分页 图片上传 判空的工具类

pageBean
分页的辅助类

package com.zk.springboot.utils;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

/**
 * 分页工具类
 *
 */
public class PageBean {

	private int page = 1;// 页码

	private int rows = 10;// 页大小

	private int total = 0;// 总记录数

	private boolean pagination = true;// 是否分页
	
//	保存上次查询的参数
	private Map<String, String[]> paramMap;
//	保存上次查询的url
	private String url;
	
	public void setRequest(HttpServletRequest request) {
		String page = request.getParameter("page");
		String rows = request.getParameter("limit");
		String pagination = request.getParameter("pagination");
		this.setPage(page);
		this.setRows(rows);
		this.setPagination(pagination);
		this.setUrl(request.getRequestURL().toString());
		this.setParamMap(request.getParameterMap());
	}

	public PageBean() {
		super();
	}

	public Map<String, String[]> getParamMap() {
		return paramMap;
	}

	public void setParamMap(Map<String, String[]> paramMap) {
		this.paramMap = paramMap;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public int getPage() {
		return page;
	}

	public void setPage(int page) {
		this.page = page;
	}
	
	public void setPage(String page) {
		if(StringUtils.isNotBlank(page)) {
			this.page = Integer.parseInt(page);
		}
	}

	public int getRows() {
		return rows;
	}

	public void setRows(String rows) {
		if(StringUtils.isNotBlank(rows)) {
			this.rows = Integer.parseInt(rows);
		}
	}

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public void setTotal(String total) {
		if(StringUtils.isNotBlank(total)) {
			this.total = Integer.parseInt(total);
		}
	}

	public boolean isPagination() {
		return pagination;
	}

	public void setPagination(boolean pagination) {
		this.pagination = pagination;
	}
	
	public void setPagination(String pagination) {
		if(StringUtils.isNotBlank(pagination) && "false".equals(pagination)) {
			this.pagination = Boolean.parseBoolean(pagination);
		}
	}
	
	/**
	 * 最大页
	 * @return
	 */
	public int getMaxPage() {
		int max = this.total/this.rows;
		if(this.total % this.rows !=0) {
			max ++ ;
		}
		return max;
	}
	
	/**
	 * 下一页
	 * @return
	 */
	public int getNextPage() {
		int nextPage = this.page + 1;
		if(nextPage > this.getMaxPage()) {
			nextPage = this.getMaxPage();
		}
		return nextPage;
	}
	
	/**
	 * 上一页
	 * @return
	 */
	public int getPreviousPage() {
		int previousPage = this.page -1;
		if(previousPage < 1) {
			previousPage = 1;
		}
		return previousPage;
	}
		

	/**
	 * 获得起始记录的下标
	 * 
	 * @return
	 */
	public int getStartIndex() {
		return (this.page - 1) * this.rows;
	}

	@Override
	public String toString() {
		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
	}

}

StringUtils
图片上传以及判空方法

package com.zking.springboot03.utils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;

public class StringUtils {
	// 私有的构造方法，保护此类不能在外部实例化
	private StringUtils() {
	}

	/**
	 * 如果字符串等于null或去空格后等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isBlank(String s) {
		boolean b = false;
		if (null == s || s.trim().equals("")) {
			b = true;
		}
		return b;
	}
	
	/**
	 * 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isNotBlank(String s) {
		return !isBlank(s);
	}

	/**
	 * set集合转string
	 * @param hasPerms
	 * @return
	 */
	public static String SetToString(Set hasPerms){
		return  Arrays.toString(hasPerms.toArray()).replaceAll(" ", "").replace("[", "").replace("]", "");
	}

	/**
	 * 转换成模糊查询所需参数
	 * @param before
	 * @return
	 */
	public static String toLikeStr(String before){
		return isBlank(before) ? null : "%"+before+"%";
	}

	/**
	 *	将图片的服务器访问地址转换为真实存放地址
	 * @param imgpath	图片访问地址（http://localhost:8080/uploadImage/2019/01/26/20190126000000.jpg）
	 * @param serverDir	uploadImage
	 * @param realDir	E:/temp/
	 * @return
	 */
	public static String serverPath2realPath(String imgpath, String serverDir, String realDir) {
		imgpath = imgpath.substring(imgpath.indexOf(serverDir));
		return imgpath.replace(serverDir,realDir);
	}

	/**
	 * 过滤掉集合里的空格
	 * @param list
	 * @return
	 */
	public static List<String> filterWhite(List<String> list){
		List<String> resultList=new ArrayList<String>();
		for(String l:list){
			if(isNotBlank(l)){
				resultList.add(l);
			}
		}
		return resultList;
	}

	/**
	 * 从html中提取纯文本
	 * @param strHtml
	 * @return
	 */
	public static String html2Text(String strHtml) {
		String txtcontent = strHtml.replaceAll("</?[^>]+>", ""); //剔出<html>的标签
		txtcontent = txtcontent.replaceAll("<a>\\s*|\t|\r|\n</a>", "");//去除字符串中的空格,回车,换行符,制表符
		return txtcontent;
	}

	public static void main(String[] args) {
	}
}

PagerAspect
用于切入分页 实现分页

package com.zk.springboot03.component;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.zking.springboot03.utils.PageBean;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * 用于所有表的分页操作
 */
@Component
@Aspect
public class PagerAspect {

    @Around("execution(* *..*Service.*Pager(..))")
    public Object invoke(ProceedingJoinPoint args) throws Throwable{
        Object[] params = args.getArgs();
        PageBean pageBean = null;
        for (Object param : params) {
            if(param instanceof PageBean){
                pageBean = (PageBean) param;
                break;
            }
        }

        if (pageBean !=null && pageBean.isPagination())
        PageHelper.startPage(pageBean.getPage(),pageBean.getRows());

        Object proceed = args.proceed(params);

        if (pageBean !=null && pageBean.isPagination()){
            PageInfo pageInfo = new PageInfo((List)proceed);
            pageBean.setTotal(pageInfo.getTotal()+"");
        }
        return proceed;
    }
}