(?i) means that the case does not match. Replace both uppercase and lowercase
html = html.replaceAll((<(?i)(|)[^]*/?>)|( )|(')|(/), );System.out.println(html);
(<(?i)(|)[^]*/?>)|( )|(')|(/) -- Match all labels with spaces and quotesIf only part is replaced, make the following modifications
(<(?i)(|)[^]*/?>) --Replace all tags
(<(?i)(p|img)[^]*/?>) --Replace p and img tags
(<(?i)a[^]*/?>) --Replace only the a tag