springmvc之獲取參數(shù)的方法(必看)

更新時間：2017年08月18日 09:24:16 投稿：jingxian

下面小編就為大家?guī)硪黄猻pringmvc之獲取參數(shù)的方法(必看)。小編覺得挺不錯的，現(xiàn)在就分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

1、導包，四大核心包，一個切面包（AOP），logging,web,springmvc

2、配置文件，核心代碼如下：

web.xml

<servlet>
  <servlet-name>springDispatcherServlet</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <init-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>classpath:springmvc.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
 </servlet>

  <!-- Map all requests to the DispatcherServlet for handling -->
 <servlet-mapping>
  <servlet-name>springDispatcherServlet</servlet-name>
  <url-pattern>/</url-pattern>
 </servlet-mapping>
 
   <!--字符編碼的filter一定要放在最前面 -->
  <filter>
   <filter-name>CharacterEncodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <!-- 配置encoding，告訴我們指定的編碼格式 -->
  <init-param>
   <param-name>encoding</param-name>
   <param-value>utf-8</param-value>
  </init-param>
  <!-- 解決響應亂碼 -->
  <init-param>
   <param-name>forceEncoding</param-name>
   <param-value>true</param-value>
  </init-param>
  </filter>
  <filter-mapping>
   <filter-name>CharacterEncodingFilter</filter-name>
   <url-pattern>/</url-pattern>
  </filter-mapping>
   <!-- 支持rest的filter -->
  <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>

springmvc.xml

<context:component-scan base-package="com.atguigu"></context:component-scan>
  <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
  <!-- 視圖分析器 -->
   <property name="prefix" value="/WEB-INF/pages/"></property>
   <property name="suffix" value=".jsp"></property>
  </bean>
</beans>

index.jsp: 首頁進入

<body>
 <a href="hello" rel="external nofollow" >hello</a><br/>
 <a href="handle01?user=123456" rel="external nofollow" >獲取請求參數(shù)</a><br/>
 <a href="handle02" rel="external nofollow" >獲取請求頭</a><br/>
 <form action="saveBook" method="post">
  圖書id<input type="text" name="id"/><br/>
  圖書name<input type="text" name="name"/><br/>
  圖書author<input type="text" name="author"/><br/>
  圖書price<input type="text" name="price"/><br/>
  圖書sales<input type="text" name="sales"/><br/>
  圖書stock<input type="text" name="stock"/><br/>
  <hr/>
  <!-- 級聯(lián)屬性來封裝值 -->
  作者name;<input type="text" name="person.name"/><br/>
  作者address;<input type="text" name="person.address"/><br/>
  <input type="submit" value="保存圖書"/>
 </form>
 <hr/>
 <h2>給頁面攜帶數(shù)據(jù)</h2>
 <a href="output01" rel="external nofollow" >output01</a>
</body>

3./WEB-INF/pages 跳轉(zhuǎn)后的內(nèi)容

1).success.jsp

<body>
 <h1>成功！</h1>
 ${msg}===${reMsg}
</body>

2).testScope.jsp

<body>
 <h1>測試數(shù)據(jù)帶在了哪個scope</h1>
 request:${requestScope.msg }<br /> 
 session:${sessionScope.msg }<br /> 
 application:${applicationScope.msg}
</body>

4.src/bean包　　Author.java　　

public class Author {
  private String name;
  private String address;　　　Book.java：

public class Book {
 private int id;
 private String name;
 private double price;
 private int sales;
 private int stock;
 private Author person;
 private String imgPath = "static/img/default.jpg";
 private String author;

src/controller 包， HelloController.java: 如果不加，則不能訪問

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {
 
 @RequestMapping("/hello") //連接地址必須加上"/hello"
 public String hello(){
  return "success";
  
 }
}

TestParamController.java

@Controller
public class TestParamController {
 
 /**
  * 1、直接給方法的參數(shù)位置寫上一個和請求帶來的參數(shù)的名字相同的變量
  * 2、這個變量就封裝的是帶來的參數(shù)的值
  * user = request.getParameter("user")
  * 3、如果沒有就是null
  * 
  * @RequestParam("user")：指定獲取哪個參數(shù)的值
  * 1、默認發(fā)送請求必須帶上這個參數(shù)；
  *   否則：HTTP Status 400 - Required String parameter 'user' is not present
  * 2、required=false可以設(shè)置不是必須的；沒帶null
  * 3、defaultValue="未命名"指定沒帶時的默認值；
  *   user = request.getParameter("user");
  */
 
