easy Exsel导出

一、首先引入依赖

二、然后封装一个VO

三、Controller层

四、Service实现类

分配到这个任务了，写个小demo记录下，具体可参考EasyExcel官方文档

我用的是web上传、下载那块代码

一、首先引入依赖

        <!--    easy Excel    -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.1.0</version>
            <exclusions>
                <exclusion>
                    <artifactId>poi-ooxml-schemas</artifactId>
                    <groupId>org.apache.poi</groupId>
                </exclusion>
            </exclusions>
        </dependency>

二、然后封装一个VO

@Data
@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode
public class ExportStudentInfoVO implements Serializable {

    private static final long serialVersionUID = -3275970951989418695L;


    @ExcelIgnore // 忽略导出
    private String stuId;

    @ExcelProperty("学生姓名")
    private String stuName;

    @ExcelProperty("学生性别")
    private String stuGender;

    @ExcelProperty("学生年龄")
    private Integer stuAge;

    @ExcelProperty("监护人联系方式")
    private String guardianPhone;

    @DateTimeFormat("yyyy-MM-dd HH:mm:ss")
    @ColumnWidth(21) //设置宽度
    @ExcelProperty(value = "入学时间")
    private Date createDate;
}

三、Controller层

@RestController
@RequestMapping("info")
public class InfoController {

    @Resource
    private InfoService infoService;

    @Operation(summary = "学生信息导出")
    @RequestMapping(value = "/excelDownload", method = RequestMethod.GET, produces = "application/json; charset=utf-8")
    public void excelOrderContainerDownload(HttpServletResponse response){
        infoService.excelDownload(response);
    }

}

四、Service实现类

这里的list，模拟从DB中查到的数据

.registerWriteHandler(new CustomCellWriteWidthConfig()) /*自适应列宽*/
.registerWriteHandler(new CustomCellWriteHeightConfig()) /*自适应行高*/
.registerWriteHandler(EasyExcelUtils.getStyleStrategy()) /*引用样式*/

以上三个是excel表格进行一个处理，让其看起来更加美观，如果要使用可以往下翻对应的代码复制使用，不加也不影响导出

@Service
@Slf4j
public class InfoServiceImpl  implements InfoService {

@Override
    public void excelDownload(HttpServletResponse response) {
        List<ExportStudentInfoVO> list = new ArrayList<>();
        list.add(new ExportStudentInfoVO("001","张三","男",18,"18488789989", new Date()));
        list.add(new ExportStudentInfoVO("002","李四","女",21,"15233337777", new Date()));
        list.add(new ExportStudentInfoVO("003","王五","男",19,"15623332333", new Date()));

        try {
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.setCharacterEncoding("utf-8");
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd");
            String currentDate = sdf.format(new Date());
            // URLEncoder.encode 可以防止中文乱码
            String fileName = URLEncoder.encode("学生信息列表" + currentDate, "UTF-8").replaceAll("\\+", "%20");
            response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");
            EasyExcel.write(response.getOutputStream(), ExportStudentInfoVO.class)
                    .sheet("学生信息")
                    .registerWriteHandler(new CustomCellWriteWidthConfig()) /*自适应列宽*/
                    .registerWriteHandler(new CustomCellWriteHeightConfig()) /*自适应行高*/
                    .registerWriteHandler(EasyExcelUtils.getStyleStrategy()) /*引用样式*/
                    .doWrite(list);
        } catch (Exception e) {
            log.error("导出失败~");
            e.printStackTrace();
        }
    }

}

引用样式

package cn.homed.common.utils.excel;

import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.metadata.style.WriteFont;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.VerticalAlignment;
 
 
public class EasyExcelUtils {
    /**
     * 设置excel样式
     */
    public static HorizontalCellStyleStrategy getStyleStrategy() {
        // 头的策略  样式调整
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        // 头背景 浅绿
        headWriteCellStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
        WriteFont headWriteFont = new WriteFont();
        // 头字号
        headWriteFont.setFontHeightInPoints((short) 12);
        // 字体样式
        headWriteFont.setFontName("宋体");
        headWriteCellStyle.setWriteFont(headWriteFont);
        // 自动换行
        headWriteCellStyle.setWrapped(true);
        // 设置细边框
        headWriteCellStyle.setBorderBottom(BorderStyle.THIN);
        headWriteCellStyle.setBorderLeft(BorderStyle.THIN);
        headWriteCellStyle.setBorderRight(BorderStyle.THIN);
        headWriteCellStyle.setBorderTop(BorderStyle.THIN);
        // 设置边框颜色 25灰度
        headWriteCellStyle.setBottomBorderColor(IndexedColors.BLACK.getIndex());
        headWriteCellStyle.setTopBorderColor(IndexedColors.BLACK.getIndex());
        headWriteCellStyle.setLeftBorderColor(IndexedColors.BLACK.getIndex());
        headWriteCellStyle.setRightBorderColor(IndexedColors.BLACK.getIndex());
        // 水平对齐方式
        headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        // 垂直对齐方式
        headWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        // 内容的策略 宋体
        WriteCellStyle contentStyle = new WriteCellStyle();
        // 设置垂直居中
        contentStyle.setWrapped(true);
        contentStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        // 设置 水平居中
//        contentStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        WriteFont contentWriteFont = new WriteFont();
        // 内容字号
        contentWriteFont.setFontHeightInPoints((short) 12);
        // 字体样式
        contentWriteFont.setFontName("宋体");
        contentStyle.setWriteFont(contentWriteFont);
        // 这个策略是 头是头的样式 内容是内容的样式 其他的策略可以自己实现
        return new HorizontalCellStyleStrategy(headWriteCellStyle, contentStyle);
    }
}

