【JAVAWEB】springmvc

springmvc主要由一個DispatcherServlet(不需要開發)，三個組件：處理器映射器，處理器適配器，視圖解析器(不需要開發)

hanlder(需要開發)，view（需要開發）組成

架構流程

用戶發送請求至前端控制器DispatcherServlet
DispatcherServlet收到請求調用HandlerMapping處理器映射器。
處理器映射器根據請求url找到具體的處理器，生成處理器對象及處理器攔截器(如果有則生成)一併返回給DispatcherServlet。
DispatcherServlet通過HandlerAdapter處理器適配器調用處理器
執行處理器(Controller，也叫後端控制器)。
Controller執行完成返回ModelAndView
HandlerAdapter將controller執行結果ModelAndView返回給DispatcherServlet
DispatcherServlet將ModelAndView傳給ViewReslover視圖解析器
ViewReslover解析後返回具體View
DispatcherServlet對View進行渲染視圖（即將模型數據填充至視圖中）。
DispatcherServlet響應用戶

springmvc與struts2不同

springmvc的入口是一個servlet即前端控制器，而struts2入口是一個filter過濾器。
springmvc是基於方法開發(一個url對應一個方法)，請求參數傳遞到方法的形參，可以設計爲單例或多例(建議單例)，struts2是基於類開發，傳遞參數是通過類的屬性，只能設計爲多例。
Struts採用值棧存儲請求和響應的數據，通過OGNL存取數據， springmvc通過參數解析器是將request請求內容解析，並給方法形參賦值，將數據和視圖封裝成ModelAndView對象，最後又將ModelAndView中的模型數據通過request域傳輸到頁面。Jsp視圖解析器默認使用jstl。

核心配置文件springmvc.xml

<?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:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">



	<!-- 掃描@Controler @Service -->
	<context:component-scan base-package="lx" />

	<!-- 處理器映射器 -->
	<!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/> -->
	<!-- 處理器適配器 -->
	<!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/> -->
	<!-- 註解驅動 -->
	<mvc:annotation-driven conversion-service="conversionServiceFactoryBean" />

	<!-- 配置Conveter轉換器 轉換工廠 （日期、去掉前後空格）。。 -->
	<bean id="conversionServiceFactoryBean"
		class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
		<!-- 配置 多個轉換器 -->
		<property name="converters">
			<list>
				<bean class="lx.springmvc.conversion.DateConveter" />
			</list>
		</property>
	</bean>

	<!-- 視圖解釋器 -->
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/" />
		<property name="suffix" value=".jsp" />
	</bean>
	<!-- 配置異常處理器 -->
	<bean class="lx.springmvc.exception.CustomerExceptionResolver"></bean>
	<!-- 上傳圖片配置實現類 -->
	<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
		<!-- 上傳圖片的大小 B 5M 1*1024*1024*5 -->
		<property name="maxUploadSize" value="5000000" />
	</bean>

	<!-- SPringmvc的攔截器 -->
	<mvc:interceptors>
		<!-- 多個攔截器 -->
		<mvc:interceptor>
			<mvc:mapping path="/**" />
			<!-- 自定義的攔截器類 -->
			<bean class="lx.springmvc.interceptor.Interceptor1" />
		</mvc:interceptor>
		<!-- <mvc:interceptor> 
		<mvc:mapping path="/**"/> 
		自定義的攔截器類 
		<bean class="com.itheima.springmvc.interceptor.Interceptor2"/> 
		</mvc:interceptor> -->
	</mvc:interceptors>
</beans>

默認參數綁定

@RequestMapping("/itemEdit")
	public ModelAndView toEdit(HttpServletRequest request,HttpServletResponse response
			,Model model){
		//servlet時代
		String id = request.getParameter("id");
		Items items = itemService.selectById(Integer.parseInt(id));
		ModelAndView mav = new ModelAndView();
		mav.addObject("item", items);
		mav.setViewName("editItem");
		return mav;
	}

簡單數據類型綁定

@RequestMapping("/itemEdit")
	public ModelAndView toEdit(
			/*@RequestParam(value="id",defaultValue="1",required=false)Integer idaa,*/
			Integer id,
			HttpServletRequest request,HttpServletResponse response
			,Model model){
		//servlet時代
//		String id = request.getParameter("id");
		Items items = itemService.selectById(id);
		ModelAndView mav = new ModelAndView();
		mav.addObject("item", items);
		mav.setViewName("editItem");
		return mav;
	}

綁定pojo

@RequestMapping("/updateitem")
	public ModelAndView updateItem(Items item){
		itemService.updateItem(item);
		ModelAndView mav = new ModelAndView();
		mav.setViewName("success");
		return mav;
	}

綁定包裝的pojo

public class QueryVo {

	private Items item;
	private List<Items> itemsList;
	public List<Items> getItemsList() {
		return itemsList;
	}

	public void setItemsList(List<Items> itemsList) {
		this.itemsList = itemsList;
	}

	public Items getItem() {
		return item;
	}

	public void setItem(Items item) {
		this.item = item;
	}
}

	
@RequestMapping("/updateitem")
	public ModelAndView updateItem(QueryVo vo){
		itemService.updateItem(vo.getItem());
		ModelAndView mav = new ModelAndView();
		mav.setViewName("success");
		return mav;
	}	
頁面

