java poi操作excel示例代码

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

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.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ReadWriteExcelFile {
    private static Properties props = new Properties();
    static {
        try {
            InputStream is = ReadWriteExcelFile.class.getClassLoader().getResourceAsStream("META-INF/ExcelHeader.properties");
            props.load(is);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static String getValue(String key) {
        String value = "";
        if (props.containsKey(key)) {
            value = props.getProperty(key, "");
        }
        return value;
    }
    private final static Logger logger = LoggerFactory.getLogger(ReadWriteExcelFile.class);
    @SuppressWarnings({ "resource", "rawtypes" })
    public static void readXLSFile() throws IOException
    {
        InputStream ExcelFileToRead = new FileInputStream("E:/source/Test.xls");
        HSSFWorkbook wb = new HSSFWorkbook(ExcelFileToRead);

        HSSFSheet sheet=wb.getSheetAt(0);
        HSSFRow row; 
        HSSFCell cell;

        Iterator rows = sheet.rowIterator();

        while (rows.hasNext())
        {
            row=(HSSFRow) rows.next();
            Iterator cells = row.cellIterator();
            
            while (cells.hasNext())
            {
                cell=(HSSFCell) cells.next();
        
                if (cell.getCellType() == HSSFCell.CELL_TYPE_STRING)
                {
                    System.out.print(cell.getStringCellValue()+" ");
                }
                else if(cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC)
                {
                    System.out.print(cell.getNumericCellValue()+" ");
                }
                else
                {
                    //U Can Handel Boolean, Formula, Errors
                }
            }
            System.out.println();
        }
    
    }
    public static void writeXLSFile(List<? extends Recording> records) throws IOException{
        //String directory=getValue("excel.file.directory");
        String directory="E:/source";
        Date d = new Date(); 
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
        String date = sdf.format(d);
        Recording record=records.get(0);
        Class<? extends Recording> cls=record.getClass();
        String className=cls.getCanonicalName();
        String[] nameAlias=className.split("\\.");
        String excelFileName=directory+File.separator+nameAlias[nameAlias.length-1]+date+".xls";
        writeXLSFile(records,excelFileName);
    }
    
    @SuppressWarnings("resource")
    public static void writeXLSFile(List<? extends Recording> records,String excelFileName) throws IOException{
        
        //String excelFileName = "E:/source/Test.xls";
        String sheetName = "Sheet1";//name of sheet

        HSSFWorkbook wb = new HSSFWorkbook();
        HSSFSheet sheet = wb.createSheet(sheetName) ;
        Recording record;
        //excel header
        HSSFRow row = sheet.createRow(0);
        record=records.get(0);
        Class<? extends Recording> cls=record.getClass();
        String className=cls.getCanonicalName();
        String[] nameAlias=className.split("\\.");
        Field[] fields=cls.getDeclaredFields();    
        //去除serialVersionUID列,
        List<Field> fieldsNoSer=new ArrayList<Field>();
        for(int i=0;i<fields.length;i++){
            String fieldName=fields[i].getName();
            if(fieldName.equalsIgnoreCase("serialVersionUID")){
                continue;
            }else{
                fieldsNoSer.add(fields[i]);
            }
        }
        for(int i=0;i<fieldsNoSer.size();i++){
            HSSFCell cell = row.createCell(i);
            String fieldName=fieldsNoSer.get(i).getName();
            cell.setCellValue(getValue(nameAlias[nameAlias.length-1]+"."+fieldName));
        }
        

        //iterating r number of rows
        for (int r=0;r < records.size(); r++ )
        {
            row = sheet.createRow(r+1);
            record=records.get(r);
            //table content
            for (int c=0;c < fieldsNoSer.size(); c++ )
            {    
                HSSFCell cell = row.createCell(c);
                //加header,方法总变量的首字母大写
                String fieldName=fieldsNoSer.get(c).getName();
                try {
                    Method method=cls.getDeclaredMethod("get"+fieldName.substring(0,1).toUpperCase()+fieldName.substring(1));
                    Object ret=method.invoke(record);
                    if(null!=ret){
                        cell.setCellValue(method.invoke(record).toString());
                    }
    
                } catch (Exception e) {
                    logger.info("write xls error,please check it");
                }
            }
        }
        FileOutputStream fileOut = new FileOutputStream(excelFileName);
        
        //write this workbook to an Outputstream.
        wb.write(fileOut);
        fileOut.flush();
        fileOut.close();
    }
    
    @SuppressWarnings({ "resource", "unused", "rawtypes" })
    public static void readXLSXFile() throws IOException
    {
        InputStream ExcelFileToRead = new FileInputStream("E:/source/Test1.xlsx");
        XSSFWorkbook  wb = new XSSFWorkbook(ExcelFileToRead);
        
        XSSFWorkbook test = new XSSFWorkbook(); 
        
        XSSFSheet sheet = wb.getSheetAt(0);
        XSSFRow row; 
        XSSFCell cell;

        Iterator rows = sheet.rowIterator();

        while (rows.hasNext())
        {
            row=(XSSFRow) rows.next();
            Iterator cells = row.cellIterator();
            while (cells.hasNext())
            {
                cell=(XSSFCell) cells.next();
        
                if (cell.getCellType() == XSSFCell.CELL_TYPE_STRING)
                {
                    System.out.print(cell.getStringCellValue()+" ");
                }
                else if(cell.getCellType() == XSSFCell.CELL_TYPE_NUMERIC)
                {
                    System.out.print(cell.getNumericCellValue()+" ");
                }
                else
                {
                    //U Can Handel Boolean, Formula, Errors
                }
            }
            System.out.println();
        }
    
    }
    
    @SuppressWarnings("resource")
    public static void writeXLSXFile() throws IOException {
        
        String excelFileName = "E:/source/Test1.xlsx";//name of excel file

        String sheetName = "Sheet1";//name of sheet

        XSSFWorkbook wb = new XSSFWorkbook();
        XSSFSheet sheet = wb.createSheet(sheetName) ;

        //iterating r number of rows
        for (int r=0;r < 5; r++ )
        {
            XSSFRow row = sheet.createRow(r);

            //iterating c number of columns
            for (int c=0;c < 5; c++ )
            {
                XSSFCell cell = row.createCell(c);
    
                cell.setCellValue("Cell "+r+" "+c);
            }
        }

        FileOutputStream fileOut = new FileOutputStream(excelFileName);

        //write this workbook to an Outputstream.
        wb.write(fileOut);
        fileOut.flush();
        fileOut.close();
    }

    public static void main(String[] args) throws IOException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
        List<Log> logs=new ArrayList<Log>();
        for(int i=1;i<2;i++){
            Log log=new Log();
            log.setId(Long.parseLong(""+(i+6)));
            log.setUserId(Long.parseLong(""+i));
            log.setUserName("www"+i);
            logs.add(log);
        }
        writeXLSFile(logs,"E:/source/aa.xls");
        
    }