Update JavaConcurrencyAdvancedCommonInterviewQuestions.md

huangshangi · web-flow · commit e88e2892eaed · 2020-06-16T10:21:01.000+08:00
单例模式实例修改，在单例方法上声明synchronized关键字是不必要的且会造成性能上的开销
diff --git a/docs/java/Multithread/JavaConcurrencyAdvancedCommonInterviewQuestions.md b/docs/java/Multithread/JavaConcurrencyAdvancedCommonInterviewQuestions.md
@@ -73,7 +73,7 @@ public class Singleton {
     private Singleton() {
     }
 
-    public synchronized static Singleton getUniqueInstance() {
+    public  static Singleton getUniqueInstance() {
        //先判断对象是否已经实例过，没有实例化过才进入加锁代码
         if (uniqueInstance == null) {
             //类对象加锁

Original file line number	Diff line number	Diff line change
`@@ -73,7 +73,7 @@ public class Singleton {`
`73`	`73`	`private Singleton() {`
`74`	`74`	`}`
`75`	`75`
`76`		`- public synchronized static Singleton getUniqueInstance() {`
	`76`	`+ public static Singleton getUniqueInstance() {`
`77`	`77`	`//先判断对象是否已经实例过，没有实例化过才进入加锁代码`
`78`	`78`	`if (uniqueInstance == null) {`
`79`	`79`	`//类对象加锁`