今天在编译Java程序的时候出现以下错误: No enclosing instance of type Main is accessible. Must qualify the allocation with an enclosing instance of type Main (e.g. x.new A() where x is an instance of Main). 我原来编写的源代码是这样的: publ

今天在编译Java程序的时候出现以下错误:

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


我原来编写的源代码是这样的:

public class Main
{
class Dog //定义一个“狗类”
{
private String name;
private int weight;
public Dog(String name, int weight)
{
this.setName(name);
this.weight = weight;
}
public int getWeight()
{
return weight;
}
public void setWeight(int weight)
{this.weight = weight;}
public void setName(String name)
{this.name = name;}
public String getName()
{return name;}
}
public static void main(String[] args)
{
Dog d1 = new Dog("dog1",1);

}
}

出现这个错误的时候,我一直不太理解。

在借鉴别人的解释之后才恍然大悟。

在代码中,我的Dog类是定义在Main中的内部类。Dog内部类是动态的内部类,而我的main方法是static静态的。

就好比静态的方法不能调用动态的方法一样。

有两种解决办法:

第一种:

将内部类Dog定义成静态static的类。

第二种:

将内部类Dog在Main类外边定义。


修改后的代码:

第一种:

public class Main 
{
	public static class Dog 
	{
		private String name;
		private int weight;
		public Dog(String name, int weight) 
		{
			this.setName(name);
			this.weight = weight;
		}
		public int getWeight() 
		{
			return weight;
		}
		public void setWeight(int weight) 
		{this.weight = weight;}
		public void setName(String name)
		{this.name = name;}
		public String getName() 
		{return name;}
	}
	public static void main(String[] args)
	{
		Dog d1 = new Dog("dog1",1);	
	}
}
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第二种:

public class Main 
{
	public static void main(String[] args)
	{
		Dog d1 = new Dog("dog1",1);	
	}
}

class Dog 
{
		private String name;
		private int weight;
		public Dog(String name, int weight) 
		{
			this.setName(name);
			this.weight = weight;
		}
		public int getWeight() 
		{
			return weight;
		}
		public void setWeight(int weight) 
		{this.weight = weight;}
		public void setName(String name)
		{this.name = name;}
		public String getName() 
		{return name;}
}
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09-14 22:39