一、包含
正则表达式如下,包含aaa或bbb为例:
^.*(aaa|bbb).*$
测试一下
public static void main(String[] args) {
System.out.println(Pattern.matches("^.*(aaa|bbb).*$", "aaa"));
System.out.println(Pattern.matches("^.*(aaa|bbb).*$", " aaa "));
System.out.println(Pattern.matches("^.*(aaa|bbb).*$", "aabbbddd"));
System.out.println(Pattern.matches("^.*(aaa|bbb).*$", "aabbdd"));
}
结果如下:
true
true
true
false
二、不包含
正则表达式如下,不包含hello为例:
^((?!hello).)*$
测试一下
public static void main(String[] args) {
System.out.println(Pattern.matches("^((?!hello).)*$", "olleh"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeq"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeqhell"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeq hell"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeqh e l l o"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeqhello"));
System.out.println(Pattern.matches("^((?!hello).)*$", "hello"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeq hello"));
System.out.println(Pattern.matches("^((?!hello).)*$", "qeqeq hello asdfsa"));
}
结果如下:
true
true
true
true
true
false
false
false
false
三、以xxx开头
正则表达式如下,以aaa开头:
^aaa.*
测试一下
public static void main(String[] args) {
System.out.println(Pattern.matches("^aaa.*", "aaabbb"));
System.out.println(Pattern.matches("^aaa.*", "aaa bbb"));
System.out.println(Pattern.matches("^aaa.*", " aaa bbb"));
System.out.println(Pattern.matches("^aaa.*", "bbbaaa"));
}
结果如下:
true
true
false
false
四、不以xxx开头
正则表达式如下,不以aaa开头:
^(?!aaa).*$
测试一下
public static void main(String[] args) {
System.out.println(Pattern.matches("^(?!aaa).*$", "aaabbb"));
System.out.println(Pattern.matches("^(?!aaa).*$", "aaa bbb"));
System.out.println(Pattern.matches("^(?!aaa).*$", " aaa bbb"));
System.out.println(Pattern.matches("^(?!aaa).*$", "bbbaaa"));
}
结果如下:
false
false
true
true