一、登录功能
登录界面主要是对用户的账号、密码以及验证码的管理和验证，应创建一个用户实体类，这里为了方便就直接在用户信息加入了username和password两个属性，后续会改进。
1.界面展示
2. 前端代码分析
2.1 在form表单中的设置action属性，为其表单创建提交地址，${pageContext.request.contextPath}用来获取虚拟路径，避免了地址更换对访问带来的错误信息。
<form action="${pageContext.request.contextPath}/loginServlet" method="post">
2.2 登录界面中的验证码图显示，当我们看不清或想切换验证码，添加一个函数给此链接，当点击图示便可以切换
<div class="form-inline"><label for="vcode">验证码：</label><input type="text" name="verifycode" class="form-control" id="verifycode" placeholder="请输入验证码" style="width: 120px;"/><a href="javascript:refreshCode()"><img src="${pageContext.request.contextPath}/checkCodeServlet" title="看不清点击刷新" id="vcode"/></a></div>
<script type="text/javascript">//切换验证码function refreshCode(){//1.获取验证码图片的对象var vcode = document.getElementById("vcode");//2.设置其src属性，加时间戳vcode.src = "${pageContext.request.contextPath}/checkCodeServlet?time="+new Date().getTime();}</script>
2.3 将xxx中的xxx改为${login_msg}，在Servlet中会定义这个信息，并用setAttribute()方法传入request中，当信息框输入错误，就会显示一个提示框，输出对应的错误提示。
<!-- 出错显示的信息框 --><div class="alert alert-warning alert-dismissible" role="alert"><button type="button" class="close" data-dismiss="alert" ><span>×</span></button><strong>${login_msg}</strong></div>
3.后端代码分析
3.1设置编码
request.setCharacterEncoding("utf-8");
3.2获取数据
//2.获取数据//2.1获取用户填写的验证码String verifycode = request.getParameter("verifycode");
3.3验证码验证
HttpSession session = request.getSession();String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");session.removeAttribute("CHECKCODE_SERVER");//确保验证码一次性if(!checkcode_server.equalsIgnoreCase(verifycode)){//验证码不正确//提示信息request.setAttribute("login_msg","验证码错误!");//跳转登录页面request.getRequestDispatcher("/login.jsp").forward(request,response);return;}Map<String,String[]> map = request.getParameterMap();
3.4封装User对象
User user = new User();try {BeanUtils.populate(user,map);} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}
3.5调用Service查询
UserService service = new UserServiceImpl();User loginUser = service.login(user);
3.6判断是否登录成功
UserService service = new UserServiceImpl();User loginUser = service.login(user);//6.判断是否登录成功if(loginUser != null){//登录成功//将用户存入sessionsession.setAttribute("user",loginUser);//跳转页面response.sendRedirect(request.getContextPath()+"/index.jsp");}else{//登录失败//提示信息request.setAttribute("login_msg","用户名或密码错误!");//跳转登录页面request.getRequestDispatcher("/login.jsp").forward(request,response);}
3.7使用sql在数据库中获取用户账号和密码
public User findUserByUsernameAndPassword(String username, String password) {try {String sql = "select * from user where username = ? and password = ?";User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), username, password);return user;} catch (Exception e) {e.printStackTrace();return null;}}
二、添加功能
1.界面展示
2.前端代码分析
2.1给表单设置提交地址
<form action="${pageContext.request.contextPath}/addUserServlet" method="post">
3.后端代码分析
3.1设置编码
request.setCharacterEncoding("utf-8");
3.2获取参数
Map<String,String[]> map = request.getParameterMap();
3.3封装对象
User user = new User();try {BeanUtils.populate(user,map);} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}
3.4调用Service保存
UserService service = new UserServiceImpl();service.addUser(user);
3.5跳转到userListServlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
3.6数据库执行语句
public void add(User user) {//1.定义sqlString sql = "insert into user values(null,?,?,?,?,?,?,null,null)";//2.执行sqltemplate.update(sql, user.getName(), user.getGender(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail());}
三、修改功能
1.界面展示
2.前端代码分析
2.1设置隐藏域 提交id
<input type="hidden" name="id" value="${user.id}">
2.2对姓名进行回显，设置 readonly 属性规定输入字段为只读，修改时无法修改姓名
<div class="form-group"><label for="name">姓名：</label><input type="text" class="form-control" id="name" name="name" value="${user.name}" readonly="readonly" placeholder="请输入姓名" /></div>
2.3为性别、地址等信息回显
<div class="form-group"><label>性别：</label><c:if test="${user.gender == '男'}"><input type="radio" name="gender" value="男" checked/>男<input type="radio" name="gender" value="女" />女</c:if><c:if test="${user.gender == '女'}"><input type="radio" name="gender" value="男" />男<input type="radio" name="gender" value="女" checked/>女</c:if></div>
<div class="form-group"><%--@declare id="address"--%><label for="address">籍贯：</label><select name="address" class="form-control" ><c:if test="${user.address == '广东'}"><option value="广东" selected>广东</option><option value="广西">广西</option><option value="湖南">湖南</option></c:if><c:if test="${user.address == '广西'}"><option value="广东" >广东</option><option value="广西" selected>广西</option><option value="湖南">湖南</option></c:if><c:if test="${user.address == '湖南'}"><option value="广东" >广东</option><option value="广西">广西</option><option value="湖南"selected>湖南</option></c:if></select></div>
3.后端代码分析
