Inception~分页拦截器的使用（积累）

package com.bee.inception.thanos.web.intercepter;

import com.bee.inception.thanos.common.bean.Pager;
import com.bee.inception.thanos.common.constant.Constants;
import com.bee.inception.thanos.common.context.PageContext;
import com.bee.inception.thanos.service.common.HotConfigService;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Enumeration;

import static com.bee.inception.thanos.common.context.PageContext.*;

/**
 * @Date: Created in 16:24 2019/3/15
 */
public class PagerInterceptor extends HandlerInterceptorAdapter {

    private static Logger logger= LoggerFactory.getLogger(PagerInterceptor.class);

    @Resource
    private HotConfigService hotConfigService;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //如果有pageIndex则用pageIndex,否则用page！page是从1开始
        int page = ServletRequestUtils.getIntParameter(request, "page", 1);
        Integer pageIndex = ServletRequestUtils.getIntParameter(request, "pageIndex", page - 1);
        Integer pageSize = hotConfigService.getIntValue(Constants.HOT_PAGESIZE, 10);

        // 封装分页信息
        if (pageIndex >= 0 && pageSize >= 0) {
            Pager pager = new Pager(pageIndex, pageSize);
            pager.setPage(page);
            //学习地方,ThreadLocal的用法
            setPager(pager);
        }
        monitorRequestUrl(request);
        return super.preHandle(request, response, handler);
    }
    /**
      *学习地方
     */
    private void monitorRequestUrl(HttpServletRequest request){
        try {
            Enumeration<String> parameterNames = request.getParameterNames();
            StringBuilder params = new StringBuilder();
            while (parameterNames.hasMoreElements()) {
                String name = parameterNames.nextElement();
                if (StringUtils.isNotBlank(name)) {
                    String value = request.getParameter(name);
                    if (value != null && value.length() > 1000) {
                        value = "[参数太长省略]";
                    }
                    params.append(name).append("=").append(value).append("&");
                }
            }
            logger.info("request uri:{} parameter:{}",request.getRequestURI(),params.toString());
        }catch (Exception e){
            logger.error("monitorRequestUrl error",e);
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        try {
            if (ex == null) {
                Pager pager = getPager();
                request.setAttribute("pager", pager);
            }
            super.afterCompletion(request, response, handler, ex);
        } finally {
            //学习地方之一,ThreadLocal取消
            PageContext.release();
        }
    }
}

工具类承接上文

 

public class PageContext {
    //学习地方ThreadLocal的用法
    private static ThreadLocal<Pager> context = new ThreadLocal<Pager>();

    public static void setPager(Pager pager) {
        context.set(pager);
    }

    public static Pager getPager() {
        return context.get();
    }

    public static void release() {
        context.remove();
    }
}