Java 错误 - 内部类中的非法静态声明

Error - Illegal static declaration in inner class

提问by user2898828

What does this mean?

这是什么意思？

Illegal static declaration in inner class Mobile.mymobile
  modifier 'static' is only allowed in constant variable declarations
Line 75,  public static void main(String[] args) {  

My code:

我的代码：

/**
 * to write a simple java class Mobile that models a mobile phone.
 * 
 * @author (jamal) 
 * @version (14/10/13)
 */
public class Mobile
{
    // type of phone
    private String phonetype;
    // size of screen in inches
    private int screensize;
    // menory card capacity
    private int  memorycardcapacity;
    // name of present service provider
    private String serviceprovider;
    // type of contract with service provider
    private int typeofcontract;
    // camera resolution in megapixels
    private int cameraresolution;
    // the percentage of charge left on the phone
    private int checkcharge;
    // wether the phone has GPS or not
    private String GPS;
    // instance variables - replace the example below with your own
    private int x;

    // The constructor method

    public Mobile(String mobilephonetype, int mobilescreensize,
        int mobilememorycardcapacity,int mobilecameraresolution,
        String mobileGPS, String newserviceprovider) {
        this.phonetype =  mobilephonetype;
        this.screensize = mobilescreensize;
        this.memorycardcapacity = mobilememorycardcapacity;
        this.cameraresolution = mobilecameraresolution;
        this.GPS = mobileGPS;

        // you do not use this ones during instantiation,you can remove them if you do not need or assign them some  default values 
        //this.serviceprovider = newserviceprovider;
        //this.typeofcontract = 12;
        //this.checkcharge = checkcharge;

        Mobile samsungPhone = new Mobile(
            "Samsung" // String mobilephonetype
        ,   1024      // int mobilescreensize 
        ,   2         // int mobilememorycardcapacity 
        ,   8         // int mobilecameraresolution 
        ,   "GPS"     // String mobileGPS
        ,   "verizon" // String newserviceprovider 
        );

        //typeofcontract = 12;
        //checkcharge = checkcharge;
    }

    // A method to display the state of the object to the screen
    public void displayMobileDetails() {
        System.out.println("phonetype: " + phonetype);
        System.out.println("screensize: " + screensize);
        System.out.println("memorycardcapacity: " + memorycardcapacity);
        System.out.println("cameraresolution: " + cameraresolution);
        System.out.println("GPS: " + GPS);
        System.out.println("serviceprovider: " + serviceprovider);
        System.out.println("typeofcontract: " + typeofcontract);
    }

    /**
     * The mymobile class implements an application that
     * simply displays "new Mobile!" to the standard output.
     */
    public class mymobile {
        public static void main(String[] args) {
            System.out.println("new Mobile!"); //Display the string.
        }
    }

    public static void buildPhones(){
        Mobile Samsung = new Mobile("Samsung", 3, 4, 8, "verizon", "GPS");
        Mobile Blackberry = new Mobile("Blackberry", 3, 4, 8, "verizon", "GPS");   
    }

    public static void main(String[] args) {
        buildPhones();
    }  
}

回答by Rajnish Mishra

You can not have a public and static field inside a static inner class

静态内部类中不能有公共和静态字段

See the Inner Class Documentation here

在此处查看内部类文档

回答by jantzl

This is well answered here: Modifier static is only allowed in constant variable declarations

这在这里得到了很好的回答： Modifier static is only allowed in constant variable declaration

In short: because mymobile is a subclass of Mobile, it cannot have a static member (the main function).

简而言之：因为 mymobile 是 Mobile 的子类，所以它不能有静态成员（主函数）。

If you can move mymobile class out of Mobile, the error should clear.

如果您可以将 mymobile 类移出 Mobile，则错误应该会清除。

回答by Niks

In Java it's not possible to add two public class in one file.you need to changemymobileclass modifier default like class mymobileor you can change Mobileclass modifier to default like class Mobile.

在 Java 中，不可能在一个文件中添加两个公共类。您需要更改mymobile类修饰符 default likeclass mymobile或者您可以将Mobile类修饰符更改为 default like class Mobile。