springboot +easyexcel 下载工具类

使用springboot +easyexcel通过web来下载Excel文件

pom文件

xml 复制代码

    <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.3.4</version>
        </dependency>

Controller 类

java 复制代码

@RestController
@Slf4j
public class TestController {

   @PostMapping(value = "/down")
    public void down(HttpServletResponse response) {
        log.info("hello java");
        TestDownloadData testDownloadData = new TestDownloadData("张三" ,"男",18 );
        TestDownloadData testDownloadData2 = new TestDownloadData("李四" ,"女",20 );
        TestDownloadData testDownloadData3 = new TestDownloadData("王五" ,"男",19 );
        List<TestDownloadData> list = Arrays.asList(testDownloadData, testDownloadData2, testDownloadData3);
        String fileName =String.format("测试_%s",getCurrentDateStr("yyyyMMddHHmmss"));
        ExcelUtil.download(response, fileName, list, TestDownloadData.class,"测试sheet");
    }

    public static String getCurrentDateStr( String pattern) {
        LocalDateTime localDateTime = LocalDateTime.now();
        DateTimeFormatter df = DateTimeFormatter.ofPattern(pattern);
        return df.format(localDateTime);
    }

}

实体类

java 复制代码

@Data
@AllArgsConstructor
@NoArgsConstructor
public class TestDownloadData {
    @ExcelProperty(value = "姓名", index = 0)
    private String name;
    @ExcelProperty(value = "性别", index = 1)
    private String sex;
    @ExcelProperty(value = "年龄", index = 2)
    private Integer age;

}

工具类

java 复制代码

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.List;

/**
 * Excel工具类
 */
@Slf4j
public class ExcelUtil {


    public static  <T> void download(HttpServletResponse response, String fileName, List<T> list,Class<T> clazz,String sheetName){
        try {
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.setCharacterEncoding("utf-8");
            fileName = URLEncoder.encode(fileName, "UTF-8").replaceAll("\\+", "%20");
            response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");
            HorizontalCellStyleStrategy horizontalCellStyleStrategy =
                    new HorizontalCellStyleStrategy(StyleUtils.getHeadStyle(), StyleUtils.getContentStyle());
            EasyExcel.write(response.getOutputStream(), clazz)
                    .sheet(sheetName)
                    .registerWriteHandler(new ExcelCellWidthStyleStrategy())
                    .registerWriteHandler(horizontalCellStyleStrategy)
                    .doWrite(list);
        } catch (Exception e) {
            log.info("下载异常,文件:"+fileName,e);
            // 重置response
            response.reset();
            response.setContentType("application/json");
            response.setCharacterEncoding("utf-8");
            Map<String, String> map = MapUtils.newHashMap();
            map.put("status", "failure");
            map.put("message", "下载文件失败" + e.getMessage());
            try {
                response.getWriter().println(JSON.toJSONString(map));
            } catch (IOException ex) {
                log.error("response写入失败,文件:"+fileName,e);
            }
        }
    }
}

配置类

java 复制代码

import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.metadata.style.WriteFont;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.VerticalAlignment;

public class StyleUtils {
 
 
    private static final String[] _formats = new String[]{
            "General",
            "0",
            "0.00",
            "#,##0",
            "#,##0.00",
            "\"$\"#,##0_);(\"$\"#,##0)",
            "\"$\"#,##0_);[Red](\"$\"#,##0)",
            "\"$\"#,##0.00_);(\"$\"#,##0.00)",
            "\"$\"#,##0.00_);[Red](\"$\"#,##0.00)",
            "0%", "0.00%", "0.00E+00",
            "# ?/?", "# ??/??",
            "m/d/yy", "d-mmm-yy",
            "d-mmm", "mmm-yy",
            "h:mm AM/PM",
            "h:mm:ss AM/PM",
            "h:mm", "h:mm:ss",
            "m/d/yy h:mm",
            "reserved-0x17",
            "reserved-0x18",
            "reserved-0x19",
            "reserved-0x1A",
            "reserved-0x1B",
            "reserved-0x1C",
            "reserved-0x1D",
            "reserved-0x1E",
            "reserved-0x1F",
            "reserved-0x20",
            "reserved-0x21",
            "reserved-0x22",
            "reserved-0x23",
            "reserved-0x24",
            "#,##0_);(#,##0)",
            "#,##0_);[Red](#,##0)",
            "#,##0.00_);(#,##0.00)",
            "#,##0.00_);[Red](#,##0.00)",
            "_(* #,##0_);_(* (#,##0);_(* \"-\"_);_(@_)",
            "_(\"$\"* #,##0_);_(\"$\"* (#,##0);_(\"$\"* \"-\"_);_(@_)",
            "_(* #,##0.00_);_(* (#,##0.00);_(* \"-\"??_);_(@_)",
            "_(\"$\"* #,##0.00_);_(\"$\"* (#,##0.00);_(\"$\"* \"-\"??_);_(@_)",
            "mm:ss",
            "[h]:mm:ss",
            "mm:ss.0",
            "##0.0E+0",
            "@" // 文本格式
    };
 
 
    /**
     * 标题样式
     * @return
     */
    public static WriteCellStyle getHeadStyle(){
        // 头的策略
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        // 背景颜色
//        headWriteCellStyle.setFillForegroundColor(IndexedColors.LIGHT_TURQUOISE1.getIndex());
//        headWriteCellStyle.setFillPatternType(FillPatternType.SOLID_FOREGROUND);
 
