JAVA对Excel的导入导出

今天需要对比2个excel表的内容找出相同；由于要学的还很多上手很慢所以在这做个分享希望对初学的有帮助；

先是pom的配置：

<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-scratchpad</artifactId>
	<version>3.11-beta2</version>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-ooxml</artifactId>
	<version>3.11-beta2</version>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-ooxml-schemas</artifactId>
	<version>3.11-beta2</version>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-excelant</artifactId>
	<version>3.11-beta2</version>
</dependency>
        <dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>easyexcel</artifactId>
   <version>1.0.1</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.8.1</version>
</dependency>

    </dependencies>

　　

下边是我网上找到的工具类但是没法在简单的java项目中实现导出所以只用了导入功能

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

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.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
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.xssf.usermodel.XSSFWorkbook;

public class ExcelUtil {
	
	private ExcelUtil() {
    }

    private final String excel2003L = ".xls";//2003- 版本的excel
    private final String excel2007U = ".xlsx";//2007+ 版本的excel

    public static final ExcelUtil getInstance() {
        return ExcelUtilHolder.instance;
    }

    private static final class ExcelUtilHolder {
        private static final ExcelUtil instance = new ExcelUtil();
    }
    private Workbook getWorkbook(InputStream inStr, String filename) throws Exception {
        Workbook workbook;
        String fileType = filename.substring(filename.lastIndexOf("."));
        if (excel2003L.equals(fileType)) {
            workbook = new HSSFWorkbook(inStr);//2003-
        } else if (excel2007U.equals(fileType)) {
            workbook = new XSSFWorkbook(inStr);//2007+
        } else {
            throw new Exception("解析的文件格式有误");
        }
        return workbook;
    }

    /**
     * 获取excel中的数据
     */
    public List<List<Object>> readExcelData(InputStream in, String filename) throws Exception {
        List<List<Object>> list;

        //创建Excel工作薄
        Workbook work = getWorkbook(in, filename);
        if (null == work) {
            throw new Exception("创建Excel工作薄为空！");
        }
        Sheet sheet = null;
        Row row = null;
        Cell cell = null;

        list = new ArrayList<List<Object>>();
        //遍历Excel中所有的sheet
        for (int i = 0; i < work.getNumberOfSheets(); i++) {
            sheet = work.getSheetAt(i);
            if (sheet == null) {
                continue;
            }

            //遍历当前sheet中的所有行
            for (int j = sheet.getFirstRowNum(); j <= sheet.getLastRowNum(); j++) {
                row = sheet.getRow(j);
                if (row == null || row.getFirstCellNum() == j) {
                    continue;
                }

                //遍历所有的列
                List<Object> li = new ArrayList<Object>();
                for (int y = row.getFirstCellNum(); y < row.getLastCellNum(); y++) {
                    cell = row.getCell(y);
                    //通过getCellValue方法获取当前行每一列中的数据
                    li.add(getCellValue(cell));
                }
                //将每一行的数据添加到list
                list.add(li);
            }
        }
        in.close();
        return list;
    }
    
    /**
     * 获取每个单元格的内容
     */
    private Object getCellValue(Cell cell) {
        Object value = null;

        DecimalFormat df = new DecimalFormat("0");//格式化number String字符串
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");//日期格式化

        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_STRING:
                value = cell.getRichStringCellValue().getString();
                break;
            case Cell.CELL_TYPE_NUMERIC:
                if ("General".equals(cell.getCellStyle().getDataFormatString())) {
                    value = df.format(cell.getNumericCellValue());
                } else if ("m/d/yy".equals(cell.getCellStyle().getDataFormatString())) {
                    value = sdf.format(cell.getDateCellValue());
                } else {
                    value = cell.getNumericCellValue();
                }
                break;
            case Cell.CELL_TYPE_BOOLEAN:
                value = cell.getBooleanCellValue();
                break;
            case Cell.CELL_TYPE_BLANK:
                value = "";
                break;
            default:
                break;
        }
        return value;
    }

