Java POI 操作读取写入 Excel
源码下载:链接: https://pan.baidu.com/s/1y7GY7NLhwbksSFoMiiOWzg 提取码:ek1z
HSSF、XSSF和SXSSF区别以及Excel导出优化
一、 POI提供了HSSF、XSSF以及SXSSF三种方式操作Excel。他们的区别如下:
HSSF:是操作Excel97-2003版本,扩展名为.xls。
XSSF:是操作Excel2007版本开始,扩展名为.xlsx。
SXSSF:是在XSSF基础上,POI3.8版本开始提供的一种支持低内存占用的操作方式,扩展名为.xlsx。
二、大家需要了解下Excel不同版本的一些区别,这些限制其实间接的局限了POI提供的API功能。
1、支持的行数、列数
Excel97-2003版本,一个sheet最大行数65536,最大列数256。
Excel2007版本开始,一个sheet最大行数1048576,最大列数16384。
2、文件大小
.xlsx文件比.xls的压缩率高,也就是相同数据量下,.xlsx的文件会小很多。
3、兼容性
Excel97-2003版本是不能打开.xlsx文件的。
Excel2007开始的版本是可以打开.xls文件的。
三、操作推荐
根据以上内容,大家可以根据自己的需求进行选择,当然海量数据的导出肯定是推荐SXSSF的方式。
编码过程中,其实不同方式的使用方式基本相同,所以互相切换也是比较简单的,只要把带有前缀的接口改成对应的就行了。如:
HSSF对应:HSSFWorkbook、HSSFSheet、HSSFRow、HSSFCell ……
XSSF对应:XSSFWorkbook、XSSFSheet、XSSFRow、XSSFCell ……
SXSSF对应:SXSSFWorkbook、Sheet、Row、Cell ……
规律还是挺明显的,除了workbook,SXSSF的接口都不带前缀,另外两种方式的各个接口都带有对应的前缀。
四、低内存占用操作
另外,前面有提到SXSSF是一种低内存占用的操作方式,因为其提供了一个新的方法:
//内存中保留100条数据,其余写入硬盘临时文件SXSSFWorkbook w3= new SXSSFWorkbook(100);
在数据量超过设置的值时,会在硬盘生成临时文件保存之前的数据,而且POI会根据规则自动删除生成的这些临时文件。
代码如下:
maven所依赖的jar包:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-scratchpad</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>23.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.5</version>
</dependency>
工具类代码如下:
package com.dzpykj.files.excel;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.EncryptedDocumentException;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import com.google.common.collect.Maps;
/**
* Excel操作工具类
* @author ChaiXY
*/
public class ExcelUtils {
// @Value("${file_base_path}")
// private static String fileBasePath;//文件的基础路径
// private static String fileBasePath = System.getProperty("user.dir") + File.separator + "excel" + File.separator;;//文件的基础路径
public static final String OFFICE_EXCEL_XLS = "xls";
public static final String OFFICE_EXCEL_XLSX = "xlsx";
/**
* 读取指定Sheet也的内容
* @param filepath filepath 文件全路径
* @param sheetNo sheet序号,从0开始,如果读取全文sheetNo设置null
*/
public static String readExcel(String filepath, Integer sheetNo)
throws EncryptedDocumentException, InvalidFormatException, IOException {
StringBuilder sb = new StringBuilder();
Workbook workbook = getWorkbook(filepath);
if (workbook != null) {
if (sheetNo == null) {
int numberOfSheets = workbook.getNumberOfSheets();
for (int i = 0; i < numberOfSheets; i++) {
Sheet sheet = workbook.getSheetAt(i);
if (sheet == null) {
continue;
}
sb.append(readExcelSheet(sheet));
}
} else {
Sheet sheet = workbook.getSheetAt(sheetNo);
if (sheet != null) {
sb.append(readExcelSheet(sheet));
}
}
}
return sb.toString();
}
/**
* 根据文件路径获取Workbook对象
* @param filepath 文件全路径
*/
public static Workbook getWorkbook(String filepath)
throws EncryptedDocumentException, InvalidFormatException, IOException {
InputStream is = null;
Workbook wb = null;
if (StringUtils.isBlank(filepath)) {
throw new IllegalArgumentException("文件路径不能为空");
} else {
String suffiex = getSuffiex(filepath);
if (StringUtils.isBlank(suffiex)) {
throw new IllegalArgumentException("文件后缀不能为空");
}
if (OFFICE_EXCEL_XLS.equals(suffiex) || OFFICE_EXCEL_XLSX.equals(suffiex)) {
try {
is = new FileInputStream(filepath);
wb = WorkbookFactory.create(is);
} finally {
if (is != null) {
is.close();
}
if (wb != null) {
wb.close();
}
}
} else {
throw new IllegalArgumentException("该文件非Excel文件");
}
}
return wb;
}
/**
* 获取后缀
* @param filepath filepath 文件全路径
*/
private static String getSuffiex(String filepath) {
if (StringUtils.isBlank(filepath)) {
return "";
}
int index = filepath.lastIndexOf(".");
if (index == -1) {
return "";
}
return filepath.substring(index + 1, filepath.length());
}
private static String readExcelSheet(Sheet sheet) {
StringBuilder sb = new StringBuilder();
if(sheet != null){
int rowNos = sheet.getLastRowNum();// 得到excel的总记录条数
for (int i = 0; i <= rowNos; i++) {// 遍历行
Row row = sheet.getRow(i);
if(row != null){
int columNos = row.getLastCellNum();// 表头总共的列数
for (int j = 0; j < columNos; j++) {
Cell cell = row.getCell(j);
if(cell != null){
cell.setCellType(CellType.STRING);
sb.append(cell.getStringCellValue() + " ");
// System.out.print(cell.getStringCellValue() + " ");
}
}
// System.out.println();
}
}
}
return sb.toString();
}
/**
* 读取指定Sheet页的表头
* @param filepath filepath 文件全路径
* @param sheetNo sheet序号,从0开始,必填