        // 字体
        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setFontName("宋体");//设置字体名字
        headWriteFont.setFontHeightInPoints((short)10);//设置字体大小
        headWriteFont.setBold(true);//字体加粗
        headWriteCellStyle.setWriteFont(headWriteFont); //在样式用应用设置的字体;
 
        // 样式
        headWriteCellStyle.setBorderBottom(BorderStyle.THIN);//设置底边框;
        headWriteCellStyle.setBottomBorderColor((short) 0);//设置底边框颜色;
        headWriteCellStyle.setBorderLeft(BorderStyle.THIN);  //设置左边框;
        headWriteCellStyle.setLeftBorderColor((short) 0);//设置左边框颜色;
        headWriteCellStyle.setBorderRight(BorderStyle.THIN);//设置右边框;
        headWriteCellStyle.setRightBorderColor((short) 0);//设置右边框颜色;
        headWriteCellStyle.setBorderTop(BorderStyle.THIN);//设置顶边框;
        headWriteCellStyle.setTopBorderColor((short) 0); //设置顶边框颜色;
 
        headWriteCellStyle.setWrapped(true);  //设置自动换行;
 
        headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);//设置水平对齐的样式为居中对齐;
        headWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);  //设置垂直对齐的样式为居中对齐;
        headWriteCellStyle.setShrinkToFit(true);//设置文本收缩至合适
 
        return headWriteCellStyle;
    }
 
 
    /**
     * 内容样式
     * @return
     */
    public static WriteCellStyle getContentStyle(){
        // 内容的策略
        WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
 
        // 背景绿色
        // 这里需要指定 FillPatternType 为FillPatternType.SOLID_FOREGROUND 不然无法显示背景颜色.头默认了 FillPatternType所以可以不指定
//        contentWriteCellStyle.setFillForegroundColor(IndexedColors.PALE_BLUE.getIndex());
//        contentWriteCellStyle.setFillPatternType(FillPatternType.SOLID_FOREGROUND);
 
        // 设置字体
        WriteFont contentWriteFont = new WriteFont();
        contentWriteFont.setFontHeightInPoints((short) 9);//设置字体大小
        contentWriteFont.setFontName("宋体"); //设置字体名字
        contentWriteCellStyle.setWriteFont(contentWriteFont);//在样式用应用设置的字体;
 
        //设置样式;
        contentWriteCellStyle.setBorderBottom(BorderStyle.THIN);//设置底边框;
        contentWriteCellStyle.setBottomBorderColor((short) 0);//设置底边框颜色;
        contentWriteCellStyle.setBorderLeft(BorderStyle.THIN);  //设置左边框;
        contentWriteCellStyle.setLeftBorderColor((short) 0);//设置左边框颜色;
        contentWriteCellStyle.setBorderRight(BorderStyle.THIN);//设置右边框;
        contentWriteCellStyle.setRightBorderColor((short) 0);//设置右边框颜色;
        contentWriteCellStyle.setBorderTop(BorderStyle.THIN);//设置顶边框;
        contentWriteCellStyle.setTopBorderColor((short) 0); ///设置顶边框颜色;
 
        contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);// 水平居中
        contentWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);// 垂直居中
        contentWriteCellStyle.setWrapped(true); //设置自动换行;
         contentWriteCellStyle.setShrinkToFit(true);//设置文本收缩至合适
 
        return contentWriteCellStyle;
    }
 
}

java 复制代码

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.collections4.CollectionUtils;
import org.apache.poi.ss.usermodel.Cell;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ExcelCellWidthStyleStrategy extends AbstractColumnWidthStyleStrategy {
    // 可以根据这里的最大宽度，按自己需要进行调整,搭配单元格样式实现类中的，自动换行，效果更好
    private static final int MAX_COLUMN_WIDTH = 50;
    private  Map<Integer, Map<Integer, Integer>> CACHE = new HashMap(8);
 
    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        boolean needSetWidth = isHead || !CollectionUtils.isEmpty(cellDataList);
        if (needSetWidth) {
            Map<Integer, Integer> maxColumnWidthMap = (Map)CACHE.get(writeSheetHolder.getSheetNo());
            if (maxColumnWidthMap == null) {
                maxColumnWidthMap = new HashMap(16);
                CACHE.put(writeSheetHolder.getSheetNo(), maxColumnWidthMap);
            }
 
            Integer columnWidth = this.dataLength(cellDataList, cell, isHead);
            if (columnWidth >= 0) {
                if (columnWidth > MAX_COLUMN_WIDTH) {
                    columnWidth = MAX_COLUMN_WIDTH;
                }
 
                Integer maxColumnWidth = (Integer)((Map)maxColumnWidthMap).get(cell.getColumnIndex());
                if (maxColumnWidth == null || columnWidth > maxColumnWidth) {
                    ((Map)maxColumnWidthMap).put(cell.getColumnIndex(), columnWidth);
                    writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), columnWidth * 256);
                }
 
            }
        }
    }
 
    private Integer dataLength(List<WriteCellData<?>> cellDataList, Cell cell, Boolean isHead) {
        if (isHead) {
            return cell.getStringCellValue().getBytes().length;
        } else {
            CellData cellData = (CellData)cellDataList.get(0);
            CellDataTypeEnum type = cellData.getType();
            if (type == null) {
                return -1;
            } else {
                switch(type) {
                    case STRING:
                        return cellData.getStringValue().getBytes().length;
                    case BOOLEAN:
                        return cellData.getBooleanValue().toString().getBytes().length;
                    case NUMBER:
                        return cellData.getNumberValue().toString().getBytes().length;
                    default:
                        return -1;
                }
            }
        }
    }
 
}