“easyExcel”匯入的代碼實作

使用easyExcel在匯入資料事有很好的使用性，方便操作，

添加依賴：

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>3.0.5</version>
</dependency>

前端決議的檔案流呼叫這個方法；

需要首先創建監聽方法類

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
 
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
 
import lombok.extern.slf4j.Slf4j;
 
 
/**
 * 讀取資料監聽器.
 * 監聽excel決議到的資料
 * @author: xiehj
 * Date: 2023-06-07
 */
@Slf4j
public class CommonExcelListener<T> extends AnalysisEventListener<T> {
 
    /**存放決議到的資料，給了一個初始容量，為了避免list的頻繁擴容帶來的性能問題.*/
    private final List<T> list = new ArrayList<>(1000);
 
    /**決議每一行都會執行該方法.*/
    @Override
    public void invoke(final T data, final AnalysisContext analysisContext) {
        this.list.add(data);
    }
 
    /**決議完成.*/
    @Override
    public void doAfterAllAnalysed(final AnalysisContext analysisContext) {
    }
 
    /**決議表頭.*/
    @Override
    public void invokeHeadMap(final Map<Integer, String> headMap, final AnalysisContext context) {
        headMap.entrySet().removeIf(h -> Objects.isNull(h.getValue()) || "".equals(h.getValue()));
    }
    public List<T> getList() {
        return this.list;
    }
 
}

創建utils,創建這個方法即可

public String importFile(final InputStream inputStream) {
        // 如果集合為空，則不用處理，
        if (Objects.isNull(inputStream)) {
            throw new ExtBusinessException("匯入檔案時，檔案流例外，");
        }
 
        final CommonExcelListener<ArticleImportVo> listener = new CommonExcelListener<>();
        EasyExcel.read(inputStream, ArticleImportVo.class, listener)
            .headRowNumber(1)
            .autoTrim(true)
            .sheet(0)
            .doRead();
        // list即為檔案流決議出的資料物體類，
        final List<ArticleImportVo> list = listener.getList();
}

通過“easyExcel”匯出檔案代碼：

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.List;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
 
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import com.alibaba.excel.EasyExcel;
import com.mocha.framework.commons.log.annotation.AuditLog;
import com.mocha.framework.commons.log.annotation.Language;
import com.mocha.sn.business.itbussiness.service.IExportCaseService;
import com.mocha.sn.business.itbussiness.vo.ArticleImportVo;
 
import lombok.extern.slf4j.Slf4j;
 
 
/**
 * 匯出資料控制器.
 * Author：xiehj
 * Date：2023-06-12
 */
@RestController
@RequestMapping("/v1/api/it/pc/business/export")
@Slf4j
public class ExportCaseController {
 
    private static final String EXCEL_TYPE = ".xlsx";
 
    @Resource
    private IExportCaseService exportCaseService;
 
    /**
     * 匯出檔案，
     * @param response 前端回應，
     */
    @GetMapping("/file")
    @AuditLog(operation = @Language(cn = "下載附件"))
    public void downloadFile(final HttpServletResponse response) {
        final List<ArticleImportVo> articleVos = exportCaseService.exportFile();
        final String excelName = "匯出資料";
        final String fileName = new String(excelName.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
        response.reset();
        response.setContentType("application/vnd.ms-excel");
        response.setCharacterEncoding("utf-8");
        response.addHeader("content-Disposition", "attachment;filename=" + fileName + EXCEL_TYPE);
        try {
            EasyExcel.write(response.getOutputStream(), ArticleImportVo.class)
                .autoCloseStream(Boolean.TRUE).sheet(excelName).doWrite(articleVos);
        } catch (final IOException e) {
            log.error("匯出檔案失敗，", e);
        }
    }
}

 在此記錄，方便下次使用時呼叫，

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