Maven项目结合POI导出Excl表格Demo-亲测可用

Maven项目结合POI导出Excl表格

一、POM文件添加依赖

 <!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.6</version>
        </dependency>

二、将ExportExcel类放进项目的util中

package com.jonychen.util.core;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.util.CellRangeAddress;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import static com.jonychen.HttpKit.getResponse;（后面有代码，复制粘贴即可）
/**
   *导出工具类
   */
public class ExportExcel{

    //显示的导出表的标题
    private String title;
    //导出表的列名
    private String[] rowName ;

    private List<Object[]> dataList = new ArrayList<Object[]>();

    HttpServletResponse response;

    //构造方法，传入要导出的数据
    public ExportExcel(String title,String[] rowName,List<Object[]>  dataList){
        this.dataList = dataList;
        this.rowName = rowName;
        this.title = title;
    }

    /*
     * 导出数据
     * */
    public void export() throws Exception{
        try{
            HSSFWorkbook workbook = new HSSFWorkbook();                        // 创建工作簿对象
            HSSFSheet sheet = workbook.createSheet(title);                     // 创建工作表

            // 产生表格标题行
            HSSFRow rowm = sheet.createRow(0);
            HSSFCell cellTiltle = rowm.createCell(0);

            //sheet样式定义【getColumnTopStyle()/getStyle()均为自定义方法 - 在下面  - 可扩展】
            HSSFCellStyle columnTopStyle = this.getColumnTopStyle(workbook);//获取列头样式对象
            HSSFCellStyle style = this.getStyle(workbook);                    //单元格样式对象

            sheet.addMergedRegion(new CellRangeAddress(0, 1, 0, (rowName.length-1)));
            cellTiltle.setCellStyle(columnTopStyle);
            cellTiltle.setCellValue(title);

            // 定义所需列数
            int columnNum = rowName.length;
            HSSFRow rowRowName = sheet.createRow(2);                // 在索引2的位置创建行(最顶端的行开始的第二行)

            // 将列头设置到sheet的单元格中
            for(int n=0;n<columnNum;n++){
                HSSFCell  cellRowName = rowRowName.createCell(n);                //创建列头对应个数的单元格
                cellRowName.setCellType(HSSFCell.CELL_TYPE_STRING);                //设置列头单元格的数据类型
                HSSFRichTextString text = new HSSFRichTextString(rowName[n]);
                cellRowName.setCellValue(text);                                    //设置列头单元格的值
                cellRowName.setCellStyle(columnTopStyle);                        //设置列头单元格样式
            }

            //将查询出的数据设置到sheet对应的单元格中
            for(int i=0;i<dataList.size();i++){

                Object[] obj = dataList.get(i);//遍历每个对象
                HSSFRow row = sheet.createRow(i+3);//创建所需的行数

                for(int j=0; j<obj.length; j++){
                    HSSFCell  cell = null;   //设置单元格的数据类型
                    if(j == 0){
                        cell = row.createCell(j,HSSFCell.CELL_TYPE_NUMERIC);
                        cell.setCellValue(i+1);
                    }else{
                        cell = row.createCell(j,HSSFCell.CELL_TYPE_STRING);
                        if(!"".equals(obj[j]) && obj[j] != null){
                            cell.setCellValue(obj[j].toString());                        //设置单元格的值
                        }
                    }
                    cell.setCellStyle(style);                                    //设置单元格样式
                }
            }
            //让列宽随着导出的列长自动适应
            for (int colNum = 0; colNum < columnNum; colNum++) {
                int columnWidth = sheet.getColumnWidth(colNum) / 256;
                for (int rowNum = 0; rowNum < sheet.getLastRowNum(); rowNum++) {
                    HSSFRow currentRow;
                    //当前行未被使用过
                    if (sheet.getRow(rowNum) == null) {
                        currentRow = sheet.createRow(rowNum);
                    } else {
                        currentRow = sheet.getRow(rowNum);
                    }
                    if (currentRow.getCell(colNum) != null) {
                        HSSFCell currentCell = currentRow.getCell(colNum);
                        if (currentCell.getCellType() == HSSFCell.CELL_TYPE_STRING) {
                            int length = currentCell.getStringCellValue().getBytes().length;
                            if (columnWidth < length) {
                                columnWidth = length;
                            }
                        }
                    }
                }
                if(colNum == 0){
                    sheet.setColumnWidth(colNum, (columnWidth-2) * 256);
                }else{
                    sheet.setColumnWidth(colNum, (columnWidth+4) * 256);
                }
            }

            if(workbook !=null){
                try
                {
                    String fileName = "Excel-Signup" + System.currentTimeMillis() + ".xls";
                    String headStr = "attachment; filename=\"" + fileName + "\"";
                    response =getResponse();
                    response.setContentType("APPLICATION/OCTET-STREAM");
                    response.setHeader("Content-Disposition", headStr);
                    OutputStream out = response.getOutputStream();
                    workbook.write(out);
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }

        }catch(Exception e){
            e.printStackTrace();
        }

    }

    /*
     * 列头单元格样式
     */
    public HSSFCellStyle getColumnTopStyle(HSSFWorkbook workbook) {

