springmvc-实现增删改查
30. 尚硅谷_佟刚_SpringMVC_RESTRUL_CRUD_显示所有员工信息.avi
现在需要使用restful风格实现增删改查，需要将post风格的请求转换成PUT 请求和DELETE 请求
1. 需要在web.xml文件中配置 HiddenHttpMethodFilter <!-- 配置 org.springframework.web.filter.HiddenHttpMethodFilter: 可以把 POST 请求转为 DELETE 或 POST 请求 --> <filter> <filter-name>HiddenHttpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class> </filter> <filter-mapping> <filter-name>HiddenHttpMethodFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> 2. 需要发送 POST 请求 3. 需要在发送 POST 请求时携带一个 name="_method" 的隐藏域, 值为 DELETE 或 PUT
我们来看下web.xml的具体配置
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0" > <!-- The front controller of this Spring Web application, responsible for handling all application requests --> <!-- 配置 org.springframework.web.filter.HiddenHttpMethodFilter: 可以把 POST 请求转为 DELETE 或 POST 请求 --> <filter> <filter-name>HiddenHttpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class> </filter> <filter-mapping> <filter-name>HiddenHttpMethodFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>springDispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 加载spirng配置文件 --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mvc.xml</param-value> </init-param> <!-- 启动就加载 --> <load-on-startup>1</load-on-startup> </servlet> <!-- 拦截所有请求 --> <servlet-mapping> <servlet-name>springDispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
1.3. 效果
① 通过POST 请求增加员工信息
② 通过PUT 请求修改员工信息
③ 通过DELETE 请求删除员工信息
④ 通过GET 请求 获取所有的 员工信息
注意点1；
<!-- springmvc只能使用原声的jstl标签，导入c标签 -->
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
Table tr td th表格使用案例
<table width="300" border="1" cellspacing="0"> <tr> <th>班级</th> <th>日期</th> <th>标题</th> </tr> <tr> <td>一班</td> <td>2012-5-10</td> <td>标题1</td> </tr> <tr> <td>二班</td> <td>2012-5-20</td> <td>标题2</td> </tr> </table>
DW软件里截图：
table案例教程布局截图
我们来看整个项目的工程如下所示：
代码如下：
DepartmentDao
package com.ibigsea.springmvc.dao; import java.util.Collection; import java.util.HashMap; import java.util.Map; import org.springframework.stereotype.Component; import com.ibigsea.springmvc.model.Department; @Component public class DepartmentDao { public static Map<Integer, Department> depts = new HashMap<Integer, Department>(); /** * 初始化部门信息 */ static { depts.put(101, new Department(101,"JAVA")); depts.put(102, new Department(102,".NET")); depts.put(103, new Department(103,"PHP")); depts.put(104, new Department(104,"C")); } /** * 获取所有的部门信息 * @return */ public Collection<Department> getAll(){ return depts.values(); } /** * 根据ID获取部门信息 * @param id * @return */ public Department getDepartmentById(Integer id){ return depts.get(id); } }
EmployeeDao
package com.ibigsea.springmvc.dao; import java.util.Collection; import java.util.HashMap; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.ibigsea.springmvc.model.Department; import com.ibigsea.springmvc.model.Employee; @Component public class EmployeeDao { @Autowired DepartmentDao departmentDao; private static Map<Integer,Employee> emps = new HashMap<Integer, Employee>(); /** * 初始化员工信息 */ static { emps.put(1001, new Employee(1001,"AA","AA@ibigsea.com",0,new Department(101, "JAVA"))); emps.put(1002, new Employee(1002,"BB","BB@ibigsea.com",0,new Department(102, ".NET"))); emps.put(1003, new Employee(1003,"CC","CC@ibigsea.com",1,new Department(103, "PHP"))); emps.put(1004, new Employee(1004,"DD","DD@ibigsea.com",0,new