正则表达式一一种强大而灵活的文本处理工具。
本以后是很简单的一个表达式，却不曾想看了快整整三天时间，各种教程文档，总算摸摸索索懂的了一些，在此也警戒自己，做事情要深入进去
String
- split()方法
我对此方法的理解是，按照正则表达式的规则，切割字符串，比如a1b2c3d使用\d+切割的话，就是把数字切割掉剩余的字符集合。
public class RexDemo {
public static void main(String[] args) {
// test();
// test2();
// test3();
// test4();
// test5();
// test6();
test7();
}
public static String input =
"As long as there is injustice, whenever a\n" +
"Targathian baby cries out, wherever a distress\n" +
"signal sounds among the stars ... We'll be there.\n" +
"This fine ship, and this fine crew ...\n" +
"Never give up! Never surrender!";
private static class Display {
private boolean regexPrinted = false;
private String regex;
Display(String regex) {
this.regex = regex;
}
void display(String message) {
if (!regexPrinted) {
out.println(regex);
regexPrinted = true;
}
out.println(message);
}
}
static void examine(String s, String regex) {
Display d = new Display(regex);
Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(s);
while (m.find())
d.display("find() '" + m.group() +
"' start = " + m.start() + " end = " + m.end());
if (m.lookingAt()) // No reset() necessary
d.display("lookingAt() start = "
+ m.start() + " end = " + m.end());
if (m.matches()) // No reset() necessary
d.display("matches() start = "
+ m.start() + " end = " + m.end());
}
private static void test7() {
for (String in : input.split("\n")) {
out.println("input : " + in);
for(String regex : new String[]{"\\w*ere\\w*", "\\w*ever", "T\\w+", "Never.*?!"})
examine(in, regex);
}
}
static public final String POEM =
"Twas brillig, and the slithy toves\n" +
"Did gyre and gimble in the wabe.\n" +
"All mimsy were the borogoves,\n" +
"And the mome raths outgrabe.\n\n" +
"Beware the Jabberwock, my son,\n" +
"The jaws that bite, the claws that catch.\n" +
"Beware the Jubjub bird, and shun\n" +
"The frumious Bandersnatch.";
private static void test6() {
Matcher m = // (字符)空格（（字符）空格（字符））
Pattern.compile("(?m)(\\S+)\\s+((\\S+)\\s+(\\S+))$")
.matcher(POEM);
while (m.find()) {
out.println(m.group());
}
// while (m.find()) {
//// for (int j = 0; j <= m.groupCount(); j++)
// System.out.println("[" + m.group(1) + "]");
// System.out.println();
// }
}
private static void test5() {
String str = "Everying is full of the linnet wings";
Matcher matcher = Pattern.compile("\\w+").matcher(str);
while (matcher.find()) {
for (int i = 0; i <= matcher.groupCount(); i++) {
out.println(" " + matcher.group());
}
}
}
private static String[] args = {"abcabccabcdefabc", "abc+", "(abc)+", "(abc){2,}"};
private static void test4() {
// out.println("Input :\"" + args[0] + "\"");
for (String arg : args) {
// out.println("Regular expression : \"" + arg + "\"");
out.println("--------------------------------------");
Pattern p = Pattern.compile(arg);
Matcher m = p.matcher(args[0]);
while (m.find()) {
out.println("Match \"" + m.group() + "\" at positions " +
m.start() + " - " + (m.end() - 1));
}
}
}
private static void test3() {
Pattern mp = Pattern.compile("\\d+");
String[] str = mp.split("我的QQ是:456456我的电话是:0532214我的邮箱是:aaa@aaa.com");
String[] split = "我的QQ是:456456我的电话是:0532214我的邮箱是:aaa@aaa.com".split("\\d+");
// out.println(split[0] + " " + split[1] + " " + split[2]);
// boolean matches = Pattern.matches("\\d+", "344e44");
// out.println(matches);
Matcher matcher = mp.matcher("helloworld344");
Boolean pattern = matcher.lookingAt();
Matcher matcher1 = mp.matcher("344helloworld");
Boolean pattern1 = matcher1.lookingAt();
// out.println(pattern + " " + pattern1);
}
private static void test2() {
final String regex = "(\\w+)@(\\w+)\\.(\\w+)";
final String string = "somebody@163.com\n"
+ "somebo@163.com\n"
+ "some@163.com";
final String subst = "*@$1.$2";
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);
// The substituted value will be contained in the result variable
final String result = matcher.replaceAll(subst);
// System.out.println("替换结果: " + result);
String reg = "\\(?0\\d{2}[) -]?\\d{8}";
String rex = "\\(?0\\d{2}[) -]?\\d{8}";
out.println("(010)55859762".matches(reg));
}
private static void test() {
// out.println("-1234".matches("-?\\d+"));
String reg = "^[a-z0-9_-]{3,15}$";
// out.println("12a".matches(reg));
// out.println("1a".matches(reg));
String reg2 = "[1-9][0-9]*";
// out.println("5000".matches(reg2));
String str = "colors";
String str2 = "colours";
String str3 = "colour";
String reg3 = "colou?rs";
// out.println(str.matches(reg3));
// out.println(str2.matches(reg3));
// out.println(str3.matches(reg3));
String reg4 = "/d+/d{10}";
// out.println("15700165675".matches(reg3));
// runoo+b，可以匹配 runoob、runooob、runoooooob 等，+ 号代表前面的字符必须至少出现一次（1次或多次）。
String reg5 = "runao\\*b";
// out.println("runao*b".matches(reg5));
// out.println("runaob".matches(reg5));
// out.println("runaooob".matches(reg5));
String reg6 = "1[0-9]{10}";
// out.println("15700166565".matches(reg6));
String reg7 = "<.*?>";
// out.println("<h1>RUNOOB-菜鸟教程</h1>".matches(reg7));
String Str = "Hello , World .";
String pattern = "(\\w)(\\s+)([.,])";
/**
* String Str = "2008-12-31";
* String pattern = "(\\d{4})-(\\d{2}-(\\d\\d))";
*/
// $0 匹配 `(\w)(\s+)([.,])` 结果为 `o空格,` 和 `d空格.`
System.out.println(Str.replaceAll(pattern, "$0")); // Hello , World .
// $1 匹配 `(\w)` 结果为 `o` 和 `d`
System.out.println(Str.replaceAll(pattern, "$1")); // Hello World
// $2 匹配 `(\s+)` 结果为 `空格` 和 `空格`
System.out.println(Str.replaceAll(pattern, "$2")); // Hell Worl
// $3 匹配 `([.,])` 结果为 `,` 和 `.`
System.out.println(Str.replaceAll(pattern, "$3")); // Hell, Worl.
}
public static String getId(String url) {
Pattern pattern = Pattern.compile("^https?://.+[:\\d+]?+/p/(\\d+)\\??.+$");
Matcher matcher = pattern.matcher(url);
if (!matcher.find()) {
return null;
}
return matcher.group(1);
}
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