    /**
     * 数据转成excel
     *
     * @param dataList   需要转换的数据
     * @param sheetName  生成的excel表名
     * @param columnName 每一列的名字(key)
     * @return
     */
    public Workbook dataToExcel(List<Map<String, String>> dataList, String sheetName, String[] columnName) {

        int columnNum = columnName.length;
        Workbook workbook = new HSSFWorkbook();
        //创建第一页，并命名
        Sheet sheet = workbook.createSheet(sheetName);
        //创建第一行
        Row row = sheet.createRow(0);

        // 创建两种单元格格式
        CellStyle cs = workbook.createCellStyle();
        CellStyle cs2 = workbook.createCellStyle();
        // 创建两种字体
        Font f = workbook.createFont();
        Font f2 = workbook.createFont();
        // 创建第一种字体样式（用于列名）
        f.setFontHeightInPoints((short) 10);
        f.setColor(IndexedColors.BLACK.getIndex());
//        f.setBold(Font.COLOR_NORMAL);
//        f.setBoldweight(Font.COLOR_RED);

        // 创建第二种字体样式（用于值）
        f2.setFontHeightInPoints((short) 10);
        f2.setColor(IndexedColors.BLACK.getIndex());


        //设置列名
        for (int i = 0; i < columnNum; i++) {
            Cell cell = row.createCell(i);
            cell.setCellValue(columnName[i]);
            cell.setCellStyle(cs);
        }
        //设置每行每列的值
        int rowNum = dataList.size();
        for (int j = 1; j <= rowNum; j++) {
            //创建一行
            Row r = sheet.createRow(j);
            for (int k = 0; k < columnNum; k++) {
                Cell cell = r.createCell(k);
                cell.setCellValue(dataList.get(j - 1).get(columnName[k]));
                cell.setCellStyle(cs2);
            }
        }
        return workbook;
    }
    static HSSFWorkbook workbook;
    public static void writeToExcel(String fileDir,String sheetName,List<Map> mapList) throws Exception{  
        //创建workbook  
    	
        File file = new File(fileDir);  
        try {  
        	workbook = new HSSFWorkbook(new FileInputStream(file));  
        } catch (FileNotFoundException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
        //流  
        FileOutputStream out = null;  
        HSSFSheet sheet = workbook.getSheet(sheetName);  
        // 获取表格的总行数  
        // int rowCount = sheet.getLastRowNum() + 1; // 需要加一  
        // 获取表头的列数  
        int columnCount = sheet.getRow(0).getLastCellNum()+1;  
        try {  
            // 获得表头行对象  
            HSSFRow titleRow = sheet.getRow(0);  
            if(titleRow!=null){ 
                for(int rowId=0;rowId<mapList.size();rowId++){
                    Map map = mapList.get(rowId);
                    HSSFRow newRow=sheet.createRow(rowId+1);
                    for (short columnIndex = 0; columnIndex < columnCount; columnIndex++) {  //遍历表头  
                        String mapKey = titleRow.getCell(columnIndex).toString().trim().toString().trim();  
                        HSSFCell cell = newRow.createCell(columnIndex);  
                        cell.setCellValue(map.get(mapKey)==null ? null : map.get(mapKey).toString());  
                    } 
                }
            }  
  
            out = new FileOutputStream(fileDir);  
            workbook.write(out);  
        } catch (Exception e) {  
            throw e;
        } finally {    
            try {    
                out.close();    
            } catch (IOException e) {    
                e.printStackTrace();  
            }    
        }    
    }  
    
    private static final String EXCEL_XLS = "xls";
    private static final String EXCEL_XLSX = "xlsx";
    public static void writeExcel(List<Map> dataList, int cloumnCount,String finalXlsxPath){
        OutputStream out = null;
        try {
            // 获取总列数
            int columnNumCount = cloumnCount;
            // 读取Excel文档
            File finalXlsxFile = new File(finalXlsxPath);
            Workbook workBook = getWorkbok(finalXlsxFile);
            // sheet 对应一个工作页
            Sheet sheet = workBook.getSheetAt(0);
            /**
             * 删除原有数据，除了属性列
             */
            int rowNumber = sheet.getLastRowNum();    // 第一行从0开始算
            System.out.println("原始数据总行数，除属性列：" + rowNumber);
            for (int i = 1; i <= rowNumber; i++) {
                Row row = sheet.getRow(i);
                sheet.removeRow(row);
            }
            // 创建文件输出流，输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out =  new FileOutputStream(finalXlsxPath);
            workBook.write(out);
            /**
             * 往Excel中写新数据
             */
            for (int j = 0; j < dataList.size(); j++) {
                // 创建一行：从第二行开始，跳过属性列
                Row row = sheet.createRow(j + 1);
                // 得到要插入的每一条记录
                Map dataMap = dataList.get(j);
                String name = dataMap.get("名字" + j).toString();
                for (int k = 0; k <= columnNumCount; k++) {
                // 在一行内循环
                Cell first = row.createCell(0);
                first.setCellValue(name);
        
