springmvc小demo的构成

Guide

这个项目会分为4个主要的部分，分别是人员管理、国际化、上传下载、json。

要达到的效果是：
1. CRUD function for person
2. Internationalization
3. Upload & Download
4. Json

The first, people manager:

Before doing this project, I need to get two entities — Department and Employee

The Department has two variables：id,name
The Employee has five variables: id, lastname, email, gender, department

Code:

public class Department {    private Integer id;    private String name;    public Department() {    }    public Department(Integer id, String name) {        this.id = id;        this.name = name;    }    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    @Override    public String toString() {        return "Department{" +                "id=" + id +                ", name='" + name + '\'' +                '}';    }}

public class Employee {    private Integer id;    private String lastname;    private String email;    private Integer gender;    private Department department;    public Employee() {    }    public Employee(Integer id, String lastname, String email, Integer gender, Department department) {        this.id = id;        this.lastname = lastname;        this.email = email;        this.gender = gender;        this.department = department;    }    public Integer getId() {        return id;    }    public String getLastname() {        return lastname;    }    public String getEmail() {        return email;    }    public Integer getGender() {        return gender;    }    public Department getDepartment() {        return department;    }    public void setId(Integer id) {        this.id = id;    }    public void setLastname(String lastname) {        this.lastname = lastname;    }    public void setEmail(String email) {        this.email = email;    }    public void setGender(Integer gender) {        this.gender = gender;    }    public void setDepartment(Department department) {        this.department = department;    }}

And then, create the propriate Dao—DepartmentDao,EmployeeDao
to imitate datebase operations.

@Repositorypublic class DepartmentDao {    private static Map<Integer, Department> departments = null;    static {        departments = new HashMap<Integer, Department>();        departments.put(701, new Department(601, "D-AA"));        departments.put(702, new Department(602, "D-BB"));        departments.put(703, new Department(603, "D-CC"));        departments.put(704, new Department(604, "D-DD"));        departments.put(705, new Department(605, "D-EE"));    }    public Collection<Department> getDepartments(){return departments.values();}    public Department getDeptById(Integer key){return departments.get(key);}}

@Repositorypublic class EmployeeDao {    private static Map<Integer, Employee> employees = null;    @Autowired    private DepartmentDao departmentDao;    static{        employees = new HashMap<Integer, Employee>();        employees.put(7001, new Employee(7001,"AA","[e-mail]", 0, new Department(7001, "D-AA")));        employees.put(7002, new Employee(7002,"BB","[e-mail]", 1, new Department(7002, "D-BB")));        employees.put(7003, new Employee(7003,"CC","[e-mail]", 0, new Department(7003, "D-CC")));        employees.put(7004, new Employee(7004,"DD","[e-mail]", 1, new Department(7004, "D-EE")));        employees.put(7005, new Employee(7005,"EE","[e-mail]", 0, new Department(7005, "D-FF")));    }    private Integer initId = 7006;    public void save(Employee employee){        if (employee.getId() == null) {            employee.setId(initId++);        }        employee.setDepartment(departmentDao.getDeptById(employee.getDepartment().getId()));        employees.put(employee.getId(), employee);    }    public Collection<Employee> getEmployees(){return employees.values();}    public Employee getEmployeeById(Integer key){return employees.get(key);}    public void delete(Integer id){employees.remove(id);}}

And the next, what I shoud do is to create a show employees’ page.

index.jsp add these codes:

<h4><a href="/emps">Show Employees</a> </h4>

EmployeeHander add these:

code:    @Autowired    EmployeeDao employeeDao;    @Autowired    DepartmentDao departmentDao;    @RequestMapping("/emps")    public String list(Map<String, Object> maps){        maps.put("employees", employeeDao.getEmployees());        return "list";    }

create list.jsp, a crude original version.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %><%--  Created by IntelliJ IDEA.  User: andy  Date: 2017/4/1  Time: 17:39  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html>    <title>employees</title>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body>    <h2>List Employee Info-7 page</h2>    <c:if test="${empty employees}">e...sorry, new company and has no employee till now.</c:if>    <c:if test="${!empty employees}">        Employee Info(${fn:length(employees)}):<br>        <table border="1" cellspacing="0" cellpadding="10">            <tr>                <th>ID</th>                <th>LastName</th>                <th>Email</th>                <th>Gender</th>                <th>Department</th>                <th>Edit</th>        <th>Delete</th>            </tr>            <c:forEach items="${employees}" var="emp">                <tr>                    <td>${emp.id}</td>                    <td>${emp.lastname}</td>                    <td>${emp.email}</td>                    <td>${emp.gender==0?"Female":"Male"}</td>                    <td>${emp.department.name}</td>                    <td><a href="#">Edit</a> </td>                    <td><a href="#">Delete</a> </td>                </tr>            </c:forEach>        </table>    </c:if></body></html>

