SpringMVC学习三

实现有点用处的增删改查，并利用了AJAX（javascript）动态修改，还有json的返回读取，以及文件上传和下载。

配置基础Employee类以及Dao类

package com.springmvc;

public class Department {//成员department
     private int id;
     private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Department(int id, String name) {

        this.id = id;
        this.name = name;
    }
    public Department() {
    }

}

package com.springmvc;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.springframework.stereotype.Repository;

@Repository//利用的是spring的注解自动加载持久层
public class DepartmentDao {
       private static Map<Integer,Department> departments = new HashMap<Integer,Department>();//内置几个属性
       static{
       departments.put(1, new Department(1,"AA"));
       departments.put(2, new Department(2,"BB"));
       departments.put(3, new Department(3,"CC"));
       departments.put(4, new Department(4,"DD"));
    }
       public Collection<Department> getDepartments(){
        return departments.values();
       }

       public Department getDepartment(int id){
           return departments.get(id);
       }
}

package com.springmvc;

public class Employee {
       private int id;
       private String name;
       private String email;
       private int sex;
       private Department department;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public int getSex() {
        return sex;
    }
    public void setSex(int sex) {
        this.sex = sex;
    }
    public Department getDepartment() {
        return department;
    }
    public void setDepartment(Department department) {
        this.department = department;
    }
    public Employee(int id, String name, String email, int sex,
            Department department) {
        this.id = id;
        this.name = name;
        this.email = email;
        this.sex = sex;
        this.department = department;
    }
    public Employee() {//要有空值建构器

    }

}

package com.springmvc;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository
public class EmployeeDao {

    @Autowired//spring的自动装配
    private  DepartmentDao departmentDao;

    private static Map<Integer,Employee> Employees = new HashMap<Integer,Employee>();

    static {
    Employees.put(1, new Employee(1,"xiaobai","11276971@qq.com",1,new Department(1,"AA")));
    Employees.put(2, new Employee(2,"xiaozhi","836659812@qq.com",0,new Department(2,"BB")));
    Employees.put(3, new Employee(3,"dabai","9798451@qq.com",1,new Department(4,"DD")));
    Employees.put(4, new Employee(4,"dahong","2324225@qq.com",0,new Department(3,"CC")));
    }
    static private int eid=4;

    public void insert(Employee employee){
        if (employee.getId()==0){
            eid++;
            employee.setId(eid);
        }
        employee.setDepartment(departmentDao.getDepartment(employee.getDepartment().getId()));
        Employees.put(employee.getId(),employee );
    }

    public void delete(int id){
        Employees.remove(id);
    }

    public Collection<Employee> getEmployees(){
        return Employees.values();
    }

    public Employee getEmployee(int id){
        return Employees.get(id);
    }
}

之后是 Controler类

package com.springmvc;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collection;
import java.util.Map;
import javax.servlet.http.HttpSession;
import javax.websocket.server.PathParam;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class EmployeeHandler {

    @Autowired
    private EmployeeDao employeeDao;

    @Autowired
    private DepartmentDao departmentDao;
    //自动填装两个bean类

    @RequestMapping("/emps")//建构一个map，将值返回给list ，查询效果实现
    public String getAll(Map<String,Object>map){
        map.put("employees", employeeDao.getEmployees());
        return "list";
    }

    @RequestMapping(value="/emp",method=RequestMethod.GET)//新增效果实现，用map填入必须参数，add界面读取和建构
    public String addView(Map<String,Object>map){
        map.put("departments", departmentDao.getDepartments());
        map.put("employee", new Employee());
        return "add";
    }

    @RequestMapping(value="/emp",method=RequestMethod.POST)
    public String save (Employee employee){//post ，添加成功页面，post将add界面的employee加入
        employeeDao.insert(employee);
        return "redirect:/emps";
    }

    @RequestMapping(value="/emp/{id}",method=RequestMethod.DELETE)
    public String delete (@PathVariable(value="id") Integer id){//根据ID来删除，pathvariable则可以拿到ID值。
        System.out.println("delete: "+id);
        employeeDao.delete(id);
        return "redirect:/emps";
    }

    @RequestMapping(value="/emp/{id}",method=RequestMethod.GET)
    public String updateClick(@PathVariable(value="id") Integer id,Map<String,Object>map){//不同的是这里用一个id值取得employee参数后放回构造，在添加页面有if判断。
        map.put("departments", departmentDao.getDepartments());
        map.put("employee",employeeDao.getEmployee(id));
        return "add";
    }

    @RequestMapping(value="/emp",method=RequestMethod.PUT)//这里代表更新操作
     public String update(Employee employee){
        employeeDao.insert(employee);
        return "redirect:/emps";
    }

    @RequestMapping("/testJson")
    @ResponseBody
    public Collection<Employee> getEmployees(){//测试JSON来返回数组

        return employeeDao.getEmployees();
    }

    @RequestMapping("/upload")//上传页面，使用的是multipartfile 所以xml配资文件里面也要有对应的解析器，空文件的判断不是null，而是empty。
    public String upLoad(MultipartFile file,HttpSession session) throws IllegalStateException, IOException{
        if(!file.isEmpty()){
            String path = session.getServletContext().getRealPath("/resources");
            String fileName=file.getOriginalFilename();
            File upfile = new File(path,fileName);
            file.transferTo(upfile);
         return  "success";
        }
        return "fail";

    }

    @RequestMapping("/download")//下载页面，使用的是流下载，实录是将其文件以流形式装换成字节数组，之后再传输。
    public ResponseEntity<byte[]> download (HttpSession session) throws IOException{
        byte[] body = null;
        InputStream in = session.getServletContext().getResourceAsStream("/resources/getclass.txt");
        body = new byte[in.available()];
        in.read(body);

