【Java从零到架构师第二季】【10】JavaScript

【Java从零到架构师第二季】【10】JavaScript

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持续学习&持续更新中…

学习态度：守破离

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Javascript_jQuery_Bootstrap

• • 整合该项目的添加客户和更新客户数据业务
  • • • 为什么要整合这两个业务
      • 实现
      • • • CustomerServlet
          • list.jsp
          • save.jsp
      • 修改之后的项目结构图
  • Javascript
  • • • 为什么需要Javascript
      • 什么是Javascript
      • JS常见用途
      • JS参考资料
      • JS编码规范
  • JS——基本知识
  • • • script标签
      • JS基础语法
      • typeof运算符
  • JS——数据类型
  • • • 数字类型
      • 字符串
      • • • 没有字符类型
          • 三种引号
          • 拼接
          • 遍历
      • 数组的遍历
      • 对象的遍历
  • JS——函数
  • • • 函数的常见用法
      • 监听标签的点击事件
  • JS——DOM *** 作
  • jQuery
  • • • 什么是jQuery
      • jQuery如何使用
      • jQuery的强大之处
      • 绑定点击事件
      • jQuery的一些细节
  • 基于jQuery的几个插件
  • • • jQuery-UI的一个demo
      • jQuery Validation的一个demo
  • Bootstrap
  • • • 栅格系统例子：
      • Bootstrap js的引入
  • 参考

整合该项目的添加客户和更新客户数据业务 为什么要整合这两个业务

该项目的edit.jsp和save.html中的内容结构大体相似，只有几处略微不同的地方。

CustomerServlet代码中这两处业务也有很多相似之处。

实现 CustomerServlet

只留一个save方法，统一处理添加客户和更新客户数据 *** 作。

@WebServlet("/customer/*")
public class CustomerServlet extends HttpServlet {

    private CustomerDao customerDao;

    @Override
    public void init() {
        customerDao = new CustomerDao();
    }

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

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        request.setCharacterEncoding("utf-8");

        final String[] split = request.getRequestURI().split("/");
        final String methodName = split[split.length - 1];
        try {
            Method method = CustomerServlet.class.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            method.invoke(this, request, response);
        } catch (Exception e) {
            try {
                Method method = CustomerServlet.class.getMethod("error", String.class, HttpServletRequest.class, HttpServletResponse.class);
                method.invoke(this, "不存在该页面", request, response);
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            e.printStackTrace();
        }
    }

    public void list(HttpServletRequest request, HttpServletResponse response) {
        try {
            final List list = customerDao.list();
            request.setAttribute("customerSize", list.size());
            request.setAttribute("customers", list);
            request.getRequestDispatcher("../pages/list.jsp").forward(request, response);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void save(HttpServletRequest request, HttpServletResponse response) {
        try {
            Customer customer = newCustomer(request);
            if (null != customer) {
                if (customer.getId() != null) {
                    // update
                    if (customerDao.update(customer)) {
                        response.sendRedirect("/eight_javascript/customer/list");
                    } else {
                        error("数据更新失败", request, response);
                    }
                } else {
                    // save
                    if (customerDao.save(customer)) {
                        response.sendRedirect("/eight_javascript/customer/list");
                    } else {
                        error("客户添加失败", request, response);
                    }
                }
            } else {
                error("用户非法输入", request, response);
            }
        } catch (Exception e) {
            error("数据保存失败", request, response);
            e.printStackTrace();
        }
    }

    public void edit(HttpServletRequest request, HttpServletResponse response) {
        try {
            String customerId = request.getParameter("id");
            if (customerId != null && !"".equals(customerId)) {
                final Integer id = Integer.valueOf(customerId);
                final Customer customer = customerDao.edit(id);

                try {
                    request.setAttribute("customer", customer);
                    request.getRequestDispatcher("../pages/save.jsp").forward(request, response);
                } catch (Exception e) {
                    e.printStackTrace();
                    error("数据编辑失败", request, response);
                }
            }
        } catch (Exception e) {
            error("数据编辑失败", request, response);
            e.printStackTrace();
        }
    }

    public void remove(HttpServletRequest request, HttpServletResponse response) {
        try {
            String customerId = request.getParameter("id");
            if (customerId != null && !"".equals(customerId)) {
                final Integer id = Integer.valueOf(customerId);
                if (customerDao.remove(id)) {
                    response.sendRedirect("/eight_javascript/customer/list");
                } else {
                    error("数据删除失败", request, response);
                }
            }
        } catch (Exception e) {
            error("数据删除失败", request, response);
            e.printStackTrace();
        }
    }

    private void error(String error, HttpServletRequest request, HttpServletResponse response) {
        try {
            request.setAttribute("error", error);
            request.getRequestDispatcher("../pages/error.jsp").forward(request, response);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private Customer newCustomer(HttpServletRequest request) {
        String customerName = request.getParameter("customer_name");
        String customerAge = request.getParameter("customer_age");
        String customerHeight = request.getParameter("customer_height");
        String customerId = request.getParameter("customer_id");
        if (
                customerName != null && customerAge != null && customerHeight != null &&
                        !"".equals(customerName) && !"".equals(customerAge) && !"".equals(customerHeight)
        ) {
            Customer customer = new Customer(
                    customerName, Integer.valueOf(customerAge), Double.valueOf(customerHeight)
            );
            if (customerId != null && !customerId.equals("")) {
                customer.setId(Integer.valueOf(customerId));
            }
            return customer;
        }
        return null;
    }

}

list.jsp

修改a标签让其直接跳转到save.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


    
    


总共有${customerSize}个客户

    
        姓名
        年龄
        身高
    

    
        
            ${customer.name}
            ${customer.age}
            ${customer.height}
            编辑
            删除
        
    





添加客户

save.jsp

使用JSTL和EL表达式来重构该页面，使得无论是更新客户数据还是添加客户，都使用该页面。

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


    
    



    
        
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