                }
            }
            // 创建文件输出流，准备输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out =  new FileOutputStream(finalXlsxPath);
            workBook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
            try {
                if(out != null){
                    out.flush();
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("数据导出成功");
    }

    /**
     * 判断Excel的版本,获取Workbook
     * @param in
     * @param filename
     * @return
     * @throws IOException
     */
    public static Workbook getWorkbok(File file) throws IOException{
        Workbook wb = null;
        FileInputStream in = new FileInputStream(file);
        if(file.getName().endsWith(EXCEL_XLS)){     //Excel 2003
            wb = new HSSFWorkbook(in);
        }else if(file.getName().endsWith(EXCEL_XLSX)){    // Excel 2007/2010
            wb = new XSSFWorkbook(in);
        }
        return wb;
    }
    

}

　　

接下来是另一个地方找到的导出工具类

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
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.hssf.util.HSSFColor;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFColor;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 
 
/**
 * 导出Excel
 * @author liuyazhuang
 *
 * @param <T>
 */
public class ExportExcelUtil<T>{
    
    // 2007 版本以上 最大支持1048576行
    public  final static String  EXCEl_FILE_2007 = "2007";
    // 2003 版本 最大支持65536 行
    public  final static String  EXCEL_FILE_2003 = "2003";
    
    /**
     * <p>
     * 导出无头部标题行Excel <br>
     * 时间格式默认：yyyy-MM-dd hh:mm:ss <br>
     * </p>
     * 
     * @param title 表格标题
     * @param dataset 数据集合
     * @param out 输出流
     * @param version 2003 或者 2007，不传时默认生成2003版本
     */
    public void exportExcel(String title, Collection<T> dataset, OutputStream out, String version) {
        if(StringUtils.isEmpty(version) || EXCEL_FILE_2003.equals(version.trim())){
            exportExcel2003(title, null, dataset, out, "yyyy-MM-dd HH:mm:ss");
        }else{
            exportExcel2007(title, null, dataset, out, "yyyy-MM-dd HH:mm:ss");
        }
    }
 
    /**
     * <p>
     * 导出带有头部标题行的Excel <br>
     * 时间格式默认：yyyy-MM-dd hh:mm:ss <br>
     * </p>
     * 
     * @param title 表格标题
     * @param headers 头部标题集合
     * @param dataset 数据集合
     * @param out 输出流
     * @param version 2003 或者 2007，不传时默认生成2003版本
     */
    public void exportExcel(String title,String[] headers, Collection<T> dataset, OutputStream out,String version) {
        if(StringUtils.isBlank(version) || EXCEL_FILE_2003.equals(version.trim())){
            exportExcel2003(title, headers, dataset, out, "yyyy-MM-dd HH:mm:ss");
        }else{
            exportExcel2007(title, headers, dataset, out, "yyyy-MM-dd HH:mm:ss");
        }
    }
 
