blocks|key|1542972|text|the+answer+by+Dave+L.的一个问题是当s2包含\d等正则表达式标记时。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1542973|您希望在s2上调用Pattern.quote()：|1542974|Pattern.compile(Pattern.quote(s2),+Pattern.CASE_INSENSITIVE).matcher(s1).find();|code-block|syntax|javascript|1542975|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/86780/is-the-contains-method-in-java-lang-string-case-sensitive/86832#86832^0|W|2|0|L|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|6|7|10|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|11|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

One problem with <a href="https://stackoverflow.com/questions/86780/is-the-contains-method-in-java-lang-string-case-sensitive/86832#86832">the answer by Dave L.</a> is when s2 contains regex markup such as <code>\d</code>, etc.

You want to call Pattern.quote() on s2:

<pre><code>Pattern.compile(Pattern.quote(s2), Pattern.CASE_INSENSITIVE).matcher(s1).find();
</code></pre>

blocks|key|1543163|text|您可以使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1543164|org.apache.commons.lang3.StringUtils.containsIgnoreCase("AbBaCca",+"bac");|code-block|syntax|javascript|1543165|对于这类事情，Apache+Commons库非常有用。这个特殊的表达式可能比正则表达式更好，因为正则表达式在性能方面总是很昂贵。|offset|length|1543166|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Apache_Commons^0|0|0|7|E|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

You can use 

<pre><code>org.apache.commons.lang3.StringUtils.containsIgnoreCase("AbBaCca", "bac");
</code></pre>

The <a href="https://en.wikipedia.org/wiki/Apache_Commons" rel="noreferrer">Apache Commons</a> library is very useful for this sort of thing. And this particular one may be better than regular expressions as regex is always expensive in terms of performance.

blocks|key|1758038|text|一种更简单的方法(不用担心模式匹配)是将两个String都转换为小写：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1758039|String+foobar+=+"fooBar";
String+bar+=+"FOO";
if+(foobar.toLowerCase().contains(bar.toLowerCase())+{
++++System.out.println("It's+a+match!");
}|code-block|syntax|javascript|1758040|entityMap^0|M|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

A simpler way of doing this (without worrying about pattern matching) would be converting both <code>String</code>s to lowercase:

<pre><code>String foobar = "fooBar";
String bar = "FOO";
if (foobar.toLowerCase().contains(bar.toLowerCase()) {
 System.out.println("It's a match!");
}
</code></pre>

blocks|key|1757959|text|是的，这是可以实现的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1757960|String+s1+=+"abBaCca";
String+s2+=+"bac";

String+s1Lower+=+s1;

//s1Lower+is+exact+same+string,+now+convert+it+to+lowercase,+I+left+the+s1+intact+for+print+purposes+if+needed

s1Lower+=+s1Lower.toLowerCase();

String+trueStatement+=+"FALSE!";
if+(s1Lower.contains(s2))+{

++++//THIS+statement+will+be+TRUE
++++trueStatement+=+"TRUE!"
}

return+trueStatement;|code-block|syntax|javascript|1757961|此代码将返回字符串"TRUE!“因为它发现你的角色被控制住了。|1757962|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Yes, this is achievable:

<pre><code>String s1 = "abBaCca";
String s2 = "bac";

String s1Lower = s1;

//s1Lower is exact same string, now convert it to lowercase, I left the s1 intact for print purposes if needed

s1Lower = s1Lower.toLowerCase();

String trueStatement = "FALSE!";
if (s1Lower.contains(s2)) {

 //THIS statement will be TRUE
 trueStatement = "TRUE!"
}

return trueStatement;
</code></pre>

This code will return the String "TRUE!" as it found that your characters were contained.

blocks|key|1543213|text|您可以使用regular+expressions，它可以工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1543214|boolean+found+=+s1.matches("(?i).*"+%2B+s2%2B+".*");|code-block|syntax|javascript|1543215|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Regular_expression^0|5|J|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

You can use <a href="http://en.wikipedia.org/wiki/Regular_expression" rel="nofollow">regular expressions</a>, and it works:

<pre><code>boolean found = s1.matches("(?i).*" + s2+ ".*");
</code></pre>

blocks|key|1543386|text|这里有一些Unicode友好的代码，如果您使用ICU4j，您可以创建它们。我猜“忽略大小写”对于方法名称来说是有问题的，因为尽管主要强度比较确实忽略了大小写，但它被描述为依赖于区域设置的细节。但它希望以用户期望的方式依赖于语言环境。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1543387|public+static+boolean+containsIgnoreCase(String+haystack,+String+needle)+{
++++return+indexOfIgnoreCase(haystack,+needle)+>=+0;
}

public+static+int+indexOfIgnoreCase(String+haystack,+String+needle)+{
++++StringSearch+stringSearch+=+new+StringSearch(needle,+haystack);
++++stringSearch.getCollator().setStrength(Collator.PRIMARY);
++++return+stringSearch.first();
}|code-block|syntax|javascript|1543388|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here's some Unicode-friendly ones you can make if you pull in ICU4j. I guess "ignore case" is questionable for the method names because although primary strength comparisons do ignore case, it's described as the specifics being locale-dependent. But it's hopefully locale-dependent in a way the user would expect.

<pre><code>public static boolean containsIgnoreCase(String haystack, String needle) {
 return indexOfIgnoreCase(haystack, needle) &gt;= 0;
}

public static int indexOfIgnoreCase(String haystack, String needle) {
 StringSearch stringSearch = new StringSearch(needle, haystack);
 stringSearch.getCollator().setStrength(Collator.PRIMARY);
 return stringSearch.first();
}
</code></pre>

blocks|key|1758569|text|"AbCd".toLowerCase().contains("abcD".toLowerCase())|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1758570|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>"AbCd".toLowerCase().contains("abcD".toLowerCase())
</code></pre>

blocks|key|1758668|text|有一种简单而简洁的方法，使用regex标志(不区分大小写{i})：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1758669|+String+s1+=+"hello+abc+efg";
+String+s2+=+"ABC";
+s1.matches(".*(?i)"%2Bs2%2B".*");

/*
+*+.*++denotes+every+character+except+line+break
+*+(?i)+denotes+case+insensitivity+flag+enabled+for+s2+(String)
+*+*/|code-block|syntax|javascript|1758670|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

There is a simple concise way, using regex flag (case insensitive {i}):

<pre><code> String s1 = "hello abc efg";
 String s2 = "ABC";
 s1.matches(".*(?i)"+s2+".*");

/*
 * .* denotes every character except line break
 * (?i) denotes case insensitivity flag enabled for s2 (String)
 * */
</code></pre>

blocks|key|1543867|text|一种方法是使用toLowerCase()或toUpperCase()方法将两个字符串转换为小写或大写，然后进行测试。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1543868|public+class+Sample+{
+++public+static+void+main(String+args[]){
++++++String+str+=+"Hello+Welcome+to+insensitive+Container";
++++++String+test+=+"Java+Testing";
++++++Boolean+bool+=+str.toLowerCase().contains(test.toLowerCase());
++++++System.out.println(bool);
+++}
}|code-block|syntax|javascript|1543869|这里是使用带有CASE_INSENSITIVE标志的java.util.regex.Pattern进行不区分大小写匹配的另一种方法。|1543870|Pattern.compile(Pattern.quote(s2),+Pattern.CASE_INSENSITIVE).matcher(s1).find();|1543871|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

One way to do it to convert both strings to lower or upper case using toLowerCase() or toUpperCase() methods and test.
<pre><code>public class Sample {
 public static void main(String args[]){
 String str = &quot;Hello Welcome to insensitive Container&quot;;
 String test = &quot;Java Testing&quot;;
 Boolean bool = str.toLowerCase().contains(test.toLowerCase());
 System.out.println(bool);
 }
}
</code></pre>
Here is another way for case insensitive matching using java.util.regex.Pattern with the CASE_INSENSITIVE flag.
<pre><code>Pattern.compile(Pattern.quote(s2), Pattern.CASE_INSENSITIVE).matcher(s1).find();
</code></pre>

blocks|key|1757821|text|我不确定你的主要问题是什么，但是的，.contains区分大小写。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1757822|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I'm not sure what your main question is here, but yes, .contains is case sensitive.

blocks|key|1758244|text|String+container+=+"+Case+SeNsitive+";
String+sub+=+"sen";
if+(rcontains(container,+sub))+{
++++System.out.println("no+case");
}

public+static+Boolean+rcontains(String+container,+String+sub)+{

++++Boolean+b+=+false;
++++for+(int+a+=+0;+a+<+container.length()+-+sub.length()+%2B+1;+a%2B%2B)+{
++++++++//System.out.println(sub+%2B+"+to+"+%2B+container.substring(a,+a%2Bsub.length()));
++++++++if+(sub.equalsIgnoreCase(container.substring(a,+a+%2B+sub.length())))+{
++++++++++++b+=+true;
++++++++}
++++}
++++return+b;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1758245|基本上，它是一个接受两个字符串的方法。它应该是contains()的一个不区分大小写的版本。使用contains方法时，您希望查看一个字符串是否包含在另一个字符串中。|unstyled|1758246|此方法获取"sub“的字符串，并检查它是否等于容器字符串的子字符串，这些子字符串的长度与"sub”相同。如果查看for循环，您将看到它在容器字符串上的子字符串(即“sub”的长度)中迭代。|offset|length|style|CODE|1758247|每次迭代都会检查容器字符串的子字符串是否对该子字符串是equalsIgnoreCase。|1758248|entityMap^0|0|0|1K|3|0|R|G|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|F|7|V|8|@$I|W|J|X|K|L]]|9|@]|A|$]]|$1|O|3|-4|5|F|7|Y|8|@]|9|@]|A|$]]]|P|$]]

<pre><code>String container = " Case SeNsitive ";
String sub = "sen";
if (rcontains(container, sub)) {
 System.out.println("no case");
}

public static Boolean rcontains(String container, String sub) {

 Boolean b = false;
 for (int a = 0; a &lt; container.length() - sub.length() + 1; a++) {
 //System.out.println(sub + " to " + container.substring(a, a+sub.length()));
 if (sub.equalsIgnoreCase(container.substring(a, a + sub.length()))) {
 b = true;
 }
 }
 return b;
}
</code></pre>

Basically, it is a method that takes two strings. It is supposed to be a not-case sensitive version of contains(). When using the contains method, you want to see if one string is contained in the other.

This method takes the string that is "sub" and checks if it is equal to the substrings of the container string that are equal in length to the "sub". If you look at the <code>for</code> loop, you will see that it iterates in substrings (that are the length of the "sub") over the container string.

Each iteration checks to see if the substring of the container string is <code>equalsIgnoreCase</code> to the sub.

blocks|key|1543613|text|import+java.text.Normalizer;

import+org.apache.commons.lang3.StringUtils;

public+class+ContainsIgnoreCase+{

++++public+static+void+main(String[]+args)+{

++++++++String+in+=+"+++Annulée+";
++++++++String+key+=+"annulee";

++++++++//+100%25+java
++++++++if+(Normalizer.normalize(in,+Normalizer.Form.NFD).replaceAll("[\\p{InCombiningDiacriticalMarks}]",+"").toLowerCase().contains(key))+{
++++++++++++System.out.println("OK");
++++++++}+else+{
++++++++++++System.out.println("KO");
++++++++}

++++++++//+use+commons.lang+lib
++++++++if+(StringUtils.containsIgnoreCase(Normalizer.normalize(in,+Normalizer.Form.NFD).replaceAll("[\\p{InCombiningDiacriticalMarks}]",+""),+key))+{
++++++++++++System.out.println("OK");
++++++++}+else+{
++++++++++++System.out.println("KO");
++++++++}

++++}

}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1543614|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>import java.text.Normalizer;

import org.apache.commons.lang3.StringUtils;

public class ContainsIgnoreCase {

 public static void main(String[] args) {

 String in = " Annulée ";
 String key = "annulee";

 // 100% java
 if (Normalizer.normalize(in, Normalizer.Form.NFD).replaceAll("[\\p{InCombiningDiacriticalMarks}]", "").toLowerCase().contains(key)) {
 System.out.println("OK");
 } else {
 System.out.println("KO");
 }

 // use commons.lang lib
 if (StringUtils.containsIgnoreCase(Normalizer.normalize(in, Normalizer.Form.NFD).replaceAll("[\\p{InCombiningDiacriticalMarks}]", ""), key)) {
 System.out.println("OK");
 } else {
 System.out.println("KO");
 }

 }

}
</code></pre>

blocks|key|1758627|text|我们可以在anyMatch和Java8的容器中使用stream|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1758628|public+class+Test2+{
++++public+static+void+main(String[]+args)+{

++++++++String+a+=+"Gina+Gini+Protijayi+Soudipta";
++++++++String+b+=+"Gini";

++++++++System.out.println(WordPresentOrNot(a,+b));
++++}//+main

++++private+static+boolean+WordPresentOrNot(String+a,+String+b)+{
++++//contains+is+case+sensitive.+That's+why+change+it+to+upper+or+lower+case.+Then+check
++++++++//+Here+we+are+using+stream+with+anyMatch
++++++++boolean+match+=+Arrays.stream(a.toLowerCase().split("+")).anyMatch(b.toLowerCase()::contains);
++++++++return+match;
++++}

}|code-block|syntax|javascript|1758629|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

We can use stream with anyMatch and contains of Java 8

<pre><code>public class Test2 {
 public static void main(String[] args) {

 String a = "Gina Gini Protijayi Soudipta";
 String b = "Gini";

 System.out.println(WordPresentOrNot(a, b));
 }// main

 private static boolean WordPresentOrNot(String a, String b) {
 //contains is case sensitive. That's why change it to upper or lower case. Then check
 // Here we are using stream with anyMatch
 boolean match = Arrays.stream(a.toLowerCase().split(" ")).anyMatch(b.toLowerCase()::contains);
 return match;
 }

}
</code></pre>

blocks|key|1543795|text|或者，您可以使用一种简单的方法，将字符串的大小写转换为子字符串的大小写，然后使用contains方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1543796|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

or you can use a simple approach and just convert the string's case to substring's case and then use contains method.

blocks|key|1543048|text|String+x="abCd";
System.out.println(Pattern.compile("c",Pattern.CASE_INSENSITIVE).matcher(x).find());|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1543049|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>String x="abCd";
System.out.println(Pattern.compile("c",Pattern.CASE_INSENSITIVE).matcher(x).find());
</code></pre>

blocks|key|1543419|text|您可以简单地执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1543420|String+s1+=+"AbBaCca";
String+s2+=+"bac";
String+toLower+=+s1.toLowerCase();
return+toLower.contains(s2);|code-block|syntax|javascript|1543421|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You could simply do something like this:

<pre><code>String s1 = "AbBaCca";
String s2 = "bac";
String toLower = s1.toLowerCase();
return toLower.contains(s2);
</code></pre>

Say I have two strings,

<pre><code>String s1 = "AbBaCca";
String s2 = "bac";
</code></pre>

I want to perform a check returning that <code>s2</code> is contained within <code>s1</code>. I can do this with:

<pre><code>return s1.contains(s2);
</code></pre>

I am pretty sure that <code>contains()</code> is case sensitive, however I can't determine this for sure from reading the documentation. If it is then I suppose my best method would be something like:

<pre><code>return s1.toLowerCase().contains(s2.toLowerCase());
</code></pre>

All this aside, is there another (possibly better) way to accomplish this without caring about case-sensitivity?

How to check if a String contains another String in a case insensitive manner in Java?

假设我有两根弦，String s1 = "AbBaCca";String s2 = "bac";我想执行一个检查，返回s1中包含的s2。我可以使用以下命令来实现：return s1.contains(s2);我非常确定contains()是区分大小写的，但是通过阅读文档，我不能确定这一点。如果是这样，那么我想我最好的方法应该是：return s1.toLowerCase().contains(s2

问如何在Java中检查一个字符串是否包含另一个不区分大小写的字符串？
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问如何在Java中检查一个字符串是否包含另一个不区分大小写的字符串？EN

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问如何在Java中检查一个字符串是否包含另一个不区分大小写的字符串？
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