Department(104, "C"))); } private static int employeeId = 1005; /** * 保存员工信息 * @param emp */ public void save(Employee emp){ if (emp.getId() == null) { emp.setId(employeeId++); } emp.setDepartment(departmentDao.getDepartmentById(emp.getDepartment().getId())); emps.put(emp.getId(), emp); } /** * 获取所有的员工信息 * @return */ public Collection<Employee> getAll(){ return emps.values(); } /** * 根据ID获取员工信息 * @param id * @return */ public Employee getEmpById(Integer id){ return emps.get(id); } /** * 根据ID删除员工信息 * @param id */ public void delEmpById(Integer id){ emps.remove(id); } }
index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <a href="emps">查询所有员工的信息</a> <br> </body> </html>
显示所有员工信息的list.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!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>员工信息</title> </head> <body> <c:if test="${ empty employees }"> 没有员工信息 </c:if> <c:if test="${ !empty employees }"> <table border="1" bordercolor="black" cellspacing="0"> <tr> <td width="40px">id</td> <td width="30px">name</td> <td width="80px">email</td> <td width="30px">sex</td> <td width="30px">department</td> <td width="40px">编辑</td> <td width="40px">删除</td> </tr> <c:forEach items="${employees }" var="emp"> <tr> <td>${emp.id }</tdemployees> <td>${emp.name }</td> <td>${emp.email }</td> <td>${emp.sex == 0 ? '男' : '女'}</td> <td>${emp.department.name}</td> <td><a href="${pageContext.request.contextPath}/edit/${emp.id }">Edit</a></td> <td><form action="${pageContext.request.contextPath}/delete/${emp.id }" method="post"> <input type="hidden" name="_method" value="DELETE"> <input type="submit" value="Delete"> </form> </td> </tr> </c:forEach> </table> </c:if> <br><br> <a href="${pageContext.request.contextPath}/emp">添加员工</a> </body> </html>
handle处理器
package com.ibigsea.springmvc.handler; import java.util.Collection; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import com.ibigsea.springmvc.dao.EmployeeDao; import com.ibigsea.springmvc.model.Employee; @Controller public class EmployeeHandler { @Autowired private EmployeeDao employeeDao; /* * 查询所有的员工信息 * */ @RequestMapping(value="/emps",method=RequestMethod.GET) public String listAllEmployees(Map<String,Object> map){ Collection<Employee> allEmployees = employeeDao.getAll(); map.put("employees", allEmployees); return"list"; } }
web.xml配置文件
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0" > <filter> <filter-name>HiddenHttpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class> </filter> <filter-mapping> <filter-name>HiddenHttpMethodFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>springDispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 加载spirng配置文件 --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mvc.xml</param-value> </init-param> <!-- 启动就加载 --> <load-on-startup>1</load-on-startup> </servlet> <!-- 拦截所有请求 --> <servlet-mapping> <servlet-name>springDispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
spring-mvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd"> <!-- 配置自动扫描包 扫描com.ibigsea.springmvc 包下的类，后期会使用spring进行管理 --> <context:component-scan base-package="com.ibigsea.springmvc"/> <!-- 配置视图解析器 如返回helloworld 为 [/WEB-INF/pages/helloworld.jsp] --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/pages/"/> <!-- 后缀 --> <property name="suffix" value=".jsp"/> </bean> </beans>
项目有几个地方需要注意的：
