Java ByteBuddy未重新定义静态方法
我尝试使用ByteBuddy重新定义两种方法,如下所示:Java ByteBuddy未重新定义静态方法,java,bytecode,byte-buddy,Java,Bytecode,Byte Buddy,我尝试使用ByteBuddy重新定义两种方法,如下所示: ClassLoader classLoader = ClassLoader.getSystemClassLoader(); ClassLoadingStrategy.Default classLoadingStrategy = ClassLoadingStrategy.Default.INJECTION; new ByteBuddy().redefine(CommandBase.class).method(returns(Item.cla
ClassLoader classLoader = ClassLoader.getSystemClassLoader();
ClassLoadingStrategy.Default classLoadingStrategy = ClassLoadingStrategy.Default.INJECTION;
new ByteBuddy().redefine(CommandBase.class).method(returns(Item.class)).intercept(MethodDelegation.to(CppItemInterceptor.class)).make().load(classLoader, classLoadingStrategy);
new ByteBuddy().redefine(CommandBase.class).method(returns(Block.class)).intercept(MethodDelegation.to(CppBlockInterceptor.class)).make().load(classLoader, classLoadingStrategy);
try {
System.out.println(CppBlockInterceptor.getBlockByText(null, "1").getLocalizedName());
System.out.println(CommandBase.getBlockByText(null, "1").getLocalizedName());
} catch (Exception e) {
e.printStackTrace();
}
对CppBlockInterceptor的直接调用产生了预期的输出,但是对应该被替换的方法的调用仍然使用旧的行为。有什么原因吗?您的
CommandBase
类在您有机会重新定义它之前已经加载了。如果不使用Java代理,Byte Buddy无法替换加载的类。尝试运行以下命令:
TypeDescription commandBase = new TypePool.Default.ofClassPath()
.locate("my.package.CommandBase");
new ByteBuddy()
.redefine(commandBase, ClassFileLocator.ForClassLoader.ofClassPath())
.method(returns(Block.class)).intercept(MethodDelegation.to(CppBlockInterceptor.class))
.make()
.load(ClassLoader.getSystemClassLoader(), ClassLoadingStrategy.Default.INJECTOR);
CppBlockInterceptor.getBlockByText(null, "1").getLocalizedName()
在调用之前不显式引用
CommandBase
,它就会工作。不过,最好使用AgentBuilder
和Java代理。被接受的答案不再是可编译的(这并不奇怪,因为5年多过去了)。使用Byte Buddy v1.10.17的正确代码如下:
TypeDescription typeDescription = TypePool.Default.ofSystemLoader()
.describe("my.package.CommandBase")
.resolve();
new ByteBuddy()
.redefine(typeDescription, ClassFileLocator.ForClassLoader.ofSystemLoader())
.method(returns(Block.class)).intercept(MethodDelegation.to(CppBlockInterceptor.class))
.make()
.load(ClassLoader.getSystemClassLoader(), ClassLoadingStrategy.Default.INJECTION);