    /**
     * <p>
     * 通用Excel导出方法,利用反射机制遍历对象的所有字段，将数据写入Excel文件中 <br>
     * 此版本生成2007以上版本的文件 (文件后缀：xlsx)
     * </p>
     * 
     * @param title
     *            表格标题名
     * @param headers
     *            表格头部标题集合
     * @param dataset
     *            需要显示的数据集合,集合中一定要放置符合JavaBean风格的类的对象。此方法支持的
     *            JavaBean属性的数据类型有基本数据类型及String,Date
     * @param out
     *            与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中
     * @param pattern
     *            如果有时间数据，设定输出格式。默认为"yyyy-MM-dd hh:mm:ss"
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public void exportExcel2007(String title, String[] headers, Collection<T> dataset, OutputStream out, String pattern) {
        // 声明一个工作薄
        XSSFWorkbook workbook = new XSSFWorkbook();
        // 生成一个表格
        XSSFSheet sheet = workbook.createSheet(title);
        // 设置表格默认列宽度为15个字节
        sheet.setDefaultColumnWidth(20);
        // 生成一个样式
        XSSFCellStyle style = workbook.createCellStyle();
        // 设置这些样式
        style.setFillForegroundColor(new XSSFColor(java.awt.Color.gray));
        style.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
        style.setBorderBottom(XSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(XSSFCellStyle.BORDER_THIN);
        style.setBorderRight(XSSFCellStyle.BORDER_THIN);
        style.setBorderTop(XSSFCellStyle.BORDER_THIN);
        style.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        // 生成一个字体
        XSSFFont font = workbook.createFont();
        font.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);
        font.setFontName("宋体"); 
        font.setColor(new XSSFColor(java.awt.Color.BLACK));
        font.setFontHeightInPoints((short) 11);
        // 把字体应用到当前的样式
        style.setFont(font);
        // 生成并设置另一个样式
        XSSFCellStyle style2 = workbook.createCellStyle();
        style2.setFillForegroundColor(new XSSFColor(java.awt.Color.WHITE));
        style2.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
        style2.setBorderBottom(XSSFCellStyle.BORDER_THIN);
        style2.setBorderLeft(XSSFCellStyle.BORDER_THIN);
        style2.setBorderRight(XSSFCellStyle.BORDER_THIN);
        style2.setBorderTop(XSSFCellStyle.BORDER_THIN);
        style2.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        style2.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
        // 生成另一个字体
        XSSFFont font2 = workbook.createFont();
        font2.setBoldweight(XSSFFont.BOLDWEIGHT_NORMAL);
        // 把字体应用到当前的样式
        style2.setFont(font2);
 
        // 产生表格标题行
        XSSFRow row = sheet.createRow(0);
        XSSFCell cellHeader;
        for (int i = 0; i < headers.length; i++) {
            cellHeader = row.createCell(i);
            cellHeader.setCellStyle(style);
            cellHeader.setCellValue(new XSSFRichTextString(headers[i]));
        }
 
        // 遍历集合数据，产生数据行
        Iterator<T> it = dataset.iterator();
        int index = 0;
        T t;
        Field[] fields;
        Field field;
        XSSFRichTextString richString;
        Pattern p = Pattern.compile("^//d+(//.//d+)?$");
        Matcher matcher;
        String fieldName;
        String getMethodName;
        XSSFCell cell;
        Class tCls;
        Method getMethod;
        Object value;
        String textValue;
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        while (it.hasNext()) {
            index++;
            row = sheet.createRow(index);
            t = (T) it.next();
            // 利用反射，根据JavaBean属性的先后顺序，动态调用getXxx()方法得到属性值
            fields = t.getClass().getDeclaredFields();
            for (int i = 0; i < fields.length; i++) {
                cell = row.createCell(i);
                cell.setCellStyle(style2);
                field = fields[i];
                fieldName = field.getName();
                getMethodName = "get" + fieldName.substring(0, 1).toUpperCase()
                        + fieldName.substring(1);
                try {
                    tCls = t.getClass();
                    getMethod = tCls.getMethod(getMethodName, new Class[] {});
                    value = getMethod.invoke(t, new Object[] {});
                    // 判断值的类型后进行强制类型转换
                    textValue = null;
                    if (value instanceof Integer) {
                        cell.setCellValue((Integer) value);
                    } else if (value instanceof Float) {
                        textValue = String.valueOf((Float) value);
                        cell.setCellValue(textValue);
                    } else if (value instanceof Double) {
                        textValue = String.valueOf((Double) value);
                        cell.setCellValue(textValue);
                    } else if (value instanceof Long) {
                        cell.setCellValue((Long) value);
                    }
                    if (value instanceof Boolean) {
                        textValue = "是";
                        if (!(Boolean) value) {
                            textValue = "否";
                        }
                    } else if (value instanceof Date) {
                        textValue = sdf.format((Date) value);
                    } else {
                        // 其它数据类型都当作字符串简单处理
                        if (value != null) {
                            textValue = value.toString();
                        }
                    }
                    if (textValue != null) {
                        matcher = p.matcher(textValue);
                        if (matcher.matches()) {
                            // 是数字当作double处理
                            cell.setCellValue(Double.parseDouble(textValue));
                        } else {
                            richString = new XSSFRichTextString(textValue);
                            cell.setCellValue(richString);
                        }
                    }
                } catch (SecurityException e) {
                    e.printStackTrace();
                } catch (NoSuchMethodException e) {
                    e.printStackTrace();
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                } finally {
                    // 清理资源
                }
            }
        }
        try {
            workbook.write(out);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    
    
