Java使用POI操作Excel

1. POI操作Excel

1.1. 依賴

<!--操作excel-->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.1.0</version>
        </dependency>

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>4.1.0</version>
        </dependency>

1.2. 讀取Excel

1.2.1. Excel文件內容

1.2.2. 代碼

 /**
     * 讀取excel
     */
    public static void readExcel() {
        InputStream inputStream = null;
        XSSFWorkbook xssfWorkbook = null;
        try {

            String past = "/操作excel.xlsx";
            inputStream = new FileInputStream(past);
            xssfWorkbook = new XSSFWorkbook(inputStream);
            //獲取sheet的個數
            int numberOfSheets = xssfWorkbook.getNumberOfSheets();
            //獲取指定的sheet
            System.out.println(numberOfSheets);

            //通過指定名稱獲取
            XSSFSheet sheet = xssfWorkbook.getSheet("筆記本");
            //通過下標獲取
            XSSFSheet sheetAt = xssfWorkbook.getSheetAt(1);
            if (sheetAt != null) {
                //最后一行有數據的
                int lastRowNum = sheetAt.getLastRowNum();
                XSSFRow row;
                short lastCellNum;
                XSSFCell cell;

                for (int i = 0; i <= lastRowNum; i++) {
                    //獲取指定行
                    row = sheetAt.getRow(i);
                    if (row == null) {
                        continue;
                    }
                    //最后一列有數據的
                    lastCellNum = row.getLastCellNum();
                    for (int j = 0; j <= lastCellNum; j++) {
                        cell = row.getCell(j);
                        if (cell == null) {
                            continue;
                        }
                        //數據類型
                        CellType cellType = cell.getCellType();
                        //字符串
                        if (CellType.STRING == cellType) {
                            System.out.println(cell.toString());
                        }
                        //數字
                        else if (CellType.NUMERIC == cellType) {
                            try {
                                System.out.println(cell.getDateCellValue());
                            } catch (Exception e) {
                                System.out.println(cell.toString());
                            }
                        }
                        //……
                        else {
                            System.out.println(cell.toString());
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
   

1.2.3. 控制台輸出結果

2
便簽名稱
便簽分類
創建時間
創建人
擁有人
小明的便簽
學習便簽
Tue Sep 03 00:00:00 CST 2019
小明
小明
小明的個人便簽
個人便簽
Sun Sep 08 00:00:00 CST 2019
小明
小明

1.3. 生成excel

1.3.1. 代碼

 /**
     * 生成excel
     */
    public static void creatExcel() {
        XSSFWorkbook xssfWorkbook = new XSSFWorkbook();

        //創建一個sheet
        XSSFSheet sheet1 = xssfWorkbook.createSheet("第一個新建的sheet");

        //設置高度和寬度，也可以每行每列單獨分開設置
        //參數為字符個數
        sheet1.setDefaultColumnWidth(20);
        sheet1.setDefaultRowHeight((short) (33 * 20));
        //第二個參數為字符寬度的1/256
        sheet1.setColumnWidth(5, 30 * 256);

        //設置單元格樣式
        XSSFCellStyle cellStyle = xssfWorkbook.createCellStyle();

        // 字體樣式
        Font fontStyle = xssfWorkbook.createFont();
        fontStyle.setBold(true);
        // 字體
        fontStyle.setFontName("等線");
        // 大小
        fontStyle.setFontHeightInPoints((short) 11);
        // 將字體樣式添加到單元格樣式中
        cellStyle.setFont(fontStyle);

        //水平居中
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        //垂直居中
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);

        //設置 單元格填充色
        DefaultIndexedColorMap defaultIndexedColorMap = new DefaultIndexedColorMap();
        XSSFColor clr = new XSSFColor(defaultIndexedColorMap);
        byte[] bytes = {
                (byte) 217,
                (byte) 217,
                (byte) 217
        };
        clr.setRGB(bytes);
        cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        cellStyle.setFillForegroundColor(clr);

        //設置單元格不為鎖定，可編輯，反是用了這個樣式的都可編輯
        cellStyle.setLocked(false);
        //鎖定整個sheet不可編輯
        sheet1.protectSheet("1231312");


        //創建一行數據
        XSSFRow row;
        XSSFCell cell;
        row = sheet1.createRow(0);
        cell = row.createCell(0);
        //設值
        cell.setCellValue("2");


        //合並單元格
        CellRangeAddress cra = new CellRangeAddress(1, 1, 0, 3); // 起始行, 終止行, 起始列, 終止列
        sheet1.addMergedRegion(cra);
        //設置合並單元格的樣式
        // 使用RegionUtil類為合並后的單元格添加邊框
        // 下邊框
        RegionUtil.setBorderBottom(BorderStyle.MEDIUM_DASHED, cra, sheet1);
        // 左邊框
        RegionUtil.setBorderLeft(BorderStyle.MEDIUM_DASHED, cra, sheet1);
        row = sheet1.getRow(1);

        //設置合並單元格內的文本樣式
        //但這個單元格的邊框樣式會覆蓋上面設置的合並單元格的樣式
        CellUtil.getCell(row, 0).setCellStyle(cellStyle);


        //設置單個單元格的樣式
        row = sheet1.createRow(2);
        cell = row.createCell(0);
        cell.setCellStyle(cellStyle);

        //設置數據校驗
        //序列校驗
        String[] strArray = {
                "星期一",
                "星期二",
                "星期三"
        };
        XSSFDataValidationHelper dvHelper = new XSSFDataValidationHelper((XSSFSheet) sheet1);
        XSSFDataValidationConstraint dvConstraint = (XSSFDataValidationConstraint) dvHelper.createExplicitListConstraint(strArray);
        CellRangeAddressList addressList = new CellRangeAddressList(3, 3, 0, 2);
        XSSFDataValidation validation = (XSSFDataValidation) dvHelper.createValidation(dvConstraint, addressList);
        //顯示報錯提示框
        validation.setShowErrorBox(true);
        validation.createErrorBox("錯誤提示", "只能選擇指定的內容！");
        //設置單元格右側顯示剪頭符號,顯示可用的選項，默認為true
        validation.setSuppressDropDownArrow(true);
        //顯示提示信息
        validation.setShowPromptBox(true);
        validation.createPromptBox("提示信息", "請選擇星期填入！");
        sheet1.addValidationData(validation);

        //保護工作薄不可被修改
        xssfWorkbook.lockStructure();
        //這個不知道有啥用
        xssfWorkbook.lockRevision();
        //鎖定excel的窗口大小，不能無限制的橫向，縱向拉伸。
        xssfWorkbook.lockWindows();

        xssfWorkbook.createSheet("第二個人sheet");


        OutputStream outputStream = null;
        try {
            outputStream = new FileOutputStream("/創建excel.xlsx");
            xssfWorkbook.write(outputStream);
            outputStream.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

1.3.2. 生成excel文件內容

1.4. 參考

https://www.cnblogs.com/gavincoder/p/9051803.html

https://blog.csdn.net/sxdtwym/article/details/54379592

https://blog.csdn.net/lipinganq/article/details/78090553