单表通用excle导出（只要是单表都可以）

首先，在contorller层中方法代码

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.bytx.salary.controller.oa.ExcelUtil;
import com.bytx.salary.controller.sys.BaseController;
import com.bytx.salary.mapper.emp.EmpEntryMapper;
import com.bytx.salary.mapper.emp.InviteMapper;
import com.bytx.salary.model.emp.EmpEntry;
import com.bytx.salary.model.emp.Invite;
import com.bytx.salary.model.emp.InviteResult;
import com.bytx.salary.model.oa.ParameterTable;
import com.bytx.salary.service.emp.EmpEntryService;
import com.bytx.salary.service.emp.InviteService;
import com.bytx.salary.service.oa.TestTableImpl;
import com.bytx.salary.utils.CustomPage;
import com.bytx.salary.utils.ReturnUtil;
import com.bytx.salary.utilsc.ChineseToSpell;
import com.bytx.salary.utilsc.ImportExeclUtil;
import com.bytx.salary.utilsc.StringUtil;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.formula.functions.T;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 导出通用单表接口中的字段选取方法
 *
 * @return
 */
@ResponseBody
@RequestMapping(value = "/getField", method = RequestMethod.POST)
public JSONObject getField(@RequestBody JSONObject params) throws Exception {
    String table_schema = "bytx_salary";//如果是一个库的话直接设置常量
    String table_name = params.getString("tableName");//这个是页面传过来的参数，也可以传多个表名
    List<Map<String, String>> columns = testTableImpl.getField(table_name, table_schema);
    for (int j = 0; j < columns.size(); j++) {
        Map<String, String> map = columns.get(j);
        if (map.get("COLUMN_NAME").toString().equals("uuid")  || map.get("COLUMN_NAME").toString().equals("creator_id") || map.get("COLUMN_NAME").toString().equals("creator")||
                map.get("COLUMN_NAME").toString().equals("create_time")|| map.get("COLUMN_NAME").toString().equals("modifier") || map.get("COLUMN_NAME").toString().equals("modifier_id")|| map.get("COLUMN_NAME").toString().equals("modify_time") || map.get("COLUMN_NAME").toString().equals("creator_org_id")) {
            columns.remove(j);
            j--;
        }
    }
    return ReturnUtil.ajaxDoneSuccess("查询成功!", columns);
}

将上边的字段传给前端，前端进行字段的选取后再将这个当成JSONArray数组

参数传到下面真正导出的方法中去：

/**
     * 导出通用单表接口
     *
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/getExcel", method = RequestMethod.POST)
    public void getExcel(@RequestBody JSONObject params) throws Exception {
        Map<String, Object> paramMap = new HashMap<>();
        JSONArray demo = (JSONArray) params.get("columns");//这个是页面传过来的字段选取（就是页面上选择导出字段）
        String d = demo.toJSONString();
        List<Map<String, String>> columns = (List<Map<String, String>>) JSONArray.parse(d);
        paramMap.put("staffName", params.get("staffName"));
        paramMap.put("staffSex", params.get("staffSex"));
        paramMap.put("staffProperty", params.get("staffProperty"));
        paramMap.put("baseCode", params.get("baseCode"));
        paramMap.put("tryState", params.get("tryState"));
        paramMap.put("reexState", params.get("reexState"));
        paramMap.put("inputTimeStart", params.get("inputTimeStart"));
        paramMap.put("inputTimeEnd", params.get("inputTimeEnd"));
        String table_schema = "bytx_salary";//如果是一个库的话直接设置常量
        String table_name = params.getString("tableName");//这个是页面传过来的参数，也可以传多个表名
        String flag = params.getString("flag");
        Date now = new Date();
        String createTime = dateFormat.format(now);//格式化然后放入字符串中
        String fileName = params.getString("fileName") + createTime;
        String sheetName = null;
        int sheetCount = 1;
//        List<Map<String, String>> columns = testTableImpl.getField(table_name, table_schema);
//        for (int j = 0; j < columns.size(); j++) {
//            Map<String, String> map = columns.get(j);
//            if (map.get("COLUMN_NAME").toString().equals("uuid")  || map.get("COLUMN_NAME").toString().equals("creator_id") || map.get("COLUMN_NAME").toString().equals("creator")||
//                    map.get("COLUMN_NAME").toString().equals("create_time")|| map.get("COLUMN_NAME").toString().equals("modifier") || map.get("COLUMN_NAME").toString().equals("modifier_id")|| map.get("COLUMN_NAME").toString().equals("modify_time") || map.get("COLUMN_NAME").toString().equals("creator_org_id")) {
//                columns.remove(j);
//                j--;
//            }
//        }
        String src = null;
        List<ParameterTable> listTable = new ArrayList<>();
        for (int i = 0; i < columns.size(); i++) {  //这是将字段的英文和表中的注释分别取出放到list集合中去
            ParameterTable parameterTable = new ParameterTable();
            parameterTable.setCOLUMN_NAME(columns.get(i).get("COLUMN_NAME"));
            parameterTable.setCOLUMN_COMMENT(columns.get(i).get("COLUMN_COMMENT"));
            listTable.add(parameterTable);
        }
        String headers[] = new String[listTable.size()];
        String tableNames[] = new String[listTable.size()];
        for (int i = 0; i < listTable.size(); i++) {   //这个是将表字段和表注释分别放入数组中去，一会导出的时候根据这个相互对应
            tableNames[i] = listTable.get(i).getCOLUMN_NAME().toString();
            headers[i] = listTable.get(i).getCOLUMN_COMMENT().toString();
        }
        src = StringUtils.join(tableNames, ",");
        HSSFWorkbook workbook = new HSSFWorkbook();
//        String headers[] = {"ID", "姓名", "性别"};
//        String tableNames[]={"id","name","sex"};
        List<Map> list = null;
        if (flag.equals("1")) {//传入标识是1那就导出选中字段的数据
            list = testTableImpl.getList(src, table_name);
        } else {
            list = testTableImpl.getLoad(src, table_name);//这是模板的下载
        }


