blocks|key|4714582|text|看看oracle关于string类的文档，特别是substring、charAt、indexOf和toUpperCase|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4714583|(你可以用这些拼图来解决你的问题)|4714584|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/String.html|1|http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#substring(int,%2520int))|2|http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#charAt(int))|3|http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#indexOf(int))|4|http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#toUpperCase()^0|A|6|0|O|9|1|Y|6|2|15|7|3|1D|B|4|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@$A|W|B|X|1|Y]|$A|Z|B|10|1|11]|$A|12|B|13|1|14]|$A|15|B|16|1|17]|$A|18|B|19|1|1A]]|C|$]]|$1|D|3|E|5|6|7|1B|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|1C|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]|P|$5|I|J|K|C|$L|Q]]|R|$5|I|J|K|C|$L|S]]|T|$5|I|J|K|C|$L|U]]]]

Take a look at oracle's documentation for the <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html" rel="nofollow">string</a> class, notably <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#substring(int,%20int)" rel="nofollow">substring</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#charAt(int)" rel="nofollow">charAt</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#indexOf(int)" rel="nofollow">indexOf</a>, and <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#toUpperCase()" rel="nofollow">toUpperCase</a>

(You can use these as puzzle pieces to solve your problem)

blocks|key|9438|text|这并不美观，但它是有效的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|9439|String+phrase+=+"camel_case";
String[]+words+=+phrase.split("_");
String+newPhrase+=+words[0];
for(int+i=1;+i<words.length;+i%2B%2B){
++newPhrase+%2B=+words[i].substring(0,1).toUpperCase()+%2B+words[i].substring(1);
}|code-block|syntax|javascript|9440|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|$]]

This isn't pretty, but it works:
<pre><code>String phrase = &quot;camel_case&quot;;
String[] words = phrase.split(&quot;_&quot;);
String newPhrase = words[0];
for(int i=1; i&lt;words.length; i++){
 newPhrase += words[i].substring(0,1).toUpperCase() + words[i].substring(1);
}
</code></pre>

blocks|key|1916002|text|这可能很好用，而且很有效。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1916003|public+class+Test+{

++++public+static+void+main(String[]+args)+{
++++++++String+phrase+=+"always_use_camel_back_notation_in_java";
++++++++while(phrase.contains("_"))+{
++++++++++++++++phrase+=+phrase.replaceFirst("_[a-z]",+String.valueOf(Character.toUpperCase(phrase.charAt(phrase.indexOf("_")+%2B+1))));
++++++++++++}
++++++++++++System.out.println(phrase);
++++++++}
++++}|code-block|syntax|javascript|1916004|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|$]]

This might be pretty, and it works

<pre><code>public class Test {

 public static void main(String[] args) {
 String phrase = "always_use_camel_back_notation_in_java";
 while(phrase.contains("_")) {
 phrase = phrase.replaceFirst("_[a-z]", String.valueOf(Character.toUpperCase(phrase.charAt(phrase.indexOf("_") + 1))));
 }
 System.out.println(phrase);
 }
 }
</code></pre>

blocks|key|2601813|text|使用split("_")并遍历这些部分是实现此目的的一种方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2601814|这里有一个使用StringBuilder的替代方案。|2601815|String+s+=+"make_me_camel_case";
StringBuilder+sb+=+new+StringBuilder(s);

for+(int+i+=+0;+i+<+sb.length();+i%2B%2B)+{
++++if+(sb.charAt(i)+==+'_')+{
++++++++sb.deleteCharAt(i);
++++++++sb.replace(i,+i%2B1,+String.valueOf(Character.toUpperCase(sb.charAt(i))));
++++}
}

System.out.println(sb.toString());+//+makeMeCamelCase|code-block|syntax|javascript|2601816|entityMap^0|2|A|0|7|D|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|U|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

Using <code>split("_")</code> and looping over those parts is one way to do it. 

Here is an alternative using a <code>StringBuilder</code>. 

<pre><code>String s = "make_me_camel_case";
StringBuilder sb = new StringBuilder(s);

for (int i = 0; i &lt; sb.length(); i++) {
 if (sb.charAt(i) == '_') {
 sb.deleteCharAt(i);
 sb.replace(i, i+1, String.valueOf(Character.toUpperCase(sb.charAt(i))));
 }
}

System.out.println(sb.toString()); // makeMeCamelCase
</code></pre>

blocks|key|1922353|text|您可以使用toCamelCase工具：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1922354|CaseUtils.toCamelCase("camel_case",+false,+new+char[]{'_'});+//+returns+"camelCase"|code-block|syntax|javascript|1922355|来自Apache+Commons+Text。|1922356|entityMap|0|LINK|mutability|MUTABLE|url|https://commons.apache.org/proper/commons-text/apidocs/org/apache/commons/text/CaseUtils.html#toCamelCase(java.lang.String,boolean,char...)|1|https://commons.apache.org/proper/commons-text/apidocs/org/apache/commons/text/CaseUtils.html#toCamelCase(java.lang.String,boolean,char...))^0|5|B|5|B|0|0|0|2|J|1|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@$9|14|A|15|1|16]]|E|$]]|$1|M|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]|U|$5|P|Q|R|E|$S|V]]]]

You can use <a href="https://commons.apache.org/proper/commons-text/apidocs/org/apache/commons/text/CaseUtils.html#toCamelCase(java.lang.String,boolean,char...)" rel="noreferrer"><code>toCamelCase</code></a> util:

<pre><code>CaseUtils.toCamelCase("camel_case", false, new char[]{'_'}); // returns "camelCase"
</code></pre>

from <a href="https://commons.apache.org/proper/commons-text/apidocs/org/apache/commons/text/CaseUtils.html#toCamelCase(java.lang.String,boolean,char...)" rel="noreferrer">Apache Commons Text</a>.

blocks|key|2601863|text|此外，Guava的CaseFormat提供了一个相当整洁的解决方案，允许您从驼峰案例转换为驼峰案例，甚至其他特定案例。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2601864|CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL,+"camel_case");+//+returns+camelCase
CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL,+"CAMEL_CASE");+//+returns+CamelCase
CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE,+"camelCase");+//+returns+CAMEL_CASE
CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_HYPHEN,+"CamelCase");+//+returns+camel-case|code-block|syntax|javascript|2601865|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/guava/wiki/StringsExplained#caseformat^0|9|A|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]]]]

Also Guava's <a href="https://github.com/google/guava/wiki/StringsExplained#caseformat" rel="noreferrer">CaseFormat</a> offers quite a neat solution that allows you to transform from and to camel case and even other specific cases.

<pre><code>CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, "camel_case"); // returns camelCase
CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, "CAMEL_CASE"); // returns CamelCase
CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, "camelCase"); // returns CAMEL_CASE
CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_HYPHEN, "CamelCase"); // returns camel-case
</code></pre>

Can anyone tell me how to convert a string in snake_case as: 

<pre><code>camel_case
</code></pre>

to a string in camelCase as:

<pre><code>camelCase
</code></pre>

in Java?

Thank you in advance.

From snake_case to camelCase in Java

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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谁能告诉我如何将snake_case中的字符串转换为：camel_case转换为camelCase中的字符串，如下所示：camelCase在Java中？提前谢谢你。

问在Java中从snake_case到camelCase
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