1、在DepartMentdao 需要使用spring的@AutoWier功能，需要使用@Component进行注解
2、在spring-xml中需要添加自动扫描 <context:component-scan base-package="com.ibigsea.springmvc"/>
运行效果如下所述
31. 尚硅谷_佟刚_SpringMVC_RESTRUL_CRUD_添加操作&表单标签.avi
1、这里在添加员工的时候使用的是springmvc的表单标签
正式介绍SpringMVC的表单标签之前，我们需要先在JSP中声明使用的标签，具体做法是在JSP文件的顶部加入以下指令：
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
2、
1.用form select标签为例，在书写JSP时，有时笔误可能会写成<form:select path="departmet" items="departments" itemLabel="departmentName" itemValue="id"></form:select>
这种写法是错误的，应该是
<form:select path="departmet" items="${departments }" itemLabel="departmentName" itemValue="id"></form:select>
3、
使用Spring的form标签主要有两个作用，第一是它会自动的绑定来自Model中的一个属性值到当前form对应的实体对象，默认是command对象 ，这样我们就可以在form表单体里面方便的使用该对象的属性了；
第二是它支持我们在提交表单的时候使用除GET和POST之外的其他方法进行提交，包括DELETE和PUT等。
现在我们在input.jsp中
<%@page import="java.util.Map"%> <%@page import="java.util.HashMap"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %> <!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>添加员工信息</title> </head> <body> <!-- 这里是使用springmvc的form标签 private Integer id; private String name; private String email; private int sex; private Department department; --> <form:form action="addEmp" method="post" modelAttribute="employ" > id:<form:input path="id"/><br> <br> 姓名:<form:input path="name"/> <br> 邮箱:<form:input path="email"/> <br> <% Map<String,String> genders = new HashMap(); genders.put("1", "男"); genders.put("0", "女"); request.setAttribute("sexMap",genders); %> 性别:<form:radiobuttons path="sex" items="${sexMap }"/> <br> department: <form:select path="department.id" itemLabel="name" items="${departments}" itemValue="id"></form:select> <br> <input type="submit" value="submit"/> </form:form> </body> </html>
我们需要绑定的域对象不在是默认的command对象，二是表单标签在不进行数据绑定是无法操作的，在运行程序的时候会报错，因为表单标签是依赖于数据绑定操作的。"employ" 对于的employ对象，该对象来自handle中map.put("employ", employee);对象，如果form表达中没有对于的对象进行绑定，form表单
就会抛出异常，所以在使用springmvc 表单中即使不显示任何数据，也要创建下面这样一个空的employee对象，这样显示表单标签才不会异常。如果employee对象中存在name值，email值，跳转到input.jsp页面的时候会把对应的值显示出来，该功能可以用于修改联系人，把联系人原来的信息显示在表单标签中。
总结：表单标签在不进行数据绑定是无法操作的，在运行程序的时候会报错，因为表单标签是依赖于数据绑定操作的。绑定对象可以使用modelAttribute制定需要绑定对象的名称，<form:form action="addEmp" method="post" modelAttribute="employ" >这个配置相当的关键，指定springmvc表单和那个对象就是自动绑定，
@RequestMapping(value="/emp",method=RequestMethod.GET) public String input(Map<String,Object> map){ Collection<Department> departments = departmentDao.getAll(); map.put("departments", departments); Employee employee = new Employee(); map.put("employ", employee); return"input"; }
4、在添加联系人的页面中，提交的部门的时候
department: <form:select path="department.id" itemLabel="name"
items="${departments}" itemValue="id"></form:select>
<br>
对于的path是department.id，对应的是部门的id，保存的时候依据部门的id值，查询出部门，再把部门保存到联系人中
/** * 保存员工信息 * @param emp */ public void save(Employee emp){ if (emp.getId() == null) { emp.setId(employeeId++); } emp.setDepartment(departmentDao.getDepartmentById(emp.getDepartment().getId())); emps.put(emp.getId(), emp); }
handler控制成的代码为
