blocks|key|301046|text|其他人已经指出了deleteCharAt方法，但这里有另一种替代方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|301047|String+prefix+=+"";
for+(String+serverId+:+serverIds)+{
++sb.append(prefix);
++prefix+=+",";
++sb.append(serverId);
}|code-block|syntax|javascript|301048|或者，使用Guava中的Joiner类:)|301049|从Java8开始，StringJoiner是标准JRE的一部分。|301050|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/guava|1|https://guava.dev/releases/snapshot-jre/api/docs/com/google/common/base/Joiner.html|2|http://docs.oracle.com/javase/8/docs/api/java/util/StringJoiner.html^0|8|C|0|0|C|6|5|5|0|C|6|1|0|9|C|9|C|2|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@$9|17|A|18|1|19]|$9|1A|A|1B|1|1C]]|E|$]]|$1|M|3|N|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@$9|1G|A|1H|1|1I]]|E|$]]|$1|O|3|-4|5|6|7|1J|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]|Y|$5|R|S|T|E|$U|Z]]]]

Others have pointed out the <code>deleteCharAt</code> method, but here's another alternative approach:
<pre><code>String prefix = &quot;&quot;;
for (String serverId : serverIds) {
 sb.append(prefix);
 prefix = &quot;,&quot;;
 sb.append(serverId);
}
</code></pre>
Alternatively, use the <a href="https://guava.dev/releases/snapshot-jre/api/docs/com/google/common/base/Joiner.html" rel="noreferrer"><code>Joiner</code></a> class from <a href="https://github.com/google/guava" rel="noreferrer">Guava</a> :)
As of Java 8, <a href="http://docs.oracle.com/javase/8/docs/api/java/util/StringJoiner.html" rel="noreferrer"><code>StringJoiner</code></a> is part of the standard JRE.

blocks|key|298684|text|另一个简单的解决方案是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|298685|sb.setLength(sb.length()+-+1);|code-block|syntax|javascript|298686|298687|更复杂的解决方案：|298688|上面的解决方案假设sb.length()+>+0+...即存在要移除的“最后一个字符”。如果你不能做这个假设，并且/或者你不能处理假设不正确而导致的异常，那么首先检查StringBuilder的长度；|offset|length|style|CODE|298689|//+Readable+version
if+(sb.length()+>+0)+{
+++sb.setLength(sb.length()+-+1);
}|298690|或|298691|//+Concise+but+harder-to-read+version+of+the+above.
sb.setLength(Math.max(sb.length()+-+1,+0));|298692|entityMap^0|0|0|0|0|9|F|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Y|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|10|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|11|8|@$L|12|M|13|N|O]]|9|@]|A|$]]|$1|P|3|Q|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|R|3|S|5|6|7|15|8|@]|9|@]|A|$]]|$1|T|3|U|5|D|7|16|8|@]|9|@]|A|$E|F]]|$1|V|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|W|$]]

Another simple solution is:

<pre><code>sb.setLength(sb.length() - 1);
</code></pre>

<hr>

A more complicated solution:

The above solution assumes that <code>sb.length() &gt; 0</code> ... i.e. there is a "last character" to remove. If you can't make that assumption, and/or you can't deal with the exception that would ensue if the assumption is incorrect, then check the StringBuilder's length first; e.g.

<pre><code>// Readable version
if (sb.length() &gt; 0) {
 sb.setLength(sb.length() - 1);
}
</code></pre>

or 

<pre><code>// Concise but harder-to-read version of the above.
sb.setLength(Math.max(sb.length() - 1, 0));
</code></pre>

blocks|key|3244431|text|if(sb.length()+>+0){
++++sb.deleteCharAt(sb.length()+-+1);
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3244432|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>if(sb.length() &gt; 0){
 sb.deleteCharAt(sb.length() - 1);
}
</code></pre>

blocks|key|301759|text|在Java8中，String类有一个静态方法join。第一个参数是要在每对字符串之间使用的字符串，第二个参数是一个Iterable<CharSequence>+(这两个参数都是接口，所以类似于List<String>。所以你可以这样做：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|301760|String.join(",",+serverIds);|code-block|syntax|javascript|301761|同样在Java8中，您可以使用新的StringJoiner类，用于在获得要放入的元素的完整列表之前就开始构造字符串的场景。|301762|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#join-java.lang.CharSequence-java.lang.Iterable-|1|https://docs.oracle.com/javase/8/docs/api/index.html?java/util/StringJoiner.html^0|M|4|1L|M|2O|C|M|4|0|0|0|H|C|H|C|1|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@$9|1A|A|1B|1|1C]]|E|$]]|$1|M|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]|U|$5|P|Q|R|E|$S|V]]]]

As of Java 8, the String class has a static method <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#join-java.lang.CharSequence-java.lang.Iterable-" rel="noreferrer"><code>join</code></a>. The first argument is a string that you want between each pair of strings, and the second is an <code>Iterable&lt;CharSequence&gt;</code> (which are both interfaces, so something like <code>List&lt;String&gt;</code> works. So you can just do this:

<pre><code>String.join(",", serverIds);
</code></pre>

Also in Java 8, you could use the new <a href="https://docs.oracle.com/javase/8/docs/api/index.html?java/util/StringJoiner.html" rel="noreferrer"><code>StringJoiner</code></a> class, for scenarios where you want to start constructing the string before you have the full list of elements to put in it.