        ExcelUtil.downLoadExcel(false, workbook, fileName, sheetName, sheetCount, headers, list, tableNames, response);//response是从下图中获取的

    }

 这是service层

import com.bytx.salary.mapper.oa.TestMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;

/**
 * Created by 13671 on 2020/6/2.
 */
@Service
public class TestTableImpl {
    @Autowired
    private TestMapper testMapper;
    public List<Map<String, String>>  getField(String table_name, String table_schema){
        return testMapper.getField(table_name,table_schema);
    }
    public List<Map> getList(String src,String table_name){
        return testMapper.getList(src,table_name);
    }
    public List<Map> getLoad(String src,String table_name){
        return testMapper.getLoad(src,table_name);
    }
}

mapper层接口：

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;
import java.util.Map;

/**
 * Created by 13671 on 2020/6/2.
 */
@Mapper
public interface TestMapper {


    List<Map<String, String>> getField(@Param("table_name") String table_name, @Param("table_schema") String table_schema);
    List<Map> getList(@Param("src")String src,@Param("table_name") String table_name);
    List<Map> getLoad(@Param("src")String src,@Param("table_name") String table_name);
}

mybatis层的SQL语句

<select id="getField"    parameterType="string"  resultType="map">
    select COLUMN_NAME,COLUMN_COMMENT FROM information_schema.COLUMNS WHERE table_name=#{table_name} and table_schema=#{table_schema}
</select>
<select id="getList"   resultType="map" statementType="STATEMENT">
    select ${src}  FROM  ${table_name}
</select>
<select id="getLoad"   resultType="map" statementType="STATEMENT">
    select ${src}  FROM  ${table_name} where uuid='111111111111111'
</select>

导出工具类中的方法：

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

/**
 * @author hz
 * @Description:  封装 excel文件导出
 * @create 2019-07-05
 */
public class ExcelUtil {
//    private static final Logger log = (Logger) LoggerFactory.getLogger(ExcelUtil.class);

    /**
     *
     * @param flag  true 第一列数据为数字序号，false 第一列为正常数据显示
     * @param workbook  HSSFWorkbook对象
     * @param fileName  下载后文件名称
     * @param sheetName 工作簿sheet表名称 null为默认名称“sheet0”
     * @param sheetCount  表列数总合
     * @param headers    表第一列 标题名称数组
     * @param list    表需要填入数据对象
     * @param tableNames 根据标题名称一一对应数据库映射字段（为了从map.get(key)取值）
     * @param response
     * @return
     */
    public static boolean  downLoadExcel(boolean flag, HSSFWorkbook workbook, String fileName, String sheetName, int sheetCount, String headers[], List<Map> list, String tableNames[], HttpServletResponse response)
            throws Exception{
        //第一列为数字序号
//        if(flag){
//            if(sheetCount!=headers.length || sheetCount-1 != tableNames.length){
//               // log.info("第一列为序号时，sheetCount参数和headers数组长度一致，且比tableNames数组长度大1，请核对代码");
//                System.out.println("请核对sheet长度和headers，tableNames");
//                return false;
//            }
//        }
//        //第一列为正常数据，不为数字
//        if(flag==false){
//            if(sheetCount!=headers.length || sheetCount != tableNames.length){
//                //log.info("sheetCount参数和headers数组tableNames数组长度应一致，请核对代码");
//                System.out.println("请核对sheet长度，headers，tableNames");
//                return false;
//            }
//        }
        int rowNum = 1;
        HSSFSheet sheet = null;
        if(sheetName==null){
            sheet = workbook.createSheet();//默认名称 “sheet0”
        }else{
            sheet = workbook.createSheet(sheetName);
        }
        for(int i=0;i<sheetCount;i++){
            sheet.setColumnWidth(i, 3766);
        }
        HSSFRow row = sheet.createRow(0);//设置第一行所有标题字段
        //表格每列所有字段名称赋值
        for (int i = 0; i < headers.length; i++) {
            row.createCell(i).setCellValue(new HSSFRichTextString(headers[i]));
        }
        for (Map map : list) {
            HSSFRow row1 = sheet.createRow(rowNum);
            if(flag){
                for(int i=0;i<headers.length;i++){
                    if(i==0){
                        row1.createCell(i).setCellValue(rowNum);
                        continue;
                    }
                    row1.createCell(i).setCellValue( map.get(tableNames[i-1]).toString());
                }

            }else{
                for(int i=0;i<headers.length;i++){
                    row1.createCell(i).setCellValue((String)((map.get(tableNames[i])==null ? "" :map.get(tableNames[i])).toString()));
                }
            }
            rowNum++;
        }
        OutputStream out = null;
        response.setContentType("application/ms-excel;charset=utf-8");
        response.setHeader("Content-disposition", "attachment;filename=" + new String(fileName.getBytes("gb2312"), "ISO8859-1") + ".xls");
        response.flushBuffer();
        out=response.getOutputStream();
        workbook.write(out);
        out.close();
        return true;
    }
    //正则表达式 用于匹配属性的第一个字母
    private static final String REGEX = "[a-zA-Z]";

}