    /**
     * <p>
     * 通用Excel导出方法,利用反射机制遍历对象的所有字段，将数据写入Excel文件中 <br>
     * 此方法生成2003版本的excel,文件名后缀：xls <br>
     * </p>
     * 
     * @param title
     *            表格标题名
     * @param headers
     *            表格头部标题集合
     * @param dataset
     *            需要显示的数据集合,集合中一定要放置符合JavaBean风格的类的对象。此方法支持的
     *            JavaBean属性的数据类型有基本数据类型及String,Date
     * @param out
     *            与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中
     * @param pattern
     *            如果有时间数据，设定输出格式。默认为"yyyy-MM-dd hh:mm:ss"
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public void exportExcel2003(String title, String[] headers, Collection<T> dataset, OutputStream out, String pattern) {
        // 声明一个工作薄
        HSSFWorkbook workbook = new HSSFWorkbook();
        // 生成一个表格
        HSSFSheet sheet = workbook.createSheet(title);
        // 设置表格默认列宽度为15个字节
        sheet.setDefaultColumnWidth(20);
        // 生成一个样式
        HSSFCellStyle style = workbook.createCellStyle();
        // 设置这些样式
        style.setFillForegroundColor(HSSFColor.GREY_50_PERCENT.index);
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        // 生成一个字体
        HSSFFont font = workbook.createFont();
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        font.setFontName("宋体"); 
        font.setColor(HSSFColor.WHITE.index);
        font.setFontHeightInPoints((short) 11);
        // 把字体应用到当前的样式
        style.setFont(font);
        // 生成并设置另一个样式
        HSSFCellStyle style2 = workbook.createCellStyle();
        style2.setFillForegroundColor(HSSFColor.WHITE.index);
        style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
        style2.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        style2.setBorderRight(HSSFCellStyle.BORDER_THIN);
        style2.setBorderTop(HSSFCellStyle.BORDER_THIN);
        style2.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
        // 生成另一个字体
        HSSFFont font2 = workbook.createFont();
        font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
        // 把字体应用到当前的样式
        style2.setFont(font2);
 
        // 产生表格标题行
        HSSFRow row = sheet.createRow(0);
        HSSFCell cellHeader;
        for (int i = 0; i < headers.length; i++) {
            cellHeader = row.createCell(i);
            cellHeader.setCellStyle(style);
            cellHeader.setCellValue(new HSSFRichTextString(headers[i]));
        }
 
