标签：get lse header equals servet response 抽象 support exce
进行HTTP服务操作时，Servet所使用的类
Serlvet
Servlet对象的根接口，声明了提供Servlet服务所需要用到方法
ServletConfig
Serlvet配置对象接口，声明了获取Servlet配置参数的方法
ServletRequest
请求的接口，声明了请求操作的常用方法
ServletResponse
响应的接口，声明了响应的常用方法
GenericServlet
实现了Servlet和ServletConfig接口，重载了init方法，新增对application对象的访问方法
public ServletContext getServletContext()
{
return getServletConfig().getServletContext();
}
public void init()
throws ServletException
{}
HttpServlet
继承了GenericServlet，重载了使用HttpServletRequst、HttpServletResponse接口使用参数的service方法，扩展了doGet和doPost方法实现业务功能
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
String protocol = req.getProtocol();
String msg = lStrings.getString("http.method_get_not_supported");
if (protocol.endsWith("1.1")) {
resp.sendError(405, msg);
} else {
resp.sendError(400, msg);
}
}
dopost
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
String protocol = req.getProtocol();
String msg = lStrings.getString("http.method_post_not_supported");
if (protocol.endsWith("1.1")) {
resp.sendError(405, msg);
} else {
resp.sendError(400, msg);
}
}
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
String method = req.getMethod();
if (method.equals("GET"))
{
long lastModified = getLastModified(req);
if (lastModified == -1L)
{
doGet(req, resp);
}
else
{
long ifModifiedSince;
try
{
ifModifiedSince = req.getDateHeader("If-Modified-Since");
}
catch (IllegalArgumentException iae)
{
long ifModifiedSince;
ifModifiedSince = -1L;
}
if (ifModifiedSince < lastModified / 1000L * 1000L)
{
maybeSetLastModified(resp, lastModified);
doGet(req, resp);
}
else
{
resp.setStatus(304);
}
}
}
else if (method.equals("HEAD"))
{
long lastModified = getLastModified(req);
maybeSetLastModified(resp, lastModified);
doHead(req, resp);
}
else if (method.equals("POST"))
{
doPost(req, resp);
}
else if (method.equals("PUT"))
{
doPut(req, resp);
}
else if (method.equals("DELETE"))
{
doDelete(req, resp);
}
else if (method.equals("OPTIONS"))
{
doOptions(req, resp);
}
else if (method.equals("TRACE"))
{
doTrace(req, resp);
}
else
{
String errMsg = lStrings.getString("http.method_not_implemented");
Object[] errArgs = new Object[1];
errArgs[0] = method;
errMsg = MessageFormat.format(errMsg, errArgs);
resp.sendError(501, errMsg);
}
}
标签：get lse header equals servet response 抽象 support exce
原文地址：https://www.cnblogs.com/MrWuNotebook/p/10121613.html