When I finished list page, the next is add page.

list.jsp

<a href="/emp">Add Employee</a>

finish jumping method.

code:    /**     * the method is help for the method of update.     * and be created when create input page.     * @param id     * @param map     */    @ModelAttribute    public void getEmployee(@RequestParam(value = "id", required = false) Integer id, Map<String,Object> map) {        if (id!=null) {            map.put("employee", employeeDao.getEmployeeById(id));        }    }    @RequestMapping(value = "/emp", method = RequestMethod.POST)    public String save(Employee employee){        if (employee != null) {            //select tag just get id, so need use method to set department info.            Integer id = employee.getDepartment().getId();            System.out.println("|007|=>> id: " + id);            employee.setDepartment(departmentDao.getDeptById(id));            System.out.println("|007|=>> employee: " + employee);            employeeDao.save(employee);        }        return "redirect:/emps";    }    @RequestMapping(value = "/emp", method = RequestMethod.GET)    public String input(Map<String, Object> map){        map.put("departments", departmentDao.getDepartments());        map.put("employee", new Employee());        return "input";    }

create input.jsp

<%@ page import="java.util.Map" %><%@ page import="java.util.HashMap" %><%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %><%--  Created by IntelliJ IDEA.  User: andy  Date: 2017/4/3  Time: 15:47  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head>    <title>ism-07</title>    <meta http-equiv="Content-Type" content="text/html charset=UTF-8"></head><body>    <h2>INPUT PAGE</h2>    <hr />    <form:form action="${pageContext.request.contextPath}/emp" method="post" accept-charset="utf-8" modelAttribute="employee">        LastName:   <form:input path="lastname"/><br>        Email:  <form:input path="email"/><br>        <%            Map<String, String> genders = new HashMap<String, String>();            genders.put("0", "Female");            genders.put("1", "Male");            request.setAttribute("genders", genders);        %>        Gender: <form:radiobuttons path="gender" items="${genders}"/><br>        Dept:   <form:select path="department.id" items="${departments}" itemLabel="name" itemValue="id"/><br>        <input type="submit" name="submit" />    </form:form></body></html>

The next, I need to imply delete function.

web.xml

code:    <!--post to delete or put-->    <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>

I need to use js to imply convert post to delete or put.
the first, add js file into project. and register resource reference in the springmvc.xml
springmvc.xml

code:     <!--static resource mapping-->    <mvc:resources mapping="/scripts/**" location="/WEB-INF/scripts"/>

using js in list.jsp

head:    <script type="text/javascript" src="${pageContext.request.contextPath}/scripts/jquery-1.9.1.min.js"></script>    <script type="text/javascript">        $(function () {            $(".delete").click(function () {                var href = $(this).attr("href");                $("form").attr("action", href).submit();                return false;            });        });    </script>body1:    <form action="" method="post">        <input type="hidden" name="_method" value="DELETE">    </form>body2:    <td><a href="/emp/${emp.id}" class="delete">Delete</a> </td>

EmployeeHandler.java

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

The next function is to imply the modify function.

input.jsp

 code:        <c:if test="${employee.id==null}">            LastName:   <form:input path="lastname"/>        </c:if>        <c:if test="${employee.id!=null}">            <form:hidden path="id"/>            <input type="hidden" name="_method" value="PUT"/>        </c:if>

list.jsp

<td><a href="/emp/${emp.id}">Edit</a> </td>

EmployeeHander.java

code:    @RequestMapping(value = "/emp", method = RequestMethod.PUT)    public String update(Employee employee){        employeeDao.save(employee);        return "redirect:/emps";    }    @RequestMapping(value = "/emp/{id}", method = RequestMethod.GET)    public String input(@PathVariable("id") Integer id, Map<String, Object> map){        map.put("employee", employeeDao.getEmployeeById(id));        map.put("departments", departmentDao.getDepartments());        return "input";    }

