From 55d939bfa484950d59cd07b1d9d6a4b02d823099 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sat, 8 Aug 2026 16:04:04 +0800
Subject: [PATCH] =?UTF-8?q?s-day07-=20Stream=E6=B5=81=E4=B8=AD=E7=9A=84?=
 =?UTF-8?q?=E5=B8=B8=E7=94=A8=E6=96=B9=E6=B3=95=5Fcount?=
MIME-Version: 1.0
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---
 .../src/com/inmind/stream07/CountDemo16.java   | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 s-day07/src/com/inmind/stream07/CountDemo16.java

diff --git a/s-day07/src/com/inmind/stream07/CountDemo16.java b/s-day07/src/com/inmind/stream07/CountDemo16.java
new file mode 100644
index 0000000..08e8a75
--- /dev/null
+++ b/s-day07/src/com/inmind/stream07/CountDemo16.java
@@ -0,0 +1,18 @@
+package com.inmind.stream07;
+
+import java.util.stream.Stream;
+
+/*
+Stream流中的常用方法_count
+long count() 返回此流中的元素数
+流是一个流水生产线，是不能倒退的。count()是一个终结方法，就是这个流结束，那个该流就无法再操作
+ */
+public class CountDemo16 {
+    public static void main(String[] args) {
+        Stream<Integer> stream = Stream.of(1, 2, 3, 4, 5);
+        long count = stream.count();
+        System.out.println(count);
+        //java.lang.IllegalStateException: stream has already been operated upon or closed
+       // stream.forEach(i -> System.out.println(i));//错误，因为流已经结束，不能再操作了
+    }
+}