大数据正式33
2017-12-25 16:19
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大数据正式33
SpringMVC
Servlet缺点一个Servlet有8行配置文件
一个Servlet只能处理一个业务
一张表可能有4+n个Servlet，所以会有32+n行配置文件
获取属性只能得到字符串类型，需要自己转换类型
获取参数只能是request.getParameter()
SpringMVC优点
不管工程中有多少servlet，只需要配置一个servlet分发器即可
springmvc中使用controller替代一个controller
获取参数的类型支持自动装换，而且支持对象的自动封装
SpringMvc有多种获取参数的方式
SprigMVC入门案例
jar包
项目结构
整体流程
代码
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <!-- servlet分发器 --> <servlet> <servlet-name>springmvc</servlet-name> <!-- 分发器 --> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 注入配置文件的地址：创建spring容器 --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:/applicationContext-mvc.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <!-- /或*.action --> <url-pattern>*.action</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
applicationContext-mvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd "> <!-- 扫描包 --> <context:component-scan base-package="com.peng"></context:component-scan> <!-- 扫描注解 --> <context:annotation-config></context:annotation-config> <bean name="/hello.action" class="com.peng.controller.HelloController"></bean> </beans>
com.peng.controller
HelloController
package com.peng.controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
public class HelloController implements Controller {
public ModelAndView handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("index.jsp");
modelAndView.addObject("msg", "hello");
return modelAndView;
}
}index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
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>
This is my JSP page.
<br>
<h1>${msg}</h1>
</body>
</html>访问名称
http://localhost/SpringMVC_inroom/hello.action（注：端口为80）
执行结果
注解形式的SpringmMVC
package com.peng.controller;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HelloController {
@RequestMapping("/hello.action")
public String helloAction(Model model) {
model.addAttribute("msg", "hello,world!");
return "index";
}
}<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd "> <!-- 扫描包 --> <context:component-scan base-package="com.peng"></context:component-scan> <!-- 扫描注解 --> <context:annotation-config></context:annotation-config> <!-- SpringMVC的注解开关 --> <mvc:annotation-driven></mvc:annotation-driven> <!-- 资源解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
添加前后缀的SpringMVC(applicationContext-mvc.xml)
<!-- 资源解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/"></property> <property name="suffix" value=".jsp"></property> </bean>
解决乱码--过滤器(web.xml)
<!-- 乱码过滤器 --> <filter> <filter-name>characterFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
数据的获取
HttpServletRequest对象的getParameter方法package com.peng.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class UserController {
@RequestMapping("/showAddUser.action")
public String showAddUser() {
return "addUser";
}
@RequestMapping("/addUser.action")
public String addUser(HttpServletRequest request, Model model) {
String username = request.getParameter("username");
System.out.println(username);
model.addAttribute("username", username);
return "addUser";
}
}与表单的name值一样的参数String username
参数名来控制
package com.peng.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class UserController {
@RequestMapping("/showAddUser.action")
public String showAddUser() {
return "addUser";
}
@RequestMapping("/addUser.action")
public String addUser(String username, Model model) {
System.out.println(username);
model.addAttribute("username", username);
return "addUser";
}
}bean对象 User
参数名来控制
package com.peng.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class UserController {
@RequestMapping("/showAddUser.action")
public String showAddUser() {
return "addUser";
}
@RequestMapping("/addUser.action")
public String addUser(User user, Model model) {
System.out.println(user.username);
model.addAttribute("username", user.username);
return "addUser";
}
}对象中的对象
参数名来控制
dog.name
gog.age
class Dog{
private String name;
public void setName(String name){
this.name=name;
}
public String getName(){
