java 寫入數據到Excel文件中_Demo

=======第一版:基本功能實現=======

import com.google.common.collect.Maps;
import org.apache.log4j.Logger;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * 將讀取到的數據庫內容寫到Excel模板表中，供下載需要
 */
public class WriterExcelFile {

    private static final Logger LOGGER = Logger.getLogger(WriterExcelFile.class.getName());

    /**
     * 將數據寫入指定path下的Excel文件中
     *      這里會有一個限制條件:列名的順序必須和數據的存儲順序一致,否則會造成混亂;這是第一版,以后再改進這個
     * @param path 文件存儲路徑
     * @param name sheet名
     * @param style Excel類型
     * @param titles 標題串
     * @param values 內容集
     * @return T\F
     */
    public static boolean generateWorkbook(String path, String name, String style, List<String> titles, List<Map<String, Object>> values) {
        Workbook workbook;
        if ("XLS".equals(style.toUpperCase())) {
            workbook = new HSSFWorkbook();
        } else {
            workbook = new XSSFWorkbook();
        }
        // 生成一個表格
        Sheet sheet = workbook.createSheet(name);
        // 設置表格默認列寬度為15個字節
        sheet.setDefaultColumnWidth((short) 15);
        // 生成樣式
        Map<String, CellStyle> styles = createStyles(workbook);
        /*
         * 創建標題行
         */
        Row row = sheet.createRow(0);
        for (int i = 0; i < titles.size(); i++) {
            Cell cell = row.createCell(i);
            cell.setCellStyle(styles.get("header"));
            cell.setCellValue(titles.get(i));
        }
        /*
         * 寫入正文
         */
        Iterator<Map<String, Object>> iterator = values.iterator();
        int index = 0;
        while (iterator.hasNext()) {
            index++;
            row = sheet.createRow(index);
            Map<String, Object> value = iterator.next();
            String content = "";
            for (Map.Entry<String, Object> map : value.entrySet()) {
                Object object = map.getValue();
                content = object.toString();
            }
            for (int i = 0; i < value.size(); i++) {
                Cell cell = row.createCell(i);
                cell.setCellStyle(styles.get("cell"));
                cell.setCellValue(content);
            }
        }
        /*
         * 寫入到文件中
         */
        boolean isCorrect = false;
        File file = new File(path);
        // 如果文件存在,則刪除已有的文件,重新創建一份新的
        if (file.exists()) {
            file.deleteOnExit();
            file = new File(path);
        }
        OutputStream outputStream = null;
        try {
            outputStream = new FileOutputStream(file);
            workbook.write(outputStream);
            isCorrect = true;
        } catch (IOException e) {
            LOGGER.error(e.getMessage());
        } finally {
            try {
                if (null != outputStream) {
                    outputStream.close();
                }
            } catch (IOException e) {
                LOGGER.error(e.getMessage());
            }
        }
        return isCorrect;
    }

    /**
     * Create a library of cell styles
     */
    private static Map<String, CellStyle> createStyles(Workbook wb) {
        Map<String, CellStyle> styles = Maps.newHashMap();
        DataFormat dataFormat = wb.createDataFormat();

        // 標題樣式
        CellStyle titleStyle = wb.createCellStyle();
        titleStyle.setAlignment(HorizontalAlignment.CENTER); // 水平對齊
        titleStyle.setVerticalAlignment(VerticalAlignment.CENTER); // 垂直對齊
        titleStyle.setLocked(true);
        titleStyle.setFillForegroundColor(IndexedColors.BLUE.getIndex());
        titleStyle.setFillBackgroundColor(IndexedColors.YELLOW.getIndex());
        Font titleFont = wb.createFont();
        titleFont.setFontHeightInPoints((short) 16);
        titleFont.setBold(true);
        titleFont.setFontName("微軟雅黑");
        titleStyle.setFont(titleFont);
        styles.put("title", titleStyle);

        // 文件頭樣式
        CellStyle headerStyle = wb.createCellStyle();
        headerStyle.setAlignment(HorizontalAlignment.CENTER);
        headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        headerStyle.setFillForegroundColor(IndexedColors.GREY_50_PERCENT.getIndex());
        headerStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex());
        headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        headerStyle.setWrapText(true);
        Font headerFont = wb.createFont();
        headerFont.setFontHeightInPoints((short) 12);
        headerFont.setColor(IndexedColors.WHITE.getIndex());
        titleFont.setFontName("微軟雅黑");
        headerStyle.setFont(headerFont);
        styles.put("header", headerStyle);

