目錄
1. 實列相關依賴
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>2.2.6</version>
</dependency>
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.9.3</version>
</dependency>
2.EasyExcel導出常見的兩種方式：
1.根據路徑保存到磁盤:
2.響應Response，用戶直接網頁下載:
正常分為三個步驟：
(1)構建一個ExcelWriter對象。
(2)再次通過write方法寫入數據。
(3)調用EasyExcel的finish。
根據路徑保存示例:
private ExcelWriter excelWriter;
public EasyExcelHelper(String path) {
excelWriter = EasyExcel.write(path).build();
//固定的excel標題：
//Class類的屬性必須使用`ExcelProperty`注解修飾。
//EasyExcel.write(path, Class).build()
}
//保存到本地磁盤
excelWriter.finish();
響應Respones示例:
private ExcelWriter excelWriter;
public EasyExcelHelper() {
excelWriter = new ExcelWriterBuilder()
.excelType(ExcelTypeEnum.XLSX)
.needHead(true)
.build();
}
public void export(HttpServletResponse response，String fileName ) {
final String exportName = fileName + ExcelTypeEnum.XLSX.getValue();
response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
response.setCharacterEncoding(StandardCharsets.UTF_8.name());
try {
excelWriter.finish();
response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + URLEncoder.encode(exportName, StandardCharsets.UTF_8.name()));
response.setHeader(HttpHeaders.CONTENT_LENGTH, String.valueOf(dataBytes.length));
} catch (IOException e) {
log.error(e.getMessage(), e);
throw new ApiException(ErrorEnum.DOWNLOAD_ERROR);
}
}
3.EaxyExcel動態標題
/**
* @param sheetStartNum 默認為0即可
* @param sheetName sheet名稱
* @param headList 動態標題，格式：List<List<String>>
* @param list 數據，格式List<List<Object>>;
*/
public void createSheet(Integer sheetStartNum, String sheetName, List headList, List list) {
WriteSheet sheet= EasyExcel.writerSheet(sheetStartNum, sheetName).build();
WriteTable table = new WriteTable();
table.setTableNo(0);
table.setHead(headList);
excelWriter.write(list, sheet, table);
}
4.EaxyExcel標題格式 策略設置
這里我使用兩個策略,分別是defaultStyle、CustomerColumnWidthStyleStrategy。同時啟用兩個策略時，如果我們創建的excel文件有標題defaultStyle將會生效。不存在標題時，直接存入數據時，CustomerColumnWidthStyleStrategy將會適當調整excel寬度。在上面構建WriteSheet的時候我們可以添加這些策略：
EasyExcel.writerSheet(sheetStartNum, sheetName).
registerWriteHandler(defaultStyle()).
registerWriteHandler(new CustomerColumnWidthStyleStrategy()).build();
/**
* 設置頭部樣式
*
* @return
*/
private HorizontalCellStyleStrategy defaultStyle() {
WriteCellStyle headWriteCellStyle = new WriteCellStyle();
//頭部樣式
headWriteCellStyle.setFillForegroundColor(IndexedColors.LIME.getIndex());
WriteFont headWriteFont = new WriteFont();
headWriteFont.setFontHeightInPoints((short) 12);
headWriteFont.setFontName("Arial");
headWriteFont.setBold(Boolean.FALSE);
headWriteFont.setColor(IndexedColors.WHITE.getIndex());
headWriteCellStyle.setWriteFont(headWriteFont);
headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
headWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
