apache poi 读写xlsx文件简单示例

package com.javaexcel;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class Sample {
	public static void main(String[] args) throws IOException { 
//		testRead();
//		testWrite();
		testChange();
	}
	/**
	 * 删除一个文件
	 */
	public static void delete(){
		File file = new File("f:/log/poi_wirte.xlsx");
		System.out.println(file.delete());
	}
	public static void testWrite(){
		Workbook workbook = null;//一个excel文件
		Sheet sheet = null;//excel一个sheet
			
		workbook = new XSSFWorkbook();
		sheet = workbook.createSheet("xssf sheet");
		Row row1 = sheet.createRow(3);
		Cell cell = row1.createCell(2);
		cell.setCellValue("new xssf cell");
		try {
			workbook.write(new FileOutputStream(new File("f:/log/poi_wirte.xlsx")));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	/**
	 * 没有发现可以修改excel文件的方法，直接覆盖后文件被损坏。只能建新文件，删除源文件，然后重命名。
	 * 删除源文件是需要关闭输入输出流，需要用OPCPackage的close方法。
	 */
	public static void testChange(){
		OPCPackage opc = null;
		Workbook workbook = null;
		Sheet sheet = null;
		try {
			opc = OPCPackage.open("f:/log/poi_change.xlsx");
			workbook = new XSSFWorkbook(opc);
//			File f = new File("f:/log/poi_change.xlsx");
			sheet = workbook.getSheetAt(0);
			Row row = sheet.createRow(1);
			row.createCell(0).setCellValue("a2");
			row.createCell(1).setCellValue("b2");
			row.createCell(2).setCellValue("c2");
			workbook.write(new FileOutputStream("f:/log/poi_change2.xlsx"));
			opc.close();
			System.out.println(new File("f:/log/poi_change.xlsx").delete());
			new File("f:/log/poi_change2.xlsx").renameTo(new File("f:/log/poi_change3.xlsx"));
		} catch (InvalidFormatException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	public static void testRead(){
		Workbook workBook = null;//一个excel文件
		Sheet sheet = null;//excel一个sheet
		try {
			workBook = WorkbookFactory.create(new File("f:/log/poi_read.xlsx"));
			sheet = workBook.getSheetAt(0);
			for(Row row:sheet){
				System.out.print(row.getRowNum()+":");
				for(Cell c:row){
					System.out.print("("+c.getColumnIndex()+":"+c+")");
				}
				System.out.print("\n");
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (InvalidFormatException e) {
			e.printStackTrace();
		}
	}
}