ThreadLocal相关demo

Author: JeffLi1993

src/org/javacore/thread/threadlocal/SafeTask.java

@@ -0,0 +1,36 @@
+package org.javacore.thread.threadlocal;
+
+import java.util.Date;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 描述:看类里面说明
+ * Created by bysocket on 16/3/8.
+ */
+public class SafeTask implements Runnable{
+    /**
+     * ThreadLocal对象不会被所有线程共享
+     * --> 线程局部变量 <--
+     */
+    private static ThreadLocal<Date> startDate = new ThreadLocal<Date>(){
+        /**
+         * 隐式实现初始化对象
+         * @return
+         */
+        @Override
+        protected Date initialValue() {
+            return new Date();
+        }
+    };
+
+    @Override
+    public void run() {
+        System.out.printf("Starting Thread:%s : %s\n",Thread.currentThread().getId(),startDate.get());
+        try {
+            TimeUnit.SECONDS.sleep((int) Math.rint(Math.random() * 10));
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.printf("Finish Thread:%s : %s\n",Thread.currentThread().getId(),startDate.get());
+    }
+}

src/org/javacore/thread/threadlocal/SafeTest.java

@@ -0,0 +1,23 @@
+package org.javacore.thread.threadlocal;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 描述:可以看到线程每个有不同的启动时间,但是结束时间也会不相同.
+ * Created by bysocket on 16/3/8.
+ */
+public class SafeTest {
+    public static void main(String[] args) {
+        SafeTask task = new SafeTask();
+        for (int i = 0 ; i < 10; i++) {
+            Thread thread = new Thread(task);
+            thread.start();
+
+            try {
+                TimeUnit.SECONDS.sleep(2);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}

src/org/javacore/thread/threadlocal/UnsafeTask.java

@@ -0,0 +1,24 @@
+package org.javacore.thread.threadlocal;
+
+import java.util.Date;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 描述:私有变量会被所有线程共享
+ * Created by bysocket on 16/3/8.
+ */
+public class UnsafeTask implements Runnable{
+    private Date startDate;
+
+    @Override
+    public void run() {
+        startDate = new Date();
+        System.out.printf("Starting Thread:%s : %s\n",Thread.currentThread().getId(),startDate);
+        try {
+            TimeUnit.SECONDS.sleep((int) Math.rint(Math.random() * 10));
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.printf("Finish Thread:%s : %s\n",Thread.currentThread().getId(),startDate);
+    }
+}

src/org/javacore/thread/threadlocal/UnsafeTest.java

@@ -0,0 +1,23 @@
+package org.javacore.thread.threadlocal;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 描述:可以看到线程每个有不同的启动时间,但是结束时间会有相同.
+ * Created by bysocket on 16/3/8.
+ */
+public class UnsafeTest {
+    public static void main(String[] args) {
+        UnsafeTask task = new UnsafeTask();
+        for (int i = 0 ; i < 10; i++) {
+            Thread thread = new Thread(task);
+            thread.start();
+
+            try {
+                TimeUnit.SECONDS.sleep(2);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}