最近學習spring boot,總結一下入門的的基礎知識
1新建maven項目,修改pom.xml
<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.sam</groupId> <artifactId>springboot3</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>springboot3 Maven Webapp</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <!-- 這里一定要配置上java的版本,如果是1.7版本的可不用配置 --> <java.version>1.8</java.version> </properties> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.1.RELEASE</version> <relativePath/> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
2新建main類如下,運行main方法,然后在瀏覽器輸入http://127.0.0.1:8080/hello
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @EnableAutoConfiguration public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } @RequestMapping("/hello") public String hello(){ return "Hello World!"; } }
這樣一個簡單的入門例子就完成了,是不是非常的簡單呢。
下面記錄一下spring boot的一些簡單配置
1在我們開發過程中,我們需要經常修改,為了避免重復啟動項目,我們可以啟用熱部署。
Spring-Loaded項目提供了強大的熱部署功能,添加/刪除/修改 方法/字段/接口/枚舉 等代碼的時候都可以熱部署,速度很快,很方便。想在Spring Boot中使用該功能非常簡單,就是在spring-boot-maven-plugin插件下面添加依賴:
<dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>springloaded</artifactId> <version>1.2.5.RELEASE</version> </dependency> </dependencies>
添加以后,用cmd進入項目目錄,通過mvn spring-boot:run啟動就支持熱部署了(這里是用mvn命令去啟動項目,並不是運行main方法)。
2修改服務器端口
一main方法類實現EmbeddedServletContainerCustomizer接口
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer; import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @EnableAutoConfiguration public class Application1 implements EmbeddedServletContainerCustomizer { @Override public void customize(ConfigurableEmbeddedServletContainer container) { container.setPort(8899); } public static void main(String[] args) { SpringApplication.run(Application1.class, args); } @RequestMapping("/hello") public String port(){ return "port 8899"; } }
二主類添加一個factory方法
import java.util.concurrent.TimeUnit; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory; import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory; import org.springframework.context.annotation.Bean; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @EnableAutoConfiguration public class Application2 { public static void main(String[] args) { SpringApplication.run(Application2.class, args); } @RequestMapping("/hello") public String hello(){ return "port 8890"; } @Bean public EmbeddedServletContainerFactory servletFactory(){ TomcatEmbeddedServletContainerFactory tomcatFactory = new TomcatEmbeddedServletContainerFactory(); tomcatFactory.setPort(8890); tomcatFactory.setSessionTimeout(10,TimeUnit.SECONDS); return tomcatFactory; } }
Hello World例子只是一個controller,可以在主類增加掃描,實現多個controller
1新建User實體類
public class User { private Integer id; private String name; 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; } }
2新建UserController
import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import springboot3.domain.User; @RequestMapping("/user") @RestController public class UserController { @RequestMapping("/{id}") public User getUserById(@PathVariable String id){ User u = new User(); u.setId(new Integer(id)); u.setName("name="+id); return u; } }
3新建DepartmentController
import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RequestMapping("/dep") @RestController public class DepartmentController { @RequestMapping("name") public String getDepName(){ return "Dep name."; } }
4新建主類
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.context.annotation.ComponentScan; @EnableAutoConfiguration @ComponentScan(value = {"springboot3.controller"}) public class Application4 { public static void main(String[] args) { SpringApplication.run(Application4.class, args); } }
運行主方法,在瀏覽器輸入http://127.0.0.1:8080/user/1
在瀏覽器輸入http://127.0.0.1:8080/user/1
上面例子中,user用到url中的變量,可以直接獲取
@RequestMapping("/users/{username}") public String userProfile(@PathVariable("username") String username) { return String.format("user %s", username); } @RequestMapping("/posts/{id}") public String post(@PathVariable("id") int id) { return String.format("post %d", id); }
支持http方法
@RequestMapping(value = "/login", method = RequestMethod.GET) public String loginGet() { return "Login Page"; } @RequestMapping(value = "/login", method = RequestMethod.POST) public String loginPost() { return "Login Post Request"; }
上面的例子,為了方便演示,都是采用restcontroller,spring boot也可以用模板
我們使用Thymeleaf模板引擎進行模板渲染,需要引入依賴:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency>
controller類
@Controller public class HtmlController { @RequestMapping("/html/{name}") public String html(@PathVariable("name") String name, Model model){ model.addAttribute("name","Hello Html "+name); return "html"; } }
接下來需要在默認的模板文件夾src/main/resources/templates/目錄下添加一個模板文件hello.html
<html xmlns:th="http://www.thymeleaf.org"> <head> <title>Getting Started: Serving Web Content</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body> <p th:text="'Hello, ' + ${name} + '!'" /> </body> </html>
訪問http://127.0.0.1:8080/html/sam
瀏覽器頁面使用HTML作為描述語言,那么必然也脫離不了CSS以及JavaScript。為了能夠瀏覽器能夠正確加載類似/css/style.css, /js/main.js等資源,默認情況下我們只需要在src/main/resources/static目錄下添加css/style.css和js/main.js文件后,Spring MVC能夠自動將他們發布,通過訪問/css/style.css, /js/main.js也就可以正確加載這些資源。