10. replacement
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //字符串的替换 Pattern p=Pattern.compile("java",Pattern.CASE_INSENSITIVE);//启用不区分大小写的匹配 Matcher m=p.matcher("java Java JAVa JaVa IloveJAVA you hateJava afasdfasdf"); while(m.find()) { p(m.group()); } } public static void p(Object o) { System.out.println(o); } }
输出;
java
Java
JAVa
JaVa
JAVA
Java
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //字符串的替换 Pattern p=Pattern.compile("java",Pattern.CASE_INSENSITIVE);//启用不区分大小写的匹配 Matcher m=p.matcher("java Java JAVa JaVa IloveJAVA you hateJava afasdfasdf"); //全部转换为大写的JAVA p(m.replaceAll("JAVA")); //单数的JAVA串转换为大写的,偶数的JAVA串转换为小写的 } public static void p(Object o) { System.out.println(o); } }
输出:
JAVA JAVA JAVA JAVA IloveJAVA you hateJAVA afasdfasdf
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //字符串的替换 Pattern p=Pattern.compile("java",Pattern.CASE_INSENSITIVE);//启用不区分大小写的匹配 Matcher m=p.matcher("java Java JAVa JaVa IloveJAVA you hateJava afasdfasdf"); //单数的JAVA串转换为大写的,偶数的JAVA串转换为小写的 StringBuffer buf=new StringBuffer(); int i=0; while(m.find()) { i++; if(i%2==0) { m.appendReplacement(buf, "java"); }else { m.appendReplacement(buf, "JAVA"); } } m.appendTail(buf);//添加尾巴 afasdfasdf p(buf); } public static void p(Object o) { System.out.println(o); } }
输出:
JAVA java JAVA java IloveJAVA you hatejava afasdfasdf
11.group
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //分组 Pattern p=Pattern.compile("(\\d{3,5})[a-z]{2}");//3到5位的数字 两位的小写字母 String s="123aa-34345bb-234cc-00"; Matcher m=p.matcher(s); while(m.find()) { p(m.group());//直接打印出整个正则表达式所表示的子串 } } public static void p(Object o) { System.out.println(o); } }
123aa
34345bb
234cc
继续分组
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //分组 Pattern p=Pattern.compile("(\\d{3,5})([a-z]{2})");//3到5位的数字 两位的小写字母 String s="123aa-34345bb-234cc-00"; Matcher m=p.matcher(s); while(m.find()) { p(m.group(1)); } } public static void p(Object o) { System.out.println(o); } }
输出:
123
34345
234
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //分组 Pattern p=Pattern.compile("(\\d{3,5})([a-z]{2})");//3到5位的数字 两位的小写字母 String s="123aa-34345bb-234cc-00"; Matcher m=p.matcher(s); while(m.find()) { p(m.group(2)); } } public static void p(Object o) { System.out.println(o); } }
输出:
aa
bb
cc
14.qulifiers
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //qulifiers Pattern p = Pattern.compile("(.{3,10})[0-9]"); String s = "aaaa5bbbb6"; Matcher m = p.matcher(s); if(m.find()) p(m.start() + "-" + m.end()); else p("not match!"); } public static void p(Object o) { System.out.println(o); } }
输出;
0-10
Possessive修改:
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //qulifiers Pattern p = Pattern.compile("(.{3,10}?)[0-9]"); String s = "aaaa5bbbb6"; Matcher m = p.matcher(s); if(m.find()) p(m.start() + "-" + m.end()); else p("not match!"); } public static void p(Object o) { System.out.println(o); } }
输出:
0-5
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //qulifiers Pattern p = Pattern.compile("(.{3,10}+)[0-9]"); String s = "aaaa5bbbb6"; Matcher m = p.matcher(s); if(m.find()) p(m.start() + "-" + m.end()); else p("not match!"); } public static void p(Object o) { System.out.println(o); } }
输出:
not match!
再度修改:
package com.zzk.cn; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { /** * @param args */ public static void main(String[] args) { //qulifiers Pattern p = Pattern.compile("(.{3,10}+)[0-9]"); String s = "aaaa5bbbb69"; Matcher m = p.matcher(s); if(m.find()) p(m.start() + "-" + m.end()); else p("not match!"); } public static void p(Object o) { System.out.println(o); } }
输出:
0-11
说明:
greedy贪婪的,一次吞进10个字符,最后的字母没有,一看不行,往外吐一个,正则已经匹配了,到此为止发现已经找到了,正则结束。(默认使用greedy)
Reluctant勉强的,往往吃最少的,先吃进3个,发现后面不是数字,仍是a,则再吃一个a,发现后面是5,是数字,就不吃了,正则结束。
Possessive,和贪婪的类似,吃进去不往外吐,都没有的情况下匹配不上。追求效率的时候用。