SpringMVC的上传下载

 StringUtils .xml

package com.tsq.util;
 
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);
	}
 
}

PageBean .java 

package com.tsq.util;
 
import java.util.HashMap;
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
	
	private String url; //保存上一次请求的URL
	
	private Map paramMap = new HashMap<>();// 保存上一次请求的参数
	
	/**
	 * 初始化pagebean的，保存上一次请求的重要参数
	 * @param req
	 */
	public void setRequest(HttpServletRequest req) {
//		1.1	需要保存上一次请求的URL
		this.setUrl(req.getRequestURL().toString());
//		1.2	需要保存上一次请求的参数	bname、price
		this.setParamMap(req.getParameterMap());
//		1.3	需要保存上一次请求的分页设置	pagination
		this.setPagination(req.getParameter("pagination"));
//		1.4	需要保存上一次请求的展示条目数
		this.setRows(req.getParameter("rows"));
//		1.5  初始化请求的页码	page
		this.setPage(req.getParameter("page"));
	}
	
	public void setPage(String page) {
		if(StringUtils.isNotBlank(page))
			this.setPage(Integer.valueOf(page));
	}
 
	public void setRows(String rows) {
		if(StringUtils.isNotBlank(rows))
			this.setRows(Integer.valueOf(rows));
	}
 
	public void setPagination(String pagination) {
//		只有在前台jsp填写了pagination=false，才代表不分页
		if(StringUtils.isNotBlank(pagination))
			this.setPagination(!"false".equals(pagination));
	}
 
 
	public String getUrl() {
		return url;
	}
 
	public void setUrl(String url) {
		this.url = url;
	}
 
	public Map getParamMap() {
		return paramMap;
	}
 
	public void setParamMap(Map paramMap) {
		this.paramMap = paramMap;
	}
 
 
 
	public PageBean() {
		super();
	}
 
	public int getPage() {
		return page;
	}
 
	public void setPage(int page) {
		this.page = page;
	}
 
	public int getRows() {
		return rows;
	}
 
	public void setRows(int rows) {
		this.rows = rows;
	}
 
	public int getTotal() {
		return total;
	}
 
	public void setTotal(int total) {
		this.total = total;
	}
 
	public void setTotal(String total) {
		this.total = Integer.parseInt(total);
	}
 
	public boolean isPagination() {
		return pagination;
	}
 
	public void setPagination(boolean pagination) {
		this.pagination = pagination;
	}
 
	/**
	 * 获得起始记录的下标
	 * 
	 * @return
	 */
	public int getStartIndex() {
		return (this.page - 1) * this.rows;
	}
	
	/**
	 * 最大页
	 * @return
	 */
	public int maxPage() {
//		total % rows == 0 ? total / rows : total / rows +1
		return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
	}
	
	/**
	 * 下一页
	 * @return
	 */
	public int nextPage() {
//		如果当前页小于最大页，那就下一页为当前页+1；如果不小于，说明当前页就是最大页，那就无需+1
		return this.page < this.maxPage() ? this.page + 1 : this.page;
	}
	
	/**
	 * 上一页
	 * @return
	 */
	public int previousPage() {
		return this.page > 1 ? this.page - 1 : this.page;
	}
 
	@Override
	public String toString() {
		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
	}
 
}

zking.tld

"1.0" encoding="UTF-8" ?>
 
"http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
    version="2.0">
    
  zking 1.1 core library
  zking core
  1.1
  <short-name>zkingshort-name>
  http://jsp.veryedu.cn
  
  
  
    page
    com.cxy.util.PageTag
    JSP
    
        pageBean
        true
        true
    
  
  

