Java 中replaceAll如何忽略大小写呢?
方式一:在正则表达式前面添加(?i)
- @Test
- public void test_replaceAll33(){
- String input = "I like Java,jAva is very easy and jaVa is so popular.";
- String replacement="cccc";
- System.out.println(input);
- System.out.println(input.replaceAll("(?i)java", replacement));
- }
@Test public void test_replaceAll33(){ String input = "I like Java,jAva is very easy and jaVa is so popular."; String replacement="cccc"; System.out.println(input); System.out.println(input.replaceAll("(?i)java", replacement)); }
测试结果:
方式二:使用Matcher 的appendReplacement 方法
- @Test
- public void test_replaceAll(){
- String input = "I like Java,jAva is very easy and jaVa is so popular.";
- String regex = "java";
- String replacement="cccc";
- StringBuffer sb =replaceAll2(input, regex, replacement);
- System.out.println(input);
- System.out.println(sb);
- }
- /***
- * replaceAll,忽略大小写
- * @param input
- * @param regex
- * @param replacement
- * @return
- */
- public StringBuffer replaceAll2(String input,String regex,String replacement){
- Pattern p = Pattern.compile(regex,Pattern.CASE_INSENSITIVE);
- Matcher m = p.matcher(input);
- StringBuffer sb = new StringBuffer();
- boolean result = m.find();
- while (result)
- {
- m.appendReplacement(sb, replacement);
- result = m.find();
- }
- m.appendTail(sb);
- return sb;
- }
@Test public void test_replaceAll(){ String input = "I like Java,jAva is very easy and jaVa is so popular."; String regex = "java"; String replacement="cccc"; StringBuffer sb =replaceAll2(input, regex, replacement); System.out.println(input); System.out.println(sb); } /*** * replaceAll,忽略大小写 * @param input * @param regex * @param replacement * @return */ public StringBuffer replaceAll2(String input,String regex,String replacement){ Pattern p = Pattern.compile(regex,Pattern.CASE_INSENSITIVE); Matcher m = p.matcher(input); StringBuffer sb = new StringBuffer(); boolean result = m.find(); while (result) { m.appendReplacement(sb, replacement); result = m.find(); } m.appendTail(sb); return sb; }
测试结果:
方式三:使用Matcher 的replaceAll
- /***
- * replaceAll,忽略大小写
- *
- * @param input
- * @param regex
- * @param replacement
- * @return
- */
- public String replaceAll3(String input, String regex, String replacement) {
- Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);
- Matcher m = p.matcher(input);
- String result = m.replaceAll(replacement);
- return result;
- }
- @Test
- public void test_replaceAll3() {
- String input = "I like Java,jAva is very easy and jaVa is so popular.";
- String regex = "java";
- String replacement = "cccc";
- String sb = replaceAll3(input, regex, replacement);
- System.out.println(input);
- System.out.println(sb);
- }
/*** * replaceAll,忽略大小写 * * @param input * @param regex * @param replacement * @return */ public String replaceAll3(String input, String regex, String replacement) { Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE); Matcher m = p.matcher(input); String result = m.replaceAll(replacement); return result; } @Test public void test_replaceAll3() { String input = "I like Java,jAva is very easy and jaVa is so popular."; String regex = "java"; String replacement = "cccc"; String sb = replaceAll3(input, regex, replacement); System.out.println(input); System.out.println(sb); }
测试结果: 参考:http://hw1287789687.iteye.com/blog/2150892