时间:2022-11-07 09:38:22 | 栏目:JAVA代码 | 点击:次
在实际项目开发中,对于Excel的导入导出还是很常见的需求,比如说将数据根据模板批量导入到数据库中,以及将数据库中的数据批量导出陈Excel的形式
现有需求: 根据检索条件查询列表并将结果导出到excel
Easypoi文档:https://easypoi.mydoc.io/#text_186900
EasyPoi的主要特点
1.设计精巧,使用简单
2.接口丰富,扩展简单
3.默认值多,write less do more
4.spring mvc支持,web导出可以简单明了
快速生成链接:start.spring.io
<!--EasyPoi导入导出--> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-base</artifactId> <version>4.3.0</version> </dependency> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-web</artifactId> <version>4.3.0</version> </dependency> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-annotation</artifactId> <version>4.3.0</version> </dependency>
sax 导入使用xercesImpl这个包(这个包可能造成奇怪的问题哈),word导出使用poi-scratchpad,都作为可选包了
pom.xml中的所有依赖:
<dependencies> <!-- 导入web支持:SpringMVC开发支持,Servlet相关的程序 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> <optional>true</optional> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!-- mybatis相关的依赖 --> <!--mybatis-plus自动的维护了mybatis以及mybatis-spring的依赖, 在springboot中这三者不能同时的出现,避免版本的冲突,表示:跳进过这个坑--> <!--mybatis-plus--> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.4.3</version> </dependency> <!--mysql驱动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <!-- alibaba的druid数据库连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.20</version> </dependency> <!-- alibaba的druid数据库连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.20</version> </dependency> <!--swagger2依赖--> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.9.2</version> <!--排除自身的依赖1.5.20版本--> <exclusions> <exclusion> <groupId>io.swagger</groupId> <artifactId>swagger-models</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger-ui</artifactId> <version>2.9.2</version> </dependency> <!--此版本解决 example="" 造成的 空字符串""无法转成Number 问题--> <dependency> <groupId>io.swagger</groupId> <artifactId>swagger-models</artifactId> <version>1.5.21</version> </dependency> <!--EasyPoi导入导出--> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-base</artifactId> <version>4.3.0</version> </dependency> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-web</artifactId> <version>4.3.0</version> </dependency> <dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-annotation</artifactId> <version>4.3.0</version> </dependency> <!--fastjson--> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.71</version> </dependency> </dependencies>
package com.example.easypoiexceldemo.utils; import cn.afterturn.easypoi.excel.ExcelExportUtil; import cn.afterturn.easypoi.excel.entity.ExportParams; import cn.afterturn.easypoi.excel.entity.enmus.ExcelType; import org.apache.commons.lang3.StringUtils; import org.apache.poi.ss.usermodel.Workbook; import org.springframework.beans.BeanUtils; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.net.URLEncoder; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Collection; import java.util.Date; import java.util.List; /** * excel工具类 * @author qzz */ public class ExcelUtils { /** * Excel导出 * * @param response response * @param fileName 文件名 * @param list 数据List * @param pojoClass 对象Class */ public static void exportExcel(HttpServletResponse response, String fileName, Collection<?> list, Class<?> pojoClass) throws IOException { if (StringUtils.isBlank(fileName)) { //当前日期 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd"); fileName = df.format(new Date()); } Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(fileName, fileName, ExcelType.HSSF), pojoClass, list); response.setCharacterEncoding("UTF-8"); response.setHeader("content-Type", "application/vnd.ms-excel"); response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls"); ServletOutputStream out = response.getOutputStream(); workbook.write(out); out.flush(); } /** * Excel导出,先sourceList转换成List<targetClass>,再导出 * * @param response response * @param fileName 文件名 * @param sourceList 原数据List * @param targetClass 目标对象Class */ public static void exportExcelToTarget(HttpServletResponse response, String fileName, Collection<?> sourceList, Class<?> targetClass) throws Exception { List targetList = new ArrayList<>(sourceList.size()); for (Object source : sourceList) { Object target = targetClass.newInstance(); BeanUtils.copyProperties(source, target); targetList.add(target); } exportExcel(response, fileName, targetList, targetClass); } /** * Excel导出----设置title---sheetName---要求Collection<?