Spring Boot 是什么
- Spring Boot 是 Spring 社区发布的一个开源项目，旨在帮助开发者快速并且更简单的构建项目。大多数 Spring Boot 项目只需要很少的配置文件。
Spring Boot 特性
- 创建独立的 Spring 项目
- 内置 Tomcat 和 Jetty 容器
- 提供一个 starter POMs 来简化 Maven 配置
- 提供了一系列大型项目中常见的非功能性特性，如安全、指标，健康检测、外部配置等
- 完全没有代码生成和 xml 配置文件
1. 创建一个 Gradle 项目
首先创建Gradle项目。
2. 创建相应的目录
因为 Spring Boot 使用 Gradle 编译，所以有固定的文件结构
目录结构
─src
build.gradle
├─main
│ ├─java
│ │ SpringController.java
│ │
│ └─resources
└─test
├─java
└─resources
3. 创建一个 Controller 类(在 main 文件夹下)
SpringController.java
import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;
//表明这是一个 Controller
@Controller
//RestController是一种Rest风格的Controller，可以直接返回对象而不返回视图，返回的对象可以使JSON，XML等
//@RestController
//使用自动配置，主动添加并解析bean，配置文件等信息
@EnableAutoConfiguration
public class SpringController {
//设置访问的url
@RequestMapping("/")
//表示返回JSON格式的结果，如果前面使用的是@RestController可以不用写
@ResponseBody
String home() {
return "Hello World!";//返回结果为字符串
}
public static void main(String[] args) throws Exception {
//通过SpringApplication的run()方法启动应用，无需额外的配置其他的文件
SpringApplication.run(SpringController.class, args);
}
}
4. 修改 build.gradle 文件
默认生成的 Gradle 文件并不能满足编译 Spring Boot 应用，需要手动修改
buildscript {
repositories {
mavenCentral()//依赖Maven仓库
}
dependencies {
//使用1.4.2.RELEASE版本的Spring框架
classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.2.RELEASE")
}
}
apply plugin: 'java'
apply plugin: 'spring-boot'
//生成的jar包包名和版本
jar {
baseName = 'gs-rest-service'
version = '0.1.0'
}
repositories {
mavenCentral()
}
//设置jdk的版本
sourceCompatibility = 1.8
targetCompatibility = 1.8
//添加编译时的依赖
dependencies {
compile("org.springframework.boot:spring-boot-starter-web")
testCompile('org.springframework.boot:spring-boot-starter-test')
}
5. 编译项目
在命令行进入到该项目根目录下，输入gradle build进行编译，编译的过程中会下载很多的jar包，如果没有科学上网可能会很慢,编译成功后输出build successful
D:\Work\IntelliJIDEA\springboot>gradle build
The plugin id 'spring-boot' is deprecated. Please use 'org.springframework.boot' instead.
:compileJava
:processResources UP-TO-DATE
:classes
:findMainClass
:jar
:bootRepackage
:assemble
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:test UP-TO-DATE
:check UP-TO-DATE
:build
BUILD SUCCESSFUL
Total time: 5.807 secs
也可以在左侧的 gradle 中点击刷新按钮，效果是一样的
6. 启动项目
• 在命令行中输入 gradle bootrun 进行启动项目
• 也可以使用左侧的 gradle 中 Task 下的 application 中的 bootRun 按钮启动
• 默认的会启动 tomcat，使用8080端口，如果端口被占用会报错
启动成功后会输出以下内容
D:\Work\IntelliJIDEA\springboot>gradle bootrun
The plugin id 'spring-boot' is deprecated. Please use 'org.springframework.boot' instead.
:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:findMainClass
:bootRun
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.4.2.RELEASE)
2016-11-30 22:14:47.878 INFO 9120 --- [ main] SpringController : Starting SpringController on H with PID 9120 (D:\WorkSpace\Intel
liJIDEA\springboot\build\classes\main started by 50185 in D:\WorkSpace\IntelliJIDEA\springboot)
2016-11-30 22:14:47.880 INFO 9120 --- [ main] SpringController : No active profile set, falling back to default profiles: default
2016-11-30 22:14:47.911 INFO 9120 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationC
onfigEmbeddedWebApplicationContext@57c758ac: startup date [Wed Nov 30 22:14:47 CST 2016]; root of context hierarchy
2016-11-30 22:14:49.330 INFO 9120 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-11-30 22:14:49.343 INFO 9120 --- [ main] o.apache.catalina.core.StandardService : Starting service Tomcat
2016-11-30 22:14:49.344 INFO 9120 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.6
2016-11-30 22:14:49.457 INFO 9120 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2016-11-30 22:14:49.458 INFO 9120 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1550 ms
2016-11-30 22:14:49.642 INFO 9120 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2016-11-30 22:14:49.647 INFO 9120 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2016-11-30 22:14:49.648 INFO 9120 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2016-11-30 22:14:49.648 INFO 9120 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2016-11-30 22:14:49.648 INFO 9120 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2016-11-30 22:14:49.941 INFO 9120 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.
