Java子類實(shí)例化總是默認(rèn)調(diào)用父類的無參構(gòu)造操作

package classTest;
class Father {
 public Father(){
 System.out.println("父類的無參構(gòu)造方法");

 }
 public Father(int a ) {
 System.err.println("父類的有參構(gòu)造方法"+a);
 } 
}
class Son extends Father{
 public Son() {
 System.out.println("子類中的無參構(gòu)造方法");
 }
 public Son(int a ) {
  System.out.println("子類中的有參構(gòu)造方法"+a);
 } 
}

public class TestExecute {
 public static void main(String[] args) {
 Son s = new Son();
 System.out.println("---------------");
 Son a = new Son(5); 
 }
}

class SuperClass {
 private int n;
 SuperClass(){ //父類的無參構(gòu)造器
  System.out.println("SuperClass()");
 }
 SuperClass(int n) { //父類的帶參構(gòu)造器
  System.out.println("SuperClass(int n)");
  this.n = n;
 }
}
class SubClass extends SuperClass{ 
 private int n;
 
 SubClass(){ //子類的無參構(gòu)造器
  super(300);//調(diào)用父類的帶參構(gòu)造器，super(300)相當(dāng)于SuperClass(300)
  System.out.println("SubClass");
 } 
 
 public SubClass(int n){ //子類的帶參構(gòu)造器
  System.out.println("SubClass(int n):"+n);
  this.n = n;
 }
}
public class TestSuperSub{
 public static void main (String args[]){
  SubClass sc = new SubClass();
  SubClass sc2 = new SubClass(200); 
 }
}

SuperClass(int n)
SubClass
SuperClass()
SubClass(int n):200