自适应列宽

package cn.homed.common.utils.excel;

import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.CellData;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.commons.collections.CollectionUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
 
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
 
public class CustomCellWriteWidthConfig extends AbstractColumnWidthStyleStrategy {
 
    private final Map<Integer, Map<Integer, Integer>> CACHE = new HashMap<>();
    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer integer, Boolean isHead) {
        boolean needSetWidth = isHead || !CollectionUtils.isEmpty(cellDataList);
        if (needSetWidth) {
            Map<Integer, Integer> maxColumnWidthMap = CACHE.computeIfAbsent(writeSheetHolder.getSheetNo(), k -> new HashMap<>());
 
            Integer columnWidth = this.dataLength(cellDataList, cell, isHead);
            // 单元格文本长度大于60换行
            if (columnWidth >= 0) {
                if (columnWidth > 60) {
                    columnWidth = 60;
                }
                Integer maxColumnWidth = maxColumnWidthMap.get(cell.getColumnIndex());
                if (maxColumnWidth == null || columnWidth > maxColumnWidth) {
                    maxColumnWidthMap.put(cell.getColumnIndex(), columnWidth);
                    Sheet sheet = writeSheetHolder.getSheet();
                    sheet.setColumnWidth(cell.getColumnIndex(), columnWidth * 256);
                }
            }
        }
    }
    /**
     * 计算长度
     * @param cellDataList
     * @param cell
     * @param isHead
     * @return
     */
    private Integer dataLength(List<WriteCellData<?>> cellDataList, Cell cell, Boolean isHead) {
        if (isHead) {
            return cell.getStringCellValue().getBytes().length;
        } else {
            CellData<?> cellData = cellDataList.get(0);
            CellDataTypeEnum type = cellData.getType();
            if (type == null) {
                return -1;
            } else {
                switch (type) {
                    case STRING:
                        // 换行符（数据需要提前解析好）
                        int index = cellData.getStringValue().indexOf("\n");
                        return index != -1 ?
                                cellData.getStringValue().substring(0, index).getBytes().length + 1 : cellData.getStringValue().getBytes().length + 1;
                    case BOOLEAN:
                        return cellData.getBooleanValue().toString().getBytes().length;
                    case NUMBER:
                        return cellData.getNumberValue().toString().getBytes().length;
                    default:
                        return -1;
                }
            }
        }
    }
}

自适应行高

package cn.homed.common.utils.excel;

import com.alibaba.excel.write.style.row.AbstractRowHeightStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
 
import java.util.Iterator;
 
public class CustomCellWriteHeightConfig extends AbstractRowHeightStyleStrategy {
    /**
     * 默认高度
     */
    private static final Integer DEFAULT_HEIGHT = 300;
 
    @Override
    protected void setHeadColumnHeight(Row row, int relativeRowIndex) {
    }
 
    @Override
    protected void setContentColumnHeight(Row row, int relativeRowIndex) {
        Iterator<Cell> cellIterator = row.cellIterator();
        if (!cellIterator.hasNext()) {
            return;
        }
        // 默认为 1行高度
        int maxHeight = 1;
        while (cellIterator.hasNext()) {
            Cell cell = cellIterator.next();
            if (cell.getCellTypeEnum() == CellType.STRING) {
                String value = cell.getStringCellValue();
                int len = value.length();
                int num = 0;
                if (len > 50) {
                    num = len % 50 > 0 ? len / 50 : len / 2 - 1;
                }
                if (num > 0) {
                    for (int i = 0; i < num; i++) {
                        value = value.substring(0, (i + 1) * 50 + i) + "\n" + value.substring((i + 1) * 50 + i, len + i);
                    }
                }
                if (value.contains("\n")) {
                    int length = value.split("\n").length;
                    maxHeight = Math.max(maxHeight, length) + 1;
                }
            }
        }
        row.setHeight((short) ((maxHeight) * DEFAULT_HEIGHT));
    }
}

五、测试

测试的话可以用postman进行测试，或者把链接粘在浏览器上

postman

postman测试的时候记得点这个下拉框选择发送并下载

然后弹出这个界面点击保存

然后桌面上就可以看到已经成功的下载下来了，数据也都是没问题的

浏览器

直接贴链接即可

可以看到数据也是没问题的

异常

最后讲一下，刚开始我这个小demo没跑起来，编译、运行都没问题，一调接口就报错了

异常是 com.alibaba.excel.exception.ExcelGenerateException: java.lang.NoClassDefFoundError: org/apache/xmlbeans/impl/common/SystemCache

搜了一下是由于缺少了相关的依赖库或者版本不匹配所致，可能需要添加 Apache POI 或者 XMLBeans 这些依赖库，并且确保版本号是兼容的。

然后加上这两个依赖就可以了，不知道你们有没有遇到

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.1.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.2</version>
        </dependency>

好了，分享就到这里，晚安