Plug - ins are java libraries that the platform loads in response to user requests for example , when the user opens a java class file , the runtime loads the java editor , or to offer services to other plug - ins for example , swt - the widget toolkit - is a plug - in 插件是java庫,平臺(tái)在響應(yīng)用戶請求(例如,當(dāng)用戶打開一個(gè)java類文件時(shí),運(yùn)行時(shí)裝入java編輯器)或?yàn)槠渌寮峁┓?wù)(例如, swt窗口小控件工具箱就是一個(gè)插件)時(shí)裝入插件。