java - 错误:找不到或加载主类应用程序

有人可以告诉我如何在此代码上运行main方法吗？
我想检查是否存在任何编译时错误或运行时错误，但我收到此错误消息“找不到或加载主类应用程序”。

class Book {
private static int internalID = 0;
private String isbn;
private int myID;

public Book(String isbnP) {
    if (isbnP == null) {
        throw new IllegalArgumentException("null ISBN not accepted");
    }
    isbn = isbnP;
    myID = internalID++;
}

public String getBookinfo() {
    return isbn;
}

public String toString() {
    return "<" + myID + "," + isbn + ">";
}
// To Do: Override Object.equals()
// Two objects are equal iff isbn of the two books are same

}

class ComSBook extends Book {
private String category;

public ComSBook(String isbnP, String catP) {
    super(isbnP);
    category = catP;
}

@override
public String getBookInfo() {
    return "ComS " + category + " " + super.getBookinfo();
}
}

class NetworkBook extends ComSBook {
private boolean isWithCD;

public NetworkBook (String isbnP, boolean withCD){
    super(isbnP,"Network");
    isWithCD = withCD;
}
@override
public String getBookInfo(){
    return super.getBookInfo() + " withCD: " + isWithCD;
}
}


class ReviewPolymorp{
public static void main(String[] args){
    Book abook = new Book("A-1");
    Book bbook = new Book("B-1");
    ComSBook csbook = new ComSBook("C-11", "General");
    NetworkBook netbook = new NetworkBook("N-11", true);

    System.out.println(abook);
    System.out.println(bbook);
    System.out.println(csbook);
    System.out.println(netbook);

    abook = csbook;
    System.out.println(abook.getBookinfo());

    bbook = netbook;
    System.out.println(bbook.getBookinfo());

    netbook = (NetworkBook) bbook;
    System.out.println(netbook.getBookinfo());

    netbook = (NetworkBook) csbook;
    System.out.println(netbook.getBookinfo());

    netbook = csbook;

}
}

最佳答案

您的文件应该是ReviewPolymorp.java，而class ReviewPolymorp{应该是public，因为它是使用main方法的程序的启动点

您可能还需要检查项目中的Main类是否为ReviewPolymorp。我只知道如何在Netbeans中做到这一点


右键单击项目
选择属性
点击运行
确保您的ReviewPolymorp i Main Class具有完全限定的名称，例如mypackage.ReviewPolymorp
然后重建您的项目