这应该可以解决问题：
(?:^|s)'([^']*?)'(?:$|s)
范例：http：//www.regex101.com/r/hG5eE1
在Java（ideone）中：
import java.util.*;import java.lang.*;import java.util.regex.*;class Main { static final String[] testcases = new String[] { "'Tumblr' is an amazing app", "Tumblr is an amazing 'app'", "Tumblr is an 'amazing' app", "Tumblr is 'awesome' and 'amazing' ", "Tumblr's users' are disappointed ", "Tumblr's 'acquisition' complete but users' loyalty doubtful" }; public static void main (String[] args) throws java.lang.Exception { Pattern p = Pattern.compile("(?:^|\s)'([^']*?)'(?:$|\s)", Pattern.MULTILINE); for (String arg : testcases) { System.out.print("Input: "+arg+" -> Matches: "); Matcher m = p.matcher(arg); if (m.find()) { System.out.print(m.group()); while (m.find()) System.out.print(", "+m.group()); System.out.println(); } else { System.out.println("NONE"); } } }}