package com.ibigsea.springmvc.handler; import java.util.Collection; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import com.ibigsea.springmvc.dao.DepartmentDao; import com.ibigsea.springmvc.dao.EmployeeDao; import com.ibigsea.springmvc.model.Department; import com.ibigsea.springmvc.model.Employee; @Controller public class EmployeeHandler { @Autowired private EmployeeDao employeeDao; @Autowired private DepartmentDao departmentDao; /* * 执行添加联系人操作，重定向到显示所有联系人的页面 * */ @RequestMapping(value="/addEmp", method=RequestMethod.POST) public String addEmp(Employee em){ employeeDao.save(em); //employeeDao.save(employ); return "redirect:/emps"; } /** * 点击添加联系人，跳转到添加联系人页面 * */ @RequestMapping(value="/emp",method=RequestMethod.GET) public String input(Map<String,Object> map){ Collection<Department> departments = departmentDao.getAll(); map.put("departments", departments); Employee employee = new Employee(); map.put("employ", employee); return"input"; } /* * 查询所有的员工信息 * */ @RequestMapping(value="/emps",method=RequestMethod.GET) public String listAllEmployees(Map<String,Object> map){ Collection<Employee> allEmployees = employeeDao.getAll(); map.put("employees", allEmployees); return"list"; } }
添加联系人可以总结成下面的三个步骤：
第一档点击添加联系人按钮的时候，请求经过handle处理跳转到handle进行处理，handle返回添加联系人的页面
添加联系人的页面使用到了spring mvc的表单标签，为了便于数据的回显，这里设置了一个modelAttribute="employ"，所以在handle中跳转到添加联系人界面input.jsp的时候都必须在请求域中设置一个空的employ对象，否则会抛出异常
map.put("departments", departments);
Employee employee = new Employee();
map.put("employ", employee);
第三步：添加联系人成功之后，重定向到url为emps的handle进行处理，再次查询出数据库中的所有数据，然后跳转到list.jsp将所有的数据显示出来
32. 尚硅谷_佟刚_SpringMVC_RESTRUL_CRUD_删除操作&处理静态资源.avi
删除操作需要使用HiddenHttpMethodFilter将post请求转化成对应的delete请求，其中表达中的name值必须是_method,vale值必须是DELETE
下面的这种方式
<td><a id="sub123" href="${pageContext.request.contextPath}/delete/${emp.id }" >Delete</a></td>
对应的是get请求，我们如何将get请求转化成post请求了，可以使用下面的方式，也可以采用视频中的方式
<td><form action="${pageContext.request.contextPath}/delete/${emp.id }" method="post"> <input type="hidden" name="_method" value="DELETE"> <input type="submit" value="Delete"> </form> </td>
我们来看list.jsp的代码
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <!-- 因为jquery文件 --> <script type="text/javascript" src="/jquery-3.3.1.min.js"></script> <script type="text/javascript"> </script> <title>员工信息</title> </head> <body> <!-- 添加一个表单将post请求转换成delete请求 name必须是_method value必须是DELETE名字不能被修改 --> </form> <c:if test="${ empty employees }"> 没有员工信息 </c:if> <c:if test="${ !empty employees }"> <table border="1" bordercolor="black" cellspacing="0"> <tr> <td width="40px">id</td> <td width="30px">name</td> <td width="80px">email</td> <td width="30px">sex</td> <td width="30px">department</td> <td width="40px">编辑</td> <td width="40px">删除</td> </tr> <c:forEach items="${employees }" var="emp"> <tr> <td>${emp.id }</tdemployees> <td>${emp.name }</td> <td>${emp.email }</td> <td>${emp.sex == 0 ? '男' : '女'}</td> <td>${emp.department.name}</td> <td><a href="${pageContext.request.contextPath}/edit/${emp.id }">Edit</a></td> <td><form action="${pageContext.request.contextPath}/delete/${emp.id }" method="post"> <input type="hidden" name="_method" value="DELETE"> <input type="submit" value="Delete"> </form> </td> </tr> </c:forEach> </table> </c:if> <br><br> <a href="${pageContext.request.contextPath}/emp">添加员工</a> </body> </html>
我们来看handler的代码
