SpringMVC------------RESTRUL_CRUD

RESTRUL_CRUD

1. RESTRUL_CRUD_需求

1. 显示所有员工信息

1. URI：emps
2. 请求方式：GET
3. 显示效果

 

1. 添加员工信息

1. 显示添加页面：
2. URI：emp
3. 请求方式：GET
4. 显示效果

 

1. 添加员工信息：
2. URI：emp
3. 请求方式：POST
4. 显示效果：完成添加，重定向到 list 页面。

 

1. 删除操作

1. URL：emp/{id}
2. 请求方式：DELETE
3. 删除后效果：对应记录从数据表中删除

1. 修改操作：lastName 不可修改！

1. 显示修改页面

1. URI：emp/{id}
2. 请求方式：GET
3. 显示效果：回显表单。

1. 修改员工信息

1. URI：emp
2. 请求方式：PUT
3. 显示效果：完成修改，重定向到 list 页面。

 

1. 相关的类

省略了Service层，为了教学方便

1. 实体类：Employee、Department
2. Handler：EmployeeHandler
3. Dao：EmployeeDao、DepartmentDao

 

1. 相关的页面

1. list.jsp
2. input.jsp
3. edit.jsp

1. RESTRUL_CRUD_显示所有员工信息

1. 搭建开发环境
   • 拷贝jar包

com.springsource.net.sf.cglib-2.2.0.jar com.springsource.org.aopalliance-1.0.0.jar com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar spring-aop-4.0.0.RELEASE.jar spring-aspects-4.0.0.RELEASE.jar commons-logging-1.1.3.jar spring-beans-4.0.0.RELEASE.jar spring-context-4.0.0.RELEASE.jar spring-core-4.0.0.RELEASE.jar spring-expression-4.0.0.RELEASE.jar spring-jdbc-4.0.0.RELEASE.jar spring-orm-4.0.0.RELEASE.jar spring-tx-4.0.0.RELEASE.jar spring-web-4.0.0.RELEASE.jar spring-webmvc-4.0.0.RELEASE.jar

• • 创建配置文件:springmvc.xml  增加context,mvc,beans名称空间。

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-4.0.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-4.0.xsd">     class="org.springframework.web.servlet.view.InternalResourceViewResolver">

• • 配置核心控制器：web.xml

springDispatcherServlet org.springframework.web.servlet.DispatcherServlet contextConfigLocation classpath:springmvc.xml 1   springDispatcherServlet /

• • 将 POST 请求转换为 PUT 或 DELETE 请求

HiddenHttpMethodFilter           org.springframework.web.filter.HiddenHttpMethodFilter               HiddenHttpMethodFilter           /*

• • 创建相关页面

/WEB-INF/views/list.jsp

index.jsp

• • 增加实体类

• • 增加DAO类

package com.sirius.springmvc.crud.dao;   import java.util.Collection; import java.util.HashMap; import java.util.Map;   import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository;   import com.sirius.springmvc.crud.entities.Department; import com.sirius.springmvc.crud.entities.Employee;   @Repository public class EmployeeDao {   private static Map employees = null;   @Autowired private DepartmentDao departmentDao;   static{ employees = new HashMap();   employees.put(1001, new Employee(1001, "E-AA", "[email protected]", 1, new Department(101, "D-AA"))); employees.put(1002, new Employee(1002, "E-BB", "[email protected]", 1, new Department(102, "D-BB"))); employees.put(1003, new Employee(1003, "E-CC", "[email protected]", 0, new Department(103, "D-CC"))); employees.put(1004, new Employee(1004, "E-DD", "[email protected]", 0, new Department(104, "D-DD"))); employees.put(1005, new Employee(1005, "E-EE", "[email protected]", 1, new Department(105, "D-EE"))); }   private static Integer initId = 1006;   public void save(Employee employee){ if(employee.getId() == null){ employee.setId(initId++); }  employee.setDepartment(departmentDao.getDepartment( employee.getDepartment().getId())); employees.put(employee.getId(), employee); }   public Collection getAll(){ return employees.values(); }   public Employee get(Integer id){ return employees.get(id); }   public void delete(Integer id){ employees.remove(id); } }

package com.sirius.springmvc.crud.dao;   import java.util.Collection; import java.util.HashMap; import java.util.Map;   import org.springframework.stereotype.Repository;   import com.sirius.springmvc.crud.entities.Department;   @Repository public class DepartmentDao {   private static Map departments = null;   static{ departments = new LinkedHashMap();   departments.put(101, new Department(101, "D-AA")); departments.put(102, new Department(102, "D-BB")); departments.put(103, new Department(103, "D-CC")); departments.put(104, new Department(104, "D-DD")); departments.put(105, new Department(105, "D-EE")); }   public Collection getDepartments(){ return departments.values(); }   public Department getDepartment(Integer id){ return departments.get(id); }   }

