Java_Web------ServletRequest實現
public interface ServletRequest
Defines an object to provide client request information to a servlet. The
servlet container creates a ServletRequest object and passes it as
an argument to the servlet's service method.
A ServletRequest object provides data including parameter name
and values, attributes, and an input stream. Interfaces that extend
ServletRequest can provide additional protocol-specific data (for
example, HTTP data is provided by HttpServletRequest.
ServletRequest是一個Java EE 接口，其中HttpServletRequest是其子接口。這兩個接口封裝了許多處理web請求的相關方法，如獲取參數名稱Name、Names，通過參數名稱獲取參數值、獲取請求協議、request請求URI、URL等，功能非常強大！下面僅列舉自己練習的幾個方法，更多方法可以參考Java EE API。
最後總結：今天我發現查看英文文檔其實並沒有想象中的那麼難，只是每看一行需要花額外多一點點的時間而已！這時間很短，但我感覺對於學習階段的我來說，看英文文檔是很有幫助的，個人感覺很爽！不懂可以下載個有道詞典嘛！
在一個Servlet中重寫一個service()方法
@Override
public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
System.out.println("servie......");
//通過request對象獲取參數值
String user = request.getParameter("user");
String password = request.getParameter("password");
System.out.println(user+": "+password);
//獲取當前請求的所有參數名稱
Enumeration<String> names = request.getParameterNames();
while(names.hasMoreElements()){
String name = names.nextElement();
System.out.println(name);
}
//獲取指定參數名的所有value
String [] values = request.getParameterValues("0");
for(String value : values){
System.out.println(value);
}
//遍歷Map集合中的鍵值對（key-value）
Map<String,String[]> map = request.getParameterMap();
for (Map.Entry<String, String[]> entry : map.entrySet()) {
System.out.println("^^"+entry.getKey() + ": "+ Arrays.asList(entry.getValue()));
}
System.out.println("==================");
System.out.println("協議名稱和版本爲："+request.getProtocol());
System.out.println("服務器名"+request.getServerName()+" ，服務器端口號： "+request.getServerPort());
System.out.println("該請求是否是安全的（即https://）"+request.isSecure());
//HttpServletRequest是ServletRequest的一個子接口
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
String httpRequestURL =new String(httpServletRequest.getRequestURL());
System.out.println("Request的URL爲："+httpRequestURL);
String method = httpServletRequest.getMethod();
System.out.println("Request請求的方式爲： "+ method);