#千锋逆战# springMVC简易模拟

SpringMVC 简易模拟

为了安全,我们将涉及数据的网页放入WEB-INF文件夹下.
- 图1.jpg

<body>
<ul>
    <c:forEach var="${errors}" items="item">
        <li>${item}</li>
    </c:forEach>
</ul>
    <form method="post" action="ProductDetail">
        name:<input name="name"> <br/>
        age:<input name="age"> <br/>
        sex:<input name="sex"> <br/>
        classRoom:<input name="classRoom"> <br/>
        <input type="submit">
    </form>
</body>

设置模拟控制器

@WebServlet(urlPatterns = {"/ProductInput", "/ProductDetail"})
public class DispatcherServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String requestURI = request.getRequestURI();

        String action = requestURI.substring(requestURI.lastIndexOf("/") + 1);

        Controller controller = null;

        if("ProductInput".equalsIgnoreCase(action)){
            controller = new ProductInputController();
        }else if("ProductDetail".equalsIgnoreCase(action)){
            controller = new ProductDetailController();
        }

        String url = controller.handleRequest(request, response);

        request.getRequestDispatcher(url).forward(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

ProductInput请求和ProductDetail请求都会通过控制器,然后由控制器转发地址.ProductInputController和ProductDetailController控制具体逻辑.

ProductInputController类直接转发,实现内部转发至WEB-INF下的jsp

public class ProductInputController implements Controller {
    @Override
    public String handleRequest(HttpServletRequest request, HttpServletResponse response) {
        return "/WEB-INF/index.html";
    }
}

ProductDetailController类接受数据并进行校验,通过校验结果返回转发地址.

public class ProductDetailController implements Controller {
    @Override
    public String handleRequest(HttpServletRequest request, HttpServletResponse response) {

        String name = request.getParameter("name");
        int age = Integer.parseInt(request.getParameter("age"));
        String sex = request.getParameter("sex");
        String classRoom = request.getParameter("classRoom");

        Student student = new Student();
        student.setAge(age);
        student.setClassRoom(classRoom);
        student.setName(name);
        student.setSex(sex);


        ProductValidate pv = new ProductValidate();
        List<String> errors = pv.validate(student);

        if(errors != null && !errors.isEmpty()){
            request.setAttribute("errors", errors);
            return "/WEB-INF/index.jsp";
        }


        System.out.println(name);
        System.out.println(age);
        System.out.println(sex);
        System.out.println(classRoom);

        return "/WEB-INF/product.jsp";
    }
}

ProductValidate类,具体实施校验方法

public class ProductValidate {

    /**
     * 校验给定的Student对象
     *
     * @param student 要校验的对象
     * @return 表单校验不成功，则将错误信息存储
     */
    public List<String> validate(Student student) {
        List<String> errors = null;

        String name = student.getName();
        int age = student.getAge();
        String classRoom = student.getClassRoom();
        String sex = student.getSex();


        errors = new ArrayList<>();

        if (name == null || name.length() == 0) {
            errors.add("product name must not be empty.");
        }

        if (classRoom == null || classRoom.length() == 0) {
            errors.add("product classRoom must not be empty.");
        }


        if (sex == null || sex.length() == 0) {
            errors.add("sex must not be empty.");
        }

        if (age < 0) {
            errors.add("the age must be a positive number.");
        }

        return errors;
    }
}

#千锋逆战# springMVC简易模拟

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