        // 设置字体
        HSSFFont font = workbook.createFont();
        //设置字体大小
        font.setFontHeightInPoints((short)11);
        //字体加粗
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        //设置字体名字
        font.setFontName("Courier New");
        //设置样式;
        HSSFCellStyle style = workbook.createCellStyle();
        //设置底边框;
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        //设置底边框颜色;
        style.setBottomBorderColor(HSSFColor.BLACK.index);
        //设置左边框;
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        //设置左边框颜色;
        style.setLeftBorderColor(HSSFColor.BLACK.index);
        //设置右边框;
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        //设置右边框颜色;
        style.setRightBorderColor(HSSFColor.BLACK.index);
        //设置顶边框;
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        //设置顶边框颜色;
        style.setTopBorderColor(HSSFColor.BLACK.index);
        //在样式用应用设置的字体;
        style.setFont(font);
        //设置自动换行;
        style.setWrapText(false);
        //设置水平对齐的样式为居中对齐;
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        //设置垂直对齐的样式为居中对齐;
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

        return style;

    }

    /*
     * 列数据信息单元格样式
     */
    public HSSFCellStyle getStyle(HSSFWorkbook workbook) {
        // 设置字体
        HSSFFont font = workbook.createFont();
        //设置字体大小
        //font.setFontHeightInPoints((short)10);
        //字体加粗
        //font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        //设置字体名字
        font.setFontName("Courier New");
        //设置样式;
        HSSFCellStyle style = workbook.createCellStyle();
        //设置底边框;
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        //设置底边框颜色;
        style.setBottomBorderColor(HSSFColor.BLACK.index);
        //设置左边框;
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        //设置左边框颜色;
        style.setLeftBorderColor(HSSFColor.BLACK.index);
        //设置右边框;
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);
        //设置右边框颜色;
        style.setRightBorderColor(HSSFColor.BLACK.index);
        //设置顶边框;
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);
        //设置顶边框颜色;
        style.setTopBorderColor(HSSFColor.BLACK.index);
        //在样式用应用设置的字体;
        style.setFont(font);
        //设置自动换行;
        style.setWrapText(false);
        //设置水平对齐的样式为居中对齐;
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        //设置垂直对齐的样式为居中对齐;
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

        return style;

    }
}

com.jonychen.HttpKit.getResponse

/**
 * Copyright (c) 2015-2016, Chill Zhuang 庄骞 (smallchill@163.com).
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.jonychen.util.core;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HttpKit {

    public static String getIp(){
       return HttpKit.getRequest().getRemoteHost();
    }

    /**
     * 获取所有请求的值
     */
    public static Map<String, String> getRequestParameters() {
        HashMap<String, String> values = new HashMap<>();
        HttpServletRequest request = HttpKit.getRequest();
        Enumeration enums = request.getParameterNames();
        while ( enums.hasMoreElements()){
            String paramName = (String) enums.nextElement();
            String paramValue = request.getParameter(paramName);
            values.put(paramName, paramValue);
        }
        return values;
    }

    /**
     * 获取 HttpServletRequest
     */
    public static HttpServletResponse getResponse() {
        HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
        return response;
    }

    /**
     * 获取 包装防Xss Sql注入的 HttpServletRequest
     * @return request
     */
    public static HttpServletRequest getRequest() {
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        return new WafRequestWrapper(request);
    }

    /**
     * 向指定URL发送GET方法的请求
     *
     * @param url 发送请求的URL
     * @param param 请求参数
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url, Map<String, String> param) {
        String result = "";
        BufferedReader in = null;
        try {
            String para = "";
            for (String key : param.keySet()) {
                para += (key + "=" + param.get(key) + "&");
            }
            if (para.lastIndexOf("&") > 0) {
                para = para.substring(0, para.length() - 1);
            }
            String urlNameString = url + "?" + para;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
            //for (String key : map.keySet()) {
            //    System.out.println(key + "--->" + map.get(key));
            //}
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url 发送请求的 URL
     * @param param  请求参数
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, Map<String, String> param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            String para = "";
            for (String key : param.keySet()) {
                para += (key + "=" + param.get(key) + "&");
            }
            if (para.lastIndexOf("&") > 0) {
                para = para.substring(0, para.length() - 1);
            }
            String urlNameString = url + "?" + para;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }

}

三、项目中写Controller逻辑层进行调用工具类导出即可

    @RequestMapping(value = "/export",method = {RequestMethod.GET, RequestMethod.POST})
    @ResponseBody
    @ApiOperation(value = "导出报表", httpMethod = "GET", notes = "导出报表,前端写一个导出地址调用此接口即可")
    public void signupExport(HttpServletRequest request, HttpServletResponse response) throws Exception {
        //获取数据
        List<SignupInfo> list = signupService.getSignupList();
        logger.info("获取全部列表数据"+JSONArray.toJSON(list));

        String title = "汇总表";
        String[] rowsName = new String[]{"序号", "姓名", "性别","手机号码", "单位名称", "省", "备注"};
        List<Object[]>  dataList = new ArrayList<>();
        Object[] objs = null;
        for (int i = 0; i < list.size(); i++) {
            SignupfdfdsInfo signupInfo= list.get(i);
            objs = new Object[rowsName.length];
            objs[0] = signupInfo.getId();
            objs[1] = signupInfo.getUserName();
            objs[2] = signupInfo.getSex();
            objs[3]=signupInfo.getMobile();
            objs[4] = signupInfo.getCompany();
            objs[5] = signupInfo.getProvince();
            objs[6] = signupInfo.getRemark();
            dataList.add(objs);
        }
        ExportExcel ex = new ExportExcel(title, rowsName, dataList);
        ex.export();
    }

可能遇到的异常：NPE（原因：导出的数据中没有值，数据库中存的值都要有默认值，我varchar型存的是无，int型的是0）