servlet配置了初始化参数后,web容器在创建servlet实例对象时,会自动将这些初始化参数封装到ServletConfig对象中,并在调用servlet的init方法时,将ServletConfig对象传递给servlet
<servlet>
<servlet-name></servlet-name>
<servlet-class></servlet-class>
<init-param>
<param-name></param-name>
<param-value></param-value>
</init-param>
</servlet>
TIPS:
在实际开发中 直接可以通过getServletConfig()得到ServletConfig对象
String | getInitParameter(String name) Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist. |
Enumeration | getInitParameterNames() Returns the names of the servlet's initialization parameters as an Enumeration of String objects, or an empty Enumeration if the servlet has no initialization parameters. |
ServletContext | getServletContext() Returns a reference to the ServletContext in which the caller is executing. |
String | getServletName() Returns the name of this servlet instance. |