Spring-StopWatch.md

Author: huifer

docs/Spring/clazz/Spring-StopWatch.md

@@ -0,0 +1,44 @@
+# Spring StopWatch
+- Author: [HuiFer](https://github.com/huifer)
+- 源码阅读仓库: [SourceHot-spring](https://github.com/SourceHot/spring-framework-read)
+
+- 全路径: `org.springframework.util.StopWatch`
+## 属性
+- taskList: 任务信息列表
+- keepTaskList: 是否保留任务信息列表
+- startTimeMillis: 任务开始的时间
+- currentTaskName: 任务名称
+- lastTaskInfo: 任务信息
+- taskCount: 任务数量
+- totalTimeMillis: 总共花费的时间
+
+## 方法
+- `org.springframework.util.StopWatch.start(java.lang.String)`
+```java
+    public void start(String taskName) throws IllegalStateException {
+        if (this.currentTaskName != null) {
+            throw new IllegalStateException("Can't start StopWatch: it's already running");
+        }
+        this.currentTaskName = taskName;
+        this.startTimeMillis = System.currentTimeMillis();
+    }
+```
+- `org.springframework.util.StopWatch.stop`
+```java
+    public void stop() throws IllegalStateException {
+        if (this.currentTaskName == null) {
+            throw new IllegalStateException("Can't stop StopWatch: it's not running");
+        }
+        // 消费的时间
+        long lastTime = System.currentTimeMillis() - this.startTimeMillis;
+        this.totalTimeMillis += lastTime;
+        // 任务信息初始化
+        this.lastTaskInfo = new TaskInfo(this.currentTaskName, lastTime);
+        if (this.keepTaskList) {
+            this.taskList.add(this.lastTaskInfo);
+        }
+        ++this.taskCount;
+        this.currentTaskName = null;
+    }
+
+```