POI导出工具类

1.导出工具类

package com.fpi.system.utils;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;

/** 
 * @author	shilei 
 * @version 创建时间:2017年12月28日 下午4:53:29 
 * 类说明: POI导出工具类
 */
public class ExportPOIUtils {
 
	//参数说明:  fileName:文件名   projects:对象集合  columnNames: 列名   keys: map中的key
	public static void start_download(HttpServletResponse response, String fileName, List<?> projects,
			String[] columnNames, String[] keys) throws IOException {
		
		//将集合中对象的属性  对应到  List<Map<String,Object>>
		List<Map<String,Object>> list=createExcelRecord(projects, keys);
 
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		try {
			//将转换成的Workbook对象通过流形式下载
			createWorkBook(list,keys,columnNames).write(os);
		} catch (IOException e) {
			e.printStackTrace();
		}
		byte[] content = os.toByteArray();
		InputStream is = new ByteArrayInputStream(content);
		// 设置response参数,可以打开下载页面
		response.reset();
		response.setContentType("application/vnd.ms-excel;charset=utf-8");
		response.setHeader("Content-Disposition", "attachment;filename="+ new String((fileName + ".xls").getBytes(), "iso-8859-1"));
		ServletOutputStream out = response.getOutputStream();
		BufferedInputStream bis = null;
		BufferedOutputStream bos = null;
		try {
			bis = new BufferedInputStream(is);
			bos = new BufferedOutputStream(out);
			byte[] buff = new byte[2048];
			int bytesRead;
			while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
				bos.write(buff, 0, bytesRead);
			}
		} catch (final IOException e) {
			throw e;
		} finally {
			if (bis != null) {
				bis.close();
			}
			if (bos != null) {
				bos.close();
			}
		}
	}
	
	private static List<Map<String, Object>> createExcelRecord(List<?> projects, String[] keys) {
		List<Map<String, Object>> listmap = new ArrayList<Map<String, Object>>();
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("sheetName", "sheet");
		listmap.add(map);
		Object project=null;
		for (int j = 0; j < projects.size(); j++) {
			project=projects.get(j);
			Map<String, Object> mapValue = new HashMap<String, Object>();
			for(int i=0; i<keys.length; i++){
				mapValue.put(keys[i], getFieldValueByName(keys[i], project));
			}
 
			listmap.add(mapValue);
		}
		return listmap;
	}
	/** 
	 * 利用反射  根据属性名获取属性值 
	 * */  
	private static Object getFieldValueByName(String fieldName, Object o) {  
		try {    
			String firstLetter = fieldName.substring(0, 1).toUpperCase();    
			String getter = "get" + firstLetter + fieldName.substring(1);    
			Method method = o.getClass().getMethod(getter, new Class[] {});    
			Object value = method.invoke(o, new Object[] {});    
			return value;    
		} catch (Exception e) {    
			e.printStackTrace();  
			return null;    
		}    
	}
    /**
     * 创建excel文档对象
     * @param keys list中map的key数组集合
     * @param columnNames excel的列名
     * */
	private static Workbook createWorkBook(List<Map<String, Object>> list,String []keys,String columnNames[]) {
        // 创建excel工作簿
        Workbook wb = new HSSFWorkbook();
        // 创建第一个sheet(页),并命名
        Sheet sheet = wb.createSheet(list.get(0).get("sheetName").toString());
        // 手动设置列宽。第一个参数表示要为第几列设;,第二个参数表示列的宽度,n为列高的像素数。
        for(int i=0;i<keys.length;i++){
            sheet.setColumnWidth((short) i, (short) (35.7 * 150));
        }
 
        // 创建第一行
        Row row = sheet.createRow((short) 0);
 
        // 创建两种单元格格式
        CellStyle cs = wb.createCellStyle();
        CellStyle cs2 = wb.createCellStyle();
 
        // 创建两种字体
        Font f = wb.createFont();
        Font f2 = wb.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(true);
 
        // 创建第二种字体样式(用于值)
        f2.setFontHeightInPoints((short) 10);
        f2.setColor(IndexedColors.BLACK.getIndex());
 
        // 设置第一种单元格的样式(用于列名)
        cs.setFont(f);
        cs.setBorderLeft(BorderStyle.THIN);
        cs.setBorderRight(BorderStyle.THIN);
        cs.setBorderTop(BorderStyle.THIN);
        cs.setBorderBottom(BorderStyle.THIN);
        cs.setAlignment(HorizontalAlignment.CENTER);

        // 设置第二种单元格的样式(用于值)
        cs2.setFont(f2);
		cs2.setBorderLeft(BorderStyle.THIN);
		cs2.setBorderRight(BorderStyle.THIN);
		cs2.setBorderTop(BorderStyle.THIN);
		cs2.setBorderBottom(BorderStyle.THIN);
		cs2.setAlignment(HorizontalAlignment.CENTER);
        //设置列名
        for(int i=0;i<columnNames.length;i++){
            Cell cell = row.createCell(i);
            cell.setCellValue(columnNames[i]);
            cell.setCellStyle(cs);
        }
        //设置每行每列的值
        for (short i = 1; i < list.size(); i++) {
            // Row 行,Cell 方格 , Row 和 Cell 都是从0开始计数的
            // 创建一行,在页sheet上
            Row row1 = sheet.createRow((short) i);
            // 在row行上创建一个方格
            for(short j=0;j<keys.length;j++){
                Cell cell = row1.createCell(j);
                cell.setCellValue(list.get(i).get(keys[j]) == null?" ": list.get(i).get(keys[j]).toString());
                cell.setCellStyle(cs2);
            }
        }
        return wb;
    }
}

2.Controller接收

@RequestMapping("exportList") 
public void exportList(HttpServletResponse response, String ids) { 
   
   String fileName = "人员档案列表"; 
   
   List<User> users = sRPService.exportList(ids); 
   
   // 列名
   String columnNames[] = { "ID", "姓名", "性别", "所属部门", "所属单位", "邮箱",
                          "电话", "手机", "学历/学位", "专业/专科方向", "直属上级", "账号锁定" };  
   // map中的key
   String keys[] = { "id", "userName", "gender", "dept", "unit", "email", 
                     "tel", "phone", "degree", "major", "parentName", "isLocked" };
   try { 
       ExportPOIUtils.start_download(response, fileName, users,columnNames, keys); 
   } catch (IOException e) { 
     e.printStackTrace(); 
   } 
}
  1. JS
//必须使用location.href
location.href = basePath+"/sRPController/exportList.do?ids="+ids;
posted @ 2021-11-09 09:09  kht  阅读(335)  评论(0编辑  收藏  举报