使用poi實現讀寫excel

pom.xml添加依賴

<!-- office文檔組件 --> 
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi</artifactId>
	<version>3.9</version>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-ooxml</artifactId>
	<version>3.9</version>
</dependency>
<dependency>
	<groupId>org.apache.xmlbeans</groupId>
	<artifactId>xmlbeans</artifactId>
	<version>2.4.0</version>
</dependency>

 

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

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.ss.usermodel.Cell;
import org.junit.Test;

public class TestExcel {

	// 讀取，全部sheet表及數據
	@Test
	public void showExcel() throws Exception {
		HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(new File("E:/temp/t1.xls")));
		HSSFSheet sheet = null;
		for (int i = 0; i < workbook.getNumberOfSheets(); i++) {// 獲取每個Sheet表
			sheet = workbook.getSheetAt(i);
			for (int j = 0; j < sheet.getLastRowNum() + 1; j++) {// getLastRowNum，獲取最后一行的行標
				HSSFRow row = sheet.getRow(j);
				if (row != null) {
					for (int k = 0; k < row.getLastCellNum(); k++) {// getLastCellNum，是獲取最后一個不為空的列是第幾個
						if (row.getCell(k) != null) { // getCell 獲取單元格數據
							System.out.print(row.getCell(k) + "\t");
						} else {
							System.out.print("\t");
						}
					}
				}
				System.out.println(""); // 讀完一行后換行
			}
			System.out.println("讀取sheet表：" + workbook.getSheetName(i) + " 完成");
		}
	}

	// 讀取，指定sheet表及數據
	@Test
	public void showExcel2() throws Exception {
		HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(new File("E:/temp/t1.xls")));
		HSSFSheet sheet = null;
		int i = workbook.getSheetIndex("xt"); // sheet表名
		sheet = workbook.getSheetAt(i);
		for (int j = 0; j < sheet.getLastRowNum() + 1; j++) {// getLastRowNum
																// 獲取最后一行的行標
			HSSFRow row = sheet.getRow(j);
			if (row != null) {
				for (int k = 0; k < row.getLastCellNum(); k++) {// getLastCellNum
																// 是獲取最后一個不為空的列是第幾個
					if (row.getCell(k) != null) { // getCell 獲取單元格數據
						System.out.print(row.getCell(k) + "\t");
					} else {
						System.out.print("\t");
					}
				}
			}
			System.out.println("");
		}
	}

	// 寫入，往指定sheet表的單元格
	@Test
	public void insertExcel3() throws Exception {
		HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(new File("E:/temp/t1.xls"))); // 讀取的文件
		HSSFSheet sheet = null;
		int i = workbook.getSheetIndex("xt"); // sheet表名
		sheet = workbook.getSheetAt(i);

		HSSFRow row = sheet.getRow(0); // 獲取指定的行對象，無數據則為空，需要創建
		if (row == null) {
			row = sheet.createRow(0); // 該行無數據，創建行對象
		}

		Cell cell = row.createCell(1); // 創建指定單元格對象。如本身有數據會替換掉
		cell.setCellValue("tt"); // 設置內容

		FileOutputStream fo = new FileOutputStream("E:/temp/t1.xls"); // 輸出到文件
		workbook.write(fo);

	}

}

 

問題：

1，excel某些單元格使用公式計算，如引用其他單元格的值，Java讀取不了需要經過計算后的值？

　　分析：原因是獲取有公式的單元格值前需要刷新公式，執行計算

　　解決：需要引用公式或保存excel(workbook.write(fo))前，添加：workbook.getCreationHelper().createFormulaEvaluator().evaluateAll();