POI和easyExcel-优快云博客

本文链接：https://blog.youkuaiyun.com/wa_ka_ka/article/details/121043669

POI使用

依赖

            <!--xls 03-->
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi</artifactId>
                <version>3.9</version>
            </dependency>
            <!--xls 07-->
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>poi-ooxml</artifactId>
                <version>3.9</version>
            </dependency>
            <!--日期格式化工具-->
            <dependency>
                <groupId>joda-time</groupId>
                <artifactId>joda-time</artifactId>
                <version>2.10.5</version>
            </dependency>

**03版excel导出：**new HSSFWorkbook();

static String PATH = "C:\\Users\\Administrator\\Desktop\\WorkSpace\\easyExcel\\src";
    @Test
    public void testWrite03() throws Exception {
        long start = System.currentTimeMillis();
        //1，创建工作簿
        HSSFWorkbook workbook = new HSSFWorkbook();
        //2，创建工作表
        Sheet sheet = workbook.createSheet("excel_1");
        //3，创建100行
        for (int i = 0; i < 65535; i++) {
            Row row = sheet.createRow(i);
            //4,创建10列，10个单元格
            for (int j = 0; j < 10; j++) {
                Cell cell = row.createCell(j);
                cell.setCellValue(j);
            }
        }
        //5，生成一张表
        FileOutputStream fileOutputStream = new FileOutputStream(PATH + "/测试表03.xls");
        workbook.write(fileOutputStream);
        //6，关闭流
        fileOutputStream.close();
        long end = System.currentTimeMillis();
        System.out.println("excel导出完毕！耗时："+(end-start)+"毫秒");

    }

excel导出完毕！耗时：1989毫秒

**07版excel导出：**new XSSFWorkbook();

    @Test
    public void testWrite07() throws Exception {
        long start = System.currentTimeMillis();
        //1，创建工作簿
        XSSFWorkbook workbook = new XSSFWorkbook();
        //2，创建工作表
        Sheet sheet = workbook.createSheet("excel_1");
        //3，创建100行
        for (int i = 0; i < 65535; i++) {
            Row row = sheet.createRow(i);
            //4,创建10列，10个单元格
            for (int j = 0; j < 10; j++) {
                Cell cell = row.createCell(j);
                cell.setCellValue(j);
            }
        }
        //5，生成一张表
        FileOutputStream fileOutputStream = new FileOutputStream(PATH + "/测试表07.xls");
        workbook.write(fileOutputStream);
        //6，关闭流
        fileOutputStream.close();
        long end = System.currentTimeMillis();
        System.out.println("excel导出完毕！耗时："+(end-start)+"毫秒");

    }

excel导出完毕！耗时：7386毫秒

**07版excel导出优化：**new HSSFWorkbook();

    @Test
    public void testWrite07() throws Exception {
        long start = System.currentTimeMillis();
        //1，创建工作簿
        HSSFWorkbook workbook = new HSSFWorkbook();
        //2，创建工作表
        Sheet sheet = workbook.createSheet("excel_1");
        //3，创建100行
        for (int i = 0; i < 65535; i++) {
            Row row = sheet.createRow(i);
            //4,创建10列，10个单元格
            for (int j = 0; j < 10; j++) {
                Cell cell = row.createCell(j);
                cell.setCellValue(j);
            }
        }
        //5，生成一张表
        FileOutputStream fileOutputStream = new FileOutputStream(PATH + "/测试表07.xls");
        workbook.write(fileOutputStream);
        //6，关闭流
        fileOutputStream.close();
        long end = System.currentTimeMillis();
        System.out.println("excel导出完毕！耗时："+(end-start)+"毫秒");

