kotlin中拓展方法反编译java代码结果

1. 简单代码

package kotlinTest.extensionmethod

class ExtensionMethodTest {

}

fun String.abc() {
    println("abc")
}

fun main() {
    "a".abc()
}

2. 用as 反编译成java 代码之后的结果

// ExtensionMethodTest.java
package kotlinTest.extensionmethod;

import kotlin.Metadata;

@Metadata(
   mv = {1, 6, 0},
   k = 1,
   xi = 2,
   d1 = {"\u0000\f\n\u0002\u0018\u0002\n\u0002\u0010\u0000\n\u0002\b\u0002\u0018\u00002\u00020\u0001B\u0005¢\u0006\u0002\u0010\u0002¨\u0006\u0003"},
   d2 = {"LkotlinTest/extensionmethod/ExtensionMethodTest;", "", "()V", "com.free.learn.main"}
)
public final class ExtensionMethodTest {
}
// ExtensionMethodTestKt.java
package kotlinTest.extensionmethod;

import kotlin.Metadata;
import kotlin.jvm.internal.Intrinsics;
import org.jetbrains.annotations.NotNull;

@Metadata(
   mv = {1, 6, 0},
   k = 2,
   xi = 2,
   d1 = {"\u0000\u000e\n\u0000\n\u0002\u0010\u0002\n\u0000\n\u0002\u0010\u000e\n\u0000\u001a\u0006\u0010\u0000\u001a\u00020\u0001\u001a\n\u0010\u0002\u001a\u00020\u0001*\u00020\u0003¨\u0006\u0004"},
   d2 = {"main", "", "abc", "", "com.free.learn.main"}
)
public final class ExtensionMethodTestKt {
   public static final void abc(@NotNull String $this$abc) {
      Intrinsics.checkNotNullParameter($this$abc, "$this$abc");
      String var1 = "abc";
      System.out.println(var1);
   }

   public static final void main() {
      abc("a");
   }

   // $FF: synthetic method
   public static void main(String[] var0) {
      main();
   }
}

2、分析

看这是生成了类的一个静态方法，this 当做参数传入