=======第一版:基本功能实现=======
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; /**
* 将读取到的数据库内容写到Excel模板表中，供下载需要
*/
public class WriterExcelFile { private static final Logger LOGGER = Logger.getLogger(WriterExcelFile.class.getName()); /**
* 将数据写入指定path下的Excel文件中
* 这里会有一个限制条件:列名的顺序必须和数据的存储顺序一致,否则会造成混乱;这是第一版,以后再改进这个
* @param path 文件存储路径
* @param name sheet名
* @param style Excel类型
* @param titles 标题串
* @param values 内容集
* @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();
}
// 生成一个表格
Sheet sheet = workbook.createSheet(name);
// 设置表格默认列宽度为15个字节
sheet.setDefaultColumnWidth((short) 15);
// 生成样式
Map<String, CellStyle> styles = createStyles(workbook);
/*
* 创建标题行
*/
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));
}
/*
* 写入正文
*/
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);
}
}
/*
* 写入到文件中
*/
boolean isCorrect = false;
File file = new File(path);
// 如果文件存在,则删除已有的文件,重新创建一份新的
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(); // 标题样式
CellStyle titleStyle = wb.createCellStyle();
titleStyle.setAlignment(HorizontalAlignment.CENTER); // 水平对齐
titleStyle.setVerticalAlignment(VerticalAlignment.CENTER); // 垂直对齐
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("微软雅黑");
titleStyle.setFont(titleFont);
styles.put("title", titleStyle); // 文件头样式
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("微软雅黑");
headerStyle.setFont(headerFont);
styles.put("header", headerStyle); // 正文样式
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：优化Excel表样式，添加数据类型判断以及一个demo测试=======
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));
} /**
* 数据写入Excel文件
*
* @param path 文件路径，包含文件全名，例如：D://file//demo.xls
* @param name sheet名称
* @param titles 行标题列
* @param values 数据集合，key为标题，value为数据
* @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(); // 从文件路径中获取文件的类型
return generateWorkbook(path, name, style, titles, values);
} /**
* 将数据写入指定path下的Excel文件中
*
* @param path 文件存储路径
* @param name sheet名
* @param style Excel类型
* @param titles 标题串
* @param values 内容集
* @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();
}
// 生成一个表格
Sheet sheet;
if (null == name || "".equals(name)) {
sheet = workbook.createSheet(); // name 为空则使用默认值
} else {
sheet = workbook.createSheet(name);
}
// 设置表格默认列宽度为15个字节
sheet.setDefaultColumnWidth((short) 15);
// 生成样式
Map<String, CellStyle> styles = createStyles(workbook);
/*
* 创建标题行
*/
Row row = sheet.createRow(0);
// 存储标题在Excel文件中的序号
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);
}
/*
* 写入正文
*/
Iterator<Map<String, Object>> iterator = values.iterator();
int index = 0; // 行号
while (iterator.hasNext()) {
index++; // 出去标题行，从第一行开始写
row = sheet.createRow(index);
Map<String, Object> value = iterator.next();
for (Map.Entry<String, Object> map : value.entrySet()) {
// 获取列名
String title = map.getKey();
// 根据列名获取序号
int i = titleOrder.get(title);
// 在指定序号处创建cell
Cell cell = row.createCell(i);
// 设置cell的样式
if (index % 2 == 1) {
cell.setCellStyle(styles.get("cellA"));
} else {
cell.setCellStyle(styles.get("cellB"));
}
// 获取列的值
Object object = map.getValue();
// 判断object的类型
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());
}
}
}
/*
* 写入到文件中
*/
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(); // 标题样式
CellStyle titleStyle = wb.createCellStyle();
titleStyle.setAlignment(HorizontalAlignment.CENTER); // 水平对齐
titleStyle.setVerticalAlignment(VerticalAlignment.CENTER); // 垂直对齐
titleStyle.setLocked(true); // 样式锁定
titleStyle.setFillForegroundColor(IndexedColors.LIGHT_YELLOW.getIndex());
Font titleFont = wb.createFont();
titleFont.setFontHeightInPoints((short) 16);
titleFont.setBold(true);
titleFont.setFontName("微软雅黑");
titleStyle.setFont(titleFont);
styles.put("title", titleStyle); // 文件头样式
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); // 颜色填充方式
headerStyle.setWrapText(true);
headerStyle.setBorderRight(BorderStyle.THIN); // 设置边界
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("微软雅黑");
headerStyle.setFont(headerFont);
styles.put("header", headerStyle); Font cellStyleFont = wb.createFont();
cellStyleFont.setFontHeightInPoints((short) 12);
cellStyleFont.setColor(IndexedColors.BLUE_GREY.getIndex());
cellStyleFont.setFontName("微软雅黑"); // 正文样式A
CellStyle cellStyleA = wb.createCellStyle();
cellStyleA.setAlignment(HorizontalAlignment.CENTER); // 居中设置
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); // 正文样式B:添加前景色为浅黄色
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：使用注解来实现，请跳转到 https://www.cnblogs.com/SummerinShire/p/11045254.html =======