【Java】【web】web.html映射配置文件

web.html影射配置文件

<!-- web.html -->
<!-- servletDemo5 -->
<servlet>
    <servlet-name>ServletDemo5</servlet-name>
    <servlet-class>com.demo.ServletDemo5</servlet-class>
    <!-- 配置信息 -->
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
</servlet>

<servlet-mapping>
    <servlet-name>ServletDemo5</servlet-name>
    <url-pattern>/demo5</url-pattern>
</servlet-mapping>

public class ServletDemo5 extends HttpServlet {

    private ServletConfig config;
    
    @Override
    public void init(ServletConfig config) throws ServletException {
        this.config = config;
    }
    
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 方式：1
         String encoding = this.config.getInitParameter("encoding");
         System.out.println(encoding);
        
        // 方式：2
        String encoding2 = super.getInitParameter("encoding");
        System.out.println(encoding2);
        
        // 方式：3
        String encoding3 = this.getServletConfig().getInitParameter("encoding");
        System.out.println(encoding3);
    }
    
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
    }

}