使用apache poi怎么实现导出excel文件

package com.icourt.util;

import org.apache.commons.collections4.CollectionUtils;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;

import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 描述:poi根据模板导出excel,根据excel坐标赋值,如(B1)
 */
public class ExcelExportUtil {

  //模板map
  private Map<String, Workbook> tempWorkbook = new HashMap<String, Workbook>();
  //模板输入流map
  private Map<String, InputStream> tempStream = new HashMap<String, InputStream>();

  /**
   * 功能:按模板向Excel中相应地方填充数据
   */
  public void writeData(String templateFilePath, Map<String, Object> dataMap, int sheetNo) throws IOException, InvalidFormatException {
    if (dataMap == null || dataMap.isEmpty()) {
      return;
    }
    //读取模板
    Workbook wbModule = getTempWorkbook(templateFilePath);
    //数据填充的sheet
    Sheet wsheet = wbModule.getSheetAt(sheetNo);

    for (Entry<String, Object> entry : dataMap.entrySet()) {
      String point = entry.getKey();
      Object data = entry.getValue();

      TempCell cell = getCell(point, data, wsheet);
      //指定坐标赋值
      setCell(cell, wsheet);
    }

    //设置生成excel中公式自动计算
    wsheet.setForceFormulaRecalculation(true);
  }

  /**
   * 功能:按模板向Excel中列表填充数据.只支持列合并
   */
  public void writeDateList(String templateFilePath, String[] heads, List<Map<Integer, Object>> datalist, int sheetNo) throws IOException, InvalidFormatException {
    if (heads == null || heads.length <= 0 || CollectionUtils.isEmpty(datalist)) {
      return;
    }
    //读取模板
    Workbook wbModule = getTempWorkbook(templateFilePath);
    //数据填充的sheet
    Sheet wsheet = wbModule.getSheetAt(sheetNo);

    //列表数据模板cell
    List<TempCell> tempCells = new ArrayList<TempCell>(heads.length);
    for (String point : heads) {
      TempCell tempCell = getCell(point, null, wsheet);
      //取得合并单元格位置 -1:表示不是合并单元格
      int pos = isMergedRegion(wsheet, tempCell.getRow(), tempCell.getColumn());
      if (pos > -1) {
        CellRangeAddress range = wsheet.getMergedRegion(pos);
        tempCell.setColumnSize(range.getLastColumn() - range.getFirstColumn());
      }
      tempCells.add(tempCell);
    }
    //赋值
    for (int i = 0; i < datalist.size(); i++) {//数据行
      Map<Integer, Object> dataMap = datalist.get(i);
      for (int j = 0; j < tempCells.size(); j++) {//列
        TempCell tempCell = tempCells.get(j);
        tempCell.setData(dataMap.get(j + 1));
        setCell(tempCell, wsheet);
        tempCell.setRow(tempCell.getRow() + 1);
      }
    }
  }

  /**
   * 功能:获取输入工作区
   */
  private Workbook getTempWorkbook(String templateFilePath) throws IOException, InvalidFormatException {
    if (!tempWorkbook.containsKey(templateFilePath)) {
      InputStream inputStream = getInputStream(templateFilePath);
      tempWorkbook.put(templateFilePath, WorkbookFactory.create(inputStream));
    }
    return tempWorkbook.get(templateFilePath);
  }

  /**
   * 功能:获得模板输入流
   */
  private InputStream getInputStream(String templateFilePath) throws FileNotFoundException {
    if (!tempStream.containsKey(templateFilePath)) {
      tempStream.put(templateFilePath, new FileInputStream((templateFilePath)));
    }
    return tempStream.get(templateFilePath);
  }

  /**
   * 功能:获取单元格数据,样式(根据坐标:B3)
   */
  private TempCell getCell(String point, Object data, Sheet sheet) {
    TempCell tempCell = new TempCell();

    //得到列  字母
    String lineStr = "";
    String reg = "[A-Z]+";
    Pattern p = Pattern.compile(reg);
    Matcher m = p.matcher(point);
    while (m.find()) {
      lineStr = m.group();
    }
    //将列字母转成列号 根据ascii转换
    char[] ch = lineStr.toCharArray();
    int column = 0;
    for (int i = 0; i < ch.length; i++) {
      char c = ch[i];
      int post = ch.length - i - 1;
      int r = (int) Math.pow(10, post);
      column = column + r * ((int) c - 65);
    }
    tempCell.setColumn(column);

    //得到行号
    reg = "[1-9]+";
    p = Pattern.compile(reg);
    m = p.matcher(point);
    while (m.find()) {
      tempCell.setRow((Integer.parseInt(m.group()) - 1));
    }

