HttpServletRequest獲取請求

public class DemoServlet01 extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//1.獲取HTTP請求消息中的請求方式
		System.out.println("請求方式：" + request.getMethod());
		//2.獲取請求行中資源名稱部分
		System.out.println("資源部分= url:" + request.getRequestURL());
		//3.獲取請求行中的參數部分
		System.out.println("請求行中的參數：" + request.getQueryString());
		//4.獲取請求行的協議和版本
		System.out.println("請求的協議個版本："+request.getProtocol());
		//5.獲取WEB應用程序的路徑
		System.out.println("獲取應用程序的路徑:"+ request.getContextPath());	
		//6.獲取Servlet的名稱或Servlet所映射的路徑 
		System.out.println("獲取Servlet的名稱:"+request.getServerName());
		System.out.println( "路徑：" + request.getServletPath());
		//7.獲取請求客戶端的IP地址
		System.out.println("獲取客戶端的IP地址：" + request.getRemoteAddr());		
		//8.獲取請求客戶端的完整主機名
		System.out.println("獲取請求客戶端的完整主機名:" + request.getRemoteHost());		
		//9.獲取請求客戶端網絡連接的端口號
		System.out.println("客戶端網絡連接的端口號:" + request.getRemotePort());		
		//10.獲取Web服務器上接收當前請求網絡連接的IP地址
		System.out.println("接收當前請求網絡連接的IP地址:" + request.getLocalAddr());		
		//11.獲取Web服務器上接收當前網絡連接IP所對應的主機名
		System.out.println("接收當前網絡連接IP所對應的主機名:"+request.getLocalName());		
		//12.獲取Web服務器上接收當前網絡連接的端口號		
		System.out.println("獲取Web服務器上接收當前網絡連接的端口號：" + request.getLocalPort());
		//13.獲取當前請求所指向的主機名		
		System.out.println("獲取當前請求所指向的主機名:" + request.getServerName());
		//14.獲取當前請求所連接的服務器端口號
		System.out.println("獲取當前請求所連接的服務器端口號:" + request.getServerPort());		
		//15.獲取請求的協議名
		System.out.println("獲取請求的協議名：" + request.getScheme());		
		//16.獲取客戶端發出請求時的完整URL
		System.out.println("獲取客戶端發出請求時的完整URL:" + request.getRequestURL());
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

public class DemoServlet02 extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		response.setCharacterEncoding("text/html;charset=utf-8");
		//1.獲取一個指定頭字段值
		System.out.println(request.getHeader("host"));
		//2.獲取指定頭字段的多個值
		Enumeration<String> names = request.getHeaderNames();
		while(names.hasMoreElements()){
			System.out.println(names.nextElement());
		}
		//3. 獲取請求頭中所有的請求頭字段的名稱
		Enumeration<String> list = request.getHeaderNames();//所有的鍵
		while(list.hasMoreElements()){
			String name = list.nextElement();
			String header = request.getHeader(name);
			response.getWriter().println(name + " === " + header + "<br/>");
		}
		//4.獲取指定名稱參數
		System.out.println("獲取指定名稱參數"+request.getParameter("username"));
		//5.獲取所有參數名
		Enumeration<String> parameterNames = request.getParameterNames();
		//6.獲取多個參數值
		System.out.println(Arrays.toString(request.getParameterValues("aihao")));
		//7.用於將請求消息中的所有參數名和值裝入進一個Map對象中返回
		Map<String, String[]> map = request.getParameterMap();
		for (String key : map.keySet()) {
			System.out.println(key + "--" + map.get(key));
		}
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}