Update README.md

README.md

@@ -57,7 +57,7 @@ I am improving and expanding the documentation all the time. If you'd like to he
 * [Spring Boot参考指南](https://github.com/qibaoguang/Spring-Boot-Reference-Guide)
 * [Java 编程要点](https://github.com/waylau/essential-java) 
 * [Java 虚拟机规范](https://github.com/waylau/java-virtual-machine-specification)
-* [深入理解Java虚拟机：JVM高级特性与最佳实践](https://github.com/Porraio/Java_Books/blob/master/%E6%B7%B1%E5%85%A5%E7%90%86%E8%A7%A3Java%E8%99%9A%E6%8B%9F%E6%9C%BA%EF%BC%9AJVM%E9%AB%98%E7%BA%A7%E7%89%B9%E6%80%A7%E4%B8%8E%E6%9C%80%E4%BD%B3%E5%AE%9E%E8%B7%B5.pdf)
+* [深入理解Java虚拟机：JVM高级特性与最佳实践](https://github.com/Porraio/Java_Books/blob/master/)
 ## Golang
 
 * Build Web Application With Golang [:us:](https://github.com/astaxie/build-web-application-with-golang), [:cn:](https://github.com/astaxie/build-web-application-with-golang/blob/master/zh)