3.1设置编码
request.setCharacterEncoding("utf-8");
3.2获取map
Map<String,String[]> map = request.getParameterMap();
3.3封装对象
User user = new User();try {BeanUtils.populate(user,map);} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}
3.4调用service修改
UserService service = new UserServiceImpl();service.updateUser(user);
3.5跳转到查询所有Servlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
3.6 sql语句
public void update(User user) {String sql = "update user set name = ?,gender = ?,age = ?,address = ?,qq = ?, email = ? where id = ? ";template.update(sql, user.getName(), user.getGender(), user.getAge(), user.getAddress(), user.getQq(), user.getEmail(),user.getId());}
四、删除功能
1.界面展示
2.前端代码分析
2.1单行选择是否删除，给出提示信息
function deleteUser(id) {//用户安全提示if (confirm("您确定要删除吗？")) {//访问路径location.href = "${pageContext.request.contextPath}/delUserServlet?id=" + id;}}
2.2为多个按钮添加单击事件，并给出是否删除选中信息提示
window.onload = function () {//给删除选中按钮添加单击事件document.getElementById("delSelected").onclick =function () {if(confirm("你确定要删除选中条目吗？")){var flag = false;//判断是否有选择条目var cbs = document.getElementsByName("uid");for (var i = 0; i < cbs.length; i++) {if(cbs[i].checked){//有一个条目选中了flag = true;break;}}if(flag){//有条目被选中//表单提交document.getElementById("form").submit();}}}//1.获取第一个cbdocument.getElementById("firstCb").onclick = function () {//2.获取下边列表中所有的cbvar cbs = document.getElementsByName("uid");//3.遍历for (var i = 0; i < cbs.length; i++) {//4.设置这些cbs[i]的checked状态 = firstCb.checkedcbs[i].checked = this.checked;}}}
2.3添加复选框，实现多条信息选中删除功能
<form id="form" action="${pageContext.request.contextPath}/delSelectServlet" method="post"><table border="1" class="table table-bordered table-hover"><tr class="success"><!-- 复选框 --><th><input type="checkbox" id="firstCb"></th><th>编号</th><th>姓名</th><th>性别</th><th>年龄</th><th>籍贯</th><th>QQ</th><th>邮箱</th><th>操作</th></tr><c:forEach items="${pb.list}" var="user" varStatus="s"><tr><!-- 复选框 --><td><input type="checkbox" name="uid" value="${user.id}"></td><td>${s.count}</td><td>${user.name}</td><td>${user.gender}</td><td>${user.age}</td><td>${user.address}</td><td>${user.qq}</td><td>${user.email}</td><td><a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a> <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id});">删除</a></td></tr></c:forEach></table></form>
3.后端代码分析
3.1获取所有id
String[] ids = request.getParameterValues("uid");
3.2调用service删除
UserService service = new UserServiceImpl();service.delSelectedUser(ids);
3.3跳转查询所有Servlet
response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
3.4 sql语句数据库查询
public void delete(int id) {//1.定义sqlString sql = "delete from user where id = ?";//2.执行sqltemplate.update(sql, id);}
五、分页查询功能
1.界面展示
2.前端代码分析
为《角标和》角标设置，当页码为1或者最大时，再点击 “<” 和 “>” 图标，就会显示无法点击的图标，用法是给 li 标签添上class="disabled"属性，但是实际上还是能点击，并且网页会报错，需要在后端代码设置。
<div><nav aria-label="Page navigation"><ul class="pagination"><!-- 左角标 --><c:if test="${pb.currentPage == 1}"><li class="disabled"></c:if><c:if test="${pb.currentPage != 1}"><li></c:if><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage - 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Previous"><span aria-hidden="true">«</span></a></li><!-- 页码 --><c:forEach begin="1" end="${pb.totalPage}" var="i"><c:if test="${pb.currentPage == i}"><li class="active"><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li></c:if><c:if test="${pb.currentPage != i}"><li><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li></c:if></c:forEach><!-- 右角标 --><c:if test="${pb.currentPage==pb.totalPage}"><li class="disabled"></c:if><c:if test="${pb.currentPage != pb.totalPage}"><li></c:if><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage + 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Next"><span aria-hidden="true">»</span></a></li><!-- 备注 --><span style="font-size: 25px;margin: 5px" >共${pb.totalCount}条数据，共${pb.totalPage}页</span></ul></nav></div>
3.后端代码分析
3.1创建实体类
private int totalCount;//总记录数private int totalPage;//总页码private List<T> list;//当前的数据private int currentPage;//当前页码private int rows;//每页显示的记录数
3.2代码编码
request.setCharacterEncoding("utf-8");//1.获取参数String currentPage = request.getParameter("currentPage");//当前页码String rows = request.getParameter("rows");//每页显示条目if(currentPage == null || "".equals(currentPage)){currentPage = "1";}if(rows == null || "".equals(rows)) {rows = "5";}//获取条件查询参数Map<String,String[]> condition = request.getParameterMap();//2.调用service查询UserService service = new UserServiceImpl();PageBean<User> pd = service.findUserByPage(currentPage,rows,condition);//3.将PageBean存入requestrequest.setAttribute("pd",pd);request.setAttribute("condition",condition);//将查询条件存入request//4.转发到list.jsprequest.getRequestDispatcher("/list.jsp").forward(request,response);
