java对象Integer不能引用传递

 /** 
     * The value of the <code>Integer</code>. 
     * 
     * @serial 
     */  
    private final int value;  
  
    /** 
     * Constructs a newly allocated <code>Integer</code> object that 
     * represents the specified <code>int</code> value. 
     * 
     * @param   value   the value to be represented by the  
     *          <code>Integer</code> object. 
     */  
    public Integer(int value) {  
    this.value = value;  
    }