简化RePlugin对宿主PathClassLoader的处理，去掉对私有API的依赖。

replugin-host-library/replugin-host-lib/src/main/java/com/qihoo360/loader2/PMF.java

@@ -26,7 +26,7 @@
 import com.qihoo360.i.Factory;
 import com.qihoo360.i.Factory2;
 import com.qihoo360.i.IModule;
-import com.qihoo360.loader.utils.PatchClassLoaderUtils;
+import com.qihoo360.replugin.PMFClassLoader;
 import com.qihoo360.replugin.helper.LogRelease;
 
 import java.io.FileDescriptor;
@@ -74,7 +74,7 @@ public static final void init(Application application) {
         Factory.sPluginManager = PMF.getLocal();
         Factory2.sPLProxy = PMF.getInternal();
 
-        PatchClassLoaderUtils.patch(application);
+        PMFClassLoader.hackHostClassLoader();
     }
 
     /**

replugin-host-library/replugin-host-lib/src/main/java/com/qihoo360/replugin/PMFClassLoader.java

@@ -0,0 +1,94 @@
+package com.qihoo360.replugin;
+
+import com.qihoo360.loader2.PMF;
+
+import java.lang.reflect.Field;
+
+/**
+ * 给宿主的ClassLoader新增一层parent ClassLoader.因为正常的ClassLoader都会遵循"双亲委派"机制,
+ * 所以宿主的PathClassLoader会尊重这个ClassLoader返回的结果.从而可以在这个ClassLoader中返回PMF想要返回的类.
+ * <p>
+ * 方案来自：
+ * https://github.com/Tencent/Shadow/blob/dev/projects/sdk/dynamic/dynamic-host/src/main/java/com/tencent/shadow/dynamic/host/DynamicRuntime.java
+ *
+ * @author [email protected]
+ */
+public class PMFClassLoader extends ClassLoader {
+
+    private PMFClassLoader(ClassLoader parent) {
+        super(parent);
+    }
+
+    @Override
+    protected Class<?> loadClass(String className, boolean resolve) throws ClassNotFoundException {
+        //
+        Class<?> c = null;
+        c = PMF.loadClass(className, resolve);
+        if (c != null) {
+            return c;
+        }
+        return super.loadClass(className, resolve);
+    }
+
+    @Override
+    protected Package getPackage(String name) {
+        final Package aPackage = super.getPackage(name);
+        if (aPackage == null) {
+            return definePackage(name, "Unknown", "0.0", "Unknown", "Unknown", "0.0", "Unknown", null);
+        } else {
+            return aPackage;
+        }
+    }
+
+    public static void hackHostClassLoader() {
+        ClassLoader hostClassLoader = PMF.class.getClassLoader();
+        final PMFClassLoader newParentClassLoader = new PMFClassLoader(hostClassLoader.getParent());
+        try {
+            PMFClassLoader.hackParentClassLoader(hostClassLoader, newParentClassLoader);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * 修改ClassLoader的parent
+     *
+     * @param classLoader          需要修改的ClassLoader
+     * @param newParentClassLoader classLoader的新的parent
+     */
+    private static void hackParentClassLoader(ClassLoader classLoader,
+                                              ClassLoader newParentClassLoader) throws Exception {
+        Field field = getParentField();
+        if (field == null) {
+            throw new Exception("在ClassLoader.class中没找到类型为ClassLoader的parent域");
+        }
+        field.setAccessible(true);
+        field.set(classLoader, newParentClassLoader);
+    }
+
+    /**
+     * 安全地获取到ClassLoader类的parent域
+     *
+     * @return ClassLoader类的parent域.或不能通过反射访问该域时返回null.
+     */
+    private static Field getParentField() {
+        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+        ClassLoader parent = classLoader.getParent();
+        Field field = null;
+        for (Field f : ClassLoader.class.getDeclaredFields()) {
+            try {
+                boolean accessible = f.isAccessible();
+                f.setAccessible(true);
+                Object o = f.get(classLoader);
+                f.setAccessible(accessible);
+                if (o == parent) {
+                    field = f;
+                    break;
+                }
+            } catch (IllegalAccessException ignore) {
+            }
+        }
+        return field;
+    }
+
+}

replugin-host-library/replugin-host-lib/src/main/java/com/qihoo360/replugin/RePluginCallbacks.java

@@ -41,20 +41,6 @@ public RePluginCallbacks(Context context) {
         mContext = context;
     }
 
-    /**
-     * 创建【宿主用的】 RePluginClassLoader 对象以支持大多数插件化特征。默认为：RePluginClassLoader的实例
-     * <p>
-     * 子类可复写此方法，来创建自己的ClassLoader，做相应的事情（如Hook宿主的ClassLoader做一些特殊的事）
-     *
-     * @param parent   该ClassLoader的父亲，通常为BootClassLoader
-     * @param original 宿主的原ClassLoader，通常为PathClassLoader
-     * @return 支持插件化方案的ClassLoader对象，可直接返回RePluginClassLoader
-     * @see RePluginClassLoader
-     */
-    public RePluginClassLoader createClassLoader(ClassLoader parent, ClassLoader original) {
-        return new RePluginClassLoader(parent, original);
-    }
-
     /**
      * 插件【插件用的】 ClassLoader对象。默认为：PluginDexClassLoader的实例
      * <p>