> list是Class<?> pojoClass类型的 * * @param response response * @param fileName 文件名 * @param list 数据List * @param pojoClass 对象Class */ public static void exportExcel(HttpServletResponse response, String title, String sheetName, String fileName, Collection<?> list, Class<?> pojoClass) throws IOException { if (StringUtils.isBlank(fileName)) { //当前日期 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd"); fileName = df.format(new Date()); } Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(title, sheetName, ExcelType.HSSF), pojoClass, list); response.setCharacterEncoding("UTF-8"); response.setHeader("content-Type", "application/vnd.ms-excel"); response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls"); ServletOutputStream out = response.getOutputStream(); workbook.write(out); out.flush(); } }
我这边使用了lombok。getter setter和构造方法通过注解 @Data @AllArgsConstructor进行添加,不使用lombok也可手动添加。
要导出的数据可在实体类对应属性上方加**@Excel()注解
**。可定义导出列的名称、宽度,以及性别可区分化(一般数据库中存储的性别为1和2),日期格式化等等。
package com.example.easypoiexceldemo.excel; import cn.afterturn.easypoi.excel.annotation.Excel; import lombok.Data; import java.util.Date; /** * 商品 * @author qzz */ @Data public class ProductExcel { /** * 商品id */ @Excel(name = "商品id") private Integer product_id; /** * 商品标题 */ @Excel(name="商品标题") private String title; /** * 商品副标题 */ @Excel(name="商品副标题") private String sub_title; /** * 商品售价 */ @Excel(name="商品售价") private Double sale_price; /** * 创建者 */ @Excel(name="创建者") private Integer create_by; /** * 创建时间 */ @Excel(name="创建时间", format = "yyyy-MM-dd") private Date create_time; /** * 修改时间 */ @Excel(name="修改时间", format = "yyyy-MM-dd") private Date update_time; /** * 修改者id */ @Excel(name="修改者id") private Integer update_by; }
@Excel 作用到filed上面,是对Excel一列的一个描述
@Excel 的属性介绍:
/** * excel导出 * @param response */ @GetMapping("/excel") @ApiOperation("根据检索条件查询列表,导出excel") public void export( HttpServletResponse response) throws IOException { //根据条件检索列表 QueryWrapper<Product> queryWrapper = new QueryWrapper(); //根据条件检索商品列表 List<Map<String, Object>> list = productService.selectList(queryWrapper); //将List<Map<String, Object>>结果集转换成List<ProductExcel> List<ProductExcel> productList = MapToEntity.setList(list,ProductExcel.class); //导出excel ExcelUtils.exportExcel(response,null,productList, ProductExcel.class); }
setList方法为工具类,用于将List<Map<String, Object>>结果集转换成List
MapToEntity工具类:
package com.example.easypoiexceldemo.utils; import org.apache.commons.lang3.StringUtils; import java.lang.reflect.Field; import java.math.BigDecimal; import java.text.ParseException; import java.text.ParsePosition; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Map; /** * List<Map<String,Object>>到List<T>数据转换 * @author qzz */ public class MapToEntity { /** * List<Map<String, Object>> 到 List<T> 数据转换 */ public static <T> List<T> setList(final List<Map<String, Object>> srcList, Class<T> clazz) { List<T> list = new ArrayList<>(); for (int i=0;i<srcList.size();i++){ try { T t = clazz.newInstance(); Field[] fields = t.getClass().getDeclaredFields(); for (Field field : fields) { if (!"serialVersionUID".equals(field.getName())) { //设置对象的访问权限,保证对private的属性的访问 field.setAccessible(true); //读取配置转换字段名,并从map中取出数据 Object v = srcList.get(i).get(field.getName()); field.set(t, convert(v, field.getType())); } } list.add(t); } catch (Exception ex) { ex.toString(); } }; return list; } /** * 字段类型转换 */ private static <T> T convert(Object obj, Class<T> type) throws ParseException { if (obj != null && StringUtils.isNotBlank(obj.toString())) { if (type.equals(String.class)) { return (T) obj.toString(); } else if (type.equals(BigDecimal.class)) { return (T) new BigDecimal(obj.toString()); }else if(type.equals(Double.class)){ return (T) Double.valueOf(obj.toString()); }else if(type.equals(Integer.class)){ return (T) Integer.valueOf(obj.toString()); }else if(type.equals(Date.class)){ if(obj!=null){ String timeStr = String.valueOf(obj); String s[] = timeStr.split("T"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return (T) sdf.parse(s[0]+" "+s[1]); }else{ return null; } } else{ //其他类型转换 return (T) obj.toString(); } } return null; } }
项目启动成功后,在浏览器中输入 http://localhost:8083/product/excel,进行访问:
打开导出的excel文档: