request对象的方法

矫情吗；* 2023-08-17 16:10 111阅读 0赞

request对象封装的是请求的数据，由服务器创建，作为实参传递给Servlet的方法，一个请求对应一个request对象，request对象可以获得请求数据。

1、获取请求行信息

（1）get提交

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            ServletOutputStream out=response.getOutputStream();
            String method= request.getMethod();
            System.out.println(method);
            String URI=request.getRequestURI();
            System.out.println(URI);
            StringBuffer URL=request.getRequestURL();
            System.out.println(URL);
            String path=request.getContextPath();
            System.out.println(path);
        }

![1392562-20190909090738936-857799042.png][]

运行结果：

![1392562-20190909090801227-267972634.png][]

getMethod()：获取提交方式

getRequestURI（）：URI

getRequestURL():URL
    
    getContextPath():项目名称

（2）post提交

![1392562-20190909091857452-845361574.png][]

2、获取请求头信息

（1）获取请求头的一条信息：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException  {
            String header=request.getHeader("Host");
            System.out.println(header);
        }

![1392562-20190910152438795-979801556.png][]

（2）获取请求头的所有信息：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException  {
            Enumeration<String> headerNames=request.getHeaderNames();//获取键的名字
            while(headerNames.hasMoreElements()){
                String headerName= headerNames.nextElement();
                String headerValue=request.getHeader(headerName);
                System.out.println(headerName+":"+headerValue);
            }
        }

![1392562-20190910153606622-1571629721.png][]

![1392562-20190910153513646-1715399903.png][]

3、获取用户信息：

（1）get提交：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException  {
            String name=request.getParameter("userName");
            String password=request.getParameter("password");
            System.out.println(name+":"+password);
        }

![1392562-20190910162404388-1646637820.png][]

![1392562-20190910162356415-1139568804.png][]

（2）post提交：

![1392562-20190910162640128-295905448.png][]

![1392562-20190910162627538-1107452911.png][]

post提交与get提交的运行结果相同。

（3）对提交的数据的同键不同值的处理：

获取提交数据的值：

![1392562-20190911102106008-51466095.png][]

![1392562-20190911102128820-1681303520.png][]

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String[] books= request.getParameterValues("book");
        if(books!=null){
            for(String shu:books){
                System.out.println(shu);
            }
        }
        }

获取名字：

<center>
          <h3>您喜欢的书有哪些：</h3>
          <form action="http://localhost:8080/MyServlet_war_exploded/abc" method="post">
                       
              <input type="checkbox" name="book1" value="xiangzi">《骆驼祥子》<br>        
              <input type="checkbox" name="book2" value="xiyou">《西游记》<br>        
              <input type="checkbox" name="book3" value="shuihu">《水浒传》<br>        
              <input type="checkbox" name="book4" value="hongloumemg">《红楼梦》<br>          
              <input type="checkbox" name="book5" value="sanguo">《三国演义》<br>
              <input type="reset" value="取消">
              <input type="submit" value="确定">
          </form>
      </center>

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     Enumeration<String> names=request.getParameterNames();
     while(names.hasMoreElements()){
         System.out.println(names.nextElement());
     }
        }

![1392562-20190911102718519-2068145824.png][]

![1392562-20190911102703009-1149297808.png][]

获取键和值:

public class MyServlet extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            Map<String,String[]> map=request.getParameterMap();
            for(Map.Entry<String,String[]> entry:map.entrySet()){
                System.out.println(entry.getKey());
                for(String str:entry.getValue()){
                    System.out.println(str);
                }
            }
     }

![1392562-20190911105828955-1988513780.png][]

![1392562-20190911105906573-117958305.png][]

转载于:https://www.cnblogs.com/zhai1997/p/11489967.html

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