导入poi所需的jar包
poi所需jar
HSSF对xls后缀名的Excel进行读取内容:
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.CellType;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
/**
* Created by M_WBCG on 2017/7/14.
*/
public class ReadExcelForHSSF {
public void read() {
File file = new File("././POI/POI1.xls");
if (!file.exists())
System.out.println("文件不存在");
try {
//1.读取Excel的对象
POIFSFileSystem poifsFileSystem = new POIFSFileSystem(new FileInputStream(file));
//2.Excel工作薄对象
HSSFWorkbook hssfWorkbook = new HSSFWorkbook(poifsFileSystem);
//3.Excel工作表对象
HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(0);
//获取sheet数量
int sheetNumber = hssfWorkbook.getNumberOfSheets();
//总行数
int rowLength = hssfSheet.getLastRowNum()+1;
//4.得到Excel工作表的行
HSSFRow hssfRow = hssfSheet.getRow(0);
//总列数
int colLength = hssfRow.getLastCellNum();
//得到Excel指定单元格中的内容
HSSFCell hssfCell = hssfRow.getCell(0);
//得到单元格样式
CellStyle cellStyle = hssfCell.getCellStyle();
for (int i = 0; i < rowLength; i++) {
//获取Excel工作表的行
HSSFRow hssfRow1 = hssfSheet.getRow(i);
for (int j = 0; j < colLength; j++) {
//获取指定单元格
HSSFCell hssfCell1 = hssfRow1.getCell(j)；
//单元格有数据就取出来，没有数据也不让其为空，因为没数据是空，那对其不能操作
Row.MissingCellPolicy RETURN_NULL_AND_BLANK//如果单元格为null，则为null
Row.MissingCellPolicy RETURN_BLANK_AS_NULL//如果单元格为null，则为null
Row.MissingCellPolicy CREATE_NULL_AS_BLANK//如果单元格为null，则转为""
//Excel数据Cell有不同的类型，当我们试图从一个数字类型的Cell读取出一个字符串时就有可能报异常：
//Cannot get a STRING value from a NUMERIC cell
//将所有的需要读的Cell表格设置为String格式
if (hssfCell1 != null) {
hssfCell1.setCellType(Cell.CELL_TYPE_STRING);
}
//获取每一列中的值
System.out.print(hssfCell1.getStringCellValue() + "\t");
}
System.out.println();
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new ReadExcelForHSSF().read();
}
}
XSSF对xlsx后缀名的Excel进行读取内容：
import org.apache.poi.ss.usermodel.*;
import java.io.*;
/**
* Created by M_WBCG on 2017/7/14.
*/
public class ReadExcelForXSSF {
public void read() {
File file = new File("././POI/POI2.xlsx");
InputStream inputStream = null;
Workbook workbook = null;
try {
inputStream = new FileInputStream(file);
workbook = WorkbookFactory.create(inputStream);
inputStream.close();
//工作表对象
Sheet sheet = workbook.getSheetAt(0);
//总行数
int rowLength = sheet.getLastRowNum()+1;
//工作表的列
Row row = sheet.getRow(0);
//总列数
int colLength = row.getLastCellNum();
//得到指定的单元格
Cell cell = row.getCell(0);
//得到单元格样式
CellStyle cellStyle = cell.getCellStyle();
System.out.println("行数：" + rowLength + ",列数：" + colLength);
for (int i = 0; i < rowLength; i++) {
row = sheet.getRow(i);
for (int j = 0; j < colLength; j++) {
cell = row.getCell(j);
//Excel数据Cell有不同的类型，当我们试图从一个数字类型的Cell读取出一个字符串时就有可能报异常：
//Cannot get a STRING value from a NUMERIC cell
//将所有的需要读的Cell表格设置为String格式
if (cell != null)
cell.setCellType(Cell.CELL_TYPE_STRING);
//对Excel进行修改
if (i > 0 && j == 1)
cell.setCellValue("1000");
System.out.print(cell.getStringCellValue() + "\t");
}
System.out.println();
}
//将修改好的数据保存
OutputStream out = new FileOutputStream(file);
workbook.write(out);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new ReadExcelForXSSF().read();
}
}
Excel写入内容使用的XSSF
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.*;
/**
* Created by M_WBCG on 2017/7/14.
*/
public class WriteExcelForXSSF {
public void write() {
Workbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet("0");
Row row = sheet.createRow(0);
CellStyle cellStyle = workbook.createCellStyle();
// 设置这些样式
cellStyle.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
cellStyle.setBorderBottom(CellStyle.BORDER_THIN);
cellStyle.setBorderLeft(CellStyle.BORDER_THIN);
cellStyle.setBorderRight(CellStyle.BORDER_THIN);
cellStyle.setBorderTop(CellStyle.BORDER_THIN);
cellStyle.setAlignment(CellStyle.ALIGN_CENTER);
row.createCell(0).setCellStyle(cellStyle);
row.createCell(0).setCellValue("姓名");
row.createCell(1).setCellStyle(cellStyle);
row.createCell(1).setCellValue("年龄");
workbook.setSheetName(0, "信息");
try {
File file = new File("././POI/POI3.xlsx");
FileOutputStream fileoutputStream = new FileOutputStream(file);
workbook.write(fileoutputStream);
fileoutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new WriteExcelForXSSF().write();
}
}