标题 在JAVA中使用正则表达式 leshui(原作)
关键字 正则表达式
在JAVA中使用正则表达式 jdk1.4中加入了java.util.regex包提供对正则表达式的支持。而且Java.lang.String类中的replaceAll和split函数也是调用的正则表达式来实现的。 正则表达式对字符串的操作主要包括:字符串匹配,指定字符串替换,指定字符串查找和字符串分割。下面就用一个例子来说明这些操作是如何实现的:<%@ page import="java.util.regex.*"%><% Pattern p=null; //正则表达式 Matcher m=null; //操作的字符串 boolean b; String s=null; StringBuffer sb=null; int i=0; //字符串匹配,这是不符合的 p = Pattern.compile("a*b"); m = p.matcher("baaaaab"); b = m.matches(); out.println(b+"<br>");//字符串匹配,这是符合的 p = Pattern.compile("a*b"); m = p.matcher("aaaaab"); b = m.matches(); out.println(b+"<br>");//字符串替换 p = Pattern.compile("ab"); m = p.matcher("aaaaab"); s = m.replaceAll("d"); out.println(s+"<br>"); p = Pattern.compile("a*b"); m = p.matcher("aaaaab"); s = m.replaceAll("d"); out.println(s+"<br>"); p = Pattern.compile("a*b"); m = p.matcher("caaaaab"); s = m.replaceAll("d"); out.println(s+"<br>");//字符串查找 p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); i=0; p = Pattern.compile("cat"); m = p.matcher("one cat two ca tsi nthe yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); p=m.pattern(); m = p.matcher("bacatab"); b = m.matches(); out.println(b+"<br>"); s = m.replaceAll("dog"); out.println(s+"<br>"); i=0; p = Pattern.compile("(fds){2,}"); m = p.matcher("dsa da fdsfds aaafdsafds aaf"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "<font color=\"red\">cat</font>"); }m.appendTail(sb);out.println(sb.toString()+"<br>");String aa=sb.toString();out.println(aa+"<br>");//字符串分割 p = Pattern.compile("a+"); String[] a=p.split("caaaaaat"); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile("a+"); a=p.split("c aa aaaa t",0); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile(" +"); a=p.split("c aa aaaa t",0); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile("\\+"); a=p.split("dsafasdfdsafsda+dsagfasdfa+sdafds"); out.println(a.length+"<br>"); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); }%>
关键字 正则表达式
在JAVA中使用正则表达式 jdk1.4中加入了java.util.regex包提供对正则表达式的支持。而且Java.lang.String类中的replaceAll和split函数也是调用的正则表达式来实现的。 正则表达式对字符串的操作主要包括:字符串匹配,指定字符串替换,指定字符串查找和字符串分割。下面就用一个例子来说明这些操作是如何实现的:<%@ page import="java.util.regex.*"%><% Pattern p=null; //正则表达式 Matcher m=null; //操作的字符串 boolean b; String s=null; StringBuffer sb=null; int i=0; //字符串匹配,这是不符合的 p = Pattern.compile("a*b"); m = p.matcher("baaaaab"); b = m.matches(); out.println(b+"<br>");//字符串匹配,这是符合的 p = Pattern.compile("a*b"); m = p.matcher("aaaaab"); b = m.matches(); out.println(b+"<br>");//字符串替换 p = Pattern.compile("ab"); m = p.matcher("aaaaab"); s = m.replaceAll("d"); out.println(s+"<br>"); p = Pattern.compile("a*b"); m = p.matcher("aaaaab"); s = m.replaceAll("d"); out.println(s+"<br>"); p = Pattern.compile("a*b"); m = p.matcher("caaaaab"); s = m.replaceAll("d"); out.println(s+"<br>");//字符串查找 p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); i=0; p = Pattern.compile("cat"); m = p.matcher("one cat two ca tsi nthe yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); p=m.pattern(); m = p.matcher("bacatab"); b = m.matches(); out.println(b+"<br>"); s = m.replaceAll("dog"); out.println(s+"<br>"); i=0; p = Pattern.compile("(fds){2,}"); m = p.matcher("dsa da fdsfds aaafdsafds aaf"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "dog"); i++; } m.appendTail(sb); out.println(sb.toString()+"<br>"); out.println(i+"<br>"); p = Pattern.compile("cat"); m = p.matcher("one cat two cats in the yard"); sb = new StringBuffer(); while (m.find()) { m.appendReplacement(sb, "<font color=\"red\">cat</font>"); }m.appendTail(sb);out.println(sb.toString()+"<br>");String aa=sb.toString();out.println(aa+"<br>");//字符串分割 p = Pattern.compile("a+"); String[] a=p.split("caaaaaat"); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile("a+"); a=p.split("c aa aaaa t",0); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile(" +"); a=p.split("c aa aaaa t",0); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); } p = Pattern.compile("\\+"); a=p.split("dsafasdfdsafsda+dsagfasdfa+sdafds"); out.println(a.length+"<br>"); for(i=0;i<a.length;i++) { out.println(a[i]+"<br>"); }%>
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