poi导出文件到excel

1.导出excel工具类

package cn.kyxt.utils;


import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
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.HorizontalAlignment;

public class ExportExcel_two {
    /**
     * @功能：手工构建一个简单格式的Excel
     */
    public static void createExcel(Map<String, List<String>> map, String[] strArray) {
        // 第一步，创建一个webbook，对应一个Excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = wb.createSheet("sheet1");
        sheet.setDefaultColumnWidth(20);// 默认列宽
        // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
        HSSFRow row = sheet.createRow((int) 0);
        // 第四步，创建单元格，并设置值表头 设置表头居中
        HSSFCellStyle style = wb.createCellStyle();
        // 创建一个居中格式
        style.setAlignment(HorizontalAlignment.CENTER);

        // 添加excel title
        HSSFCell cell = null;
        for (int i = 0; i < strArray.length; i++) {
            cell = row.createCell((short) i);
            cell.setCellValue(strArray[i]);
            cell.setCellStyle(style);
        }

        // 第五步，写入实体数据 实际应用中这些数据从数据库得到,list中字符串的顺序必须和数组strArray中的顺序一致
        int i = 0;
        for (String str : map.keySet()) {
            row = sheet.createRow((int) i + 1);
            List<String> list = map.get(str);

            // 第四步，创建单元格，并设置值
            for (int j = 0; j < strArray.length; j++) {
                row.createCell((short) j).setCellValue(list.get(j));
            }

            // 第六步，将文件存到指定位置
            try {
                FileOutputStream fout = new FileOutputStream("C:/Users/whj/Desktop/" + new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()).toString() +"合同审核信息"+".xls");
                wb.write(fout);
                fout.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            i++;
        }
    }
}

2.测试类

package cn.kyxt.utils;

import java.io.FileOutputStream;
import java.io.OutputStream;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.UUID;

import cn.kyxt.dao.impl.HXXM.HTGL.HTSHDaoImpl;
import cn.kyxt.dao.inte.HXXM.HTGL.HTSH.HTSHDao;
import cn.kyxt.domain.hxxm.htgl.htsh.HTSH;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

/**
 * 创建excel，写入数据，然后下载到本地
 *
 */
public class TestExport_two {

    public static void main(String[] args) {
        Map<String, List<String>> memberMap = getStatistics();
        String[] strArray = excelTitle();
        ExportExcel_two.createExcel(memberMap, strArray);
    }

    private static Map<String, List<String>> getStatistics() {
        HTSHDao htshDao = new HTSHDaoImpl();
        List<HTSH> htshList = htshDao.Display();
        Map<String, List<String>> map = new HashMap<String, List<String>>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        for (int i = 0; i < htshList.size(); i++) {
            ArrayList<String> htsh = new ArrayList<String>();
            htsh.add(htshList.get(i).getHT_ID());
            htsh.add(htshList.get(i).getHT_NAME());
            htsh.add(String.valueOf(htshList.get(i).getHT_TYPEID()));
            htsh.add(String.valueOf(htshList.get(i).getFZR_TYPEID()));
            htsh.add(htshList.get(i).getFZR_NAME());

            htsh.add(htshList.get(i).getFZR_PHONE());
            htsh.add(htshList.get(i).getCJDW_ID());
            htsh.add(String.valueOf( htshList.get(i).getXK_ID()));
            htsh.add(htshList.get(i).getHT_JFDW());
            htsh.add(htshList.get(i).getCYR_NAME());

            htsh.add(String.valueOf(htshList.get(i).getHT_HTZT()));
            htsh.add(htshList.get(i).getHT_HTJE());
            htsh.add(sdf.format(htshList.get(i).getHT_KSRQ()));
            htsh.add(sdf.format(htshList.get(i).getHT_ZZRQ()));
            htsh.add(htshList.get(i).getHT_XMZH());

            htsh.add(String.valueOf(htshList.get(i).getHT_GLKS()));
            htsh.add(htshList.get(i).getHT_CDBH());
            htsh.add(String.valueOf(htshList.get(i).getXMLBJB_ID()));
            htsh.add(String.valueOf(htshList.get(i).getXMJB_ID()));
            htsh.add(String.valueOf(htshList.get(i).getXMFL_ID()));

            htsh.add(String.valueOf(htshList.get(i).getXMLY_ID()));
            htsh.add(String.valueOf(htshList.get(i).getHT_YJLB()));
            htsh.add(String.valueOf(htshList.get(i).getHT_HZXS()));
            htsh.add(String.valueOf(htshList.get(i).getGMJJHY_DL()));
            htsh.add(String.valueOf(htshList.get(i).getGMJJHY_ZL()));

            htsh.add(String.valueOf(htshList.get(i).getHT_SHIJMB()));
            htsh.add(htshList.get(i).getHT_BZ());
            htsh.add(String.valueOf(htshList.get(i).getHT_ZZXS()));
            htsh.add(String.valueOf(htshList.get(i).getHT_SHZT()));
            map.put("数据", htsh);
        }
        return map;
    }

    /**
     * 创建excel title
     */
    public static String[] excelTitle() {
        String[] strArray = {"合同编号", "合同名称", "合同类别", "负责人类型", "负责人姓名",
                "负责人电话","承接单位","学科","甲方单位","参与人姓名",
                "合同状态","合同金额","开始日期","终止日期","项目账号",
                "管理科室","存档编号","项目类别级别","项目级别","项目分类",
                "项目来源","研究类别","合作形式","国民经济行业（大类）","国民经济行业（中类）",
                "社会经济目标","备注","组织形式","审核状态"};
        return strArray;
    }
}