Java POI 导出EXCEL经典实现

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
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.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
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.XSSFClientAnchor;
import org.apache.poi.xssf.usermodel.XSSFComment;
import org.apache.poi.xssf.usermodel.XSSFDrawing;
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;

import com.jy.modules.platform.sysorg.dto.ModifyPwdVO;
import com.jy.modules.platform.sysorg.dto.SysOrgDTO;

@SuppressWarnings("all")
public class ExportExcel<T> {

    public String exportExcel(String sheetTitle,Collection<T> dataset, OutputStream out) {
        return exportExcel(sheetTitle, null, dataset, out, "yyyy-MM-dd");
    }

    public String exportExcel(String sheetTitle,String[] headers, Collection<T> dataset,
            OutputStream out) {
        return exportExcel(sheetTitle, headers, dataset, out, "yyyy-MM-dd");
    }

　　

/**
* 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上
*
* @param title
* 表格标题名
* @param headers
* 表格属性列名数组
* @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,byte[](图片数据)
* @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"yyy-MM-dd"
*/

    @SuppressWarnings("unchecked")
    public String exportExcel(String title, String[] headers,
            Collection<T> dataset, OutputStream out, String pattern) {
        String state = "fail";
        // 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(12);
        // 生成一个样式
        XSSFCellStyle style = workbook.createCellStyle();
        // 设置这些样式
        style.setFillForegroundColor(HSSFColor.GREEN.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
        XSSFFont font = workbook.createFont();
        font.setFontName(HSSFFont.FONT_ARIAL);
        font.setColor(HSSFColor.BLACK.index);
        font.setFontHeightInPoints((short) 12);
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        // 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(HSSFColor.LIGHT_YELLOW.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
        XSSFFont font2 = workbook.createFont();
        font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
        // 把字体应用到当前的样式
        style2.setFont(font2);

        // 声明一个画图的顶级管理器
        XSSFDrawing patriarch = sheet.createDrawingPatriarch();
        // 定义注释的大小和位置,详见文档
        /*XSSFComment comment = patriarch.createCellComment(new XSSFClientAnchor(0,
                0, 0, 0, (short) 4, 2, (short) 6, 5));
        // 设置注释内容
        comment.setString(new XSSFRichTextString("可以在POI中添加注释！"));
        // 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.
        comment.setAuthor("leno");*/

        // 产生表格标题行
        XSSFRow row;
        int index = 0;
        if(headers!=null){
            row = sheet.createRow(0);
            index++;
            for (short i = 0; i < headers.length; i++) {
                XSSFCell cell = row.createCell(i);
                cell.setCellStyle(style);
                XSSFRichTextString text = new XSSFRichTextString(headers[i]);
                cell.setCellValue(text);
            }
        }

        Iterator<T> itt = dataset.iterator();
        boolean columnTitle =false;
        while (itt.hasNext()) {
            row = sheet.createRow(index);
            index++;
            T t = (T) itt.next();
            Field[] fields = t.getClass().getDeclaredFields();
            int titleIndex = 0;
            for (short i = 0; i < fields.length; i++) {
                Field field = fields[i];
                String fieldName = field.getName();
                if("serialVersionUID".equals(fieldName)){
                    continue;
                }else{
                    XSSFCell cell = row.createCell(titleIndex);
                    titleIndex++;
                    cell.setCellStyle(style);
                    cell.setCellValue(fieldName);
                }
            }
            break;
        }
        itt = null;
        Iterator<T> it = dataset.iterator();
        // 遍历集合数据，产生数据行
        while (it.hasNext()) {
            row = sheet.createRow(index);
            index++;
            T 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
            Field[] fields = t.getClass().getDeclaredFields();
            int cellIndex = 0;
            for (short i = 0; i < fields.length; i++) {
                Field field = fields[i];
                String fieldName = field.getName();
                if("serialVersionUID".equals(fieldName)){
                    continue;
                }

                XSSFCell cell = row.createCell(cellIndex);
                cellIndex++;
                String getMethodName = "get"
                        + fieldName.substring(0, 1).toUpperCase()
                        + fieldName.substring(1);

                try {
                    Class tCls = t.getClass();
                    Method getMethod = tCls.getMethod(getMethodName,
                            new Class[] {});
                    Object value = getMethod.invoke(t, new Object[] {});
                    if(value == null){
                        continue;
                    }
                    cell.setCellStyle(style2);
                    // 判断值的类型后进行强制类型转换
                    String textValue = null;
                    if (value instanceof Date) {
                        Date date = (Date) value;
                        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
                        textValue = sdf.format(date);
                    } else if (value instanceof byte[]) {
                        // 有图片时，设置行高为60px;
                        row.setHeightInPoints(60);
                        // 设置图片所在列宽度为80px,注意这里单位的一个换算
                        sheet.setColumnWidth(i, (short) (35.7 * 80));
                        // sheet.autoSizeColumn(i);
                        byte[] bsValue = (byte[]) value;
                        HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0,
                                1023, 255, (short) 6, index, (short) 6, index);
                        anchor.setAnchorType(2);
                        patriarch.createPicture(anchor, workbook.addPicture(
                                bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG));
                    } else {
                        // 其它数据类型都当作字符串简单处理
                        textValue = value.toString();
                    }
                    // 如果不是图片数据，就利用正则表达式判断textValue是否全部由数字组成
                    if (textValue != null) {
                        Pattern p = Pattern.compile("^//d+(//.//d+)?$");
                        Matcher matcher = p.matcher(textValue);
                        if (matcher.matches()) {
                            // 是数字当作double处理
                            cell.setCellValue(Double.parseDouble(textValue));
                        } else {
                            XSSFRichTextString richString = new XSSFRichTextString(
                                    textValue);
                            XSSFFont font3 = workbook.createFont();
                            font3.setColor(HSSFColor.BLUE.index);
                            richString.applyFont(font3);
                            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();
                }
            }
        }
        try {
            workbook.write(out);
            state = "succes";
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return state;
        }
    }
}

public static void main(String[] args) throws FileNotFoundException {
        // TODO Auto-generated method stub
        ExportExcel<test> ex = new ExportExcel<test>();
        List<test> dataset = new ArrayList<test>();
        for(int i =0;i<8;i++){
            test dto = new test();
            dto.setUsername("9999");
            dto.setPassword("hahahah ");
            dto.setNewpwd("111");
            dto.setSource("66666");
            dataset.add(dto);
        }
        OutputStream out = new FileOutputStream("E://a.xlsx");
        //ex.exportExcel("机构导出",dataset,out);
        String header[] = new String[]{"ID","机构编码","机构名称","机构类型"};
        ex.exportExcel("机构导出",header,dataset,out);
    }