Update out-of-date java client examples (#627)

* update out-of-date java client examples

* Remove semaphore from AsyncSimpleConsumerExample

Signed-off-by: Aaron Ai <yangkun.ayk@gmail.com>

---------

Signed-off-by: Aaron Ai <yangkun.ayk@gmail.com>
Co-authored-by: Aaron Ai <yangkun.ayk@gmail.com>
diff --git a/java/client/src/main/java/org/apache/rocketmq/client/java/example/AsyncProducerExample.java b/java/client/src/main/java/org/apache/rocketmq/client/java/example/AsyncProducerExample.java
index 0a52c82..fe6ba17 100644
--- a/java/client/src/main/java/org/apache/rocketmq/client/java/example/AsyncProducerExample.java
+++ b/java/client/src/main/java/org/apache/rocketmq/client/java/example/AsyncProducerExample.java
@@ -67,6 +67,6 @@
         Thread.sleep(Long.MAX_VALUE);
         // Close the producer when you don't need it anymore.
         // You could close it manually or add this into the JVM shutdown hook.
-        // producer.shutdown();
+        // producer.close();
     }
 }
diff --git a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerDelayMessageExample.java b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerDelayMessageExample.java
index a4dcf96..7c84388 100644
--- a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerDelayMessageExample.java
+++ b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerDelayMessageExample.java
@@ -61,6 +61,6 @@
         }
         // Close the producer when you don't need it anymore.
         // You could close it manually or add this into the JVM shutdown hook.
-        // producer.shutdown();
+        // producer.close();
     }
 }
\ No newline at end of file
diff --git a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerFifoMessageExample.java b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerFifoMessageExample.java
index a39a980..9b310a8 100644
--- a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerFifoMessageExample.java
+++ b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerFifoMessageExample.java
@@ -59,6 +59,6 @@
         }
         // Close the producer when you don't need it anymore.
         // You could close it manually or add this into the JVM shutdown hook.
-        // producer.shutdown();
+        // producer.close();
     }
 }
diff --git a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerNormalMessageExample.java b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerNormalMessageExample.java
index b8e510c..c8650b8 100644
--- a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerNormalMessageExample.java
+++ b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerNormalMessageExample.java
@@ -57,6 +57,6 @@
         }
         // Close the producer when you don't need it anymore.
         // You could close it manually or add this into the JVM shutdown hook.
-        // producer.shutdown();
+        // producer.close();
     }
 }
diff --git a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerTransactionMessageExample.java b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerTransactionMessageExample.java
index d05f2a9..8eec609 100644
--- a/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerTransactionMessageExample.java
+++ b/java/client/src/main/java/org/apache/rocketmq/client/java/example/ProducerTransactionMessageExample.java
@@ -73,6 +73,6 @@
 
         // Close the producer when you don't need it anymore.
         // You could close it manually or add this into the JVM shutdown hook.
-        // producer.shutdown();
+        // producer.close();
     }
 }