pdf转为特定分辨率的图片

Someusefuloperationswritteninjavatochangethepageofpdffiletopictures.describe:Sometimesweneedtoextractapageofpdffiletoanewpdffileorchangeeachpagetopictureswithhighqualityorlowquality.Therearetwofilesof".java"inmyproject,oneisnamed"MainEntrance"andanotheroneis