解决FilterIter 类中构造器filter 传入null 无法进行迭代器迭代

hutool-core/src/main/java/cn/hutool/core/collection/FilterIter.java

@@ -84,7 +84,7 @@ public class FilterIter<E> implements Iterator<E> {
 	private boolean setNextObject() {
 		while (iterator.hasNext()) {
 			final E object = iterator.next();
-			if (null != filter && filter.accept(object)) {
+			if (null == filter || filter.accept(object)) {
 				nextObject = object;
 				nextObjectSet = true;
 				return true;

hutool-core/src/test/java/cn/hutool/core/collection/FilterIterTest.java

@@ -0,0 +1,31 @@
+package cn.hutool.core.collection;
+
+import org.junit.Test;
+
+import java.util.Iterator;
+
+/**
+ * {@link FilterIter} 单元测试
+ * @author chao.wang
+ */
+public class FilterIterTest {
+
+	@Test
+	public void checkFilterIter() {
+		Iterator<String> it = ListUtil.of("1", "2").iterator();
+		// filter 为null
+		FilterIter<String> filterIter = new FilterIter<>(it, null);
+		while (filterIter.hasNext()) {
+			System.out.println(filterIter.next());
+		}
+
+		System.out.println();
+		it = ListUtil.of("1", "2").iterator();
+		// filter 不为空
+		filterIter = new FilterIter<>(it, (key) -> key.equals("1"));
+		while (filterIter.hasNext()) {
+			System.out.println(filterIter.next());
+		}
+	}
+
+}