Apache POI 是一个强大的Java库，专门用来处理Microsoft Office文档，包括Word、Excel和PowerPoint等。POI为开发者提供了简单而有效的API，以便在Java应用中读取、创建和修改Office文件。如果你想在你的Java项目中处理Office文档，掌握POI将是一个非常有用的技能。以下是POI的一些关键功能和使用技巧：

安装POI

首先，确保在你的项目中集成Apache POI库。可以通过Maven引入依赖：

<dependency>  
    <groupId>org.apache.poi</groupId>  
    <artifactId>poi-ooxml</artifactId>  
    <version>5.2.3</version> <!-- 使用最新版本 -->  
</dependency>  

处理Excel文档

读取Excel文件

import org.apache.poi.ss.usermodel.*;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.IOException;  
public class ExcelReader {  
    public static void main(String[] args) throws IOException {  
        FileInputStream file = new FileInputStream(new File("example.xlsx"));  
        Workbook workbook = WorkbookFactory.create(file);  
        Sheet sheet = workbook.getSheetAt(0);  
        for (Row row : sheet) {  
            for (Cell cell : row) {  
                switch (cell.getCellType()) {  
                    case STRING:  
                        System.out.print(cell.getStringCellValue() + "\t");  
                        break;  
                    case NUMERIC:  
                        System.out.print(cell.getNumericCellValue() + "\t");  
                        break;  
                    default:  
                        System.out.print("Unsupported Cell Type");  
                }  
            }  
            System.out.println();  
        }  
        workbook.close();  
        file.close();  
    }  
}  

创建Excel文件

import org.apache.poi.ss.usermodel.*;  
import org.apache.poi.xssf.usermodel.XSSFWorkbook;  
import java.io.FileOutputStream;  
import java.io.IOException;  
public class ExcelWriter {  
    public static void main(String[] args) throws IOException {  
        Workbook workbook = new XSSFWorkbook();  
        Sheet sheet = workbook.createSheet("Example Sheet");  
        Row headerRow = sheet.createRow(0);  
        Cell headerCell = headerRow.createCell(0);  
        headerCell.setCellValue("Name");  
        headerCell = headerRow.createCell(1);  
        headerCell.setCellValue("Age");  
        Row row = sheet.createRow(1);  
        Cell cell = row.createCell(0);  
        cell.setCellValue("John Doe");  
        cell = row.createCell(1);  
        cell.setCellValue(30);  
        try (FileOutputStream fileOut = new FileOutputStream("example.xlsx")) {  
            workbook.write(fileOut);  
        }  
        workbook.close();  
    }  
}  

处理Word文档

读取Word文件

import org.apache.poi.xwpf.usermodel.*;  
import java.io.FileInputStream;  
import java.io.IOException;  
public class WordReader {  
    public static void main(String[] args) throws IOException {  
        FileInputStream fis = new FileInputStream("example.docx");  
        XWPFDocument document = new XWPFDocument(fis);  
        for (XWPFParagraph paragraph : document.getParagraphs()) {  
            System.out.println(paragraph.getText());  
        }  
        document.close();  
        fis.close();  
    }  
}  

创建Word文件

import org.apache.poi.xwpf.usermodel.*;  
import java.io.FileOutputStream;  
import java.io.IOException;  
public class WordWriter {  
    public static void main(String[] args) throws IOException {  
        XWPFDocument document = new XWPFDocument();  
        XWPFParagraph paragraph = document.createParagraph();  
        XWPFRun run = paragraph.createRun();  
        run.setText("This is an example paragraph.");  
        try (FileOutputStream out = new FileOutputStream("example.docx")) {  
            document.write(out);  
        }  
        document.close();  
    }  
}  

处理PowerPoint演示文稿

读取PPTX文件

import org.apache.poi.xslf.usermodel.XMLSlideShow;  
import org.apache.poi.xslf.usermodel.XSLFSlide;  
import java.io.FileInputStream;  
import java.io.IOException;  
public class PowerPointReader {  
    public static void main(String[] args) throws IOException {  
        FileInputStream fis = new FileInputStream("example.pptx");  
        XMLSlideShow ppt = new XMLSlideShow(fis);  
        for (XSLFSlide slide : ppt.getSlides()) {  
            System.out.println(slide.getTitle());  
        }  
        ppt.close();  
        fis.close();  
    }  
}  

创建PPTX文件

import org.apache.poi.xslf.usermodel.XMLSlideShow;  
import org.apache.poi.xslf.usermodel.XSLFSlide;  
import org.apache.poi.xslf.usermodel.XSLFTextBox;  
import java.io.FileOutputStream;  
import java.io.IOException;  
public class PowerPointWriter {  
    public static void main(String[] args) throws IOException {  
        XMLSlideShow ppt = new XMLSlideShow();  
        XSLFSlide slide = ppt.createSlide();  
        XSLFTextBox shape = slide.createTextBox();  
        shape.setText("Hello, Apache POI!");  
        try (FileOutputStream out = new FileOutputStream("example.pptx")) {  
            ppt.write(out);  
        }  
        ppt.close();  
    }  
}  

结语

通过Apache POI，你可以轻松地在Java应用程序中处理Microsoft Office文档。这为开发者们提供了许多可能性，例如生成报表、读取数据进行分析等。花些时间来深入了解POI的各种功能，你将能够更有效地驾驭Office文档处理的复杂性。