 @RequestMapping("/handle01")
 public String handle01(
   @RequestParam(value = "user", required = false, defaultValue = "未命名") String user) {
  System.out.println("獲取的User:" + user);
  return "success";
 }
 
 /**
  * 獲取請求頭；
  *   request.getHeader("User-Agent")
  * 注解做了下面這些事情
  * @RequestHeader("User-Agent")String userAgent;
  *   userAgent = request.getHeader("User-Agent");*/
 @RequestMapping("/handle02")
 public String handle02(
   @RequestHeader(value = "User-Agent", required = false, defaultValue = "沒有的") String userAgent) {
  System.out.println("User-Agent:" + userAgent);
  return "success";
 }
 
 /**
  * 獲取某個cookie的值;
  * JSESSIONID=B05C018F82AA1B0BD3845831FADFE49A
  * @CookieValue("JSESSIONID")String jid
  * 注解做了下面這些事情
  * Cookie[] cookies = request.getCookies();
  * for(Cookie c:cookies){
  *  if(c.getName().equals("JSESSIONID")){
  *   jid = c.getValue();
  *  }
  * }*/
 @RequestMapping("/handle03")
 public String handle03(
   @CookieValue(value = "JSESSIONID", required = false, defaultValue = "hhhhh") String jid) {
  System.out.println("jid：" + jid);
  return "success";
 }

 /*傳入POJO；直接幫我們封裝頁面的值； 方便簡單，少寫很多代碼，實現(xiàn)代碼分離，解耦和
  * 1、book = new Book();
  * 2、把book對象中的每一個屬性的值查出來,request.getParameter(屬性)；
  * 3、把這個值設(shè)置進去
  * 注意：因為SpringMVC會進行類型轉(zhuǎn)換，所以提交的數(shù)據(jù)一定要是合法的，否則400錯誤*/
 @RequestMapping("/saveBook")
 public String handle04(Book book) {
  System.out.println("book的值：" + book);
  return "success";
 }

 @RequestMapping("/handle05")
 // pringMVC還允許我們在請求參數(shù)上使用原生的ServletAPI HttpServletRequest HttpServletResponse
 // HttpSession
 public String handle05(HttpSession session, HttpServletRequest request,
   HttpServletResponse response) {
  session.setAttribute("msg", "哈哈哈");

  request.setAttribute("reqMsg", "嘿嘿嘿");

  return "success";
 }

}

src/dataout/ DataOutPutController.java 給頁面攜帶數(shù)據(jù)

@Controller //給頁面攜帶數(shù)據(jù)
public class DataOutPutController {

 /**
  * 1、返回值改為ModelAndView（包含模型數(shù)據(jù)（Model）和要去的頁面地址（View））；
  *   數(shù)據(jù)放在請求域中；
  * 2、在請求參數(shù)上傳入Model、Map、ModelMap都行；給他們里面保存的數(shù)據(jù)會放在請求域中
  * Model、Map、ModelMap最終其實都是再有用BindingAwareModelMap；
  * 相當于給BindingAwareModelMap中保存數(shù)據(jù)就是給請求域中保存
  * Model   Map
  *  ||   ||
  *  ||   \/
  *  ||  ModelMap
  *  \/   \/
  *  ExtendedModelMap【隱含模型】 extends ModelMap implements Model
  *   \/
  *  BindingAwareModelMap
  * @return
  */
 @RequestMapping("/output04")
 public String output04(ModelMap model){
  //視圖解析器會對視圖名進行拼串
  model.addAttribute("msg","output04");
  System.out.println(model.getClass());
  return "testScope";
  
 }
 @RequestMapping("/output03")
 public String output03(Model model){
  model.addAttribute("msg", "output03");
  System.out.println(model.getClass());
  return "testScope";
 }
 @RequestMapping("/output02")
 public String output02(Map<String,Object>map){
  //視圖解析器會對視圖名進行拼串
  map.put("msg", "output02");
  System.out.println(map.getClass());
  return "testScope";
 }
 @RequestMapping("/output01")
 public ModelAndView output01(){
  //視圖解析器會對視圖名進行拼串
  ModelAndView modelAndView = new ModelAndView();
  modelAndView.setViewName("testScope");
  modelAndView.addObject("msg", "output01");
  return modelAndView;
  
 }
}

以上這篇springmvc之獲取參數(shù)的方法(必看)就是小編分享給大家的全部內(nèi)容了，希望能給大家一個參考，也希望大家多多支持腳本之家。

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