    //获取模板指定单元格样式,设置到tempCell(写列表数据的时候用)
    Row rowIn = sheet.getRow(tempCell.getRow());
    if (rowIn == null) {
      rowIn = sheet.createRow(tempCell.getRow());
    }
    Cell cellIn = rowIn.getCell(tempCell.getColumn());
    if (cellIn == null) {
      cellIn = rowIn.createCell(tempCell.getColumn());
    }
    tempCell.setCellStyle(cellIn.getCellStyle());
    tempCell.setData(data);
    return tempCell;
  }

  /**
   * 功能:给指定坐标单元格赋值
   */
  private void setCell(TempCell tempCell, Sheet sheet) {
    if (tempCell.getColumnSize() > -1) {
      CellRangeAddress rangeAddress = mergeRegion(sheet, tempCell.getRow(), tempCell.getRow(), tempCell.getColumn(), tempCell.getColumn() + tempCell.getColumnSize());
      setRegionStyle(tempCell.getCellStyle(), rangeAddress, sheet);
    }

    Row rowIn = sheet.getRow(tempCell.getRow());
    if (rowIn == null) {
      copyRows(tempCell.getRow() - 1, tempCell.getRow() - 1, tempCell.getRow(), sheet);//复制上一行
      rowIn = sheet.getRow(tempCell.getRow());
    }
    Cell cellIn = rowIn.getCell(tempCell.getColumn());
    if (cellIn == null) {
      cellIn = rowIn.createCell(tempCell.getColumn());
    }
    //根据data类型给cell赋值
    if (tempCell.getData() instanceof String) {
      cellIn.setCellValue((String) tempCell.getData());
    } else if (tempCell.getData() instanceof Integer) {
      cellIn.setCellValue((int) tempCell.getData());
    } else if (tempCell.getData() instanceof Double) {
      cellIn.setCellValue((double) tempCell.getData());
    } else {
      cellIn.setCellValue((String) tempCell.getData());
    }
    //样式
    if (tempCell.getCellStyle() != null && tempCell.getColumnSize() == -1) {
      cellIn.setCellStyle(tempCell.getCellStyle());
    }
  }

  /**
   * 功能:写到输出流并移除资源
   */
  public void writeAndClose(String templateFilePath, OutputStream os) throws IOException, InvalidFormatException {
    if (getTempWorkbook(templateFilePath) != null) {
      getTempWorkbook(templateFilePath).write(os);
      tempWorkbook.remove(templateFilePath);
    }
    if (getInputStream(templateFilePath) != null) {
      getInputStream(templateFilePath).close();
      tempStream.remove(templateFilePath);
    }
  }

  /**
   * 功能:判断指定的单元格是否是合并单元格
   */
  private Integer isMergedRegion(Sheet sheet, int row, int column) {
    for (int i = 0; i < sheet.getNumMergedRegions(); i++) {
      CellRangeAddress range = sheet.getMergedRegion(i);
      int firstColumn = range.getFirstColumn();
      int lastColumn = range.getLastColumn();
      int firstRow = range.getFirstRow();
      int lastRow = range.getLastRow();
      if (row >= firstRow && row <= lastRow) {
        if (column >= firstColumn && column <= lastColumn) {
          return i;
        }
      }
    }
    return -1;
  }

  /**
   * 功能:合并单元格
   */
  private CellRangeAddress mergeRegion(Sheet sheet, int firstRow, int lastRow, int firstCol, int lastCol) {
    CellRangeAddress rang = new CellRangeAddress(firstRow, lastRow, firstCol, lastCol);
    sheet.addMergedRegion(rang);
    return rang;
  }

  /**
   * 功能:设置合并单元格样式
   */
  private void setRegionStyle(CellStyle cs, CellRangeAddress region, Sheet sheet) {
    for (int i = region.getFirstRow(); i <= region.getLastRow(); i++) {
      Row row = sheet.getRow(i);
      if (row == null) row = sheet.createRow(i);
      for (int j = region.getFirstColumn(); j <= region.getLastColumn(); j++) {
        Cell cell = row.getCell(j);
        if (cell == null) {
          cell = row.createCell(j);
          cell.setCellValue("");
        }
        cell.setCellStyle(cs);
      }
    }
  }

