java 正则表达式

用到正则时，可以来参考一下，看api最好了，里面都有

public static void main(String[] args) {

//简单认识正则表达式的概念

/*

p("abc".matches("..."));

p("a8729a".replaceAll("\\d", "-"));

Pattern p = Pattern.compile("[a-z]{3}");

Matcher m = p.matcher("fgh");

p(m.matches());

p("fgha".matches("[a-z]{3}"));

*/

 

//初步认识. * + ?

/*

p("a".matches("."));

p("aa".matches("aa"));

p("aaaa".matches("a*"));

p("aaaa".matches("a+"));

p("".matches("a*"));

p("aaaa".matches("a?"));

p("".matches("a?"));

p("a".matches("a?"));

p("214523145234532".matches("\\d{3,100}"));

p("192.168.0.aaa".matches("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}"));

p("192".matches("[0-2][0-9][0-9]"));

*/

 

//范围

/*

p("a".matches("[abc]"));

p("a".matches("[^abc]"));

p("A".matches("[a-zA-Z]"));

p("A".matches("[a-z]|[A-Z]"));

p("A".matches("[a-z[A-Z]]"));

p("R".matches("[A-Z&&[RFG]]"));

*/

 

//认识\s \w \d \

/*

p(" \n\r\t".matches("\\s{4}"));

p(" ".matches("\\S"));

p("a_8".matches("\\w{3}"));

p("abc888&^%".matches("[a-z]{1,3}\\d+[&^#%]+"));

p("\\".matches("\\\\"));

*/

 

//POSIX Style

//p("a".matches("\\p{Lower}"));

 

//boundary

/*

p("hello sir".matches("^h.*"));

p("hello sir".matches(".*ir$"));

p("hello sir".matches("^h[a-z]{1,3}o\\b.*"));

p("hellosir".matches("^h[a-z]{1,3}o\\b.*"));

//whilte lines

p(" \n".matches("^[\\s&&[^\\n]]*\\n$"));

 

p("aaa 8888c".matches(".*\\d{4}."));

p("aaa 8888c".matches(".*\\b\\d{4}."));

p("aaa8888c".matches(".*\\d{4}."));

p("aaa8888c".matches(".*\\b\\d{4}."));

*/

 

//email

//p("[e-mail]".matches("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+"));

 

//matches find lookingAt

/*

Pattern p = Pattern.compile("\\d{3,5}");

String s = "123-34345-234-00";

Matcher m = p.matcher(s);

p(m.matches());

m.reset();

p(m.find());

p(m.start() + "-" + m.end());

p(m.find());

p(m.start() + "-" + m.end());

p(m.find());

p(m.start() + "-" + m.end());

p(m.find());

//p(m.start() + "-" + m.end());

p(m.lookingAt());

p(m.lookingAt());

p(m.lookingAt());

p(m.lookingAt());

*/

 

//replacement

/*

Pattern p = Pattern.compile("java", Pattern.CASE_INSENSITIVE);

Matcher m = p.matcher("java Java JAVa JaVa IloveJAVA you hateJava afasdfasdf");

StringBuffer buf = new StringBuffer();

int i=0;

while(m.find()) {

i++;

if(i%2 == 0) {

m.appendReplacement(buf, "java");

} else {

m.appendReplacement(buf, "JAVA");

}

}

m.appendTail(buf);

p(buf);

*/

 

//group

/*

Pattern p = Pattern.compile("(\\d{3,5})([a-z]{2})");

String s = "123aa-34345bb-234cc-00";

Matcher m = p.matcher(s);

while(m.find()) {

p(m.group());

}

*/

 

//qulifiers

/*

Pattern p = Pattern.compile(".{3,10}+[0-9]");

String s = "aaaa5bbbb68";

Matcher m = p.matcher(s);

if(m.find())

p(m.start() + "-" + m.end());

else 

p("not match!");

*/

 

//non-capturing groups

/*

Pattern p = Pattern.compile(".{3}(?=a)");

String s = "444a66b";

Matcher m = p.matcher(s);

while(m.find()) {

p(m.group());

}

*/

 

//back refenrences

/*

Pattern p = Pattern.compile("(\\d(\\d))\\2");

String s = "122";

Matcher m = p.matcher(s);

p(m.matches());

*/

 

//flags的简写

//Pattern p = Pattern.compile("java", Pattern.CASE_INSENSITIVE);

p("Java".matches("(?i)(java)"));

}

 

public static void p(Object o) {

System.out.println(o);

}