    }

excel导出完毕！耗时：2015毫秒

HSSFWorkbook：适用于03版，只能导出65535行数据，超出报错
XSSFWorkbook：适用于07版，导出数据行数不受限制，但效率低
HSSFWorkbook：是07版优化，提高执行效率

excel导入：

@Test
    public void test03() throws Exception {
        FileInputStream fileInputStream = new FileInputStream("C:\\Users\\Administrator\\Desktop\\WorkSpace\\easyExcel\\src\\read_test.xls");
        HSSFWorkbook workbook = new HSSFWorkbook(fileInputStream);
        HSSFSheet sheet = workbook.getSheetAt(0); //获取第一个工作表
        HSSFRow row = sheet.getRow(0);  //获取第一行标题
        if (row != null){  //如果第一行不为空
            int numberOfCells = row.getPhysicalNumberOfCells(); //获取总列数
            for (int cellnum = 0; cellnum < numberOfCells; cellnum++) {
                Cell cell = row.getCell(cellnum);
                if (cell != null){
                    String cellValue = cell.getStringCellValue();
                    System.out.print(cellValue+" | ");
                }
            }
            System.out.println();
        }

        //获取表中内容
        int numberOfRows = sheet.getPhysicalNumberOfRows();  //获取总行数
        for (int rownum = 1; rownum < numberOfRows; rownum++) {
            Row rowData = sheet.getRow(rownum);
            if (rowData != null){
                //读取列数据
                int numberOfCells = rowData.getPhysicalNumberOfCells();
                for (int cellNum = 0; cellNum < numberOfCells; cellNum++) {
                    Cell cell = rowData.getCell(cellNum);
                    if (cell != null){
                        //判断数据类型
                        int cellType = cell.getCellType();
                        String cellValue = "";
                        switch (cellType){
                            case HSSFCell.CELL_TYPE_STRING:  //String类型
                                cellValue = cell.getStringCellValue();
                                break;
                            case HSSFCell.CELL_TYPE_BOOLEAN: //布尔类型
                                cellValue = String.valueOf(cell.getBooleanCellValue());
                                break;
                            case HSSFCell.CELL_TYPE_NUMERIC: //数字和日期类型
                                if (HSSFDateUtil.isCellDateFormatted(cell)){
                                    Date date = cell.getDateCellValue();
                                    cellValue = new DateTime(date).toString("yyyy-MM-dd");
                                }else {
                                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);
                                    cellValue = cell.toString();
                                }
                                break;
                            case HSSFCell.CELL_TYPE_ERROR:
                                cellValue = String.valueOf(cell.getErrorCellValue());
                                break;
                        }
                        System.out.print(cellValue+" | ");
                    }
                }
                System.out.println();
            }
        }
        fileInputStream.close();

    }

工号 | 姓名 | 出生日期 | 薪资 |
111111 | 张三 | 2000-07-11 | 8888.8 |
222222 | 王五 | 2001-04-11 | 6666.6 |

计算公式

@Test
    public void test04() throws Exception {
        FileInputStream fileInputStream = new FileInputStream("C:\\Users\\Administrator\\Desktop\\WorkSpace\\easyExcel\\src\\read_test1.xlsx");
        XSSFWorkbook workbook = new XSSFWorkbook(fileInputStream);
        XSSFSheet sheet = workbook.getSheetAt(0);
        XSSFRow row = sheet.getRow(3);
        XSSFCell cell = row.getCell(0);
        //拿到计算公式
        XSSFFormulaEvaluator formulaEvaluator = new XSSFFormulaEvaluator((XSSFWorkbook) workbook);
        //拿到单元格内容
        int cellType = cell.getCellType();
        switch (cellType){
            case Cell.CELL_TYPE_FORMULA: //公式
                String cellFormula = cell.getCellFormula();
                System.out.println("公式："+cellFormula);
                //计算
                CellValue evaluate = formulaEvaluator.evaluate(cell);
                String cellValue = evaluate.formatAsString();
                System.out.println(cellValue);
        }
        fileInputStream.close();
    }

公式：SUM(A1:A3)
303.0

easyExcel使用

依赖

            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>easyexcel</artifactId>
                <version>3.0.1</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.18.12</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.41</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>

写文件

excel对象实体

@Data
public class DemoData {
    @ExcelProperty("字符串标题")
    private String string;
    @ExcelProperty("日期标题")
    private Date date;
    @ExcelProperty("数字标题")
    private Double doubleData;
    /**
     * 忽略这个字段
     */
    @ExcelIgnore
    private String ignore;
}