1. 显示所有员工信息
   • 增加页面链接

To Employee List

• • 增加处理器

package com.sirius.springmvc.crud.handlers;   import java.util.Map;   import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping;   import com.sirius.springmvc.crud.dao.EmployeeDao;   @Controller public class EmployeeHandler {   @Autowired private EmployeeDao employeeDao ;   @RequestMapping("/empList") public String empList(Map map){ map.put("empList", employeeDao.getAll());        //默认存放到request域中         return "list"; }  }

• • SpringMVC中没遍历的标签，需要使用jstl标签进行集合遍历增加jstl标签库jar包

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>        Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">   对不起，没有找到任何员工！                                            EmpId LastName Gender Email DepartmentName Edit Delete ${emp.id } ${emp.lastName } ${emp.gender==0?"Female":"Male" } ${emp.email } ${emp.department.departmentName } Edit Delete

1. RESTRUL_CRUD_添加操作&表单标签

• 在list.jsp上增加连接

Add Employee

• 增加处理器方法

@RequestMapping(value="/empInput",method=RequestMethod.GET) public String empInput(Map map){ map.put("deptList", departmentDao.getDepartments()); //解决错误：java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute Employee employee = new Employee(); //map.put("command", employee); map.put("employee", employee); return "add"; }

• 显示添加页面

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8" import="java.util.*"%> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %> Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">    modelAttribute="employee">          LastName :          Email :          <%                  Map map = new HashMap();                  map.put("1", "Male");                  map.put("0","Female");                  request.setAttribute("genders", map);          %>         Gender : delimiter=" "/>          DeptName :                  department.id"                                                  items="${deptList }"                                                  itemLabel="departmentName"                                                  itemValue="id">

• 显示表单信息时，会报错：

HTTP Status 500 -   type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/views/add.jsp at line 18 15:                         ② 表单回显 16:          --> 17:          18:                  LastName : 19:                  Email : 20:                  <% 21:                          Map map = new HashMap(); Stacktrace:         org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)         org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:410)         org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)         org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)         javax.servlet.http.HttpServlet.service(HttpServlet.java:803)         org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:209)         org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:266)         org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1225)         org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1012)         org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)         org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)         org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931)         org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822)         javax.servlet.http.HttpServlet.service(HttpServlet.java:690)         org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)         javax.servlet.http.HttpServlet.service(HttpServlet.java:803)         org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)         org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) root cause java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute         org.springframework.web.servlet.support.BindStatus.(BindStatus.java:141)

 

1. 使用 Spring的表单标签

1. 通过 SpringMVC 的表单标签可以实现将模型数据中的属性和 HTML 表单元素相绑定，以实现表单数据更便捷编辑和表单值的回显
2. form 标签
   1. 一般情况下，通过 GET 请求获取表单页面，而通过 POST 请求提交表单页面，因此获取表单页面和提交表单页面的 URL 是相同的。
   2. 只要满足该最佳条件的契约， 标签就无需通过 action 属性指定表单提交的 URL
   3. 可以通过 modelAttribute 属性指定绑定的模型属性，若没有指定该属性，则默认从 request 域对象中读取 command 的表单 bean，如果该属性值也不存在，则会发生错误。
3. SpringMVC 提供了多个表单组件标签，如 、 等，用以绑定表单字段的属性值，它们的共有属性如下：
   1. path：表单字段，对应 html 元素的 name 属性，支持级联属性
   2. htmlEscape：是否对表单值的 HTML 特殊字符进行转换，默认值为 true
   3. cssClass：表单组件对应的 CSS 样式类名
   4. cssErrorClass：表单组件的数据存在错误时，采取的 CSS 样式
4. form:input、form:password、form:hidden、form:textarea：对应 HTML 表单的 text、password、hidden、textarea 标签
5. form:radiobutton：单选框组件标签，当表单 bean 对应的属性值和 value 值相等时，单选框被选中
6. form:radiobuttons：单选框组标签，用于构造多个单选框
   1. items：可以是一个 List、String[] 或 Map
   2. itemValue：指定 radio 的 value 值。可以是集合中 bean 的一个属性值
   3. itemLabel：指定 radio 的 label 值
   4. delimiter：多个单选框可以通过 delimiter 指定分隔符
7. form:checkbox：复选框组件。用于构造单个复选框
8. form:checkboxs：用于构造多个复选框。使用方式同 form:radiobuttons 标签
9. form:select：用于构造下拉框组件。使用方式同 form:radiobuttons 标签
10. form:option：下拉框选项组件标签。使用方式同 form:radiobuttons 标签
11. form:errors：显示表单组件或数据校验所对应的错误
    1. ：显示表单所有的错误
    2. ：显示所有以 user 为前缀的属性对应的错误
    3. path= “username” /> ：显示特定表单对象属性的错误

