项目中需要对代码进行混淆处理，由于项目是标准的maven项目，便使用了proguard-maven-plugin来自动化混淆过程，但是在使用过程中也不免踩到了一些坑，网上也很少有提及，在此记录一下。
踩过的坑
spring bean名称冲突问题
默认proguard混淆后的类名类似a.class，b.class，但是不同包路径下类名可能发生重名，在spring中默认会把类名作为bean的名称，导致会报spring bean名称冲突的问题，可以通过重新实现BeanNameGenerator接口来解决：
@SpringBootApplication
@ComponentScan("com.abc.def")
public class Application {
public static void main(String[] args) {
new SpringApplicationBuilder(Application.class)
.beanNameGenerator(new CustomBeanNameGenerator())
.run(args);
}
private static class CustomBeanNameGenerator implements BeanNameGenerator {
@Override
public String generateBeanName(BeanDefinition d, BeanDefinitionRegistry r) {
return d.getBeanClassName();
}
}
}spring获取不到jar包里的包路径
spring boot启动后实现ApplicationRunner接口的初始化类并没有执行，也没有错误日志产生。后来把spring容器注册的Bean打印出来发现除了入口类和spring自己的类都没有加载。spring启动debug模式并调整日志级别为TRACE，发现spring没有解析出包含basePackage的jar包来，假设basePackage为com/abc/def/，不混淆代码的日志如下：
2019-11-24 19:33:49.703 [TRACE] [main] [o.s.c.i.s.PathMatchingResourcePatternResolver : 323] Resolved classpath location [com/abc/def/] to resources [URL [jar:file:/tmp/foo/lib/service-facade-1.0.jar!com/abc/def/], URL [jar:file:/tmp/foo/lib/service-impl-1.0.jar!com/abc/def/]]经proguard混淆后日志如下：
2019-11-24 19:33:49.703 [TRACE] [main] [o.s.c.i.s.PathMatchingResourcePatternResolver : 323] Resolved classpath location [com/abc/def/] to resources []但是将混淆后jar包先解压后再压缩处理，却可以正常加载。也就是说proguard在打包过程中把包路径信息丢失了。需要配置keepdirectories参数。
JDK9编译的jar包类冲突
JDK9编译出来的jar包会和一些类冲突，需要配置inLibsFilter排除掉。
多jar包混淆
默认proguard-maven-plugin插件只能通过injar参数将一个jar包混淆，而常见的项目都是多模块项目，这时就需要通过配置assembly参数来实现。
参考配置
Pom.xml:
<plugin>
<groupId>com.github.wvengen</groupId>
<artifactId>proguard-maven-plugin</artifactId>
<version>2.2.0</version>
<executions>
<execution>
<id>release</id>
<phase>package</phase>
<goals>
<goal>proguard</goal>
</goals>
<configuration>
<assembly>
<inclusions>
<inclusion>
<groupId>com.abc.def</groupId>
<artifactId>lib1</artifactId>
</inclusion>
<inclusion>
<groupId>com.abc.def</groupId>
<artifactId>lib2</artifactId>
</inclusion>
</inclusions>
</assembly>
<!--exclude jdk9-->
<inLibsFilter>!META-INF/versions/9/**.class</inLibsFilter>
<proguardInclude>proguard.conf</proguardInclude>
<libs>
<lib>${java.home}/lib/rt.jar</lib>
<lib>${java.home}/lib/jce.jar</lib>
</libs>
<!--<silent>true</silent>-->
</configuration>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>net.sf.proguard</groupId>
<artifactId>proguard-base</artifactId>
<version>6.2.0</version>
</dependency>
</dependencies>
</plugin>proguard.conf:
-dontshrink
-dontoptimize
-keepdirectories
-adaptclassstrings
-dontusemixedcaseclassnames
-flattenpackagehierarchy 'com.abc.def'
-keepattributes Exceptions,InnerClasses,Signature,Deprecated,SourceFile,LineNumberTable,LocalVariable*Table,*Annotation*,Synthetic,EnclosingMethod
-keep class com.abc.def.Application
-keep class * extends org.springframework.boot.ApplicationRunner
# Keep - Applications. Keep all application classes, along with their 'main'
# methods.
-keepclasseswithmembers public class * {
public static void main(java.lang.String[]);
}
# Also keep - Enumerations. Keep the special static methods that are required in
# enumeration classes.
-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}
# Keep names - Native method names. Keep all native class/method names.
-keepclasseswithmembers,includedescriptorclasses,allowshrinking class * {
native <methods>;
}