我是Java初学者,正在尝试使用IntelliJ运行我的代码,我刚刚将它安装为JDK 1.7的IDE。下面这段代码甚至不能编译,并不断给我错误:

Error: Could not find or load main class libTest

Code

import java.lang.Integer;
import java.lang.String;
import java.lang.System;
import java.util.*;

class book {

    private String name = "trial";
    private int bookCode=1;
    private int issued=0;

     public void Issue(){
         if(issued==0) {
             issued=1;
             System.out.println("You have succesfully issued the book");
         }
         else {
             System.out.println("The book is already issued. Please contact the librarian for further details");
         }
    }

    public int checkCode() {
        return bookCode;
    }

    String readName() {
        return name;
    }

    public void setName(String newName){
        name=newName;
    }

    public void setBookCode(int newCode){
        bookCode=newCode;
    }
}

class library {
    private ArrayList books=new ArrayList();

    public void getList(){
        for(int bk:books){
            String bName=books(bk).readName();
            System.out.println((bk+1)+")  "+bName);
        }
    }
}

public class libTest{
    public static void main(String[] args){
        library newLib= new library();
        System.out.println("code working");
   }
}

有任何改变,我必须在编译器设置??或者是代码。


当前回答

In my case the problem seemed to be related to upgrading IntelliJ. When I did this I overwrote the files from the old IntelliJ with the files from the new IntelliJ (2017 community to 2018 community). After that all of my projects were broken. I tried everything in this thread and none of them worked. I tried upgrading gradle to the latest version (4 to 4.8) and that didn't work. The only thing that worked for me was deleting the entire IntelliJ folder and reinstalling it. All of my projects worked after that.

其他回答

在创建项目时选择maven作为类型 (不要勾选“从原型创建”复选框) 在项目资源管理器中,右键单击src下main下的java 选择新课 使用公共静态void main完成类 从运行菜单中选择运行

In my case, the application runs well when code initially was under /src directory under the project. Later I added /main/java directory after the /src, then "Could not find or load main class ..." error happened. At that time you couldn't add /src/main/java/YourMain.java to the run configuration. What I did was to remove the run configuration, then right click the project->Open Module Settings (or F4 after click the Project panel)->Project Settings->Modules delete (x) the old Content Root and + Add Content Root, choose /src/main/java. Rebuild the project and it runs.

使缓存无效并重新启动IntelliJ,这对我有用。

如果您正在使用gradle,请尝试从命令行通过命令重建项目:

gradle clean build 

您可能指定了一个错误的包,并且包的层次结构也不正确。看下面

在这种情况下,ide会突出显示错误的路径。