package test;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class Test {

public static void main(String[] args) {

testDOTALL();

}

public static void testDOTALL() {

String str =

"aaa\nbbb";

String

pattern = ".+";

//

DOTALL

//点匹配全部内容，包括系统换行符

print(str,

pattern, Pattern.DOTALL,

"DOTALL");

// NOT

DOTALL:set flag not is Pattern.DOTALL

//点匹配不全部内容的情况，也就是说系统换行符不会被匹配

print(str,

pattern, Pattern.CASE_INSENSITIVE, "NOT DOT

ALL");

//

UNIX_LINES

//以

\n为行分隔符，这里aaa\n的匹配结果是两行aaa和bbb

print(str,

pattern, Pattern.UNIX_LINES,

"UNIX_LINES");

str =

"aaa\r\nbbb";

//如果指定此模式，window下的行分隔符’\r’也被当作常规字符处理。

print(str,

pattern, Pattern.UNIX_LINES, "UNIX_LINES IN

WINDOWS");

//

COMMENTS

str =

"aaba\r\naab ab\r\nbbb";

pattern =

"aa.+#comment";

//注释模式是从#到末尾都是注释，该正则表达式只编译#之前的字符串作为pattern.

print(str,

pattern, Pattern.COMMENTS,

"COMMENT");// whitespace is

ignored.

//

MULTILINE

pattern =

".+b$";

//多行模式^、$分别表示匹配行首和行尾。

print(str,

pattern, Pattern.MULTILINE,

"NULTILINE");

//

LITERAL

pattern =

"bb";

//将正则表达式中常用的字符视为单个字符处理，比如点(.)在此模式中只匹配点字符，不匹配除点之外的其他字符。

print(str,

pattern, Pattern.LITERAL,

"LITERAL");

// .+is

literal and not as regex pattern

pattern =

".+bb";

print(str,

pattern, Pattern.LITERAL,

"LITERAL");

//如果Unicode的编码和字符的Ascoll码值是一样的，则进行匹配，如A和\u0041

print("AA","\u0041",Pattern.CANON_EQ,"CANON_EQ");

//unicode的匹配中区分大小写

print("aa","\u0041",Pattern.UNICODE_CASE,"UNICODE_CASE");

//unicode的匹配中不区分大小写

print("aa","\u0041",Pattern.UNICODE_CASE|Pattern.CASE_INSENSITIVE,"UNICODE_CASE|CASE_INSENSITIVE");

//只有jdk1.7+才支持，在正则中使用UNICODE_CHARACTOR_CLASS进行匹配，详细信息见文章末尾的列表。

print("aaAB","\\p{Lower}",Pattern.UNICODE_CHARACTER_CLASS,"UNICODE_CHARACTER_CLASS");

print("aaAB","\\p{Upper}",Pattern.UNICODE_CHARACTER_CLASS,"UNICODE_CHARACTER_CLASS");

}

public static void print(String str, String

pattern, int mode, String modeName) {

Pattern p =

Pattern.compile(pattern, mode);

Matcher m =

p.matcher(str);

System.out.println("set pattern

mode:" +

modeName+"

PATTERN:"+pattern);

int i =

0;

while

(m.find()) {

i++;

System.out.println("group(" +

String.valueOf(i) + "):" +

m.group(0));

}

}

}