POI Excel 合并数据相同的行

import java.io.Serializable;

/**
 * POI Excel报表导出，列合并实体<br>
 * 
 * @author WQ
 *
 */
public class PoiModel implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private String content;  
      
    private String oldContent;  
  
    private int rowIndex;  
  
    private int cellIndex;

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public String getOldContent() {
        return oldContent;
    }

    public void setOldContent(String oldContent) {
        this.oldContent = oldContent;
    }

    public int getRowIndex() {
        return rowIndex;
    }

    public void setRowIndex(int rowIndex) {
        this.rowIndex = rowIndex;
    }

    public int getCellIndex() {
        return cellIndex;
    }

    public void setCellIndex(int cellIndex) {
        this.cellIndex = cellIndex;
    }

    public PoiModel() {
    }

    public PoiModel(String content, String oldContent, int rowIndex,
            int cellIndex) {
        this.content = content;
        this.oldContent = oldContent;
        this.rowIndex = rowIndex;
        this.cellIndex = cellIndex;
    }

    @Override
    public String toString() {
        return "PoiModel [content=" + content + ", oldContent=" + oldContent
                + ", rowIndex=" + rowIndex + ", cellIndex=" + cellIndex + "]";
    }  
  
}

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class Demo {

    /** 
     * @param title 标题集合 tilte的长度应该与list中的model的属性个数一致 
     * @param maps 内容集合 
     * @param mergeIndex 合并单元格的列 
     */  
    public static String createExcel(String[] title, Map<String, List<Map<String, String>>> maps, int[] mergeIndex){  
        if (title.length==0){  
            return null;  
        }  
        /*初始化excel模板*/  
        Workbook workbook = new XSSFWorkbook();  
        Sheet sheet = null;  
        int n = 0;  
        for(Map.Entry<String, List<Map<String, String>>> entry : maps.entrySet()){  
            try {  
                sheet = workbook.createSheet();  
                workbook.setSheetName(n, entry.getKey());  
                workbook.setSelectedTab(0);  
            }catch (Exception e){  
                e.printStackTrace();  
            }  
            /*初始化head，填值标题行（第一行）*/  
            Row row0 = sheet.createRow(0);  
            for(int i = 0; i<title.length; i++){  
                /*创建单元格，指定类型*/  
                Cell cell_1 = row0.createCell(i, Cell.CELL_TYPE_STRING);  
                cell_1.setCellValue(title[i]);  
            }  
            /*得到当前sheet下的数据集合*/  
            List<Map<String, String>> list = entry.getValue();  
            /*遍历该数据集合*/  
            List<PoiModel> poiModels = new ArrayList();  
            if(null!=workbook){  
                Iterator iterator = list.iterator();  
                int index = 1;
                while (iterator.hasNext()){  
                    Row row = sheet.createRow(index);  
                    /*取得当前这行的map，该map中以key，value的形式存着这一行值*/  
                    Map<String, String> map = (Map<String, String>)iterator.next();  
                    /*循环列数，给当前行塞值*/  
                    for(int i = 0; i<title.length; i++){  
                        String old = "";  
                        /*old存的是上一行统一位置的单元的值，第一行是最上一行了，所以从第二行开始记*/  
                        if(index > 1){  
                            old = poiModels.get(i)==null?"":poiModels.get(i).getContent();  
                        }  
                        /*循环需要合并的列*/  
                        for(int j = 0; j < mergeIndex.length; j++){  
                            if(index == 1){  
                                /*记录第一行的开始行和开始列*/  
                                PoiModel poiModel = new PoiModel();  
                                poiModel.setOldContent(map.get(title[i]));  
                                poiModel.setContent(map.get(title[i]));  
                                poiModel.setRowIndex(1);  
                                poiModel.setCellIndex(i);  
                                poiModels.add(poiModel);  
                                break;  
                            }else if(i > 0 && mergeIndex[j] == i){/*这边i>0也是因为第一列已经是最前一列了，只能从第二列开始*/  
                                /*当前同一列的内容与上一行同一列不同时，把那以上的合并, 或者在当前元素一样的情况下，前一列的元素并不一样，这种情况也合并*/  
                                /*如果不需要考虑当前行与上一行内容相同，但是它们的前一列内容不一样则不合并的情况，把下面条件中
　　　　　　　　　　　　　　　　　　||poiModels.get(i).getContent().equals(map.get(title[i])) && !poiModels.get(i - 1).getOldContent().equals(map.get(title[i-1]))去掉就行*/  
                                if(!poiModels.get(i).getContent().equals(map.get(title[i])) || poiModels.get(i).getContent().equals(map.get(title[i])) 
　　　　　　　　　　　　　　　　　　　　&& !poiModels.get(i - 1).getOldContent().equals(map.get(title[i-1]))){  
                                    /*当前行的当前列与上一行的当前列的内容不一致时，则把当前行以上的合并*/  
                                    CellRangeAddress cra=new CellRangeAddress(poiModels.get(i).getRowIndex(), index - 1, poiModels.get(i).getCellIndex(), poiModels.get(i).getCellIndex());  
                                    //在sheet里增加合并单元格  
                                    sheet.addMergedRegion(cra);  
                                    /*重新记录该列的内容为当前内容，行标记改为当前行标记，列标记则为当前列*/  
                                    poiModels.get(i).setContent(map.get(title[i]));  
                                    poiModels.get(i).setRowIndex(index);  
                                    poiModels.get(i).setCellIndex(i);  
                                }  
                            }  
                            /*处理第一列的情况*/  
                            if(mergeIndex[j] == i && i == 0 && !poiModels.get(i).getContent().equals(map.get(title[i]))){  
                                /*当前行的当前列与上一行的当前列的内容不一致时，则把当前行以上的合并*/  
                                CellRangeAddress cra=new CellRangeAddress(poiModels.get(i).getRowIndex(), index - 1, poiModels.get(i).getCellIndex(), poiModels.get(i).getCellIndex());  
                                //在sheet里增加合并单元格  
                                sheet.addMergedRegion(cra);  
                                /*重新记录该列的内容为当前内容，行标记改为当前行标记*/  
                                poiModels.get(i).setContent(map.get(title[i]));  
                                poiModels.get(i).setRowIndex(index);  
                                poiModels.get(i).setCellIndex(i);  
                            }  
  