        // 正文樣式
        CellStyle cellStyle = wb.createCellStyle();
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle.setWrapText(true);
        cellStyle.setBorderRight(BorderStyle.THIN);
        cellStyle.setRightBorderColor(IndexedColors.BLACK.getIndex());
        cellStyle.setBorderLeft(BorderStyle.THIN);
        cellStyle.setLeftBorderColor(IndexedColors.BLACK.getIndex());
        cellStyle.setBorderTop(BorderStyle.THIN);
        cellStyle.setTopBorderColor(IndexedColors.BLACK.getIndex());
        cellStyle.setBorderBottom(BorderStyle.THIN);
        cellStyle.setBottomBorderColor(IndexedColors.BLACK.getIndex());
        styles.put("cell", cellStyle);

        return styles;
    }
}

 

=======第二版：優化Excel表樣式，添加數據類型判斷以及一個demo測試=======

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.*;

public class WriterExcelUtil {

    private static final Logger LOGGER = LoggerFactory.getLogger(WriterExcelUtil.class.getName());

    public static void main(String[] args) {
        String path = "E://demo.xlsx";
        String name = "test";
        List<String> titles =Lists.newArrayList();
        titles.add("id");
        titles.add("name");
        titles.add("age");
        titles.add("birthday");
        titles.add("gender");
        titles.add("date");
        List<Map<String, Object>> values = Lists.newArrayList();
        for (int i = 0; i < 10; i++) {
            Map<String, Object> map = Maps.newHashMap();
            map.put("id", i + 1D);
            map.put("name", "test_" + i);
            map.put("age", i * 1.5);
            map.put("gender", "man");
            map.put("birthday", new Date());
            map.put("date",  Calendar.getInstance());
            values.add(map);
        }
        System.out.println(writerExcel(path, name, titles, values));
    }

    /**
     * 數據寫入Excel文件
     *
     * @param path 文件路徑，包含文件全名，例如：D://file//demo.xls
     * @param name sheet名稱
     * @param titles 行標題列
     * @param values 數據集合，key為標題，value為數據
     * @return True\False
     */
    public static boolean writerExcel(String path, String name, List<String> titles, List<Map<String, Object>> values) {
        LOGGER.info("path : {}", path);
        String style = path.substring(path.lastIndexOf("."), path.length()).toUpperCase(); // 從文件路徑中獲取文件的類型
        return generateWorkbook(path, name, style, titles, values);
    }

    /**
     * 將數據寫入指定path下的Excel文件中
     *
     * @param path   文件存儲路徑
     * @param name   sheet名
     * @param style  Excel類型
     * @param titles 標題串
     * @param values 內容集
     * @return True\False
     */
    private static boolean generateWorkbook(String path, String name, String style, List<String> titles, List<Map<String, Object>> values) {
        LOGGER.info("file style : {}", style);
        Workbook workbook;
        if ("XLS".equals(style.toUpperCase())) {
            workbook = new HSSFWorkbook();
        } else {
            workbook = new XSSFWorkbook();
        }
        // 生成一個表格
        Sheet sheet;
        if (null == name || "".equals(name)) {
            sheet = workbook.createSheet(); // name 為空則使用默認值
        } else {
            sheet = workbook.createSheet(name);
        }
        // 設置表格默認列寬度為15個字節
        sheet.setDefaultColumnWidth((short) 15);
        // 生成樣式
        Map<String, CellStyle> styles = createStyles(workbook);
        /*
         * 創建標題行
         */
        Row row = sheet.createRow(0);
        // 存儲標題在Excel文件中的序號
        Map<String, Integer> titleOrder = Maps.newHashMap();
        for (int i = 0; i < titles.size(); i++) {
            Cell cell = row.createCell(i);
            cell.setCellStyle(styles.get("header"));
            String title = titles.get(i);
            cell.setCellValue(title);
            titleOrder.put(title, i);
        }
        /*
         * 寫入正文
         */
        Iterator<Map<String, Object>> iterator = values.iterator();
        int index = 0; // 行號
        while (iterator.hasNext()) {
            index++; // 出去標題行，從第一行開始寫
            row = sheet.createRow(index);
            Map<String, Object> value = iterator.next();
            for (Map.Entry<String, Object> map : value.entrySet()) {
                // 獲取列名
                String title = map.getKey();
                // 根據列名獲取序號
                int i = titleOrder.get(title);
                // 在指定序號處創建cell
                Cell cell = row.createCell(i);
                // 設置cell的樣式
                if (index % 2 == 1) {
                    cell.setCellStyle(styles.get("cellA"));
                } else {
                    cell.setCellStyle(styles.get("cellB"));
                }
                // 獲取列的值
                Object object = map.getValue();
                // 判斷object的類型
                SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                if (object instanceof Double) {
                    cell.setCellValue((Double) object);
                } else if (object instanceof Date) {
                    String time = simpleDateFormat.format((Date) object);
                    cell.setCellValue(time);
                } else if (object instanceof Calendar) {
                    Calendar calendar = (Calendar) object;
                    String time = simpleDateFormat.format(calendar.getTime());
                    cell.setCellValue(time);
                } else if (object instanceof Boolean) {
                    cell.setCellValue((Boolean) object);
                } else {
                    cell.setCellValue(object.toString());
                }
            }
        }
        /*
         * 寫入到文件中
         */
        boolean isCorrect = false;
        try {
            File file = new File(path);
            OutputStream outputStream = new FileOutputStream(file);
            workbook.write(outputStream);
            outputStream.close();
            isCorrect = true;
        } catch (IOException e) {
            isCorrect = false;
            LOGGER.error("write Excel file error : {}", e.getMessage());
        }
        try {
            workbook.close();
        } catch (IOException e) {
            isCorrect = false;
            LOGGER.error("workbook closed error : {}", e.getMessage());
        }
        return isCorrect;
    }

