class Cup {
  Cup(int marker) {
    System.out.println("Cup(" + marker + ")");
  }
  void f(int marker) {
    System.out.println("f(" + marker + ")");
  }
}

class Cups {
  static Cup c1;
  static Cup c2;
  static {
    c1 = new Cup(1);
    c2 = new Cup(2);
  }
  Cups() {
    System.out.println("Cups()");
  }
}

public class ExplicitStatic {
  public static void main(String[] args) {
    System.out.println("Inside main()");
    Cups.c1.f(99);  // (1)
  }
  static Cups x = new Cups();  // (2)
  static Cups y = new Cups();  // (2) 
} ///:~

在標記為(1)的行內訪問static對象c1的時候，或在行(1)標記為注釋，同時(2)行不標記成注釋的時候，用于Cups的static初始化模塊就會運行。若(1)和(2)都被標記成注釋，則用于Cups的static初始化進程永遠不會發生。

4. 非靜態實例的初始化
針對每個對象的非靜態變量的初始化，Java 1.1提供了一種類似的語法格式。下面是一個例子：


//: Mugs.java
// Java 1.1 "Instance Initialization"

class Mug {
  Mug(int marker) {
    System.out.println("Mug(" + marker + ")");
  }
  void f(int marker) {
    System.out.println("f(" + marker + ")");
  }
}

public class Mugs {
  Mug c1;
  Mug c2;
  {
    c1 = new Mug(1);
    c2 = new Mug(2);
    System.out.println("c1 & c2 initialized");
  }
  Mugs() {
    System.out.println("Mugs()");
  }
  public static void main(String[] args) {
    System.out.println("Inside main()");
    Mugs x = new Mugs();
  }
} ///:~

大家可看到實例初始化從句：


  {
    c1 = new Mug(1);
    c2 = new Mug(2);
    System.out.println("c1 & c2 initialized");
  }