1.导入依赖
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>8.5.34</version>
</dependency>
<!-- tomcat对jsp支持 -->
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jasper</artifactId>
<version>8.5.16</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.0.10.RELEASE</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.0.10.RELEASE</version>
<scope>compile</scope>
</dependency>
2.加载spring mvc的相关配置信息
创建一个WebConfig类继承WebMvcConfigurationSupport类,
需要加上@Configuration,@EnableWebMvc,@ComponentScan(basePackages = {"扫描mvc包的名称"})
代码:
//表示这是一个配置类,配置<beans></beans>
@Configuration
//表示配置视图解析器,开启注解的相关配置,以及<bean></bean>等等。
@EnableWebMvc
//表示包扫描
@ComponentScan(basePackages = {"springboot.controller"})
public class WebConfig extends WebMvcConfigurationSupport {
/**
* 配置springMVC视图解析器
*/
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
//配置前缀
viewResolver.setPrefix("/WEB-INF/views/");
//配置后缀
viewResolver.setSuffix(".jsp");
//可以在jsp页面中通过${}访问beans
viewResolver.setExposeContextBeansAsAttributes(true);
return viewResolver;
}
}
3.加载spring容器相关配置信息
创建Service_DaoConfig配置类,只需要@Configuration,@ComponentScan注解即可,
这个类主要是扫描service和dao层的,代码如下:
//表示配置类
@Configuration
//如果写了dao层,那么这里也需要扫描一下dao层
@ComponentScan("springboot.service")
public class Service_DaoConfig {
}
4.加载springMVC的dispatcherservlet
创建SpittrWebAppInitializer类继承AbstractAnnotationConfigDispatcherServletInitializer类
代码如下:
public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
/**
* 加载spring容器配置信息
* @return
*/
@Override
protected Class<?>[] getRootConfigClasses() {
return new Class[] {Service_DaoConfig.class};
}
/**
* 加载springmvc配置信息
* @return
*/
@Override
protected Class<?>[] getServletConfigClasses() {
return new Class[]{WebConfig.class};
}
/**
* springmvc映射 拦截url所有请求"/"
* @return
*/
@Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
}
5.在service层创建一个IndexService业务类,代码如下:
@Service
public class IndexService {
public String show() {
return "我是service层";
}
}
6.创建一个IndexController类,代码如下:
@Controller
public class IndexContrller {
@Autowired
private IndexService indexService;
/**
* value:访问地址
* produces:解决乱码问题
* @return
*
*/
@RequestMapping(value = "/index1", produces = "text/html;charset=UTF-8")
@ResponseBody
public String index() {
return "手写springboot。。。";
}
@RequestMapping(value = "/index2", produces = "text/html;charset=UTF-8")
public String springboot(Model model) {
String str = indexService.show();
model.addAttribute("str",str);//返回到jsp页面显示数据
return "springboot";
}
}
7.新建一个WEB-INF => views => springboot.jsp文件,代码如下:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>springboot</title>
</head>
<body>
<h1>这是一个手写的springboot框架</h1>
这里显示后台返回的数据为:【${str}】
</body>
</html>
8.创建一个启动程序SpringBootApp类,代码如下:
public class SpringBootApp {
public static void main(String[] args) throws LifecycleException, ServletException {
// 创建Tomcat容器对象
Tomcat tomcatServer = new Tomcat();
// 设置端口号
tomcatServer.setPort(8080);
// 读取项目路径 加载静态资源
StandardContext ctx = (StandardContext) tomcatServer.addWebapp("/", new File("src/main").getAbsolutePath());
// 禁止重新载入
ctx.setReloadable(false);
// class文件读取地址
File additionWebInfClasses = new File("target/classes");
// 创建WebRoot
WebResourceRoot resources = new StandardRoot(ctx);
// tomcat内部读取Class执行(/WEB-INF/classes虚拟出来的路劲)
resources.addPreResources(
new DirResourceSet(resources, "/WEB-INF/classes", additionWebInfClasses.getAbsolutePath(), "/"));
tomcatServer.start();
// 异步等待请求执行
tomcatServer.getServer().await();
}
}
9.测试启动程序
输入地址: http://localhost:8080/index1
http://localhost:8080/index2