!854 update 优化使用getFirst()替代get(0)以提高代码可读性

* update 优化使用getFirst()替代get(0)以提高代码可读性

ruoyi-common/ruoyi-common-core/src/main/java/org/dromara/common/core/utils/TreeBuildUtils.java

@@ -64,7 +64,7 @@ public class TreeBuildUtils extends TreeUtil {
         if (CollUtil.isEmpty(list)) {
             return CollUtil.newArrayList();
         }
-        K k = ReflectUtils.invokeGetter(list.get(0), "parentId");
+        K k = ReflectUtils.invokeGetter(list.getFirst(), "parentId");
         return TreeUtil.build(list, k, DEFAULT_CONFIG, nodeParser);
     }
 

ruoyi-common/ruoyi-common-excel/src/main/java/org/dromara/common/excel/core/CellMergeHandler.java

@@ -66,7 +66,7 @@ public class CellMergeHandler {
         }
 
         // 获取有合并注解的字段
-        Map<Field, FieldColumnIndex> mergeFields = getFieldColumnIndexMap(rows.get(0).getClass());
+        Map<Field, FieldColumnIndex> mergeFields = getFieldColumnIndexMap(rows.getFirst().getClass());
         // 如果没有需要合并的字段则返回空集
         if (CollUtil.isEmpty(mergeFields)) {
             return Collections.emptyList();

ruoyi-common/ruoyi-common-excel/src/main/java/org/dromara/common/excel/core/DropDownOptions.java

@@ -154,7 +154,7 @@ public class DropDownOptions {
         sonList.forEach(everySon -> {
             if (parentGroupByIdMap.containsKey(sonHowToGetParentIdFunction.apply(everySon))) {
                 // 找到对应的上级
-                T parentObj = parentGroupByIdMap.get(sonHowToGetParentIdFunction.apply(everySon)).get(0);
+                T parentObj = parentGroupByIdMap.get(sonHowToGetParentIdFunction.apply(everySon)).getFirst();
                 // 提取名称和ID作为Key
                 String key = howToBuildEveryOption.apply(parentObj);
                 // Key对应的Value

ruoyi-common/ruoyi-common-excel/src/main/java/org/dromara/common/excel/core/ExcelDownHandler.java

@@ -282,10 +282,10 @@ public class ExcelDownHandler implements SheetWriteHandler {
                     continue;
                 }
                 // 取第一个
-                String str = data.get(0);
+                String str = data.getFirst();
                 rowData.add(str);
                 // 通过移除的方式避免重复
-                data.remove(0);
+                data.removeFirst();
                 // 设置可以继续
                 flag = true;
             }

ruoyi-common/ruoyi-common-mybatis/src/main/java/org/dromara/common/mybatis/handler/PlusDataPermissionHandler.java

@@ -112,7 +112,7 @@ public class PlusDataPermissionHandler {
         }
         Object defaultValue = "-1";
         NullSafeStandardEvaluationContext context = new NullSafeStandardEvaluationContext(defaultValue);
-        context.addPropertyAccessor(new NullSafePropertyAccessor(context.getPropertyAccessors().get(0), defaultValue));
+        context.addPropertyAccessor(new NullSafePropertyAccessor(context.getPropertyAccessors().getFirst(), defaultValue));
         context.setBeanResolver(beanResolver);
         DataPermissionHelper.getContext().forEach(context::setVariable);
         Set<String> conditions = new HashSet<>();