headWriteCellStyle.setWrapped(Boolean.FALSE);
headWriteCellStyle.setBorderRight(BorderStyle.NONE);
headWriteCellStyle.setBorderLeft(BorderStyle.NONE);
//內容樣式
WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
contentWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
return new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
}
/**
* 列寬設置
* memo:當數據不存在標題時，defaultStyle頭部樣式將失效，該設置將會生效
*/
private class CustomerColumnWidthStyleStrategy extends AbstractColumnWidthStyleStrategy {
private static final int MAX_COLUMN_WIDTH = 7000;
@Override
protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<CellData> cellDataList, Cell cell, Head head,
Integer relativeRowIndex, Boolean isHead) {
writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), MAX_COLUMN_WIDTH);
}
}
5.EaxyExcel 同值合並策略
上面我們添加了excel標題策略，現在我們再添加一個同值合並策略。筆者當前遇到一個需求，需要根據數據中一個字段的集合拆分成多條數據，拆分出來的數據相同值需要合並，所以添加了下面的策略。策略的添加方式與上面一致。
參數說明：
mergeRowIndex:合並開始的位置，第一行為0，正常是標題行，一般我們從1開始。
eachRow:多少行合並一次，假設我們現在根據某個屬性將一條數據拆分成3條，如果我們不希望這3條以外的數據發生相同值合並，那么可以設置為3。
mergeColumnIndex:合並列的下標數據，第一列為0，假設等於[0,1,3]，那么就意味着只有這3列會發生合並。
這三個參數配合使用，可以達到這樣的效果：從x行開始，每y條數據發生合並，合並z[z1,z2,z3]的列。
/**
* 相同值合並策略
*/
public class ExcelMergeStrategy implements CellWriteHandler {
/**
* 合並起始行
*/
private int mergeRowIndex;
/**
* 多少行合並一次
*/
private int eachRow;
/**
* 合並字段的下標
*/
private int[] mergeColumnIndex;
public ExcelMergeStrategy(int mergeRowIndex, int[] mergeColumnIndex, int eachRow) {
if (mergeRowIndex < 0) {
throw new IllegalArgumentException("mergeRowIndex must be greater than 0");
}
if (eachRow < 0) {
throw new IllegalArgumentException("eachRow must be greater than 0");
}
this.mergeRowIndex = mergeRowIndex;
this.mergeColumnIndex = mergeColumnIndex;
this.eachRow = eachRow;
}
@Override
public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Head head, Integer columnIndex, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
int curRowIndex = cell.getRowIndex();
//當前列
int curColIndex = cell.getColumnIndex();
//合並條件：
//1.當前行>合並起始行，默認標題行（0）不參加合並
//2.間隔行（eachRow）的上下兩條不參加合並
//2.1間隔行（eachRow）==0時，不設置間隔
if (isMerge(curRowIndex)) {
IntStream.range(0, mergeColumnIndex.length).anyMatch(i -> {
if (curColIndex == mergeColumnIndex[i]) {
mergeWithPrevRow(writeSheetHolder, cellData, cell, curRowIndex, curColIndex);
return true;
}
return false;
});
}
}
@Override
public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
}
/**
* 判斷是否合並
* 1.當前位置必須大於開始位置：curRowIndex > mergeRowIndex
* 2.根據eachRow 判斷數據分割的間隔
* 2.1如果根據eachRow=0，默認不合並
* 2.2如果1如果根據eachRow>0,分割后的第一條數據不會與之前的合並：（curRowIndex-mergeRowIndex）%eachRow==0
*
* @return
*/
private boolean isMerge(Integer curRowIndex) {
if ((curRowIndex > mergeRowIndex) && eachRow > 0) {
if ((curRowIndex - mergeRowIndex) % eachRow == 0) {
return false;
}
return true;
}
return false;
}