  /**
   * 功能:copy rows
   */
  private void copyRows(int startRow, int endRow, int pPosition, Sheet sheet) {
    int pStartRow = startRow - 1;
    int pEndRow = endRow - 1;
    int targetRowFrom;
    int targetRowTo;
    int columnCount;
    CellRangeAddress region = null;
    int i;
    int j;
    if (pStartRow == -1 || pEndRow == -1) {
      return;
    }
    // 拷贝合并的单元格
    for (i = 0; i < sheet.getNumMergedRegions(); i++) {
      region = sheet.getMergedRegion(i);
      if ((region.getFirstRow() >= pStartRow)
          && (region.getLastRow() <= pEndRow)) {
        targetRowFrom = region.getFirstRow() - pStartRow + pPosition;
        targetRowTo = region.getLastRow() - pStartRow + pPosition;
        CellRangeAddress newRegion = region.copy();
        newRegion.setFirstRow(targetRowFrom);
        newRegion.setFirstColumn(region.getFirstColumn());
        newRegion.setLastRow(targetRowTo);
        newRegion.setLastColumn(region.getLastColumn());
        sheet.addMergedRegion(newRegion);
      }
    }
    // 设置列宽
    for (i = pStartRow; i <= pEndRow; i++) {
      Row sourceRow = sheet.getRow(i);
      columnCount = sourceRow.getLastCellNum();
      if (sourceRow != null) {
        Row newRow = sheet.createRow(pPosition - pStartRow + i);
        newRow.setHeight(sourceRow.getHeight());
        for (j = 0; j < columnCount; j++) {
          Cell templateCell = sourceRow.getCell(j);
          if (templateCell != null) {
            Cell newCell = newRow.createCell(j);
            copyCell(templateCell, newCell);
          }
        }
      }
    }
  }

  /**
   * 功能:copy cell,不copy值
   */
  private void copyCell(Cell srcCell, Cell distCell) {
    distCell.setCellStyle(srcCell.getCellStyle());
    if (srcCell.getCellComment() != null) {
      distCell.setCellComment(srcCell.getCellComment());
    }
    int srcCellType = srcCell.getCellType();
    distCell.setCellType(srcCellType);
  }

  /**
   * 描述:临时单元格数据
   */
  class TempCell {
    private int row;
    private int column;
    private CellStyle cellStyle;
    private Object data;
    //用于列表合并,表示几列合并
    private int columnSize = -1;

    public int getColumn() {
      return column;
    }

    public void setColumn(int column) {
      this.column = column;
    }

    public int getRow() {
      return row;
    }

    public void setRow(int row) {
      this.row = row;
    }

    public CellStyle getCellStyle() {
      return cellStyle;
    }

    public void setCellStyle(CellStyle cellStyle) {
      this.cellStyle = cellStyle;
    }

    public Object getData() {
      return data;
    }

    public void setData(Object data) {
      this.data = data;
    }

    public int getColumnSize() {
      return columnSize;
    }

    public void setColumnSize(int columnSize) {
      this.columnSize = columnSize;
    }
  }

  public static void main(String[] args) throws FileNotFoundException, IOException, InvalidFormatException {
    String templateFilePath = ExcelExportUtil.class.getClassLoader().getResource("plugin/ProTiming.xlsx").getPath();
    File file = new File("/Users/sql/Downloads/test/data.xlsx");
    OutputStream os = new FileOutputStream(file);

    ExcelExportUtil excel = new ExcelExportUtil();
    Map<String, Object> dataMap = new HashMap<String, Object>();
    dataMap.put("B1", "03_Alpha_项目工作时间统计表");
    dataMap.put("B2", "统计时间：2017/01/01 - 2017/03/31");

    excel.writeData(templateFilePath, dataMap, 0);

    List<Map<Integer, Object>> datalist = new ArrayList<Map<Integer, Object>>();
    Map<Integer, Object> data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");

    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);

    data = new HashMap<Integer, Object>();
    data.put(1, "3/10/17");
    data.put(2, "18:50");
    data.put(3, "19:00");
    data.put(4, "李子鹏");
    data.put(5, "新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用新增项目键值对接口,供任务计时调用");
    data.put(6, "代码开发");
    data.put(7, "3.17");
    datalist.add(data);
    data = new HashMap<Integer, Object>();
    data.put(1, "");
    data.put(2, "");
    data.put(3, "");
    data.put(4, "");
    data.put(5, "");
    data.put(6, "");
    data.put(7, "");
    datalist.add(data);

    String[] heads = new String[]{"B4", "C4", "D4", "E4", "F4", "G4", "H4"};
    excel.writeDateList(templateFilePath, heads, datalist, 0);

    //写到输出流并移除资源
    excel.writeAndClose(templateFilePath, os);

    os.flush();
    os.close();
  }

}