update readme

README.md

@@ -61,6 +61,47 @@ If the invoked interface method has a return type but not a `void` type, its byt
 - [x] void return type
 - [ ] other return type
 
+
+## Principle
+
+Before:
+
+
+
+```
+
+invokeinterface #3,  2            // InterfaceMethod Callback.onProgress:(I)V
+
+
+```
+
+
+After:
+
+
+```
+
+invokestatic  #23                 // Method buoy$onProgress:(LCallback;I)V
+
+
+static void buoy$onProgress(JavaSample$Callback, int);
+Code:
+   0: aload_0
+   1: ldc           #25                 // String Callback
+   3: ldc           #27                 // String Callback.onProgress:(int)void
+   5: invokestatic  #33                 // Method com/smartdengg/interfacebuoy/compiler/InterfaceBuoy.proxy:(Ljava/lang/Object;Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
+   8: iload_1
+   9: invokeinterface #37,  2           // InterfaceMethod Callback.onProgress:(I)V
+  14: return
+
+
+```
+
+1. Replaces `invokeinterface ` with `invokestatic` at compile time.
+
+2. Generated `Buoy$onProgress` method at compile time to prevent calling interface methods on an null object.
+
+
 ## About me
 
 email : hi4joker@gmail.com

interface-buoy-app/src/main/AndroidManifest.xml

@@ -3,6 +3,7 @@
   package="com.smartdengg.interfacebuoy.sample">
 
   <application
+    android:name=".App"
     android:allowBackup="true"
     android:icon="@mipmap/ic_launcher"
     android:label="@string/app_name"

interface-buoy-app/src/main/java/com/smartdengg/interfacebuoy/sample/App.java

@@ -0,0 +1,17 @@
+package com.smartdengg.interfacebuoy.sample;
+
+import android.app.Application;
+import com.smartdengg.interfacebuoy.compiler.BuoySettings;
+
+/**
+ * 创建时间:  2019/02/18 11:15 <br>
+ * 作者:  SmartDengg <br>
+ * 描述:
+ */
+public class App extends Application {
+
+  @Override public void onCreate() {
+    super.onCreate();
+    BuoySettings.loggable = true;
+  }
+}

interface-buoy-app/src/main/java/com/smartdengg/interfacebuoy/sample/MainActivity.java

@@ -5,7 +5,6 @@
 import android.support.annotation.Nullable;
 import android.util.Log;
 import android.view.View;
-import com.smartdengg.interfacebuoy.compiler.BuoySettings;
 
 /**
  * 创建时间:  2019/01/31 18:02 <br>
@@ -20,7 +19,6 @@ public class MainActivity extends Activity {
   @Override protected void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
-    BuoySettings.loggable = true;
 
     //Test null interface reference
     setCallback(new Callback() {