excel导出修改：判空

gic-enterprise-download/src/main/java/com/gic/download/utils/DownloadUtils.java

@@ -54,6 +54,9 @@ public class DownloadUtils {
          * @date 2017年3月16日 上午11:45:45
          */
         protected String convertProperty(T bean, String propertyName, Object property) {
+            if (property == null) {
+                return "";
+            }
             try {
                 Class clazz = getPropertyType(bean, propertyName);
                 if (Date.class.equals(clazz)) {
@@ -67,7 +70,7 @@ public class DownloadUtils {
                 LOGGER.info("bean:" + bean + ",Property:" + propertyName + e.getMessage(), e);
                 return null;
             }
-            return property == null ? "" : property.toString();
+            return property.toString();
         }
 
         protected Class getPropertyType(T bean, String propertyName) {
@@ -112,6 +115,9 @@ public class DownloadUtils {
         }
 
         protected String convertPropertyOfDouble(Object bean, String propertyName, Object property) {
+            if (property == null) {
+                return "";
+            }
             try {
                 Class clazz = getPropertyTypeOfDouble(bean, propertyName);
                 if (Date.class.equals(clazz)) {
@@ -125,7 +131,7 @@ public class DownloadUtils {
                 LOGGER.info("bean:" + bean + ",Property:" + propertyName + e.getMessage(), e);
                 return null;
             }
-            return property == null ? "" : property.toString();
+            return property.toString();
         }
 
         protected Class getPropertyTypeOfDouble(Object bean, String propertyName) {