Print in Order: fix

Author: sofkyle

LeetCodePrj/Java/leetcode/easy/page7/EasyPage7.java

@@ -5,29 +5,47 @@
 public class EasyPage7 {
     @Test
     public void testPrintInOrder() throws Exception {
-        Runnable first = new Runnable() {
+        Thread first = new Thread(new Runnable() {
             @Override
             public void run() {
                 System.out.println("first");
             }
-        };
-        Runnable second = new Runnable() {
+        });
+        Thread second = new Thread(new Runnable() {
             @Override
             public void run() {
                 System.out.println("second");
             }
-        };
-        Runnable third = new Runnable() {
+        });
+        Thread third = new Thread(new Runnable() {
             @Override
             public void run() {
                 System.out.println("third");
             }
-        };
+        });
 
         PrintInOrder printInOrder = new PrintInOrder();
-        printInOrder.first(first);
-        printInOrder.second(second);
-        printInOrder.third(third);
+        new Thread(() -> {
+            try {
+                printInOrder.first(first);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }).start();
+        new Thread(() -> {
+            try {
+                printInOrder.second(second);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }).start();
+        new Thread(() -> {
+            try {
+                printInOrder.third(third);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }).start();
 
         System.in.read();
     }

LeetCodePrj/Java/leetcode/easy/page7/PrintInOrder.java

@@ -6,8 +6,8 @@
 import java.util.concurrent.locks.ReentrantLock;
 
 public class PrintInOrder {
-    private Semaphore semaphoreSecond = new Semaphore(1);
-    private Semaphore semaphoreThird = new Semaphore(1);
+    private static Semaphore semaphoreSecond = new Semaphore(1);
+    private static Semaphore semaphoreThird = new Semaphore(1);
 
     public PrintInOrder() {
         try {