private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, CellData cellData, Cell cell, int curRowIndex, int curColIndex) {
//獲取當前行的當前列的數據和上一行的當前列列數據，通過上一行數據是否相同進行合並
Object curData = cellData.getType() == CellDataTypeEnum.STRING ? cellData.getStringValue() : cellData.getNumberValue();
Cell preCell = cell.getSheet().getRow(curRowIndex - 1).getCell(curColIndex);
Object preData = preCell.getCellTypeEnum() == CellType.STRING ? preCell.getStringCellValue() :
preCell.getNumericCellValue();
// 比較當前行的第一列的單元格與上一行是否相同，相同合並當前單元格與上一行
if (Objects.equals(curData, preData)) {
Sheet sheet = writeSheetHolder.getSheet();
List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
boolean isMerged = false;
for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
CellRangeAddress cellRangeAddr = mergeRegions.get(i);
// 若上一個單元格已經被合並，則先移出原有的合並單元，再重新添加合並單元
if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
sheet.removeMergedRegion(i);
cellRangeAddr.setLastRow(curRowIndex);
sheet.addMergedRegion(cellRangeAddr);
isMerged = true;
}
}
// 若上一個單元格未被合並，則新增合並單元
if (!isMerged) {
CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, curColIndex,
curColIndex);
sheet.addMergedRegion(cellRangeAddress);
}
}
}
}
6.動態標題拓展（自定義動態標題注解與工具類）
使用場景：當我們需要動態設置excel標題時，但存在部分標題是固定的情況時，我們可以創建一個DemoVO對象使用DynamicColumn修飾這些屬性。通過調用conver方法將DemoVO轉換成一個ColumnData對象的集合。
然后通過commons-beanutils包的BeanUtils.describe()方法將查詢的集合數據映射成Map。
List<DemoVO> data = query();
List<ColumnData> columnList = conver(DemoVO.class);
//excel數據
List<List<Object>> excelData = Lists.newArrayList();
for (DemoVO o : data) {
//對象轉map
Map<String,String> oMap = BeanUtils.describe(o);
List<Object> baseList = Lists.newArrayList();
for (ColumnData columnData : columnList) {
//按照標題順序設置值
baseList.add(oMap.get(columnData.getFieldName()));
}
excelData.add(baseList);
}
1.自定義動態excel注解
@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface DynamicColumn {
String name();//excel標題
int index(); //標題順序
}
@Data
public class DemoVO {
@DynamicColumn(name = "庫存", index = 0)
private String stockState;
@DynamicColumn(name = "編碼", index = 1)
private String skuCode;
@DynamicColumn(name = "描述", index = 2)
private String skuDesc;
//動態拆分成多個標題
private List<String> address;
}
2.注解對應對象
@Builder
@Data
public class ColumnData {
/**
* excel 標題
*/
private String columnName;
/**
* 字段 屬性
*/
private String fieldName;
/**
* 排序
*/
private int index;
}
3.注解轉對象工具類
public static <R> List<ColumnData> conver(final Class<R> clazz) {
List<ColumnData> list = Lists.newArrayList();
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
DynamicColumn annotation = field.getAnnotation(DynamicColumn.class);
if (!Objects.isNull(annotation)) {
ColumnData columnData = ColumnData.builder().
columnName(annotation.name()).
index(annotation.index()).
fieldName(field.getName()).