package com.ibigsea.springmvc.handler; import java.util.Collection; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import com.ibigsea.springmvc.dao.DepartmentDao; import com.ibigsea.springmvc.dao.EmployeeDao; import com.ibigsea.springmvc.model.Department; import com.ibigsea.springmvc.model.Employee; @Controller public class EmployeeHandler { @Autowired private EmployeeDao employeeDao; @Autowired private DepartmentDao departmentDao; /* * 执行添加联系人操作，重定向到显示所有联系人的页面 * */ @RequestMapping(value="/delete/{id}", method=RequestMethod.DELETE) public String deletEmp(@PathVariable("id") Integer id ){ employeeDao.delEmpById(id); //employeeDao.save(employ); return "redirect:/emps"; } /* * 执行添加联系人操作，重定向到显示所有联系人的页面 * */ @RequestMapping(value="/addEmp", method=RequestMethod.POST) public String addEmp(Employee em){ employeeDao.save(em); return "redirect:/emps"; } /** * 点击添加联系人，跳转到添加联系人页面 * */ @RequestMapping(value="/emp",method=RequestMethod.GET) public String input(Map<String,Object> map){ Collection<Department> departments = departmentDao.getAll(); map.put("departments", departments); Employee employee = new Employee(); map.put("employ", employee); return"input"; } /* * 查询所有的员工信息 * */ @RequestMapping(value="/emps",method=RequestMethod.GET) public String listAllEmployees(Map<String,Object> map){ Collection<Employee> allEmployees = employeeDao.getAll(); map.put("employees", allEmployees); return"list"; } }
注意点：
在web.xml中配置
<!-- 拦截所有请求 --> <servlet-mapping> <servlet-name>springDispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
拦截所以的请求，如果访问静态资源文件也会被拦截。但是对于的访问静态资源的文件没有在handler中进行映射处理，就会导出错误，为了能够直接访问静态资源文件不会出现问题，需要在spring-mvc.xml文件中进行下面的配置
<!-- 配置运行可以访问静态资源文化 --> <mvc:default-servlet-handler/> <mvc:annotation-driven></mvc:annotation-driven>
spring-mvc.xml的代码如下
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd"> <!-- 配置自动扫描包 扫描com.ibigsea.springmvc 包下的类，后期会使用spring进行管理 --> <context:component-scan base-package="com.ibigsea.springmvc"/> <!-- 配置视图解析器 如返回helloworld 为 [/WEB-INF/pages/helloworld.jsp] --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/pages/"/> <!-- 后缀 --> <property name="suffix" value=".jsp"/> </bean> <!-- 配置运行可以访问静态资源文化 --> <mvc:default-servlet-handler/> <mvc:annotation-driven></mvc:annotation-driven> </beans>
33. 尚硅谷_佟刚_SpringMVC_RESTRUL_CRUD_修改操作.avi
修改操作
1、在修改页面显示需要修改的联系人，但是联系人的name属性不能被修改
2、修改联系人需要使用PUT方式提交
这里因为要在input.jsp中显示需要修改的联系人，需要对input.jsp做下面的修改
<!-- 注意不能写成
<form:hidden path="_method" value="PUT"/>
1、因为传递参数的时候，需要封装成javabean对象，java对象中不存在_method这个属性，上面的path="id"在javabean对象中存在
2、并且 <form:hidden标签中不存在value属性
只能使用下面的这种形式传递，不能使用form表单的hidden属性传递_method标签
-->
<c:if test="${ employ.id != null}">
<form:hidden path="id"/>
<input type="hidden" name="_method" value="PUT"/>
</c:if>
我们来看下程序的代码
<%@page import="java.util.Map"%> <%@page import="java.util.HashMap"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>添加员工信息</title> </head> <body> <!-- 这里是使用springmvc的form标签 private Integer id; private String name; private String email; private int sex; private Department department; --> <form:form action="${pageContext.request.contextPath}/addEmp" method="post" modelAttribute="employ" > <!-- 判断id的值是否存在，如果存在就是修改联系人，不显示id标签 --> <!-- 判断id的值是否存在，如果存在就是修改联系人，联系人的name属性不能被修改 --> <c:if test="${ employ.id == null}"> id:<form:input path="id"/><br> <br> 姓名:<form:input path="name"/> <br> </c:if> <!-- 不等于null，需要将联系人id的值重新传递到handle进行处理 对象中存在id属性，可以直接传递,并且需要将表单的post请求转化成put请求。我们需要传递一个_method属性，对应的value值是PUT传递到handle中--> <c:if test="${ employ.id != null}"> <form:hidden path="id"/> <input type="hidden" name="_method" value="PUT"/> </c:if> 邮箱:<form:input path="email"/> <br> <% Map<String,String> genders = new HashMap(); genders.put("1", "男"); genders.put("0", "女"); request.setAttribute("sexMap",genders); %> 性别:<form:radiobuttons path="sex" items="${sexMap }"/> <br> department: <form:select path="department.id" itemLabel="name" items="${departments}" itemValue="id"></form:select> <br> <input type="submit" value="submit"/> </form:form> </body> </html>
