优雅自定义请求&servlet方法调用一体化

开篇

新入手java开发，在学习servlet的过程中，大家都知道sevlet是请求响应模式，那么一个httpservlet之定义了service(),doget(),dopost()方法，极大的限制开发效率，如何做到网络请求就像调用java中的函数一样轻松？，接下来就该问题简单聊一聊个人想法。

Filter分发请求

过滤器在站点初始化的时候会init，通过在web.xml中的url-pattern配置，所有的该路径下的请求都会最先通过Filter的doFilter方法,那么，我们就可以再该方法中分发我们的请求，前提是，我们要对URL进行处理，在去分发。

 @Override    public void init(FilterConfig filterConfig) throws ServletException {    //获取web.xml中的init-param参数(扩展性强)        Log.e("Encoding-start");        String s = filterConfig.getInitParameter("sqlit");        if (s==null||s.equals("")){            sqlit = "!";        }else sqlit = s;    }

 @Override    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {//这里可以强转servletRequest的实质就是HttpServletRequest 对象        HttpServletRequest req = (HttpServletRequest) servletRequest;        String[] strs = req.getRequestURI().toString().split(sqlit);       if (strs.length>1)         servletRequest.setAttribute("method",strs[1]);        servletRequest.setCharacterEncoding("utf-8");        servletResponse.setContentType("text/html;charset=utf-8");        Log.e("Encoding-do");        String context = servletRequest.getServletContext().getContextPath();        String dispatcherPath = strs[0].replace(context,"");        servletRequest.getRequestDispatcher(dispatcherPath).forward(servletRequest,servletResponse);    }

创建Servlet基类BaseAction

该基类我们要处理一件事，就是讲请求分发至方法，不同的请求调用对应的方法。

package com.yzz.java.base;import com.yzz.java.util.Log;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;/** * Created by yzz on 2017/9/6. * mail:[e-mail] */public class BaseAction extends HttpServlet{    protected HttpServletRequest req;    protected HttpServletResponse resp;    @Override    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        this.req = req;        this.resp = resp;        String method = (String) req.getAttribute("method");        try {            this.getClass().getMethod(method).invoke(this);        } catch (Exception e) {            e.printStackTrace();        }    }}

使用

集成BaseAction,然后使用跟普通的java类没有任何区别

package com.yzz.java.action.cookie;import com.yzz.java.base.BaseAction;import com.yzz.java.util.Log;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.net.URLEncoder;import java.util.List;import java.util.Map;/** * Created by yzz on 2017/9/6. * mail:[e-mail] */public class CookieServlet extends BaseAction {    public void setCookie() throws Exception{        String name = req.getParameter("name");        Log.e(name);        Map<String,String[]> map = req.getParameterMap();        for (Map.Entry<String,String[]> en:map.entrySet()){            for (String str:en.getValue()) {                String encodestr = URLEncoder.encode(str,"utf-8");                Log.e(encodestr);                Cookie cookie = new Cookie(en.getKey(),encodestr);                cookie.setPath(getServletContext().getContextPath());                cookie.setHttpOnly(true);                cookie.setMaxAge(10);                resp.addCookie(cookie);            }        }        resp.getWriter().write("已保存cookie");    }    public void deleteCookie() throws Exception{        Cookie[] cookie = req.getCookies();        for (Cookie c:cookie){            c.setMaxAge(0);            resp.addCookie(c);        }        resp.getWriter().write("删除成功");    }}

总结

本工具尚未实现将body的参数转化为Bean像SpringMVC一样，由于时间问题，我就不做这块了，下次再补充。欢迎交流，各位大佬。