 Clazz.java

package com.tsq.model;
 
public class Clazz {
    protected Integer cid;
 
    protected String cname;
 
    protected String cteacher;
 
    protected String pic;
 
    public Clazz(Integer cid, String cname, String cteacher, String pic) {
        this.cid = cid;
        this.cname = cname;
        this.cteacher = cteacher;
        this.pic = pic;
    }
 
    public Clazz() {
        super();
    }
 
    public Integer getCid() {
        return cid;
    }
 
    public void setCid(Integer cid) {
        this.cid = cid;
    }
 
    public String getCname() {
        return cname;
    }
 
    public void setCname(String cname) {
        this.cname = cname;
    }
 
    public String getCteacher() {
        return cteacher;
    }
 
    public void setCteacher(String cteacher) {
        this.cteacher = cteacher;
    }
 
    public String getPic() {
        return pic;
    }
 
    public void setPic(String pic) {
        this.pic = pic;
    }
}

ClazzMapper.java

package com.tsq.mapper;
 
import com.tsq.model.Clazz;
import com.tsq.util.PageBean;
import org.springframework.stereotype.Repository;
 
import java.util.List;
 
@Repository
public interface ClazzMapper {
    int deleteByPrimaryKey(Integer cid);
 
    int insert(Clazz record);
 
    int insertSelective(Clazz record);
 
    Clazz selectByPrimaryKey(Integer cid);
 
    int updateByPrimaryKeySelective(Clazz record);
 
    int updateByPrimaryKey(Clazz record);
 
    List listPager(Clazz record);
 
}

ClazzMapper.xml

"1.0" encoding="UTF-8" ?>
"-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
"com.tsq.mapper.ClazzMapper" >
  "BaseResultMap" type="com.tsq.model.Clazz" >
    
      "cid" jdbcType="INTEGER" javaType="java.lang.Integer" />
      "cname" jdbcType="VARCHAR" javaType="java.lang.String" />
      "cteacher" jdbcType="VARCHAR" javaType="java.lang.String" />
      "pic" jdbcType="VARCHAR" javaType="java.lang.String" />
    
  
  "Base_Column_List" >
    cid, cname, cteacher, pic
  
 
  "listPager" resultType="com.tsq.model.Clazz" parameterType="com.tsq.model.Clazz" >
    select
    "Base_Column_List" />
    from t_struts_class
   
     <if test="cname != null and cname !=''">
       and cname like CONCAT('%',#{cname},'%')
     if>
     <if test="cid != null and cid !=''">
      and cid =#{cid}
     if>
   
  
 
  "selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    "Base_Column_List" />
    from t_struts_class
    where cid = #{cid,jdbcType=INTEGER}
  
  "deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_struts_class
    where cid = #{cid,jdbcType=INTEGER}
  
  "insert" parameterType="com.tsq.model.Clazz" >
    insert into t_struts_class (cid, cname, cteacher, 
      pic)
    values (#{cid,jdbcType=INTEGER}, #{cname,jdbcType=VARCHAR}, #{cteacher,jdbcType=VARCHAR}, 
      #{pic,jdbcType=VARCHAR})
  
  "insertSelective" parameterType="com.tsq.model.Clazz" >
    insert into t_struts_class
    "(" suffix=")" suffixOverrides="," >
      <if test="cid != null" >
        cid,
      if>
      <if test="cname != null" >
        cname,
      if>
      <if test="cteacher != null" >
        cteacher,
      if>
      <if test="pic != null" >
        pic,
      if>
    
    "values (" suffix=")" suffixOverrides="," >
      <if test="cid != null" >
        #{cid,jdbcType=INTEGER},
      if>
      <if test="cname != null" >
        #{cname,jdbcType=VARCHAR},
      if>
      <if test="cteacher != null" >
        #{cteacher,jdbcType=VARCHAR},
      if>
      <if test="pic != null" >
        #{pic,jdbcType=VARCHAR},
      if>
    
  
  "updateByPrimaryKeySelective" parameterType="com.tsq.model.Clazz" >
    update t_struts_class
    