        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition", "attachment;filename=getclass.txt");
        ResponseEntity<byte[]> respon = new ResponseEntity<byte[]>(body,headers,HttpStatus.OK);
        return respon;
    }

}

add ，界面。

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ page import="java.util.Map" %>
<%@ page import="java.util.HashMap" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/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=ISO-8859-1">
<title>Add employee</title>
</head>
<body>
<form:form action="/HelloWeb/emp" method="POST" modelAttribute="employee">

<c:if test="${employee.id == 0 }">

            LastName: <form:input path="name" />
            <form:errors path="name"></form:errors>
        </c:if>
        <c:if test="${employee.id != 0 }">
            <form:hidden path="id" />
           <form:input path="name"  type="hidden"/>
            </c:if>

Email:<form:input path="email"/><br>
<%
    Map<String,String> genders = new HashMap<String,String>();
    genders.put("1", "Male");
    genders.put("2", "Female");
    request.setAttribute("genders", genders);

 %>
 Sex:<form:radiobuttons path="sex" items="${ genders}"/><br>
 Departments:<form:select path="department.id" items="${departments}" itemLabel="name" itemValue="id"></form:select>
 <input type="submit" value="Submit">

</form:form>
</body>
</html>

modelattribute 就是其controler，employeeHandler给的值

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    <%@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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
     <c:if test="${empty requestScope.employees} }">
     No employees imformation!
     </c:if>
     <c:if test="${!empty requestScope.employees}">
     <table border="1" >
     <tr>
     <th>ID</th>
     <th>Name</th>
     <th>Emai</th>
     <th>Sex</th>
     <th>DepatmentName</th>
     <th>EDIT</th>
     <th>DELETE</th>
     </tr>
     <c:forEach items="${requestScope.employees}" var="emp">
     <tr>
     <td>${emp.id }</td>
     <td>${emp.name }</td>
     <td>${emp.email }</td>
     <td>${emp.sex==0?'Female':'Male' }</td>
     <td>${emp.department.name }</td>
     <td><a href="emp/${emp.id }">Edit</a></td>
     <td>
<form action="/HelloWeb/emp/${emp.id}" method="post">
<input type="hidden" name="_method" value="DELETE"/>
<input type="submit" value="delete"/>
</form>
     </td>
     </tr>
     </c:forEach>
     </table>

     </c:if>
     <a href="/HelloWeb/emp">add new employee</a><br><br>

</body>
</html>

requestScope，则是employees的内容

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
 <%@ 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=ISO-8859-1">
<title>Insert title here</title>
<script type="text/javascript" src="scripts/jquery-3.2.1.min.js"></script>
<script >
$(function(){
    $("#testJson").click(function(){
        var url = this.href;
        var args = {};
        $.post(url, args, function(data){
            for(var i=0; i<data.length; i++){
                var id = data[i].id;
                var name = data[i].name;
                alert(id + ": " + name);
            }
        })
        return false;
    })
})
</script>
</head>
<body>
<a href="/HelloWeb/path/pathVariable/5">PathVariable</a>
<a href="/HelloWeb/path/RequestParam?name=xiaozhi&password=no">RequestParam</a>
<a href="/HelloWeb/path/cookie">Cookie</a>
<a href="/HelloWeb/requestHeader">RequestHeader</a>
<a href="/HelloWeb/testModel">ModelAndView</a>
<a href="/HelloWeb/testModel2">ModelAndView2</a>
<a href="/HelloWeb/emps">emps</a>
<a href="/HelloWeb/testJson" id="testJson">Test Json</a>

<form action="/HelloWeb/path/rest/5" method="post">
<input type="hidden" name="_method" value="put"/>
<input type="submit" value="put 5"/>
</form>

<form action="/HelloWeb/path/rest/5" method="post">
<input type="hidden" name="_method" value="DELETE"/>
<input type="submit" value="delete"/>
</form>

<form action="/HelloWeb/path/rest" method="post">
<input type="submit" value="test post"/>
</form>

<form action="/HelloWeb/testPOJO" method="post">
ID<input type="text" name="id"><br>
Name<input type="text" name="name"><br>
Salary<input type="text" name="salary"><br>
Province<input type="text" name="address.province"><br>
City<input type="text" name="address.city"><br>
<input type="submit" name="submit">
</form>
<br>
<form action="/HelloWeb/upload" method="post" enctype="multipart/form-data">
<input type="file" name="file"/>
<input type="submit" value="sub"/>
</form>
<br>
<a href="/HelloWeb/download">Download</a>

</body>
</html>

注意，这里使用了javascript。ajax技术，需要在对应目录下导入min.js文件，因为处理的是json，所以，需要json的处理bean，在bean中配置，以及file文件的配置。

<?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">
<!-- 自动扫描，加载Bean -->
<context:component-scan base-package="com.springmvc"></context:component-scan>

<!-- 这是ModelAndView里面的解析，类的返回 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>

<mvc:annotation-driven/>  

<bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    <property name="supportedMediaTypes">
        <list>
            <value>text/html;charset=UTF-8</value>
        </list>
    </property>
</bean>    

<!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->
        </list>
    </property>
</bean>   

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" >
<value>100000</value>
</property>
<property name="defaultEncoding">
<value>UTF-8</value>
</property>
</bean>
</beans>

注： 在表头请求的方法中，只有post 和 get ，需要自己配置过滤器，在表单中添加hidden属性，将post映射成delete和put。