spring笔记3 spring MVC的基础知识3

4，spring MVC的视图

　　Controller得到模型数据之后，通过视图解析器生成视图，渲染发送给用户，用户就看到了结果。

视图：view接口，来个源码查看；它由视图解析器实例化，是无状态的，所以线程安全。

spring mvc提供是视图种类如图所示，根据需要选择合适的视图：

视图解析器：值提供一个把视图名称，结合本地化得到视图实例的方法；

spring mvc提供的具体视图解析器有，除去两个抽象的，一共有14个；用户可选择多个视图解析器，通过orderNo指定优先级，默认的ContenNegotiatingViewResolver优先级最高，InternalResourceViewResolver,XsltViewResolver优先级最低；

下面分别对常用的视图举例，记录配置和使用方法：

Jsp和JStL的配置和使用方法：

jsp页面的写法：这里用到了三个标签库，还有国际化信息：

<%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8"  %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@taglib prefix="fm" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<c:set var="ctx" value="${pageContext.request.contextPath}"/>
<html>
<head>
    <title>${title}</title>
</head>
<body>
<h1>${title}</h1>
<form:form modelAttribute="account" method="post" action="${ctx}/account/${action}">
    <table width="100%" border="1px">
        <thead>
        <tr>
            <td colspan="2"></td>
        </tr>
        </thead>
        <tr>
            <td><fm:message key="account.username"/> </td>
            <td>
                <form:errors path="userName" cssStyle="color: red;font: bolder;"/>
                <form:input path="userName" size="50" htmlEscape="true"/>
            </td>
        </tr>
        <tr>
            <td><spring:message code="account.password"/></td>
            <td>
                <form:errors path="password" cssStyle="color: red;font: bolder;"/>
                <form:password path="password" size="50" htmlEscape="true"/>
            </td>
        </tr>
        <tr>
            <td>昵称</td>
            <td>
                <form:errors path="nickName" cssStyle="color: red;font: bolder;"/>
                <form:input path="nickName" size="50" htmlEscape="true"/>
            </td>
        </tr>
        <tr>
            <td><fm:message key="account.birthday"/></td>
            <td>
                <form:errors path="birthday" cssStyle="color: red;font: bolder;"/>
                <form:input path="birthday" size="50" htmlEscape="true"/>
            </td>
        </tr>
        <%--<tr>--%>
            <%--<td>有效期</td>--%>
            <%--<td>--%>
                <%--<form:errors path="validateTime" cssStyle="color: red;font: bolder;"/>--%>
                <%--<form:input path="validateTime" size="50" htmlEscape="true"/>--%>
            <%--</td>--%>
        <%--</tr>--%>
       <tr>
            <td><input type="submit" value="注册"/></td>
            <td><input type="reset" value="重置"/></td>
        </tr>
    </table>
</form:form>
</body>
</html>

关于spring提供的form标签，如果是列表选择，一般带一个隐藏的字段，字段名是选择标签的名称前面加个下划线，保证服务器表单对象和页面表单组件数据一致；

Freemarker模版视图：

首先看配置：

然后是使用了spring提供的宏的一个简单模版：

<#import "spring.ftl" as spring />
<html>
<head>
    <title>${title}</title>
</head>
  <body>
  <table width="100%" border="1px;">

  <#list accountList as account>
      <tr>
          <td>${account_index}</td>
          <td>${account[0]}</td>
          <td>${account[1]}</td>
          <td>${account[2]}</td>
      </tr>
     </#list>
  </table>
  </body>
</html>

pdf:配置方法：

生成的视图类：

package com.lfc.sh.web.sp.view;

import com.google.common.base.Charsets;
import com.lfc.sh.web.sp.util.AppConstant;
import com.lowagie.text.Element;
import com.lowagie.text.Font;
import com.lowagie.text.Table;
import com.lowagie.text.pdf.BaseFont;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.view.document.AbstractPdfView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.util.List;
import java.util.Map;

public class UserListPdfView extends AbstractPdfView {
    @Override
    protected void buildPdfDocument(Map<String, Object> model, com.lowagie.text.Document document, com.lowagie.text.pdf.PdfWriter writer, HttpServletRequest request, HttpServletResponse response) throws Exception {