    /**
     * Create a library of cell styles
     */
    /**
     * @param wb
     * @return
     */
    private static Map<String, CellStyle> createStyles(Workbook wb) {
        Map<String, CellStyle> styles = Maps.newHashMap();

        // 標題樣式
        CellStyle titleStyle = wb.createCellStyle();
        titleStyle.setAlignment(HorizontalAlignment.CENTER); // 水平對齊
        titleStyle.setVerticalAlignment(VerticalAlignment.CENTER); // 垂直對齊
        titleStyle.setLocked(true); // 樣式鎖定
        titleStyle.setFillForegroundColor(IndexedColors.LIGHT_YELLOW.getIndex());
        Font titleFont = wb.createFont();
        titleFont.setFontHeightInPoints((short) 16);
        titleFont.setBold(true);
        titleFont.setFontName("微軟雅黑");
        titleStyle.setFont(titleFont);
        styles.put("title", titleStyle);

        // 文件頭樣式
        CellStyle headerStyle = wb.createCellStyle();
        headerStyle.setAlignment(HorizontalAlignment.CENTER);
        headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        headerStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex()); // 前景色
        headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND); // 顏色填充方式
        headerStyle.setWrapText(true);
        headerStyle.setBorderRight(BorderStyle.THIN); // 設置邊界
        headerStyle.setRightBorderColor(IndexedColors.BLACK.getIndex());
        headerStyle.setBorderLeft(BorderStyle.THIN);
        headerStyle.setLeftBorderColor(IndexedColors.BLACK.getIndex());
        headerStyle.setBorderTop(BorderStyle.THIN);
        headerStyle.setTopBorderColor(IndexedColors.BLACK.getIndex());
        headerStyle.setBorderBottom(BorderStyle.THIN);
        headerStyle.setBottomBorderColor(IndexedColors.BLACK.getIndex());
        Font headerFont = wb.createFont();
        headerFont.setFontHeightInPoints((short) 12);
        headerFont.setColor(IndexedColors.WHITE.getIndex());
        titleFont.setFontName("微軟雅黑");
        headerStyle.setFont(headerFont);
        styles.put("header", headerStyle);

        Font cellStyleFont = wb.createFont();
        cellStyleFont.setFontHeightInPoints((short) 12);
        cellStyleFont.setColor(IndexedColors.BLUE_GREY.getIndex());
        cellStyleFont.setFontName("微軟雅黑");
        
        // 正文樣式A
        CellStyle cellStyleA = wb.createCellStyle();
        cellStyleA.setAlignment(HorizontalAlignment.CENTER); // 居中設置
        cellStyleA.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyleA.setWrapText(true);
        cellStyleA.setBorderRight(BorderStyle.THIN);
        cellStyleA.setRightBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleA.setBorderLeft(BorderStyle.THIN);
        cellStyleA.setLeftBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleA.setBorderTop(BorderStyle.THIN);
        cellStyleA.setTopBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleA.setBorderBottom(BorderStyle.THIN);
        cellStyleA.setBottomBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleA.setFont(cellStyleFont);
        styles.put("cellA", cellStyleA);

        // 正文樣式B:添加前景色為淺黃色
        CellStyle cellStyleB = wb.createCellStyle();
        cellStyleB.setAlignment(HorizontalAlignment.CENTER);
        cellStyleB.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyleB.setFillForegroundColor(IndexedColors.LIGHT_YELLOW.getIndex());
        cellStyleB.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        cellStyleB.setWrapText(true);
        cellStyleB.setBorderRight(BorderStyle.THIN);
        cellStyleB.setRightBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleB.setBorderLeft(BorderStyle.THIN);
        cellStyleB.setLeftBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleB.setBorderTop(BorderStyle.THIN);
        cellStyleB.setTopBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleB.setBorderBottom(BorderStyle.THIN);
        cellStyleB.setBottomBorderColor(IndexedColors.BLACK.getIndex());
        cellStyleB.setFont(cellStyleFont);
        styles.put("cellB", cellStyleB);

        return styles;
    }
}

 =======第三版：使用注解來實現，請跳轉到 https://www.cnblogs.com/SummerinShire/p/11045254.html =======