JAVA在编写内部类时No enclosing instance of type XXX is accessible. Must qualify原因及解决

秒速五厘米 2024-04-19 15:12 19阅读 0赞

错误信息如下：

No enclosing instance of type Analysis\_IDCard is accessible. Must qualify the allocation with an enclosing instance of type Analysis\_IDCard (e.g. x.new A() where x is an instance of Analysis\_IDCard).

导致的原因为：

package AnalysisNo;
    
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Scanner;
    
    public class Analysis_IDCard {
    	
    	public  class IdInformation{
    	   public  String idnumber;  
    	   public  String birthday;
    	   public  String sex;
    	   
    	   public IdInformation(String idnumber,String birthday,String sex)
    	   {
    		   this.birthday=birthday;
    		   this.idnumber=idnumber;
    		   this.sex=sex;
    	   }
    	    public String getbirthday() {
    	        return birthday;
    	    }
    
    	    public String getidnumber() {
    	        return idnumber;
    	    }
    
    	    public String getsex() {
    	        return sex;
    	    }
    
    	}

在main方法中实例化

IdInformation idinfo= new IdInformation(sIDCard,sdate,nSex);  //这样是不行的

改成

IdInformation idinfo= new Analysis_IDCard().new IdInformation(sIDCard,sdate,nSex); //这样就可以了

网上查阅了资料之后发现是main方法之前是有一个static修饰的，需要在调用之前先实例化父类Analysis\_IDCard，其实错误提示中已经很明显了 （e.g. x.new A() where x is an instance of Analysis\_IDCard）

还有一种方法是给IdInformation内部类加上static修饰符即可。

public class Analysis_IDCard {
    	
    	public  static class IdInformation{

IdInformation idinfo= new IdInformation(sIDCard,sdate,nSex);  //上面加了static这样实例化就行了