        // 遍历集合数据，产生数据行
        Iterator<T> it = dataset.iterator();
        int index = 0;
        T t;
        Field[] fields;
        Field field;
        HSSFRichTextString richString;
        Pattern p = Pattern.compile("^//d+(//.//d+)?$");
        Matcher matcher;
        String fieldName;
        String getMethodName;
        HSSFCell cell;
        Class tCls;
        Method getMethod;
        Object value;
        String textValue;
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        while (it.hasNext()) {
            index++;
            row = sheet.createRow(index);
            t = (T) it.next();
            // 利用反射，根据JavaBean属性的先后顺序，动态调用getXxx()方法得到属性值
            fields = t.getClass().getDeclaredFields();
            for (int i = 0; i < fields.length; i++) {
                cell = row.createCell(i);
                cell.setCellStyle(style2);
                field = fields[i];
                fieldName = field.getName();
                getMethodName = "get" + fieldName.substring(0, 1).toUpperCase()
                        + fieldName.substring(1);
                try {
                    tCls = t.getClass();
                    getMethod = tCls.getMethod(getMethodName, new Class[] {});
                    value = getMethod.invoke(t, new Object[] {});
                    // 判断值的类型后进行强制类型转换
                    textValue = null;
                    if (value instanceof Integer) {
                        cell.setCellValue((Integer) value);
                    } else if (value instanceof Float) {
                        textValue = String.valueOf((Float) value);
                        cell.setCellValue(textValue);
                    } else if (value instanceof Double) {
                        textValue = String.valueOf((Double) value);
                        cell.setCellValue(textValue);
                    } else if (value instanceof Long) {
                        cell.setCellValue((Long) value);
                    }
                    if (value instanceof Boolean) {
                        textValue = "是";
                        if (!(Boolean) value) {
                            textValue = "否";
                        }
                    } else if (value instanceof Date) {
                        textValue = sdf.format((Date) value);
                    } else {
                        // 其它数据类型都当作字符串简单处理
                        if (value != null) {
                            textValue = value.toString();
                        }
                    }
                    if (textValue != null) {
                        matcher = p.matcher(textValue);
                        if (matcher.matches()) {
                            // 是数字当作double处理
                            cell.setCellValue(Double.parseDouble(textValue));
                        } else {
                            richString = new HSSFRichTextString(textValue);
                            cell.setCellValue(richString);
                        }
                    }
                } catch (SecurityException e) {
                    e.printStackTrace();
                } catch (NoSuchMethodException e) {
                    e.printStackTrace();
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                } finally {
                    // 清理资源
                }
            }
        }
        try {
            workbook.write(out);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

导出 需要一个实体类：

public class Hu {

    public Hu() {
        super();
        // TODO Auto-generated constructor stub
    }

    private String name;

    public void setName(String name) {
        this.name = name;
    }

    public Hu(String name) {
        super();
        this.name = name;
    }

    public String getName() {
        return name;
    }
    
    
}

准备工作就弄好了  接下来 实践

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import entity.Hu;
import util.ExcelUtil;
import util.ExportExcelUtil;

public class Poitest {
    public static void main(String[] args) throws Exception {
        InputStream in = new FileInputStream(new File("C:\Users\Administrator\Desktop\进件满.xlsx"));
        InputStream in1 = new FileInputStream(new File("C:\Users\Administrator\Desktop\test.xlsx"));
        List<List<Object>> list = ExcelUtil.getInstance().readExcelData(in, "进件满.xlsx");
        List<List<Object>> list1 = ExcelUtil.getInstance().readExcelData(in1, "test.xlsx");
        List<String> li1 = new ArrayList<String>();
        System.out.println(list1.size());
        String n = "";
        for(int i = 0; i < list.size(); i++) {
            if(list1.contains(list.get(i))) {
//                list1.remove(list.get(i));
                n = list.get(i).toString();
//               l.add(String.valueOf(s));
               n = n.replace("[", "");
               n = n.replace("]", "");
                li1.add(n);
            }
        }

       ExportExcelUtil<Hu> util = new ExportExcelUtil<Hu>();
         // 准备数据
       List<Hu> list5 = new ArrayList();
       Hu h = new Hu();
       String a = "";
       for(Object s:li1) {
           a = String.valueOf(s);
//           l.add(String.valueOf(s));
           a = a.replace("[", "");
           a = a.replace("]", "");
           list5.add(new Hu(a));
           ;
       }
       
       String[] columnNames = {"姓名"};
       util.exportExcel("用户导出", columnNames, list5, new FileOutputStream("C:\Users\Administrator\Desktop\test1.xlsx"), ExportExcelUtil.EXCEl_FILE_2007);
        
    }

}

然后会在规定的excel文件里写入你比较成功的内容

这样就实现了excel的导入导出

参考博客：https://blog.csdn.net/l1028386804/article/details/79659605