Class B extends Class A
当我们new B()时，类加载器自动加载A的代码

public class ClassInit {

  /**
   * @Title:       main
   * @Description:   类初始化顺序测试
   * @param:       @param args  
   * @return:     void  
   * @throws
   */
  public static void main(String[] args) {
    // TODO Auto-generated method stub    
    new B();
  }

}

class A {
  static{
    System.out.println("A的static代码块...");
  }
  public String s1 = prtString("A的成员变量...");
  public static String s2 = prtString("A的static变量...");
  public A(){
    System.out.println("A的构造函数...");
  }

  public static String prtString(String str) {
    System.out.println(str);
    return null;
  }
}

class B extends A{
  public String ss1 = prtString("B的成员变量...");
  public static String ss2 = prtString("B的static变量...");
  public B(){
    System.out.println("B的构造函数...");
  }
  private static A a = new A();
  static{
    System.out.println("B的static代码块...");
  }
  {
    System.out.println("代码块...");
  }  
}