第一个：
http://www.javadecompilers.com/
该站点提供了一个用户界面，用于从.class和.jar'二进制'文件中提取源代码。
推荐选择编译器：
Procyon
open-source, https://bitbucket.org/mstrobel/procyon/wiki/Java Decompiler Author: Mike Strobel Updated in 2015. Handles language enhancements from Java 5 and beyond, up to Java 8, including:
Enum declarations
Enum and String switch statements
Local classes (both anonymous and named)
Annotations
Java 8 Lambdas and method references (i.e., the :: operator).
Java 7 is required to run.
第二个：
https://jdec.app/