      <if test="cname != null" >
        cname = #{cname,jdbcType=VARCHAR},
      if>
      <if test="cteacher != null" >
        cteacher = #{cteacher,jdbcType=VARCHAR},
      if>
      <if test="pic != null" >
        pic = #{pic,jdbcType=VARCHAR},
      if>
    
    where cid = #{cid,jdbcType=INTEGER}
  
  "updateByPrimaryKey" parameterType="com.tsq.model.Clazz" >
    update t_struts_class
    set cname = #{cname,jdbcType=VARCHAR},
      cteacher = #{cteacher,jdbcType=VARCHAR},
      pic = #{pic,jdbcType=VARCHAR}
    where cid = #{cid,jdbcType=INTEGER}
  

ClazzBiz.xml

package com.tsq.biz;
 
import com.tsq.model.Clazz;
import com.tsq.util.PageBean;
 
import java.util.List;
 
public interface ClazzBiz {
    int deleteByPrimaryKey(Integer cid);
 
    int insert(Clazz record);
 
    int insertSelective(Clazz record);
 
    Clazz selectByPrimaryKey(Integer cid);
 
    int updateByPrimaryKeySelective(Clazz record);
 
    int updateByPrimaryKey(Clazz record);
 
    List listPager(Clazz record, PageBean pageBean);
}

ClazzBizImpl.java

package com.tsq.biz.impl;
 
import com.tsq.biz.ClazzBiz;
import com.tsq.mapper.ClazzMapper;
import com.tsq.model.Clazz;
import com.tsq.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
@Service
public class ClazzBizImpl implements ClazzBiz {
    @Autowired
    private ClazzMapper clazzMapper;
 
    @Override
    public int deleteByPrimaryKey(Integer cid) {
        return clazzMapper.deleteByPrimaryKey(cid);
    }
 
    @Override
    public int insert(Clazz record) {
        return clazzMapper.insert(record);
    }
 
    @Override
    public int insertSelective(Clazz record) {
        return clazzMapper.insertSelective(record);
    }
 
    @Override
    public Clazz selectByPrimaryKey(Integer cid) {
        return clazzMapper.selectByPrimaryKey(cid);
    }
 
    @Override
    public int updateByPrimaryKeySelective(Clazz record) {
        return clazzMapper.updateByPrimaryKeySelective(record);
    }
 
    @Override
    public int updateByPrimaryKey(Clazz record) {
        return clazzMapper.updateByPrimaryKey(record);
    }
 
    @Override
    public List listPager(Clazz record, PageBean pageBean) {
        return clazzMapper.listPager(record);
    }
 
 
}

ClazzController .java 

package com.tsq.controller;
 
import com.tsq.biz.ClazzBiz;
import com.tsq.model.Clazz;
import com.tsq.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
 
 
import javax.servlet.http.HttpServletRequest;
import java.util.List;
 
@Controller
@RequestMapping("/clz")
public class ClazzController {
    @Autowired
    private ClazzBiz clazzBiz;
 
    @RequestMapping("/list")
    public  String list(Clazz clazz, HttpServletRequest request){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        List list = this.clazzBiz.listPager(clazz,pageBean);
        request.setAttribute("lst",list);
        request.setAttribute("pageBean",pageBean);
        return "clzList";
    }
 
    @RequestMapping("/toEdit")
    public  String toEdit(Clazz clazz, HttpServletRequest request){
        Integer cid = clazz.getCid();
        if(cid!=null){
            List lst = this.clazzBiz.listPager(clazz, null);
            request.setAttribute("b",lst.get(0));
        }
        return "clzEdit";
    }
 
    @RequestMapping("/add")
    public  String add(Clazz clazz, HttpServletRequest request){
        this.clazzBiz.insertSelective(clazz);
        return "redirect:/clz/list";
    }
 
    @RequestMapping("/del")
    public  String delete(Clazz clazz, HttpServletRequest request){
        this.clazzBiz.deleteByPrimaryKey(clazz.getCid());
        return "redirect:/clz/list";
    }
 