1. 添加员工实验代码

• 表单

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8" import="java.util.*"%> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>  "http://www.w3.org/TR/html4/loose.dtd">              LastName :          Email :          <%                  Map map = new HashMap();                  map.put("1", "Male");                  map.put("0","Female");                  request.setAttribute("genders", map);          %>          Gender : delimiter=" "/>          DeptName :                                                                    items="${deptList }"                                                  itemLabel="departmentName"                                                  itemValue="id">

• 控制器方法

@Controller public class EmployeeHandler { @RequestMapping(value="/empAdd",method=RequestMethod.POST) public String empAdd(Employee employee){ employeeDao.save(employee); return "redirect:/empList"; } }

1. RESTRUL_CRUD_删除操作&处理静态资源

1. 删除实验代码

• 页面链接

Delete

• 控制器方法

@RequestMapping(value="/empDelete/{id}" ,method=RequestMethod.DELETE) public String empDelete(@PathVariable("id") Integer id){ employeeDao.delete(id); return "redirect:/empList"; }

1. HiddenHttpMethodFilter过滤器

1. 发起请求，无法执行，因为delete请求必须通过post请求转换为delete请求，借助：HiddenHttpMethodFilter过滤器

1. 需要使用jQuery来转换请求方式

• 加入jQuery库文件

/scripts/jquery-1.9.1.min.js

• jQuery库文件不起作用

警告: No mapping found for HTTP request with URI [/SpringMVC_03_RESTFul_CRUD/scripts/jquery-1.9.1.min.js] in DispatcherServlet with name 'springDispatcherServlet'

• 解决办法，SpringMVC 处理静态资源

SpringMVC 处理静态资源:

1. 1. 为什么会有这样的问题:

优雅的 REST 风格的资源URL 不希望带 .html 或 .do 等后缀

若将 DispatcherServlet 请求映射配置为 /,

则 Spring MVC 将捕获 WEB 容器的所有请求, 包括静态资源的请求, SpringMVC 会将他们当成一个普通请求处理,

因找不到对应处理器将导致错误。

• 1. 解决: 在 SpringMVC 的配置文件中配置
• 配置后，原来的请求又不好使了

需要配置

1. 关于作用

default-servlet-name="default"/>

1. 通过jQuery转换为DELETE请求

class="delete" href="empDelete/${emp.id }">Delete

 

 

1. 删除操作流程图解

 

 

1. RESTRUL_CRUD_修改操作

 

1. 根据id查询员工对象，表单回显

• 页面链接

Edit

• 控制器方法

//修改员工 - 表单回显 @RequestMapping(value="/empEdit/{id}",method=RequestMethod.GET) public String empEdit(@PathVariable("id") Integer id,Map map){ map.put("employee", employeeDao.get(id)); map.put("deptList",departmentDao.getDepartments()); return "edit"; }

• 修改页面

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8" import="java.util.*"%> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>  "http://www.w3.org/TR/html4/loose.dtd">    <form:form action="${pageContext.request.contextPath }/empUpdate" method="POST" modelAttribute="employee">                        <%--          LastName :           --%>                                    hidden" name="_method" value="PUT">                  <%-- 这里不要使用form:hidden标签，否则会报错。 value="PUT"/>                          Spring的隐含标签，没有value属性，同时,path指定的值，在模型对象中也没有这个属性(_method)，所以回显时会报错。                          org.springframework.beans.NotReadablePropertyException:                          Invalid property '_method' of bean class [com.sirius.springmvc.crud.entities.Employee]:                          Bean property '_method' is not readable or has an invalid getter method:                          Does the return type of the getter match the parameter type of the setter?                   --%>                                     Email :          <%                  Map map = new HashMap();                  map.put("1", "Male");                  map.put("0","Female");                  request.setAttribute("genders", map);          %>          Gender :          DeptName :                                                                    items="${deptList }"                                                  itemLabel="departmentName"                                                  itemValue="id">                    form:form>

 

1. 提交表单，修改数据

• 控制器方法

@RequestMapping(value="/empUpdate",method=RequestMethod.PUT) public String empUpdate(Employee employee){ employeeDao.save(employee);         //用户名称不需要修改，会被置空         return "redirect:/empList"; } @ModelAttribute public void getEmployee( @RequestParam(value="id",required=false) Integer id,Map map){   if(id!=null){      map.put("employee", employeeDao.get(id));   } }