我们来看下handle层的代码
package com.ibigsea.springmvc.handler; import java.util.Collection; import java.util.Map; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import com.ibigsea.springmvc.dao.DepartmentDao; import com.ibigsea.springmvc.dao.EmployeeDao; import com.ibigsea.springmvc.model.Department; import com.ibigsea.springmvc.model.Employee; @Controller public class EmployeeHandler { @Autowired private EmployeeDao employeeDao; @Autowired private DepartmentDao departmentDao; /** * 点击修改联系人，跳转到修改联系人页面，显示需要修改的联系人信息，其中联系人的名字不能被修改 * */ @RequestMapping(value="/edit/{id}",method=RequestMethod.GET) public String input(@PathVariable("id") Integer id,Map<String,Object> map){ Collection<Department> departments = departmentDao.getAll(); map.put("departments", departments); //通过id查找需要修改的联系人 Employee employee = employeeDao.getEmpById(id); map.put("employ", employee); return"input"; } /** * 这里需要在执行修改联系人在保存的时候先查询出来，否则自己保存 * m is :Employee [id=1002, name=null, email=BB@ibigsea.com, sex=0, department=Department [id=101, name=null]] * 会存在联系人名字为空的情况，修改修改联系人页面没有传递联系人姓名的属性值 * */ @ModelAttribute public void getEmployee(@RequestParam(value="id",required = false) Integer id ,Map<String,Object> map){ if(id != null){ Employee employee = employeeDao.getEmpById(id); //map.put("employ", employee)名字和@ModelAttribute("employ")中的一一对应 map.put("employ", employee); } } /*** * 保存修改联系人页面，修改的联系人，对应的action是addEmp * <form:form action="addEmp" method="post" modelAttribute="employ" > * 对应的访问方式是对应的访问方式是PUT方式 * <input type="hidden" name="_method" value="PUT"/> * * 注意点2: * 这里在修改修改联系人的时候，需要被修改联系人的name属性不能被修改 * m is :Employee [id=1002, name=null, email=BB@ibigsea.com, sex=0, department=Department [id=101, name=null]] * */ @RequestMapping(value="/addEmp", method=RequestMethod.PUT) public String update(@ModelAttribute("employ")Employee em){ System.out.println("em is :"+em.toString()); employeeDao.save(em); return "redirect:/emps"; } /* * 执行添加联系人操作，重定向到显示所有联系人的页面 * */ @RequestMapping(value="/delete/{id}", method=RequestMethod.DELETE) public String deletEmp(@PathVariable("id") Integer id ){ employeeDao.delEmpById(id); //employeeDao.save(employ); return "redirect:/emps"; } /* * 执行添加联系人操作，重定向到显示所有联系人的页面 * */ @RequestMapping(value="/addEmp", method=RequestMethod.POST) public String addEmp(Employee em){ employeeDao.save(em); return "redirect:/emps"; } /** * 点击添加联系人，跳转到添加联系人页面 * */ @RequestMapping(value="/emp",method=RequestMethod.GET) public String input(Map<String,Object> map){ Collection<Department> departments = departmentDao.getAll(); map.put("departments", departments); Employee employee = new Employee(); map.put("employ", employee); return"input"; } /* * 查询所有的员工信息 * */ @RequestMapping(value="/emps",method=RequestMethod.GET) public String listAllEmployees(Map<String,Object> map){ Collection<Employee> allEmployees = employeeDao.getAll(); map.put("employees", allEmployees); return"list"; } }
整个工程的代码下载路径地址是：
https://pan.baidu.com/s/1vP_BYybJnAByqSsp35o3Cg
posted on 2018-04-16 11:33 luzhouxiaoshuai 阅读(6632) 评论(0) 编辑 收藏 举报
