Java实现导出Excel

项目中实现的代码：

一.
//controller
@RequestMapping(value = "/exportAccountManager")
    public void exportAccountManager(HttpServletRequest request, HttpServletResponse response,
            @RequestParam String fileName, String orgNo, String consNo, String consName, Integer consState) {
        String templateFileName = request.getSession().getServletContext().getRealPath("/") + "resources/templates/"
                + fileName;
        try (InputStream input = new BufferedInputStream(new FileInputStream(templateFileName));
                OutputStream output = response.getOutputStream();) {
            Map<String, Object> params = buildParam(orgNo, consNo, consName, consState);
            List<AccountManagerModel> dataList = accountManagerService.queryAccountManagerList(params);
            CommonUtils.exportExcel(response, fileName, "客户清单.xls", input, output, dataList);
        } catch (Throwable ex) {
            LOGGER.error("导出客户清单失败：", ex);
        }
    }



//参数
 private Map<String, Object> buildParam(String orgNo, String consNo, String consName, Integer consState) {
        Map<String, Object> params = new HashMap<String, Object>();
        CommonUtils.addOrgParam(orgNo, commonService, params);
        params.put("consNo", consNo);
        params.put("consName", consName);
        params.put("consState", consState);
        return params;
    }
二.工具类中导出相关
 public static void exportExcel(HttpServletResponse response, String fileName, String cnFileName, InputStream input,
            OutputStream output, List<?> dataList) throws IOException {
        cnFileName = URLEncoder.encode(cnFileName, StandardCharsets.UTF_8.name());
        response.setHeader("Content-Disposition", "attachment;filename=" + cnFileName);
        response.setContentType("application/vnd.ms-excel");
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("dataList", dataList);
        exportExcel(input, output, params);
        output.flush();
    }

    public static void exportExcel(InputStream is, OutputStream os, Map<String, Object> params) throws IOException {
        Context context = PoiTransformer.createInitialContext();
        if (MapUtils.isNotEmpty(params)) {
            Iterator<Map.Entry<String, Object>> iterator = params.entrySet().iterator();
            while (iterator.hasNext()) {
                Map.Entry<String, Object> entry = iterator.next();
                context.putVar(entry.getKey(), entry.getValue());
            }
        }
        JxlsHelper jxlsHelper = JxlsHelper.getInstance();
        Transformer transformer = jxlsHelper.createTransformer(is, os);
        JexlExpressionEvaluator evaluator = (JexlExpressionEvaluator) transformer.getTransformationConfig()
                .getExpressionEvaluator();
        evaluator.getJexlEngine().setSilent(true); // 设置静默模式，不报警告
        
        // 函数强制，自定义功能
        Map<String, Object> funcs = new HashMap<String, Object>();
        funcs.put("utils", new JxlsUtils());
        evaluator.getJexlEngine().setFunctions(funcs);
        
        // 必须要这个，否者表格函数统计会错乱
        jxlsHelper.setUseFastFormulaProcessor(false).processTemplate(context, transformer);
    }

三.service
@Override
    public List<AccountManagerModel> queryAccountManagerList(Map<String, Object> params) throws Exception {
        return accountManagerMapper.queryAccountManagerList(params);
    }

//service接口
 public List<AccountManagerModel> queryAccountManagerList(Map<String, Object> params) throws Exception;
四.mapper
//mapper接口
  public List<AccountManagerModel> queryAccountManagerList(Map<String, Object> params) throws Exception;
////mapper映射xml

<select id="queryAccountManagerList" parameterType="java.util.Map" resultMap="AccountManagerResultMap">
        select 
            a.cons_id,
            a.cons_no,
            a.cons_name,
            a.cons_address,
            a.legal_person,
            a.legal_person_phone,
            a.bill_person,
            a.bill_person_phone,
            a.electric_person,
            a.electric_person_phone,
            a.entrusted_person,
            a.entrusted_person_phone,
            a.cons_state,
            a.org_no,
            b.org_name
       from be_cons_info a, o_org b
      where a.org_no = b.org_no
        <if test="orgNo != null and orgNo != ''">
            and FIND_IN_SET(a.org_no, #{orgNo})
        </if>
        <if test="consNo != null and consNo != ''">
            and a.cons_no like concat('%', #{consNo}, '%')
        </if>
        <if test="consName != null and consName != ''">
            and a.cons_name like concat('%', #{consName}, '%')
        </if>
        <if test="consState != null">
            and a.cons_state = #{consState}
        </if>
        <if test="powerCompany != null and powerCompany != ''">
            and b.org_name like concat('%', #{powerCompany}, '%')
        </if>
    </select>

 五.前端Html

<div class="tool_wrapper">
        <button class="ui-btn ui-btn-primary" onclick="addAccountManager();">新增</button>
        <button class="ui-btn ui-btn-primary left20" onclick="editAccountManager();">修改</button>
        <!-- <button class="ui-btn ui-btn-primary left20" onclick="cancelAccountManager();">注销</button> -->
        <button class="ui-btn ui-btn-primary left20 fileinput-button">
            <span>导入Excel</span>
            <input id="fileupload" type="file" name="file" accept="application/vnd.ms-excel">
        </button>
        <button class="ui-btn ui-btn-primary left20" onclick="exportXls()">导出Excel</button>
        <button class="ui-btn ui-btn-primary left20" onclick="downloadXlsTemplate()">下载模板</button>
    </div>

六.js

function exportXls() {
    var params = getSearchTableParams();
    var url = getUrl("accountManager/exportAccountManager?fileName=cons.xls", params, true);
    window.location.href = basePath + url;
}

/**
 * 获取查询表格参数
 * @returns Array
 */
function getSearchTableParams() {
  var params = [];
  $(".search_table input,.search_table select").each(function () {
    var _this = $(this);
    params.push({
      name: _this.attr('name'),
      value: _this.val()
    });
  });
  return params;
}

/**
 * 获取URL
 *
 * @param url URL
 * @param params URL参数
 * @param urlContainParam URL是否包含参数，默认不含参数
 * @returns
 */
function getUrl(url, params, urlContainParam) {
  if (params == null || params.length == 0)
    return url;
  if (urlContainParam == null)
    urlContainParam = false;
  var arr = [url];
  $(params).each(function (i, e) {
    if (i == 0 && urlContainParam == false) {
      arr.push("?" + e.name + "=" + e.value);
    } else {
      arr.push("&" + e.name + "=" + e.value);
    }
  });
  return arr.join('');
}