servlert中的代码如下:public void init(ServletConfig config) throws ServletException {
// Put your code here
super.init(config);
String str = config.getInitParameter("email"); str = "afsf";
}
web.xml的配置信息如下:
<servlet-mapping>
<servlet-name>customOpe</servlet-name>
<url-pattern>/servlet/customOpe</url-pattern>
<init-param>
<param-name>email</param-name>
<param-value>qiyadeng</param-value>
</init-param>
<init-param>
<param-name>name</param-name>
<param-value>qiyadeng</param-value>
</init-param>
</servlet-mapping>在servlert无法用 String str = config.getInitParameter("email");返回为null?
// Put your code here
super.init(config);
String str = config.getInitParameter("email"); str = "afsf";
}
web.xml的配置信息如下:
<servlet-mapping>
<servlet-name>customOpe</servlet-name>
<url-pattern>/servlet/customOpe</url-pattern>
<init-param>
<param-name>email</param-name>
<param-value>qiyadeng</param-value>
</init-param>
<init-param>
<param-name>name</param-name>
<param-value>qiyadeng</param-value>
</init-param>
</servlet-mapping>在servlert无法用 String str = config.getInitParameter("email");返回为null?
<servlet-name>ReadInitParameter</servlet-name>
<servlet-class>com.test.ReadInitParameter</servlet-class>
<init-param>
<param-name>email</param-name>
<param-value>[email protected]</param-value>
</init-param>
<init-param>
<param-name>name</param-name>
<param-value>qiyadeng</param-value>
</init-param>
</servlet> <servletclass>com.test.ReadInitParameter</servlet-class>是servlet的完整路径,包括包名。
配置好了web.xml,现在可以在程序中读取初始化的参数了。在init(ServletConfig config)方法中传递了一个ServletConfig参数,可以这样获取初始化参数: public void init(ServletConfig config) throws ServletException
{
super.init(config);
String email = config.getInitParameter("email");
String name = config.getInitParameter("name");
}在其他的方法中象doGet(),doPost(),service()方法中可以用getServeltConfig()方法得到一个ServetConfig对象,在利用该对象的getInitParameter()方法取到对应的初始化参数。
String email = getServletConfig().getInitParameter("email");
String name= getServletConfig().getInitParameter("name");
servlet-mapping>
<servlet-name>customOpe </servlet-name>
<url-pattern>/servlet/customOpe </url-pattern>
<init-param>
<param-name>email </param-name>
<param-value>qiyadeng </param-value>
</init-param>
<init-param>
<param-name>name </param-name>
<param-value>qiyadeng </param-value>
</init-param>
</servlet-mapping>
你这个配置里面的email后面还有一空格去掉配置的里的空格,或在servlet中加一个空格String str = config.getInitParameter("email ");