Spring Boot 之 HelloWorld详解

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SpringBoot介绍~<暂时假装有>

配置

<?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.nowcoder</groupId>
    <artifactId>wenda</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>wenda</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.6.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>

Controller层

简单Hello输出

@Controller
public class IndexController {
@RequestMapping(path = {"/","/index"})
@ResponseBody
    public String index(){
        return "Hello";
    }
}

访问:

http://127.0.0.1:8080/index
http://127.0.0.1:8080/

输出:

Hello

参数解析输出

路径传递

@Controller
public class IndexController {
@RequestMapping(path = {"/","/index"})
@ResponseBody
    public String index(){
        return "Hello";
    }

    @RequestMapping(path = {"/profile/{userId}"})
    @ResponseBody
    public String profile(@PathVariable("userId")  int  userId ){
        return String.format("Profile Page of %d",userId);
    }
}

访问http://127.0.0.1:8080/profile/2

Profile Page of 2

参数解析输出例2

@RequestMapping(path = {"/profile/{groupId}/{userId}"})
@ResponseBody
public String profile(@PathVariable("userId")  int  userId ,
                      @PathVariable("groupId")  String  groupId ){
    return String.format("Profile Page of %s / %d",groupId,userId);
    }

访问http://127.0.0.1:8080/profile/admin/10086

Profile Page of admin / 10086

eg3请求参数传递

@RequestMapping(path = {"/profile/{groupId}/{userId}"})
@ResponseBody
public String profile(@PathVariable("userId")  int  userId ,
                      @PathVariable("groupId")  String  groupId ,
                      @RequestParam("type")  int  type ,
                      @RequestParam("key")  String  key ){
    return String.format("Profile Page of %s / %d , t:%d k:%s",groupId,userId,type,key);
}

访问http://127.0.0.1:8080/profile/admin/10086?type=2&key=w

Profile Page of admin / 10086 , t:2 k:w

模板Velocity使用

controller

@RequestMapping(path = {"/vm"},method = {RequestMethod.GET})
public String template(Model model){
    model.addAttribute("value1","vvvv1");
    return "home";
}

指向home.html 渲染

<html>
<body>
<pre>
    #*
    你看不到我~~~~
    *#
    $!{value1}
    $!{value2} ## 如果不存在,强制为空
    ${value3}
</pre>
</body>
</html>

依赖

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-velocity</artifactId>
</dependency>

application.properties 配置

spring.velocity.suffix=.html

访问http://127.0.0.1:8080/vm

    vvvv1
         ${value3}

总结

  1. @Controller 注释来定义说这是一个网页入口
  2. @RequestMapping 指定访问地址or传入参数
  3. 用@PathVariable和@RequestParam对传入参数做解析
  4. 用@ResponseBody or 模板文件 返回结果

技术分享图片

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