java无法找到或加载主类com。约翰纳森·马克史密斯。格雷德尔。你好世界

Question

我使用以下命令编译并运行helloworld jar文件，但出现了一个错误

Could not find or load main class com.johnathanmarksmith.gradle.HelloWorld

谁能告诉我怎么修吗

mkdir runnablejar
cd runnablejar
mkdir -p src/main/java
mkdir -p src/main/resources
mkdir -p src/test/java
mkdir -p src/test/resources
mkdir -p com/johnathanmarksmith/gradle
vi com/johnathanmarksmith/gradle/HelloWorld.java
(insert)
package com.johnathanmarksmith.gradle;
public class HelloWorld
{
    public static void main(String[] args) 
    { 
        System.out.println("Hello World!"); 
    } 
}
vi build.gradle
apply plugin: 'java' 

 jar { 
        baseName = 'smith' 
        version = '1.0' 
        manifest { 
                     attributes 'Main-Class': 'com.johnathanmarksmith.gradle.HelloWorld' } 
     }
gradle build
java -jar ./build/libs/smith-1.0.jar

我的结果是成功

:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:jar
:assemble
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:test UP-TO-DATE
:check UP-TO-DATE
:build

BUILD SUCCESSFUL

Answer 1

问题是您在项目的根目录下创建了包文件夹，而不是在src/main/java下

应该是：

mkdir -p src/main/java/com/johnathanmarksmith/gradle
vi src/main/java.com/johnathanmarksmith/gradle/HelloWorld.java

现在它应该可以正常工作了