<td><input type="text" name="item.name" value="${item.name }" /></td>

綁定數組

@RequestMapping("/item/itemsupdate")
	public ModelAndView deleteItem(Integer[] ids){
		ModelAndView mav = new ModelAndView();
		mav.setViewName("success");
		return mav;
	}	
頁面
可以批量刪除和修改
<c:forEach items="${itemList }" var="item" varStatus="s">
<tr>
    <td><input type="checkbox" name="ids" value="${item.id}"></td>
	<td><input type="text" name="itemsList[${s.index}].name" value="${item.name}"></td>
	<td><input type="text" name="itemsList[${s.index}].price" value="${item.price}"></td>
	<td><fmt:formatDate value="${item.createtime}" pattern="yyyy-MM-dd HH:mm:ss"/></td>
<%-- 	<td>${item.createtime }</td> --%>
	<td>${item.detail }</td>
	
	<td><a href="${pageContext.request.contextPath }/itemEdit.action?id=${item.id}">修改</a></td>

</tr>
</c:forEach>

Controller方法返回值

1.ModelAndView 無敵的，帶着數據返回視圖路徑。
@RequestMapping("/itemList")
	public ModelAndView itemList(){
		List<Items> list = itemService.queryItemList();
		ModelAndView model = new ModelAndView();
		model.addObject("itemList", list);
		model.setViewName("itemList");
		return model;
	}
2.String 返回視圖路徑，model帶數據 （推薦：解耦，數據視圖分離）
@RequestMapping(value = "/itemlist.action")
	public String itemList(Model model) {
		List<Items> list = itemService.selectItemsList();
        model.addAttribute("itemList", list);
		return "itemList";
	}
3.void ajax請求合適

重定向與轉發

return "redirect:/item/itemlist.action";
return "forward:/item/itemlist.action";

異常處理

CustomerExceptionResolver.java

package lx.springmvc.exception;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
/**
 * 
 * @author lx
 *
 */
public class CustomerExceptionResolver implements HandlerExceptionResolver{

	@Override
	public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object obj,
			Exception e) {
		ModelAndView mav = new ModelAndView();
		if(e instanceof MessageException){
			//已知異常
			mav.addObject("error",((MessageException) e).getMsg());
		}else{
		mav.addObject("error", "未知異常");
		}
		mav.setViewName("error");
		return mav;
	}

}

MessageException.java

package lx.springmvc.exception;

public class MessageException extends Exception{

	private String msg;

	public String getMsg() {
		return msg;
	}

	public void setMsg(String msg) {
		this.msg = msg;
	}

	public MessageException(String msg) {
		super();
		this.msg = msg;
	}
	
}

上傳圖片

先配置Tomcat虛擬目錄

@RequestMapping(value = "/updateitem.action")

	public String updateitem(Items items,MultipartFile pictureFile) throws Exception{
//D:\fileupload
		String name = UUID.randomUUID().toString().replaceAll("-", "");
		String ext = FilenameUtils.getExtension(pictureFile.getOriginalFilename());
		pictureFile.transferTo(new File ("D:\\fileupload\\" + name + "." + ext));
		items.setPic(name + "." + ext);
		itemService.updateItemsById(items);
		return "redirect:/item/itemlist.action";
		
	}

jsp

<!-- 上傳圖片是需要指定屬性 enctype="multipart/form-data" -->
	<!-- <form id="itemForm" action="" method="post" enctype="multipart/form-data"> -->
	<form id="itemForm"	action="${pageContext.request.contextPath }/updateitem.action" method="post" enctype="multipart/form-data">

json數據交互

jsp

<script type="text/javascript">
 $(function(){
// alert(1);
var params = '{	"id": 1,"name": "測試商品","price": 99.9,"detail": "測試商品描述","pic": "123456.jpg"}';
   $.ajax({
	   url : "${pageContext.request.contextPath }/json.action",
	   data : params,
	   contentType : "application/json;charset=UTF-8",
	   type : "post",
	   dataType : "json",
	   success : function(data){
		   alert(data.name);
	   }
   });
});
</script>

@RequestMapping(value = "/json.action")

	public @ResponseBody 
	Items json(@RequestBody Items items){
		
//	System.out.println(items);
	return items;	
	}

@RequestMapping(value = "/json.action")

	public void json(@RequestBody Items items){
		
	System.out.println(items);
	}

攔截器

package lx.springmvc.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

public class Interceptor1 implements HandlerInterceptor{

	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object arg2, Exception arg3)
			throws Exception {
		System.out.println("頁面渲染後");
		
	}

	@Override
	public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception {
		System.out.println("方法後");
		
	}

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
		System.out.println("方法前");
				// URL  http://localhost:8080/springmvc-mybatis/login.action
				//URI /login.action
				String requestURI = request.getRequestURI();
				if(!requestURI.contains("/login")){
					String username = (String) request.getSession().getAttribute("USER_SESSION");
					if(null == username){
						response.sendRedirect(request.getContextPath() + "/login.action");
						return false;
					}
				}
				return true;
	}

	
}

@RequestMapping(value = "/login.action",method = RequestMethod.GET)
	public String login(){
		return "login";
	}
	@RequestMapping(value = "/login.action",method = RequestMethod.POST)
	public String login(String username,HttpSession httpSession){
		httpSession.setAttribute("USER_SESSION", username);
		return "redirect:/item/itemlist.action";
	}

【JAVAWEB】springmvc

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分別使用js和JQuery實現html首頁圖片輪播以及廣告圖片定時彈出

【JAVAWEB】struts2

【JAVAWEB】springmvc

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