*/
public static Row readTitle(String filepath, int sheetNo)
throws IOException, EncryptedDocumentException, InvalidFormatException {
Row returnRow = null;
Workbook workbook = getWorkbook(filepath);
if (workbook != null) {
Sheet sheet = workbook.getSheetAt(sheetNo);
returnRow = readTitle(sheet);
}
return returnRow;
}
/**
* 读取指定Sheet页的表头
*/
public static Row readTitle(Sheet sheet) throws IOException {
Row returnRow = null;
int totalRow = sheet.getLastRowNum();// 得到excel的总记录条数
for (int i = 0; i < totalRow; i++) {// 遍历行
Row row = sheet.getRow(i);
if (row == null) {
continue;
}
returnRow = sheet.getRow(0);
break;
}
return returnRow;
}
/**
* 创建Excel文件
* @param filepath filepath 文件全路径
* @param sheetName 新Sheet页的名字
* @param titles 表头
* @param values 每行的单元格
*/
public static boolean writeExcel(String filepath, String sheetName, List<String> titles,
List<Map<String, Object>> values) throws IOException {
boolean success = false;
OutputStream outputStream = null;
if (StringUtils.isBlank(filepath)) {
throw new IllegalArgumentException("文件路径不能为空");
} else {
String suffiex = getSuffiex(filepath);
if (StringUtils.isBlank(suffiex)) {
throw new IllegalArgumentException("文件后缀不能为空");
}
Workbook workbook;
if ("xls".equals(suffiex.toLowerCase())) {
workbook = new HSSFWorkbook();
} else {
workbook = new XSSFWorkbook();
}
// 生成一个表格
Sheet sheet;
if (StringUtils.isBlank(sheetName)) {
// name 为空则使用默认值
sheet = workbook.createSheet();
} else {
sheet = workbook.createSheet(sheetName);
}
// 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();
// 行号
int index = 1;
while (iterator.hasNext()) {
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 {
if (object != null) {
cell.setCellValue(object.toString());
}
}
}
index++;
}
try {
outputStream = new FileOutputStream(filepath);
workbook.write(outputStream);
success = true;
} finally {
if (outputStream != null) {
outputStream.close();
}
if (workbook != null) {
workbook.close();
}
}
return success;
}
}
/**
* 设置格式
*/
private static Map<String, CellStyle> createStyles(Workbook wb) {
Map<String, CellStyle> styles = Maps.newHashMap();
// 标题样式
XSSFCellStyle titleStyle = (XSSFCellStyle) 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
XSSFCellStyle headerStyle = (XSSFCellStyle) 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
XSSFCellStyle cellStyleA = (XSSFCellStyle) 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
XSSFCellStyle cellStyleB = (XSSFCellStyle) 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;
}
/**
* 将源文件的内容复制到新Excel文件(可供理解Excel使用,使用价值不大)
* @param srcFilepath 源文件全路径
* @param desFilepath 目标文件全路径
*/
public static void writeExcel(String srcFilepath, String desFilepath)
throws IOException, EncryptedDocumentException, InvalidFormatException {
FileOutputStream outputStream = null;
String suffiex = getSuffiex(desFilepath);
if (StringUtils.isBlank(suffiex)) {
throw new IllegalArgumentException("文件后缀不能为空");
}
Workbook workbook_des;
if ("xls".equals(suffiex.toLowerCase())) {
workbook_des = new HSSFWorkbook();
} else {
workbook_des = new XSSFWorkbook();
}
Workbook workbook = getWorkbook(srcFilepath);
if (workbook != null) {
int numberOfSheets = workbook.getNumberOfSheets();
for (int k = 0; k < numberOfSheets; k++) {
Sheet sheet = workbook.getSheetAt(k);
Sheet sheet_des = workbook_des.createSheet(sheet.getSheetName());
if (sheet != null) {
int rowNos = sheet.getLastRowNum();
for (int i = 0; i <= rowNos; i++) {
Row row = sheet.getRow(i);
Row row_des = sheet_des.createRow(i);
if(row != null){
int columNos = row.getLastCellNum();
for (int j = 0; j < columNos; j++) {
Cell cell = row.getCell(j);
Cell cell_des = row_des.createCell(j);
if(cell != null){
cell.setCellType(CellType.STRING);
cell_des.setCellType(CellType.STRING);
cell_des.setCellValue(cell.getStringCellValue());
}
}
}
}
}
}
}
try {
outputStream = new FileOutputStream(desFilepath);
workbook_des.write(outputStream);
} finally {
if (outputStream != null) {
outputStream.close();
}
if (workbook != null) {
workbook_des.close();
}
}
}
public static void main(String[] args) {
}
}
读取与写入Excel文件
文章参考:Java POI 操作Excel(读取/写入)
作者:两把伞
来源:CSDN
原文:https://blog.csdn.net/zuoyouzouzou/article/details/86480123
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