        String fileName = new String("用户列表".getBytes(), Charsets.ISO_8859_1);
        response.setHeader(AppConstant.RESPONSE_HEADER, "inline;filename=" + fileName);
        Table table = new Table(5);
        table.setWidth(100);
        table.setBorder(1);
        table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_CENTER);
        table.getDefaultCell().setVerticalAlignment(Element.ALIGN_MIDDLE);
        Font font = new Font(BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H", false), 12, Font.BOLD, Color.BLACK);
        ModelAndView modelAndView= (ModelAndView) model.get("modelAndView");
        List<Object[]> accountList = (List<Object[]>)modelAndView.getModel().get("accountList");
        if(accountList!=null&&!accountList.isEmpty())
        for (Object[] account : accountList) {
            table.addCell(account[0].toString());
            table.addCell(account[3].toString());
            table.addCell(account[4].toString());
            table.addCell(account[2].toString());
            table.addCell(account[1].toString());
        }

        document.addTitle("用户列表");
        document.add(table);
    }
}

效果：

json:配置方式

controller的写法：

最终效果：

xls：配置方法：

实现方法，引入poi；

package com.lfc.sh.web.sp.view;

import com.google.common.base.Charsets;
import com.lfc.sh.web.sp.util.AppConstant;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.springframework.web.servlet.view.document.AbstractExcelView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
import java.util.Map;

/**
 * Company: Copyright© 2009 www.7road.com All rights reserved.
 * com.lfc.sh.web.sp.view
 * Create Date: 13-11-19 下午12:14
 * Note:一个xls的视图
 */
public class UserListXlsView extends AbstractExcelView {

    @Override
    protected void buildExcelDocument(Map<String, Object> model, HSSFWorkbook workbook, HttpServletRequest request, HttpServletResponse response) throws Exception {

        String fileName = new String("用户列表".getBytes(), Charsets.ISO_8859_1);
        response.setHeader(AppConstant.RESPONSE_HEADER, "inline;filename=" + fileName);


        HSSFSheet sheet=workbook.createSheet("用户列表");
        HSSFRow head=sheet.createRow(0);
        head.createCell(0).setCellValue("编号");
        head.createCell(1).setCellValue("密码");
        head.createCell(2).setCellValue("昵称");
        head.createCell(3).setCellValue("用户名");
        head.createCell(4).setCellValue("生日");


        List<Object[]> accountList= (List<Object[]>) model.get("accountList");

        int rowNum=1;
        for(Object[] account:accountList)
        {
            HSSFRow row=sheet.createRow(rowNum);
            rowNum++;
            row.createCell(0).setCellValue(account[0].toString());
            row.createCell(1).setCellValue(account[3].toString());
            row.createCell(2).setCellValue(account[2].toString());
            row.createCell(3).setCellValue(account[4].toString());
            row.createCell(4).setCellValue(account[5].toString());
        }
    }
}

RessourceBoundleViewResolver,不同的地区用户提供不同类型的视图；

/account/list.(class)=org.springframework.web.servlet.view.InternalResourceViewResolver

内容协商视图：ContentNegotiatingViewResolver

配置方式：

        <property name="prefix" value="/WEB-INF/view/"/>
        <property name="suffix" value=".jsp"/>
        <property name="contentType" value="text/html;charset=UTF-8"/>
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    </bean>


    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basename" value="/i18n/content"/>
        <property name="cacheSeconds" value="0"/>
        <property name="defaultEncoding" value="UTF-8"/>
    </bean>


    <!-- 定义无Controller的path<->view直接映射 -->
    <!--<mvc:view-controller path="/" view-name="redirect:/task"/>-->

    <bean class="org.springframework.web.servlet.view.BeanNameViewResolver">
        <property name="order" value="3"/>
    </bean>

    <bean id="userListPdf" class="com.lfc.sh.web.sp.view.UserListPdfView"></bean>

    <bean id="userListJson" class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
        <property name="prettyPrint" value="true"/>
        <property name="renderedAttributes" value="accountList"/>
    </bean>

    <bean id="userListXls" class="com.lfc.sh.web.sp.view.UserListXlsView"></bean>

    <!--<bean class="org.springframework.web.servlet.view.ResourceBundleViewResolver">-->
    <!--<property name="basename" value="/i18n/views"/>-->
<!--</bean>-->
    
    <bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
         <property name="order" value="0"/>
        <property name="defaultContentType" value="text/html"/>
        <property name="ignoreAcceptHeader" value="true"/>
        <property name="favorParameter" value="true"/>
        <property name="favorPathExtension" value="false"/>
        <property name="parameterName" value="content"/>
        <property name="mediaTypes">
            <map>
                <entry key="html" value="text/html"/>
                <entry key="json" value="application/json"/>
            </map>
        </property>
        <property name="defaultViews">
            <list>
                <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView"></bean>
            </list>
        </property>

    </bean>