POI的基本使用

在开发中，我们难免会遇到一些关于EXCEL、WORD的操作，这是我们可以使用阿帕奇的POI，当然你也可以使用阿里的EasyPOI，看个人爱好，下面我将介绍阿帕奇的POI

了解一下，两个版本，一个是03版本，后缀是.xls，最多65535行，耗时时间短，07版本，后缀是.xlsx，最多无限制行，耗时间较长

首先是进行写表操作，如果表不存在，会自动创建表。

03版本

/**
 * @Auther: luo
 * @Date: 2020/8/16 14:01
 * @Description:
 */
public class Test01 {
    public static void main(String[] args) throws IOException {
        new Test01().test01();
    }
    public void test01() throws IOException {
        //HSSF 创建03版本的工作簿
        Workbook workbook = new HSSFWorkbook();
        //创建工作表
        Sheet sheet1 = workbook.createSheet("sheet1");
        //创建第一行
        Row row = sheet1.createRow(0);
        //设置第一列
        Cell cell = row.createCell(0, CellType.STRING);
        cell.setCellValue("str");
        //设置第二列
        Cell cell1 = row.createCell(1, CellType.STRING);
        cell1.setCellValue("str2");
        //写出
        workbook.write(new FileOutputStream("D:\\IDEA2018\\workplace\\POI\\"+"b.xls"));
    }
}

输出试试

07版本

public  void test02() throws IOException {
        Workbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet("teacher");
        Row row = sheet.createRow(0);
        Cell rowCell = row.createCell(0);
        rowCell.setCellValue("name");
        Cell rowCell2 = row.createCell(1);
        rowCell2.setCellValue("age");
        workbook.write(new FileOutputStream("D:\\IDEA2018\\workplace\\POI\\"+"a.xlsx"));
    }

读表操作

public void test04()throws IOException{
            String path="D:\\IDEA2018\\workplace\\POI\\";
            //获取文件流
            FileInputStream fileInputStream = new FileInputStream(path + "a.xls");
            //读取文件
            Workbook workbook = new HSSFWorkbook(fileInputStream);
            Sheet sheet = workbook.getSheetAt(0);
            Row row = sheet.getRow(0);
            //得到有效的单元格数
            int cells = row.getPhysicalNumberOfCells();
            //输出第一行的标题
            for (int i = 0; i < cells; i++){
                System.out.print(row.getCell(i)+"  ");
            }
            System.out.println();
            //得到有效的行数
            int rowCount = sheet.getPhysicalNumberOfRows();
            //输出数据
            for (int rowNum = 1; rowNum < rowCount; rowNum++){
                Row rowData = sheet.getRow(rowNum);
                if (rowData != null){
                    //读取单元格
                    int cellCount = rowData.getPhysicalNumberOfCells();
                    for (int cellNum = 0; cellNum < cellCount; cellNum++){
                        Cell cell = rowData.getCell(cellNum);
                        if(cell != null){
                            //匹配单元格的内容数据类型
                            CellType cellType = cell.getCellType();
                            String value="";
                            switch (cellType){
                                case _NONE:
                                    break;
                                case BLANK:
                                    break;
                                case ERROR:
                                    break;
                                case STRING://字符串类型
                                    value = cell.getStringCellValue();
                                    break;
                                case BOOLEAN:
                                    value = String.valueOf(cell.getBooleanCellValue());
                                    break;
                                case FORMULA: //公式Formula
                                    //拿到计算公式
                                    String cellFormula = cell.getCellFormula();
                                    //System.out.println(cellFormula);
                                    FormulaEvaluator formulaEvaluator = new HSSFFormulaEvaluator((HSSFWorkbook) workbook);
                                    CellValue evaluate = formulaEvaluator.evaluate(cell);
                                    value = evaluate.formatAsString();
                                    break;
                                case NUMERIC://数字Numeric(日期,数字)
                                    if(HSSFDateUtil.isCellDateFormatted(cell)){//是日期
                                        Date date = cell.getDateCellValue();
                                        value=new DateTime(date).toString("yyyy-MM-dd");
                                    }else {
                                        NumberFormat nf = NumberFormat.getInstance();
                                        value = String.valueOf(nf.format(cell.getNumericCellValue())).replace(",", "");
//                                    cell.setCellType(CellType.STRING);
//                                    value=cell.toString();
                                    }
                                    break;
                                default:
                                    break;
                            }
                            System.out.print(value+"  ");
                        }
                    }
                    System.out.println();
                }
            }
            fileInputStream.close();
        }

"C:\Program Files\Java\jdk1.8.0_144\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\IntelliJ IDEA\IntelliJ IDEA 2018.2.4\lib\idea_rt.jar=56295:D:\IntelliJ IDEA\IntelliJ IDEA 2018.2.4\bin" -Dfile.encoding=UTF-8 -classpath "D:\IntelliJ IDEA\IntelliJ IDEA 2018.2.4\lib\idea_rt.jar;D:\IntelliJ bin\rep\org\apache\commons\commons-compress\1.18\commons-compress-1.18.jar;D:\apache-maven-3.5.4-bin\rep\com\github\virtuald\curvesapi\1.06\curvesapi-1.06.jar;D:\apache-maven-3.5.4-bin\rep\org\apache\poi\ooxml-schemas\1.4\ooxml-schemas-1.4.jar;D:\apache-maven-3.5.4-bin\rep\org\apache\xmlbeans\xmlbeans\3.0.1\xmlbeans-3.0.1.jar;D:\apache-maven-3.5.4-bin\rep\joda-time\joda-time\2.10.5\joda-time-2.10.5.jar" T
name  age  
罗罗  23  
金金  22  

Process finished with exit code 0