测试类

public class EasyExcelTest {

    @Test
    public void simpleWrite() {
        String fileName = "C:\\Users\\Administrator\\Desktop\\WorkSpace\\easyExcel\\src\\easy_test.xls";
        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
        // 如果这里想使用03 则 传入excelType参数即可
        EasyExcel.write(fileName, DemoData.class)
                .sheet("模板")
                .doWrite(() -> {
                    // 分页查询数据
                    return data();
                });
    }

    private List<DemoData> data() {
        List<DemoData> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            DemoData data = new DemoData();
            data.setString("字符串" + i);
            data.setDate(new Date());
            data.setDoubleData(0.56);
            list.add(data);
        }
        return list;
    }

}

请添加图片描述

读文件

监听器

public class DemoDataListener extends AnalysisEventListener<DemoData> {
    private static final Logger LOGGER = LoggerFactory.getLogger(DemoDataListener.class);
    /**
     * 每隔5条存储数据库，实际使用中可以3000条，然后清理list ，方便内存回收
     */
    private static final int BATCH_COUNT = 3000;
    /**
     * 缓存的数据
     */
    private List<DemoData> list = new ArrayList<>(BATCH_COUNT);
    /**
     * 假设这个是一个DAO，当然有业务逻辑这个也可以是一个service。当然如果不用存储这个对象没用。
     */
    private DemoDAO demoDAO;

    public DemoDataListener() {
        // 这里是demo，所以随便new一个。实际使用如果到了spring,请使用下面的有参构造函数
        demoDAO = new DemoDAO();
    }

    /**
     * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来
     *
     * @param demoDAO
     */
    public DemoDataListener(DemoDAO demoDAO) {
        this.demoDAO = demoDAO;
    }

    /**
     * 这个每一条数据解析都会来调用
     *
     * @param data    one row value. Is is same as {@link AnalysisContext#readRowHolder()}
     * @param context
     */
    @Override
    public void invoke(DemoData data, AnalysisContext context) {
        LOGGER.info("解析到一条数据:{}", JSON.toJSONString(data));
        list.add(data);
        // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
        if (list.size() >= BATCH_COUNT) {
            saveData();
            // 存储完成清理 list
            list = new ArrayList<>(BATCH_COUNT);
        }
    }

    /**
     * 所有数据解析完成了 都会来调用
     *
     * @param context
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        // 这里也要保存数据，确保最后遗留的数据也存储到数据库
        saveData();
        LOGGER.info("所有数据解析完成！");
    }

    /**
     * 加上存储数据库
     */
    private void saveData() {
        LOGGER.info("{}条数据，开始存储数据库！", list.size());
        demoDAO.save(list);
        LOGGER.info("存储数据库成功！");
    }
}

dao层

public class DemoDAO {
    public void save(List<DemoData> list) {
        // 如果是mybatis,尽量别直接调用多次insert,自己写一个mapper里面新增一个方法batchInsert,所有数据一次性插入
    }
}

测试类

@Test
    public void simpleRead() {
        // 写法1：JDK8+ ,不用额外写一个DemoDataListener
        // since: 3.0.0-beta1
        String fileName = "C:\\Users\\Administrator\\Desktop\\WorkSpace\\easyExcel\\src\\easy_test.xls";
        // 这里 需要指定读用哪个class去读，然后读取第一个sheet 文件流会自动关闭
        // 这里每次会读取3000条数据 然后返回过来 直接调用使用数据就行
        EasyExcel.read(fileName, DemoData.class, new PageReadListener<DemoData>(dataList -> {
            for (DemoData demoData : dataList) {
                System.out.println(JSON.toJSONString(demoData));
            }
        })).sheet().doRead();

    }

{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串0”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串1”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串2”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串3”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串4”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串5”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串6”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串7”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串8”}
{“date”:1635514919700,“doubleData”:0.56,“string”:“字符串9”}

了解更多：https://www.yuque.com/easyexcel/doc