regex in java

Pattern类：
例子：
        Pattern pattern = Pattern.compile("[,\\s]+");
        String[] result = pattern.split("one two three,four,five, six");
        for(int i = 0; i<result.length; i++){
            System.out.println(result[i]);
        }
输出结果是：
one
two
three
four
five
six
Pattern类的静态方法compile用来编译正则表达式，在此[,\\s]+表示若干个","或者若干个空格匹配
split方法使用正则匹配将字符串切割成各子串并且返回

Matcher类：
注意，Matcher的获得是通过Pattern.matcher(CharSequence charSequence);输入必须是实现了CharSequence接口的类
常用方法：
matches()判断整个输入串是否匹配，整个匹配则返回true
例如下面会输出true
        String str1 = "hello";
        Pattern pattern1 = Pattern.compile("hello");
        Matcher matcher1 = pattern1.matcher(str1);
        System.out.println(matcher1.matches());

lookingAt()从头开始寻找，找到匹配则返回true
例如下面会输出true
        String str2 = "hello yangfan!";
        Pattern pattern2 = Pattern.compile("hello");
        Matcher matcher2 = pattern2.matcher(str2);
        System.out.println(matcher2.lookingAt());

find()扫描输入串，寻找下一个匹配子串，存在则返回true
例如下面将会将所有no替换成yes
        Pattern pattern = Pattern.compile("no");
        Matcher matcher = pattern.matcher("Does jianyue love yangfan? no;" +
                "Does jianyue love yangfan? no;Does jianyue love yangfan? no;");
        StringBuffer sb = new StringBuffer();
        boolean find = matcher.find();
        while(find){
            matcher.appendReplacement(sb, "yes");
            find = matcher.find();
        }
        matcher.appendTail(sb);
        System.out.println(sb.toString());