConditionalOnMissingBean |
容器中不存在指定Bean; |
@ConditionalOnExpression |
满足SpEL表达式指定 |
@ConditionalOnClass |
系统中有指定的类 |
@ConditionalOnMissingClass |
系统中没有指定的类 |
@ConditionalOnSingleCandidate |
容器中只有一个指定的Bean,或者这个Bean是首选Bean |
@ConditionalOnProperty |
系统中指定的属性是否有指定的值 |
@ConditionalOnResource |
类路径下是否存在指定资源文件 |
@ConditionalOnWebApplication |
当前是web环境 |
@ConditionalOnNotWebApplication |
当前不是web环境 |
@ConditionalOnJndi JNDI |
存在指定项 |
我们怎么知道哪些自动配置类生效?可以通过在配置文件中启用 debug=true
属性;来让控制台打印自动配置报告,这样我们就可以很方便的知道哪些自动配置类生效:
# 开启springboot的debug模式,这里是在application.yml中配置的
debug: true
项目运行时控制台打印结果
============================
CONDITIONS EVALUATION REPORT
============================
Positive matches:(自动配置类启用的)
-----------------
AopAutoConfiguration matched:
- @ConditionalOnProperty (spring.aop.auto=true) matched (OnPropertyCondition)
AopAutoConfiguration.ClassProxyingConfiguration matched:
- @ConditionalOnMissingClass did not find unwanted class 'org.aspectj.weaver.Advice' (OnClassCondition)
- @ConditionalOnProperty (spring.aop.proxy-target-class=true) matched (OnPropertyCondition)
# ...省略
Negative matches:(没有启动,没有匹配成功的自动配置类)
-----------------
ActiveMQAutoConfiguration:
Did not match:
- @ConditionalOnClass did not find required class 'javax.jms.ConnectionFactory' (OnClassCondition)
AopAutoConfiguration.AspectJAutoProxyingConfiguration:
Did not match:
- @ConditionalOnClass did not find required class 'org.aspectj.weaver.Advice' (OnClassCondition)
# ...省略
Exclusions:
-----------
None
Unconditional classes:
----------------------
org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration
org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration
org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration
org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration
org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration
一. 启动
1. idea启动
2. 命令行启动
luckymoney> mvn spring-boot:run
3. 服务器端打包方式
luckymoney> mvn clean package
# ...
luckymoney> java -jar target/luckymoney-0.0.1-SNAPSHOP.jar
二、配置
0. 使用0
src/main/resources/application.properties
:
server.port = 8081
server.servlet.context-path = /luckymoney
1. 使用1
- src/main/resources/
application.yml
server:
port: 8082
servlet:
context-path: /luckymoney
minMoney: 1
description: 最少要发${minMoney}元
- src/main/java/top/onefine/luckymoney/HelloController.java:
@Value
注解
package top.onefine.luckymoney;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.math.BigDecimal;
@RestController
public class HelloController {
@Value("${minMoney}")
private BigDecimal minMoney;
@Value("${description}")
private String description;
@GetMapping("/hello")
public String say() {
return "开启SpringBoot! 金额:" + minMoney + ", 说明:" + description;
}
}
2. 使用2
src/main/resources/application.yml
:
spring:
profiles:
active: prod
src/main/resources/application-dev.yml
:
# 开发环境
server:
port: 8082
servlet:
context-path: /luckymoney
# 使用对象配置
limit:
minMoney: 0.01
maxMoney: 9999
description: 最少要发${limit.minMoney}元,最多${limit.maxMoney}
src/main/resources/application-prod.yml
:
# 生产环境
server:
port: 8082
servlet:
context-path: /luckymoney
# 使用对象配置
limit:
minMoney: 1
maxMoney: 9999
description: 最少要发${limit.minMoney}元,最多${limit.maxMoney}
src/main/java/top/onefine/luckymoney/LimitConfig.java
:@Component
和@ConfigurationProperties
注解
package top.onefine.luckymoney;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.math.BigDecimal;
@Component
@ConfigurationProperties(prefix = "limit")
public class LimitConfig {
private BigDecimal minMoney;
private BigDecimal maxMoney;
private String description;
public BigDecimal getMinMoney() {
return minMoney;
}
public void setMinMoney(BigDecimal minMoney) {
this.minMoney = minMoney;
}
public BigDecimal getMaxMoney() {
return maxMoney;
}
public void setMaxMoney(BigDecimal maxMoney) {
this.maxMoney = maxMoney;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
src/main/java/top/onefine/luckymoney/HelloController.java
:
package top.onefine.luckymoney;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@Autowired
private LimitConfig limitConfig;
@GetMapping("/hello")
public String say() {
return "开启SpringBoot! 金额:" + limitConfig.getMinMoney() + ", 说明:" + limitConfig.getDescription();
}
}
默认启用的是生产环境的配置,服务器端打包方式运行时启用开发环境的配置:java -jar -Dspring.profiles.active=dev target/luckymoney-0.0.1-SNAPSHOP.jar
三、Controller的使用
1. Controller
maven添加依赖:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
2. src/main/resources/templates/index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>SpringBoot入门</h1>
</body>
</html>
3. src/main/java/top/onefine/luckymoney/HelloController.java
返回html页面(不常用)
package top.onefine.luckymoney;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import java.math.BigDecimal;
@Controller
public class HelloController {
@Autowired
private LimitConfig limitConfig;
@GetMapping("/hello")
public String say() {
return "index";
}
}
或者返回String:
package top.onefine.luckymoney;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
@ResponseBody
public class HelloController {
@Autowired
private LimitConfig limitConfig;
@GetMapping("/hello")
public String say() {
return "开启SpringBoot! 金额:" + limitConfig.getMinMoney() + ", 说明:" + limitConfig.getDescription();
}
}
注意:
@RestController // @RestController = @Controller + @ResponseBody
//@Controller
//@ResponseBody