embedded.AnnotationConfigEmbeddedWebApplicationContext@57c758ac: startup date [Wed Nov 30 22:14:47 CST 2016]; root of context hierarchy
2016-11-30 22:14:50.022 INFO 9120 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto java.lang.String SpringController.home()
2016-11-30 22:14:50.026 INFO 9120 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.Respons
eEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletReque
st)
2016-11-30 22:14:50.026 INFO 9120 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springf
ramework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http
.HttpServletResponse)
2016-11-30 22:14:50.050 INFO 9120 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.sp
ringframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-30 22:14:50.050 INFO 9120 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springfram
ework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-30 22:14:50.088 INFO 9120 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class or
g.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-11-30 22:14:50.209 INFO 9120 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2016-11-30 22:14:50.263 INFO 9120 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2016-11-30 22:14:50.267 INFO 9120 --- [ main] SpringController : Started SpringController in 2.734 seconds (JVM running for 3.049
)
2016-11-30 22:14:57.820 INFO 9120 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet'
2016-11-30 22:14:57.820 INFO 9120 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2016-11-30 22:14:57.836 INFO 9120 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed i
n 16 ms
> Building 80% > :bootRun
7. 通过浏览器访问该项目
该项目因为配置的路径为根路径，所以直接访问
localhost:8080即可如果想停止运行该项目可以在命令行中按
Ctrl+C，输入Y即可停止
额外篇，通过Gradle传参给程序
build.gradle
group 'gradle-spring-boot'
version '1.0-SNAPSHOT'
ext.maxHeapSize = '-Xmx1500m' // default is 1G, but could be changed via command line or launched task type
buildscript {
repositories {
mavenCentral()
maven { url "https://plugins.gradle.org/m2/" }
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:1.4.1.RELEASE")
classpath "com.github.jengelman.gradle.plugins:shadow:1.2.4"
classpath "co.riiid:gradle-github-plugin:0.4.2" // github releases
}
}
apply plugin: 'java'
apply plugin: 'spring-boot'
apply plugin: 'application'
mainClassName = 'org.dreams.Application'
// 生成的jar包包名和版本
jar {
baseName = 'gs-rest-service'
version = '0.1.0'
}
repositories {
mavenCentral()
}
//设置jdk的版本
sourceCompatibility = 1.8
targetCompatibility = 1.8
//添加编译时的依赖
dependencies {
compile("org.springframework.boot:spring-boot-starter-web")
testCompile('org.springframework.boot:spring-boot-starter-test')
}
task runPrivate() {
addJvmArgIfEmpty "key", "value"
tasks.compileJava.execute()
tasks.bootRun.execute()
}
def addJvmArgIfEmpty(String key, String value) {
boolean hasSystemProperty = System.getProperty(key) != null;
if (!hasSystemProperty) {
bootRun.jvmArgs.add('-D' + key + '=' + value)
}
}
增加静态块
package org.dreams.controller;
import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;
//表明这是一个 Controller
@Controller
//RestController是一种Rest风格的Controller，可以直接返回对象而不返回视图，返回的对象可以使JSON，XML等
//@RestController
//使用自动配置，主动添加并解析bean，配置文件等信息
@EnableAutoConfiguration
public class SpringController {
static {
System.out.println("========" + System.getProperty("key"));
}
//设置访问的url
@RequestMapping("/")
//表示返回JSON格式的结果，如果前面使用的是@RestController可以不用写
@ResponseBody
String home() {
return "Hello World!";//返回结果为字符串
}
public static void main(String[] args) throws Exception {
//通过SpringApplication的run()方法启动应用，无需额外的配置其他的文件
SpringApplication.run(SpringController.class, args);
}
}
增加 Application.java
package org.dreams;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;
//@SpringBootApplication(scanBasePackages = "org.dreams.controller")
@SpringBootApplication
@EnableScheduling
public class Application {
public static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
}
}
运行:
gradle runPrivate
