一般我們新建一個servlet總要完成對應的環境配置，我們先來看看一個簡單得web.xml配置servlet:

<servlet>
    <servlet-name>FindAllProvinceServlet</servlet-name>
    <servlet-class>com.canyugan.web.servlet.FindAllProvinceServlet</servlet-class>
 </servlet>
 <servlet-mapping>
    <servlet-name>FindAllProvinceServlet</servlet-name>
    <url-pattern>/FindAllProvinceServlet</url-pattern>
 </servlet-mapping>
 

首先我們壓迫瞭解一個機制（不是機智），Servlet註解技術：

@WebServlet   取代servlet配置
@WebFilter       取代filter配置
@WebInitParam   取代初始化引數配置（servlet、filter）
@WebListener      取代listener配置

然後我們來看看註解後的程式碼：

@WebServlet(urlPatterns={"/one","/two"})//{}裡可以設定多個servlet名
public class HelloServlet extends HttpServlet 
{
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException 
	{
		response.getWriter().print("I am Annotation servlet build by 參與感");
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException 
	{
		doGet(request, response);
	}
}
 

@WebFilter(urlPatterns="/*")//多個servlet要攔截的話，加*
public class EncodingFilter implements Filter 
{

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 
			throws IOException, ServletException 
	{
		//編碼
		response.setContentType("text/html;charset=utf-8");
		chain.doFilter(request, response);
	}

	
	public void init(FilterConfig fConfig) throws ServletException 
	{
		
	}

	@Override
	public void destroy() 
	{
		
	}
}