POI实现Excel报表导出

墨蓝 2022-05-17 09:11 387阅读 0赞

**1.导入Apache POI的JAR包**  
POI JAR 包（Apache官网中可以直接下载）

**2.熟悉常用对象**

<table> 
 <thead> 
  <tr> 
   <th>对象</th> 
   <th align="center">作用</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td><code>HSSFSheet</code></td> 
   <td align="center">excel的表单</td> 
  </tr> 
  <tr> 
   <td><code>HSSFRow</code></td> 
   <td align="center">excel的行</td> 
  </tr> 
  <tr> 
   <td><code>HSSFCell</code></td> 
   <td align="center">excel的格子单元</td> 
  </tr> 
  <tr> 
   <td><code>HSSFFont</code></td> 
   <td align="center">excel字体</td> 
  </tr> 
  <tr> 
   <td><code>HSSFDataFormat</code></td> 
   <td align="center">日期格式</td> 
  </tr> 
  <tr> 
   <td><code>HSSFHeader</code></td> 
   <td align="center">sheet头</td> 
  </tr> 
  <tr> 
   <td><code>HSSFFooter</code></td> 
   <td align="center">sheet尾</td> 
  </tr> 
  <tr> 
   <td><code>HSSFCellStyle</code></td> 
   <td align="center">cell样式</td> 
  </tr> 
  <tr> 
   <td><code>HSSFDateUtil</code></td> 
   <td align="center">日期</td> 
  </tr> 
  <tr> 
   <td><code>HSSFPrintSetup</code></td> 
   <td align="center">打印</td> 
  </tr> 
  <tr> 
   <td><code>HSSFErrorConstants</code></td> 
   <td align="center">错误信息表</td> 
  </tr> 
 </tbody> 
</table>

**3、上代码：**

package com.pzoom.xiaochen.excel;
    
    import java.io.OutputStream;
    import java.util.ArrayList;
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFCellStyle;
    import org.apache.poi.hssf.usermodel.HSSFFont;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.hssf.util.HSSFColor;
    
    public class ExcelFileGenerator { 
    
        private final int SPLIT_COUNT = 15; //Excel每个工作表的行数
    
        private ArrayList fieldName = null; //excel数据的抬头栏，即名称栏
    
        private ArrayList fieldData = null; //excel导出的实际数据
    
        private HSSFWorkbook workBook = null;//一个excel文件
    
        //有参构造器，限定了使用此类时，必须首先构建好两个list参数，并将所需数据放入上述两个list。
        //其中fieldName这个list可以使用泛型约束List<String>
        //fieldData这个可以使用泛型约束List<List<Object>>
        public ExcelFileGenerator(ArrayList fieldName, ArrayList fieldData) {
            this.fieldName = fieldName;
            this.fieldData = fieldData;
        }
        /** * @return HSSFWorkbook */
        public HSSFWorkbook createWorkbook() {
            workBook = new HSSFWorkbook();//创建一个工作簿
            int rows = fieldData.size();//清点出输入数据的行数
            int sheetNum = 0;//将工作表个数清零
            //根据数据的行数与每个工作表所能容纳的行数，求出需要创建工作表的个数
            if (rows % SPLIT_COUNT == 0) {
                sheetNum = rows / SPLIT_COUNT;
            } else {
                sheetNum = rows / SPLIT_COUNT + 1;
            }
    
            for (int i = 1; i <= sheetNum; i++) {
                HSSFSheet sheet = workBook.createSheet("Page " + i);//创建工作表
                HSSFRow headRow = sheet.createRow(0); //创建第一栏，抬头栏
                for (int j = 0; j < fieldName.size(); j++) {
                    HSSFCell cell = headRow.createCell(j);//创建抬头栏单元格
                    //设置单元格格式
                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);
                    sheet.setColumnWidth(j, 6000);
                    HSSFCellStyle style = workBook.createCellStyle();
                    HSSFFont font = workBook.createFont();
                    font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
                    short color = HSSFColor.RED.index;
                    font.setColor(color);
                    style.setFont(font);
                    //将数据填入单元格
                    if(fieldName.get(j) != null){
                        cell.setCellStyle(style);
                        cell.setCellValue((String) fieldName.get(j));
                    }else{
                        cell.setCellStyle(style);
                        cell.setCellValue("-");
                    }
                }
                //创建数据栏单元格并填入数据
                for (int k = 0; k < (rows < SPLIT_COUNT ? rows : SPLIT_COUNT); k++) {
                    if (((i - 1) * SPLIT_COUNT + k) >= rows)
                        break;
                    HSSFRow row = sheet.createRow(k + 1);
                    ArrayList rowList = (ArrayList) fieldData.get((i - 1)
                            * SPLIT_COUNT + k);
                    for (int n = 0; n < rowList.size(); n++) {
                        HSSFCell cell = row.createCell( n);
                        if(rowList.get(n) != null){
                            cell.setCellValue((String) rowList.get(n).toString());
                        }else{
                            cell.setCellValue("");
                        }
                    }
                }
            }
            return workBook;
        }
        //将信息写入输出流的方法。
        public void exportExcel(OutputStream os) throws Exception {
            workBook = createWorkbook();
            workBook.write(os);
            os.close();
        }
    }

**4、测试**

@Test
        public void testExcel() throws Exception
        {
            ExcelFileGenerator generator = new ExcelFileGenerator(Lists.newArrayList("1","2","3"), Lists.newArrayList(Lists.newArrayList("aa","bb","cc"), Lists.newArrayList("dd","ee","ff")));
            generator.exportExcel(new FileOutputStream(new File("a.xls")));
        }