                            /*最后一行没有后续的行与之比较，所有当到最后一行时则直接合并对应列的相同内容*/  
                            if(mergeIndex[j] == i && index == list.size()){  
                                CellRangeAddress cra=new CellRangeAddress(poiModels.get(i).getRowIndex(), index, poiModels.get(i).getCellIndex(), poiModels.get(i).getCellIndex());  
                                //在sheet里增加合并单元格  
                                sheet.addMergedRegion(cra);  
                            }  
                        }  
                        Cell cell = row.createCell(i, Cell.CELL_TYPE_STRING);  
                        cell.setCellValue(map.get(title[i]));  
                        /*在每一个单元格处理完成后，把这个单元格内容设置为old内容*/  
                        poiModels.get(i).setOldContent(old);  
                    }  
                    index++;  
                }  
            }  
            n++;  
        }  
        /*生成临时文件*/  
        FileOutputStream out = null;  
        String localPath = null;  
        File tempFile = null;  
        String fileName = String.valueOf(new Date().getTime()/1000);  
        try {  
            tempFile = File.createTempFile(fileName, ".xlsx");  
            localPath = tempFile.getAbsolutePath();  
            out = new FileOutputStream(localPath);  
            workbook.write(out);  
        }catch (IOException e){  
            e.printStackTrace();  
        }finally {  
            try {  
                out.flush();  
                out.close();  
            }catch (IOException e){  
                e.printStackTrace();  
            }  
        }  
        return localPath;  
    }  
  
    public static void main(String[] args) throws IOException{  
        /*此处标题的数组则对应excel的标题*/  
        String[] title = {"id","标题","描述","负责人","开始时间"};  
        List<Map<String, String>> list = new ArrayList();  
        /*这边是制造一些数据，注意每个list中map的key要和标题数组中的元素一致*/  
        for(int i = 0; i<10; i++){  
            HashMap<String, String> map = new HashMap();  
            if(i > 5){  
                if(i<7){  
                    map.put("id","333");  
                    map.put("标题","mmmm");  
                }else {  
                    map.put("id","333");  
                    map.put("标题","aaaaa");  
                }  
            }else if (i >3){  
                map.put("id","222");  
                map.put("标题","哈哈哈哈");  
            }else if (i>1 && i<3){  
                map.put("id","222");  
                map.put("标题","hhhhhhhh");  
            }else {  
                map.put("id","222");  
                map.put("标题","bbbb");  
            }  
            map.put("描述","sssssss");  
            map.put("负责人","vvvvv");  
            map.put("开始时间","2017-02-27 11:20:26");  
            list.add(map);  
        }  
        Map<String, List<Map<String, String>>> map = new HashMap();  
        map.put("测试合并数据", list);  
        System.out.println(createExcel(title, map, new int[]{0,1,2}));  
    }  
  
}