SpringMVC丶

官方

https://docs.spring.io/spring-framework/docs/current/reference/html/web.html

创建项目

• 父工程依赖
• 设置web支持

• lib套路（与classes同级）

• web.xml

• SpringMVC配置文件springmvc-servlet.xml

• 新建页面

• XxxController

@Controller//   @RestController不走视图解析器
@RequestMapping("/hello")
public class HelloController {
    @RequestMapping("/h1")
    //@ResponseBody//不走视图解析器，直接返回字符串（配合@Controller使用的）
    public String hello(Model model) {
        //封装数据
        model.addAttribute("msg","hello springmvcAnnotation");
        return "hello";
    }
}

SpringMVC执行流程

RestFul风格

@Controller
public class ControllerTest4 {
    @RequestMapping("/add/{a}/{b}")
    public String test1(@PathVariable int a, @PathVariable int b, Model model) {
        //@PathVariable 与 @RequestParam 的区别
        int result = a + b;
        model.addAttribute("msg","结果为："+result);
        return "test";
    }
}

整合SSM

源码

拦截器

mvc配置文件

<!--拦截器配置-->
<mvc:interceptors>
    <mvc:interceptor>
        <!--包括请求下的所有请求-->
        <mvc:mapping path="/**"/>
        <bean class="com.hello.config.MyInterceptor"/>
    </mvc:interceptor>
</mvc:interceptors>

实现 HandlerInterceptor 接口

public class MyInterceptor implements HandlerInterceptor {
    //return true 放行  执行下一个拦截器
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("============处理前==============");
        return true;
    }
}

文件上传

依赖

<!--文件上传-->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.3</version>
</dependency>
<!--这个包与 javax.servlet-->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
</dependency>

<form action="${pageContext.request.contextPath}/upload" enctype="multipart/form-data" method="post">
    <input type="file" name="file"><br><br>
    <input type="submit" value="上传">
</form>

javax.servlet-api对应代码

@Controller
public class FileController {

    @RequestMapping("/upload")
    public String fileUpload(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
        String uploadFilename = file.getOriginalFilename();
        if ("".equals(uploadFilename)) {
            return "redirect:/index.jsp";
        }
        System.out.println("上传文件名：" + uploadFilename);
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址：" + realPath);

        InputStream is = file.getInputStream();
        FileOutputStream os = new FileOutputStream(new File(realPath, uploadFilename));

        int len = 0;
        byte[] buffer = new byte[1024];
        while ((is.read(buffer)) != -1) {
            os.write(buffer, 0, len);
            os.flush();
        }
        os.close();
        is.close();
        return "redirect:/index.jsp";

    }

    @RequestMapping("/upload2")
    public String fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址：" + realPath);
        file.transferTo(new File(realPath + "/" + file.getOriginalFilename()));
        return "redirect:/index.jsp";
    }
}