Examples of the application of Java's regular expressions (see Java's application of the regular Expressions): Test code package test; /** * In string matches () method, the split () method uses regular expressions . * @author fhd001 */ public class regextest { public Static void main (String[] args) { /* * Ordinary characters */ String str1 = "abc45abc345"; String[]arr1 = str1.split ("abc"); for (STRING STRING : ARR1) { system.out.print (string+ "-->"); }         SYSTEM.OUT.PRINTLN (); /* * Simple escape characters * You must use a double backslash when you are using Java to relay the literal characters. Two slash escape into a slash, * escape those special characters with this slash character . */ String str2 = ^$ () []{}.? +*|"; boolean flag = str2.matches ("//^//$ //(//)//[//]//{//}//.//?//+//*//|");      SYSTEM.OUT.PRINTLN (flag); /* * Escape Character /q.../e . */ String str3 = ^$ () []{}.? +*|99999 "; boolean flag2 = Str3.matches ("//q^$ () []{}.? +*|//E//D{5} "); system.out.println (FLAG2); /* * Character Set */ String str4 = "dfddri334"; boolean flag4 = str4.matches (". +"); system.out.println (FLAG4); String str5 = "#$%^* ())%"; boolean flag5 = str5.matches ("//W{9}"); system.out.println (FLAG5); string str6 = "4GFFMDKEKRHHR"; boolean flag6 = str6.matcheS ("//w+"); system.out.println (FLAG6); string str7 = "fjfdke eett "; boolean flag7 = str7.matches ("//w+//s+//w{4}//s?"); system.out.println (Flag7); String str8 = " erefff "; boolean flag8 = str8.matches ("//s+//s+//s+"); system.out.println (FLAG8); string str9 = "456776888"; boolean flag9 = str9.matches ("//d+"); system.out.println (FLAG9); String str10 = "rtydfgrgwvr "; boolean flag10 = str10.matches ("//D+"); system.out.println (FLAG10); /* * custom character set [ ] */ String str11 = "fdfeetg 34566"; boolean flag11 = str11.matches ("[fdetg]+//s+[3-6]+"); system.out.println (flag11); String str12 = "rtyuie 5768"; boolean flag12 = str12.matches ("[^abcdf]+ s+[^1234]+ "); system.out.println (FLAG12); &nbsP /* * matching number qualifier */ //Greedy mode String str13 = " ytreggcv454444444333 "; boolean flag13 = str13.matches ("//w{20}"); system.out.println ( FLAG13); boolean flag14 = str13.matches ("//w{10,21}"); system.out.println (FLAG14); boolean flag15 = str13.matches ("//w{18,}");         SYSTEM.OUT.PRINTLN (FLAG15); String str14 = "4"; boolean flag16 = str14.matches ("//d?"); system.out.println (FLAG16); string str15 = "DDCVGT"; boolean Flag17 = str15.matches ("//d+//d?"); system.out.println (flag17); string str16 = "e33tf44t44t"; boolean flag18 = str16.matches ("//w+//W*"); system.out.println (flag18); //(just one example) String str17 = "34567ghjkkld"; boolean flag19 = str17.matches ("//d{2,7}"? w{8,11} "); system.out.println (flag19); //occupancy mode (one case only) String str18 = " 22222DDDDD "; &NBSp; boolean flag20 = str18.matches ("//d{2,5}+//w{6}"); system.out.println (FLAG20); /* * character Boundaries */ string str19 = "A444545rot44tm"; boolean flag21 = str19.matches ("^a//w+m$"); System.out.println (flag21); /* * Selection Expressions xxx | xxx */         STRING STR20 = "ABC123ABC"; boolean flag22 = str20.matches ("(abc|123) {3}"); System.out.println (flag22); /* * Group ( ) . * above modifiers are decorated for one character. If you want to make a set of characters * decoration to be used () */ &Nbsp; string str21 = "123qwe123qwe"; boolean flag23 = str21.matches ("(123qwe) {2}");         SYSTEM.OUT.PRINTLN (flag23); /* * [] in the intersection and the set */ String str22 = "abcdefgh1234567"; boolean flag24 = str22.matches ("[a-z1-9]+"); //Collection System.out.println (fLAG24); boolean flag25 = str22.matches ("[a-z1-9&&[a-h1-7]]+"); //intersection system.out.println (flag25); } }
Result code -->45-->345--> true true true True true true true true true true true true true true true true true false true true true true True