理清servlet的关系

javax.servlet.servlet是个接口

javax.servlet.GenericServlet实现上面的接口

javax.servlet.http.HttpServlet继承了javax.servlet.GenericServlet

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[color=red]javax.servlet.servlet接口中有这么些抽象的方法[/color]
void destroy()

ServletConfig getServletConfig()

java.lang.String getServletInfo()

void init(ServletConfig config)

void service(ServletRequest req, ServletResponse res)
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javax.servlet.GenericServlet实现上面的接口所以它也会有这些的方法的.
但是,javax.servlet.GenericServlet还可以实现其他的接口还可以继承一个类.因为java语言可以实现
多个接口.所以,它还会有其他的一些方法.
实际上javax.servlet.GenericServlet实现了这么几个接口:
java.io.Serializable, Servlet, ServletConfig
继承了object这个对象.

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javax.servlet.http.HttpServlet继承了javax.servlet.GenericServlet
那么GenericServlet有的方法它都有,而且还有自己的方法.

protected void doDelete(HttpServletRequest req, HttpServletResponse resp)

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

protected void doHead(HttpServletRequest req, HttpServletResponse resp)

protected void doOptions(HttpServletRequest req, HttpServletResponse resp)

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

protected void doPut(HttpServletRequest req, HttpServletResponse resp)

protected void doTrace(HttpServletRequest req, HttpServletResponse resp)

protected long getLastModified(HttpServletRequest req)

protected void service(HttpServletRequest req, HttpServletResponse resp)

void service(ServletRequest req, ServletResponse res)

这些都是它特有的方法