return this.name;
}
}class User{
private dog;
public void setDog(Dog dog{
this.dog=dog;
}
public Dog getDog(){
return this.dog;
}
}package com.peng.controller;
import javax.servlet.http.HttpServletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class UserController {
@RequestMapping("/showAddUser.action")
public String showAddUser() {
return "addUser";
}
@RequestMapping("/addUser.action")
public String addUser(String username, Model model) {
System.out.println(user.dog.name);
model.addAttribute("username", user.dog.name);
return "addUser";
}
}日期问题
格式问题2017/12/25这个错误； 2017-12-25这个可以；
解决（Controller中）
@InitBinder
public void InitBinder(ServletRequestDataBinder srdb) {
srdb.registerCustomEditor(java.util.Date.class, new CustomDateEditor(
new SimpleDateFormat("yyyy-MM-dd"), true));
}参数的同名提交
Stringa,b,c
例子
@RequestMapping("/addUser.action")
public String addUser(
HttpServletRequest request,
Model model,
Date date,
String like) {
String username = request.getParameter("username");
System.out.println(username + date.toString() + like);
model.addAttribute("username", username);
return "addUser";
}String[]
{a,b,c}数组形式例子
@RequestMapping("/addUser.action")
public String addUser(
HttpServletRequest request,
Model model,
Date date,
String[] like) {
String username = request.getParameter("username");
System.out.println(username + date.toString() + Arrays.toString(like));
model.addAttribute("username", username);
return "addUser";
}参数名称不一致的问题
问题呈现form表单提交过来的name和参数中的name值不相同时--因为要见名知义，稍微改动了参数的名称
@RequestParam("hobby")String[] hobbies
@RequestParam
value--对应form中的name值
defaultValue--默认的值
require--必须传过来时有参数
例子
@RequestMapping("/addUser.action")
public String addUser(
HttpServletRequest request,
Model model,
Date date,
@RequestParam(value = "like", defaultValue = "啥也不喜欢！") String[] likes) {
String username = request.getParameter("username");
System.out.println(username + date.toString() + Arrays.toString(likes));
model.addAttribute("username", username);
return "addUser";
}文件上传
注意的坑form中的参数
method：post
enctype：multipart/form-data
file文件标签
必须有name属性
文件解析器
必须有id属性
id属性的值必须是：multipartResolver
改三个地方
jsp中
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML > <html> <head> <title>Add User</title> </head> <body bgcolor="#0000ff" text="#ffffff"> <form action="addUser.action" method="POST" enctype="multipart/form-data"> <table border="1"> <tr> <td>用户名：</td> <td><input type="text" name="username" /> </td> </tr> <tr> <td>时间：</td> <td><input type="date" name="date" /> </td> </tr> <tr> <td>上传文件：</td> <td><input type="file" name="file" /> </td> </tr> <tr> <td>爱好：</td> <td>篮球<input type="checkbox" name="like" value="basketball" /> 足球<input type="checkbox" name="like" value="football" /> 乒乓球<input type="checkbox" name="like" value="pingpangball" /> </tr> <tr> <td>提交：</td> <td><input type="submit" value="确认" /> </td> </tr> </table> </form> </body> </html>
解析器（必须有id和class）
<!-- 文件上传解析器 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="utf-8"></property> <property name="maxUploadSize" value="10485760000"></property> <property name="maxInMemorySize" value="40960"></property> </bean>
后台
package com.peng.controller;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
@Controller
public class UserController {
@RequestMapping("/showAddUser.action")
public String showAddUser() {
return "addUser";
}
@RequestMapping("/addUser.action")
public String addUser(@RequestParam MultipartFile file) throws IOException {
FileUtils.writeByteArrayToFile(new File(
"C:\\Users\\Administrator.PC-20160710IJPJ\\Desktop\\haha.png"),
file.getBytes());
System.out.println(file.toString());
return "addUser";
}
@InitBinder public void InitBinder(ServletRequestDataBinder srdb) { srdb.registerCustomEditor(java.util.Date.class, new CustomDateEditor( new SimpleDateFormat("yyyy-MM-dd"), true)); }}
请求和重定向
默认是转发重定向--不能直接写界面，尤其是WEB-INF下的界面
return "redirect:请求" return "redirect:addUser.action"
补充
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 
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