The second function is internationalization

the first is to add some interceptor in springmvc.xml

code:    <!--to configure resolve convert-->    <bean class="org.springframework.web.servlet.i18n.SessionLocaleResolver" id="localeResolver"/>    <!--to configure international resource file-->    <bean class="org.springframework.context.support.ResourceBundleMessageSource" id="messageSource">        <property name="basename" value="i18n"/>        <property name="defaultEncoding" value="UTF-8"/>    </bean>    <!--to configure international request interceptor, the request which is based on session or cookie must be configured-->    <mvc:interceptors>        <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/>    </mvc:interceptors>    <!--page jumping directly do not through handler-->    <mvc:view-controller path="/i18n" view-name="i18n"/>    <mvc:view-controller path="/i18n2" view-name="/i18n2"/>

the second is to create three .properties file,namely i18n.properties,i18n_en_US.properties, i18n_zh_CN.properties.

i18n.properties:    i18n.user=user    i18n.pass=passi18n_en_US.properties:    i18n.user=user    i18n.pass=passi18n_zh_CN.properties:    i18n.user=用户名    i18n.pass=密码

the third is create i18n.jsp and i18n2.jsp
i18n.jsp

<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %><%--  Created by IntelliJ IDEA.  User: andy  Date: 2017/4/4  Time: 11:32  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head>    <title>I18N</title>    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body>    <h1>I18N-1</h1>    <fmt:message key="i18n.user"/>    <br><br>    <fmt:message key="i18n.pass"/>    <br><br>    <a href="/i18n?locale=zh_CH">中文</a>    &nbsp; | &nbsp;    <a href="/i18n?locale=en_US">English</a>    <hr><br>    <a href="/i18n2">I18n2</a></body></html>

i18n2.jsp

<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %><%-- Created by IntelliJ IDEA. User: andy Date: 2017/4/4 Time: 11:32 To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head>   <title>I18N2</title>   <meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body>   <h1>I18N-2</h1>   <fmt:message key="i18n.user"/>   <br><br>   <fmt:message key="i18n.pass"/>   <br><br>   <hr><br>   <a href="/i18n">I18N</a></body></html>

the end is to add link in index.jsp

<h4><a href="/i18n">I18N</a> </h4>

The third function is upload function

the first is to add resolver in springmvc.xml

code:    <!--implement upload and download function-->    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">        <property name="defaultEncoding" value="UTF-8"/>        <property name="maxUploadSize" value="1024000"/>    </bean>

the second is to write a form in index.jsp

code:    <h4>upload</h4>    <form action="/upload" method="post" enctype="multipart/form-data">        File: <input type="file" name="file"/><br>        Desc: <input type="text" name="desc"/><br>        <input type="submit" value="submit"/>    </form>

the third is to finish handler

code:    @RequestMapping(value = "/upload", method = RequestMethod.POST)    public String fileUpload(@RequestParam(value = "desc", required = false) String desc, @RequestParam("file")MultipartFile file, HttpServletRequest request) throws IOException {        System.out.println("|-> desc: " + desc);        System.out.println("|-> file: " + file.getOriginalFilename());        InputStream in = file.getInputStream();        String path = request.getSession().getServletContext().getRealPath("/WEB-INF/files/" + new Date().getTime() + "_" + file.getOriginalFilename());        System.out.println("|-> filePath: " + path);        File uFile = new File(path);        FileOutputStream out = new FileOutputStream(uFile);        byte[] bytes = new byte[1024 * 8];        int len=-1;        while((len=in.read(bytes))!=-1){            out.write(bytes,0, len );        }        out.flush();        out.close();        in.close();        return "success";    }

The Fourth function is to imply download function

index.jsp

<h4><a href="/download">a.txt</a> </h4>

handler:

code:    @RequestMapping("/download")    public ResponseEntity<byte[]> fileDownload(HttpSession session) throws IOException {        ServletContext servletContext = session.getServletContext();        InputStream in = servletContext.getResourceAsStream("/WEB-INF/files/a.txt");        byte[] body = new byte[in.available()];        in.read(body);        //add head        HttpHeaders headers = new HttpHeaders();        headers.add("Content-Disposition", " attachment;filename=a.txt");        //add body        HttpStatus statusCode = HttpStatus.OK;        ResponseEntity<byte[]> response = new ResponseEntity<>(body, headers, statusCode);        return response;    }

The Fifth function is to return json

index.jsp

<h4><a href="/testJson">Employees' List Json</a> </h4>

handler

code:    @ResponseBody    @RequestMapping("/testJson")    public Collection<Employee> returnJson(){        Collection<Employee> employees = employeeDao.getEmployees();        return employees;    }