build();
list.add(columnData);
}
}
list.sort(Comparator.comparingInt(ColumnData :: getIndex));
return list;
}
7.實際使用
public void export() throws Exception {
String path = "D:/mytest/mycase.xlsx";
new File(path).createNewFile();
EasyExcelHelper easyExcelHelper = new EasyExcelHelper(path);
List<DemoVO> results=query();
//獲取注解定義的標題
List<ColumnData> columnList = DynamicColumnUtil.conver(DemoVO.class);
//設置標題,數據
List<List<String>> titles = Lists.newArrayList();
columnList.stream().forEach(c -> titles.add(Lists.newArrayList(c.getColumnName())));
List<List<Object>> excelData = Lists.newArrayList();
//設置合並策略
int[] mergeColumnIndex = columnList.stream().mapToInt(ColumnData :: getIndex).toArray();
easyExcelHelper.mergeStrategy(1, mergeColumnIndex, 5);
boolean isFirst = true;//第一次需要設置動態標題
for (DemoVO o : data) {
//對象轉map
Map<String,String> oMap = BeanUtils.describe(o);
List<Object> baseList = Lists.newArrayList();
for (ColumnData columnData : columnList) {
//按照標題順序設置值
baseList.add(oMap.get(columnData.getFieldName()));
if (isFirst) {
for (String address : o.getAddress()) {
titles.add(address);
}
isFirst=false;
}
//設置值
for (String address : o.getAddress()) {
List<Object> row = Lists.newArrayList();
row.addAll(baseList);//公共部分
row.add(address));
excelData.add(row);
}
}
easyExcelHelper.createSheet(0, "測試", titles, excelData);
easyExcelHelper.getExcelWriter().finish();
}
8.EasyExcelHelper工具類完整代碼
EasyExcelHelper實際是以上Eaxyexcel功能的封裝，部分代碼上面均有展示，下方直接給出，方便大家參考：
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.CellData;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.metadata.WriteSheet;
import com.alibaba.excel.write.metadata.WriteTable;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.metadata.style.WriteFont;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import lombok.Data;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import java.util.List;
import java.util.Objects;
import java.util.stream.IntStream;
/**
* @author penggaofeng
* @date 2021/1/25 13:41
* @description：1.輔助實現動態標題；2.實現行數據合並
* @modified By：
* @version: 1.0
*/
@Data
public class EasyExcelHelper {
private ExcelWriter excelWriter;
private ExcelMergeStrategy excelMergeStrategy;
public EasyExcelHelper(String path) {
excelWriter = EasyExcel.write(path).build();
}
/**
* 動態插入
*
* @param sheetStartNum
* @param sheetName sheet名稱
* @param headList 動態標題，格式：List<List<String>>
* @param list 數據
*/
public void createSheet(Integer sheetStartNum, String sheetName, List headList, List list) {
WriteSheet sheet;
if (Objects.isNull(excelMergeStrategy)) {
sheet = EasyExcel.writerSheet(sheetStartNum, sheetName).
registerWriteHandler(defaultStyle()).
registerWriteHandler(new CustomerColumnWidthStyleStrategy()).build();
} else {
sheet = EasyExcel.writerSheet(sheetStartNum, sheetName).
registerWriteHandler(defaultStyle()).
registerWriteHandler(excelMergeStrategy).
registerWriteHandler(new CustomerColumnWidthStyleStrategy()).build();
}
WriteTable table = new WriteTable();
table.setTableNo(0);
table.setHead(headList);
excelWriter.write(list, sheet, table);
}
/**
* 創建合並策略
*
* @param mergeRowIndex 合並開始行 （從1開始，忽略標題）
* @param mergeColumnIndex 合並列（列下標，從0開始）
* @param eachRow 合並間隔，指定幾條數據之間合並
*/
public void mergeStrategy(int mergeRowIndex, int[] mergeColumnIndex, int eachRow) {
excelMergeStrategy = new ExcelMergeStrategy(mergeRowIndex, mergeColumnIndex, eachRow);
}
/**
* 設置頭部樣式
*
* @return
*/
private HorizontalCellStyleStrategy defaultStyle() {
WriteCellStyle headWriteCellStyle = new WriteCellStyle();
//頭部樣式
headWriteCellStyle.setFillForegroundColor(IndexedColors.LIME.getIndex());
WriteFont headWriteFont = new WriteFont();
headWriteFont.setFontHeightInPoints((short) 12);
headWriteFont.setFontName("Arial");
headWriteFont.setBold(Boolean.FALSE);
headWriteFont.setColor(IndexedColors.WHITE.getIndex());
