java程序猿人生第二步：hello world

本是古典何须时尚 2022-04-24 06:48 189阅读 0赞

[https://blog.csdn.net/persistencegoing/article/details/84376427][https_blog.csdn.net_persistencegoing_article_details_84376427]

配置好jdk环境后就可以敲代码了.

集成[开发环境][Link 1]（[IDE][]，Integrated Development Environment ）是用于提供程序开发环境的应用程序，一般包括代码编辑器、[编译器][Link 2]、[调试][Link 3]器和[图形用户界面][Link 4]等工具。集成了代码编写功能、分析功能、[编译][Link 5]功能、调试功能等一体化的开发软件服务套。所有具备这一特性的软件或者软件套（组）都可以叫集成开发环境。

首先新手推荐使用IDE：eclipse和idea,可以先用eclipse,用过之后再学idea，这样你就知道哪个好用了，IDE可以理解为敲代码的软件工具。

eclipse的下载地址：[https://www.eclipse.org/downloads/][https_www.eclipse.org_downloads]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70][]

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下载后默认安装java相关的

然后新建eclipse项目空间

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 2][]

create a new java project,新建一个java项目

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 3][]

选择finish

打开项目，鼠标选择src,右键new,选择package,新建包

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 4][]

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更改名字com.first.project，记得是英文符号(  .  )

**package的名字都是小写**

**![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 6][]**

右键包名，new，选择class

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 7][]

class的名字首字母大写，必须驼峰命名法（两个单词首字母都要大写）

下面的打钩，自动生成main主方法（程序入口）

在main方法下面打

System.out.println("hello world");

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 8][]

红色地方有个\*号，表示没有保存，如果断电可能你未保存的东西就没有了，所以经常要有保存的习惯，ctrl+s是快捷保存

然后按F11，运行代码

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlcnNpc3RlbmNlZ29pbmc_size_16_color_FFFFFF_t_70 9][]

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**eclipse操作的快捷键：**[https://blog.csdn.net/persistencegoing/article/details/89379359][https_blog.csdn.net_persistencegoing_article_details_89379359]

**下一篇： **

[https://blog.csdn.net/persistencegoing/article/details/89875894][https_blog.csdn.net_persistencegoing_article_details_89875894]

[https_blog.csdn.net_persistencegoing_article_details_84376427]: https://blog.csdn.net/persistencegoing/article/details/84376427
[Link 1]: https://baike.baidu.com/item/%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83
[IDE]: https://baike.baidu.com/item/IDE
[Link 2]: https://baike.baidu.com/item/%E7%BC%96%E8%AF%91%E5%99%A8/8853067
[Link 3]: https://baike.baidu.com/item/%E8%B0%83%E8%AF%95
[Link 4]: https://baike.baidu.com/item/%E5%9B%BE%E5%BD%A2%E7%94%A8%E6%88%B7%E7%95%8C%E9%9D%A2/3352324
[Link 5]: https://baike.baidu.com/item/%E7%BC%96%E8%AF%91/1258343
[https_www.eclipse.org_downloads]: https://www.eclipse.org/downloads/
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[https_blog.csdn.net_persistencegoing_article_details_89379359]: https://blog.csdn.net/persistencegoing/article/details/89379359
[https_blog.csdn.net_persistencegoing_article_details_89875894]: https://blog.csdn.net/persistencegoing/article/details/89875894