    @RequestMapping("/edit")
    public  String edit(Clazz clazz, HttpServletRequest request){
        this.clazzBiz.updateByPrimaryKeySelective(clazz);
        return "redirect:/clz/list";
    }
 
}

clzList.jsp(主界面) 

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<%@ taglib uri="http://jsp.veryedu.cn" prefix="z"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
"-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    "Content-Type" content="text/html; charset=UTF-8">
    
            href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
            rel="stylesheet">
    
            src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js">
    
    
"form-inline"
      action="${pageContext.request.contextPath }/clz/list" method="post">
    
"form-group mb-2">
        "text" class="form-control-plaintext" name="cname"
               placeholder="请输入班级名称">
        
        
        "pagination" value="false" type="hidden">
    
    "submit" class="btn btn-primary mb-2">查询
    "btn btn-primary mb-2" href="${pageContext.request.contextPath }/clz/toEdit">新增
 
"table table-striped bg-success">
    
    
        
        
        
        
        
    
    
    
    var="b" items="${lst }">
        
            
            
            
            
            
        
    
    
"col">ID
"col">名字
"col">教师
"col">图片
"col">操作
${b.cid }
${b.cname }
${b.cteacher }
${b.pic}
                "${pageContext.request.contextPath }/clz/toEdit?cid=${b.cid}">修改
                "${pageContext.request.contextPath }/clz/del?cid=${b.cid}">删除
            
"${pageBean }">
 

结果如下

 clzEdit.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
"-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    "Content-Type" content="text/html; charset=UTF-8">
    
"${pageContext.request.contextPath }/clz/${empty b ? 'add' : 'edit'}" method="post">
    cid:"text" name="cid" value="${b.cid }">
    cname:"text" name="cname" value="${b.cname }">
    cteacher:"text" name="cteacher" value="${b.cteacher }">
    "submit">

二、图片上传

1、步骤
1、springmvc.xml中添加多功能解析器配置

2、前台的页面 添加 多功能表单设置  multipart/form-data

3、后台要利用multipartFile类进行 文件接收

        注：multipartFile的属性名一定要跟form中的表单属性名一致

4、在idea中完成图片请求地址与硬盘中地址的映射关系

2、导pom依赖

      commons-fileupload
      commons-fileupload
      1.3.3

3、springmvc-servlet.xml配置

"multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        
        "defaultEncoding" value="UTF-8">
        
        "maxUploadSize" value="52428800">
        
        "resolveLazily" value="true"/>
    

4、Dto编写

Dto：接收参数，参数不仅仅存在于实体类Model中。

package com.tsq.util;
 
import com.tsq.model.Clazz;
import org.springframework.web.multipart.MultipartFile;
 
public class ClazzDto extends Clazz {
    private MultipartFile picFile;
 
    public MultipartFile getPicFile() {
        return picFile;
    }
 
    public void setPicFile(MultipartFile picFile) {
        this.picFile = picFile;
    }
}

将clazz.java 里的属性private 改为 protected

 5、编写ClazzController.java

//    文件上传
    @RequestMapping("/upload")
    public String upload(ClazzDto clazzDto){
        try {
            //前台上传的文件
            MultipartFile picFile = clazzDto.getPicFile();
            //实际应该配置到resource.properties中
            String diskPath="E:/temp/images/";//图片存放地址
            //http://localhost:8080/upload/mvc/...png
            String requestPath="/upload/mvc/";//数据库保存地址，也是访问地址
 
            //拿到上传文件的名字
            String filename = picFile.getOriginalFilename();
            FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(diskPath+filename));
 
            //将图片上传图片之后，并且将图片地址更新到数据库中
            Clazz clazz=new Clazz();
            clazz.setCid(clazzDto.getCid());
            clazz.setPic(requestPath+filename);
 
            this.clazzBiz.updateByPrimaryKeySelective(clazz);
        }catch (Exception e){
            e.printStackTrace();
        }
        return "redirect:/clz/list";
    }