使用IDEA的反编译插件反编译jar包

反编译插件介绍

安装IDEA后, 一般自带反编译插件, Java Bytecode Decompiler
如果没有可以自己安装下

1.首先找到插件的jar包, 在IDEA安装目录的plugins文件夹下

D:\IntelliJ IDEA 2021.2.2\plugins\java-decompiler\lib

2.运行java命令, 指定插件的jar包目录和你要反编译的jar包目录还有生成反编译后jar包的目录

命令如下:

java -cp "D:\IntelliJ IDEA 2021.2.2\plugins\java-decompiler\lib\java-decompiler.jar" ^
org.jetbrains.java.decompiler.main.decompiler.ConsoleDecompiler -dgs=true ^
E:\project\operation-module-capabilityStatistics-1.18.0.jar "E:\game"

当jre版本低于class文件的版本时会报错:

错误信息:

Error: A JNI error has occurred, please check your installation and try again
Exception in thread “main” java.lang.UnsupportedClassVersionError: org/jetbrains/java/decompiler/main/decompiler/ConsoleDecompiler has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)

class文件版本跟jdk版本对应关系如下

49 = Java 5
50 = Java 6
51 = Java 7
52 = Java 8
53 = Java 9
54 = Java 10
55 = Java 11
56 = Java 12
57 = Java 13
58 = Java 14
59 = Java 15
60 = Java 16

我们可以指定自己安装的高版本JDK来运行, 比如这里我用自己安装的JDK11来运行