// 重構(gòu)前
Arrays.asList("apple", "lemon", "banana");
// 重構(gòu)后
List<String> fruits = Arrays.asList("apple", "lemon", "banana");

// 重構(gòu)前
public double getArea(double r) {
  return 3.14 * r * r;
}
// 重構(gòu)后
private static final double PI = 3.14;
public double getArea(double r) {
  return PI * r * r;
}

// 重構(gòu)前
public void method() {
  int height = 1;
  int width = 2;
  int area = height * width;
}
// 重構(gòu)后
public void method() {
  int height = 1;
  int width = 2;
  int area = getArea(height, width);
}
private int getArea(int height, int width) {
  return height * width;
}

// 重構(gòu)前
private static final double PI = 3.14;
public double getArea(double r) {
  return PI * r * r;
}
// 重構(gòu)后
private static final double PI = 3.14;
public double getArea(double r) {
  return 3.14 * r * r;
}

// 重構(gòu)前
public void method() {
  int height = 1;
  int width = 2;
  int area = getArea(height, width);
}
private int getArea(int height, int width) {
  return height * width;
}
// 重構(gòu)后
public void method() {
  int height = 1;
  int width = 2;
  int area = height * width;
}

// 重構(gòu)前
public class Clazz {
  public Interface method() {
    final boolean isValid = true;
    return new Interface() {
      public boolean isValid() {
        return isValid;
      }
    };
  }
}
// 重構(gòu)后
public class Clazz {
  private final class MyInterface extends Interface {
    private final boolean isValid;
    private MyInterface(boolean isValid) {
      this.isValid = isValid;
    }
    public boolean isValid() {
      return isValid;
    }
  }
  public Interface method() {
    final boolean isValid = true;
    return new MyInterface(isValid);
  }
}

// 重構(gòu)前
Runnable runnable = () -> {
  // do something
};
// 重構(gòu)后
Runnable runnable = new Runnable() {
  @Override
  public void run() {
    // do something
  }
};

// 重構(gòu)前
public void order(String[] books) {
  for (int i = 0; i < books.length; i++) {
    // do something
  }
}
// 重構(gòu)后
public void order(String[] books) {
  for (String book : books) {
    // do something
  }
}

// 重構(gòu)前
public class Foo {
  // ...
}
public void myMethod() {
  Foo myClass = new Foo();
}
// 重構(gòu)后
public class Bar {
  // ...
}
public void myMethod() {
  Bar myClass = new Bar();
}