headWriteCellStyle.setWriteFont(headWriteFont);
headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
headWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
headWriteCellStyle.setWrapped(Boolean.FALSE);
headWriteCellStyle.setBorderRight(BorderStyle.NONE);
headWriteCellStyle.setBorderLeft(BorderStyle.NONE);
//內容樣式
WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
contentWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
return new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
}
/**
* 列寬設置
* memo:當數據不存在標題時，defaultStyle頭部樣式將失效，該設置將會生效
*/
private class CustomerColumnWidthStyleStrategy extends AbstractColumnWidthStyleStrategy {
private static final int MAX_COLUMN_WIDTH = 7000;
@Override
protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<CellData> cellDataList, Cell cell, Head head,
Integer relativeRowIndex, Boolean isHead) {
writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), MAX_COLUMN_WIDTH);
}
}
/**
* 相同值合並策略
*/
public class ExcelMergeStrategy implements CellWriteHandler {
/**
* 合並起始行
*/
private int mergeRowIndex;
/**
* 多少行合並一次
*/
private int eachRow;
/**
* 合並字段的下標
*/
private int[] mergeColumnIndex;
public ExcelMergeStrategy(int mergeRowIndex, int[] mergeColumnIndex, int eachRow) {
if (mergeRowIndex < 0) {
throw new IllegalArgumentException("mergeRowIndex must be greater than 0");
}
if (eachRow < 0) {
throw new IllegalArgumentException("eachRow must be greater than 0");
}
this.mergeRowIndex = mergeRowIndex;
this.mergeColumnIndex = mergeColumnIndex;
this.eachRow = eachRow;
}
@Override
public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Head head, Integer columnIndex, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
int curRowIndex = cell.getRowIndex();
//當前列
int curColIndex = cell.getColumnIndex();
//合並條件：
//1.當前行>合並起始行，默認標題行（0）不參加合並
//2.間隔行（eachRow）的上下兩條不參加合並
//2.1間隔行（eachRow）==0時，不設置間隔
if (isMerge(curRowIndex)) {
IntStream.range(0, mergeColumnIndex.length).anyMatch(i -> {
if (curColIndex == mergeColumnIndex[i]) {
mergeWithPrevRow(writeSheetHolder, cellData, cell, curRowIndex, curColIndex);
return true;
}
return false;
});
}
}
@Override
public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
}
/**
* 判斷是否合並
* 1.當前位置必須大於開始位置：curRowIndex > mergeRowIndex
* 2.根據eachRow 判斷數據分割的間隔
* 2.1如果根據eachRow=0，默認不合並
* 2.2如果1如果根據eachRow>0,分割后的第一條數據不會與之前的合並：（curRowIndex-mergeRowIndex）%eachRow==0
*
* @return
*/
private boolean isMerge(Integer curRowIndex) {
if ((curRowIndex > mergeRowIndex) && eachRow > 0) {
if ((curRowIndex - mergeRowIndex) % eachRow == 0) {
return false;
}
return true;
}
return false;
}
private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, CellData cellData, Cell cell, int curRowIndex, int curColIndex) {
//獲取當前行的當前列的數據和上一行的當前列列數據，通過上一行數據是否相同進行合並
Object curData = cellData.getType() == CellDataTypeEnum.STRING ? cellData.getStringValue() : cellData.getNumberValue();
Cell preCell = cell.getSheet().getRow(curRowIndex - 1).getCell(curColIndex);
Object preData = preCell.getCellTypeEnum() == CellType.STRING ? preCell.getStringCellValue() :
preCell.getNumericCellValue();
// 比較當前行的第一列的單元格與上一行是否相同，相同合並當前單元格與上一行
if (Objects.equals(curData, preData)) {
Sheet sheet = writeSheetHolder.getSheet();
List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
boolean isMerged = false;
for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
CellRangeAddress cellRangeAddr = mergeRegions.get(i);
// 若上一個單元格已經被合並，則先移出原有的合並單元，再重新添加合並單元
if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
sheet.removeMergedRegion(i);
cellRangeAddr.setLastRow(curRowIndex);
sheet.addMergedRegion(cellRangeAddr);
isMerged = true;
}
}
// 若上一個單元格未被合並，則新增合並單元
if (!isMerged) {
CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, curColIndex,
curColIndex);
sheet.addMergedRegion(cellRangeAddress);
}
}
}
}
}