springboot Filter 截取 restful 的请求参数

初学springboot ，想自己定义一个 filter 截取参数用来验证签名，发现HttpServletRequest 并不能直接获取 json字符串，只能获取链接里的参数。

首先定义一个Filter文件， 然后实现Filter 的接口

package smaug.common.filters;import com.alibaba.fastjson.JSONObject;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.http.HttpServletRequest;import java.io.IOException;import java.util.Map;/** * Created by naonao on 17/5/14. */@WebFilter(filterName = "smaugFilter2", urlPatterns = "/*")public class SmaugFilter extends BaseFilter implements Filter {    Logger logger = LoggerFactory.getLogger(this.getClass());    @Override    public void init(FilterConfig filterConfig) throws ServletException {    }    @Override    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;        //获取nginx http的真实IP        String realIp = httpServletRequest.getHeader("X-Real-IP");//        Map<String, Object> map = readJsonMap(httpServletRequest);//        logger.info("filter => " + servletRequest.getRemoteHost() + "  " + JSONObject.toJSONString(map));        String quaryString = httpServletRequest.getQueryString();        logger.info("quaryString => " + quaryString);        String restUrl = (httpServletRequest.getRequestURL().toString());        filterChain.doFilter(servletRequest, servletResponse);    }    @Override    public void destroy() {    }}

然后将filter添加都请求链中

package smaug.common.configs;import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.stereotype.Component;import smaug.common.filters.SmaugFilter;/** * Created by naonao on 17/5/14. */@Componentpublic class FilterConfig {    @Bean    public FilterRegistrationBean filterRegistrationBean() {        FilterRegistrationBean bean = new FilterRegistrationBean();        bean.setFilter(smaugFilter());        bean.setOrder(1);        bean.addUrlPatterns("/*");        return bean;    }    @Bean    public SmaugFilter smaugFilter() {        return new SmaugFilter();    }}

因为article 方法是post 的，所以在postman 里 用post的方法 输入以下链接

http://localhost:3031/smaug/test/article?a=1&b=2

看到的log

2017-05-14 16:22:34.736  INFO 70532 --- [nio-3031-exec-1] smaug.common.filters.SmaugFilter         : quaryString => a=1&b=2

哈哈，现在都是restful的 天下，这样的filter显然不能满足当初定下的目标。注释掉的代码有用处了哈哈
就是这行代码

Map<String, Object> map = readJsonMap(httpServletRequest);

SmaugFilter 继承了一个父类的BaseFilter

package smaug.common.filters;import com.alibaba.fastjson.JSONObject;import com.alibaba.fastjson.TypeReference;import org.springframework.stereotype.Component;import javax.servlet.http.HttpServletRequest;import java.io.BufferedReader;import java.util.Map;/** * Created by naonao on 17/5/14. */public class BaseFilter {    public String readJSONString(HttpServletRequest request) {        StringBuffer json = new StringBuffer();        String line = null;        try {            BufferedReader reader = request.getReader();            while ((line = reader.readLine()) != null) {                json.append(line);            }        } catch (Exception e) {            System.out.println(e.toString());        }        return json.toString();    }    public Map<String, Object> readJsonMap(HttpServletRequest request) {        String json = readJSONString(request);        return JSONObject.parseObject(json, new TypeReference<Map<String, Object>>() {        });    }}

此时postman的参数

    "name" : "闹闹",    "age" : 12,    "requestId" : "12esdadfe3ed"}

得到的log日志

{"requestId":"12esdadfe3ed","name":"闹闹","age":12}

此时可以针对不同的请求进行不同的预先操作，比如 权限验证