blocks|key|3030478|text|只需获取最后一个字符出现的位置。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3030479|for(String+serverId+:+serverIds)+{
+sb.append(serverId);
+sb.append(",");
}
sb.deleteCharAt(sb.lastIndexOf(","));|code-block|syntax|javascript|3030480|由于lastIndexOf将执行反向搜索，并且您知道它将在第一次尝试时找到，因此性能在这里不是问题。|offset|length|style|CODE|3030481|编辑|BOLD|3030482|由于我不断得到我的答案(谢谢大家)，这是值得的：|3030483|在Java8及以后的版本中，使用StringJoiner会更加清晰易懂。它有一个用于简单分隔符的方法，一个用于前缀和后缀的重载方法。|3030484|取自此处的示例：example|3030485|使用简单分隔符的示例：|3030486|3030487|+StringJoiner+mystring+=+new+StringJoiner("-");++++++++++//+Joining+multiple+strings+by+using+add()+method+++++++mystring.add("Logan");+++++++mystring.add("Magneto");+++++++mystring.add("Rogue");+++++++mystring.add("Storm");++++++++System.out.println(mystring);|blockquote|3030488|3030489|输出：|3030490|3030491|+Logan-磁石-流氓-风暴|3030492|3030493|3030494|带有后缀和前缀的示例：|3030495|3030496|+StringJoiner+mystring+=+new+StringJoiner(",",+"(",+")");++++++++++//+Joining+multiple+strings+by+using+add()+method+++++++mystring.add("Negan");+++++++mystring.add("Rick");+++++++mystring.add("Maggie");+++++++mystring.add("Daryl");++++++++System.out.println(mystring);|3030497|3030498|输出|3030499|3030500|+(尼根，里克，玛吉，达里尔)|3030501|3030502|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/util/StringJoiner.html|1|https://beginnersbook.com/2017/10/java-8-stringjoiner/^0|0|0|2|B|0|0|2|0|0|1|5|G|C|0|0|8|7|1|0|8|3|0|0|0|0|0|0|0|0|0|8|3|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1V|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|1W|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|1X|8|@$I|1Y|J|1Z|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|20|8|@$I|21|J|22|K|O]]|9|@]|A|$]]|$1|P|3|Q|5|6|7|23|8|@]|9|@]|A|$]]|$1|R|3|S|5|6|7|24|8|@$I|25|J|26|K|O]]|9|@$I|27|J|28|1|29]]|A|$]]|$1|T|3|U|5|6|7|2A|8|@]|9|@$I|2B|J|2C|1|2D]]|A|$]]|$1|V|3|W|5|6|7|2E|8|@$I|2F|J|2G|K|O]]|9|@]|A|$]]|$1|X|3|-4|5|6|7|2H|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|10|7|2I|8|@]|9|@]|A|$]]|$1|11|3|-4|5|6|7|2J|8|@]|9|@]|A|$]]|$1|12|3|13|5|6|7|2K|8|@]|9|@]|A|$]]|$1|14|3|-4|5|6|7|2L|8|@]|9|@]|A|$]]|$1|15|3|16|5|10|7|2M|8|@]|9|@]|A|$]]|$1|17|3|-4|5|6|7|2N|8|@]|9|@]|A|$]]|$1|18|3|-4|5|6|7|2O|8|@]|9|@]|A|$]]|$1|19|3|1A|5|6|7|2P|8|@$I|2Q|J|2R|K|O]]|9|@]|A|$]]|$1|1B|3|-4|5|6|7|2S|8|@]|9|@]|A|$]]|$1|1C|3|1D|5|10|7|2T|8|@]|9|@]|A|$]]|$1|1E|3|-4|5|6|7|2U|8|@]|9|@]|A|$]]|$1|1F|3|1G|5|6|7|2V|8|@]|9|@]|A|$]]|$1|1H|3|-4|5|6|7|2W|8|@]|9|@]|A|$]]|$1|1I|3|1J|5|10|7|2X|8|@]|9|@]|A|$]]|$1|1K|3|-4|5|6|7|2Y|8|@]|9|@]|A|$]]|$1|1L|3|-4|5|6|7|2Z|8|@]|9|@]|A|$]]]|1M|$1N|$5|1O|1P|1Q|A|$1R|1S]]|1T|$5|1O|1P|1Q|A|$1R|1U]]]]

Just get the position of the last character occurrence.

<pre><code>for(String serverId : serverIds) {
 sb.append(serverId);
 sb.append(",");
}
sb.deleteCharAt(sb.lastIndexOf(","));
</code></pre>

Since <code>lastIndexOf</code> will perform a reverse search, and you know that it will find at the first try, performance won't be an issue here.

EDIT

Since I keep getting ups on my answer (thanks folks ), it is worth regarding that:

On Java 8 onward it would just be more legible and explicit to use <a href="https://docs.oracle.com/javase/8/docs/api/java/util/StringJoiner.html" rel="noreferrer">StringJoiner</a>.
It has one method for a simple separator, and an overload for prefix and suffix.

Examples taken from here: <a href="https://beginnersbook.com/2017/10/java-8-stringjoiner/" rel="noreferrer">example</a>

Example using simple separator:

<blockquote>
<pre><code> StringJoiner mystring = new StringJoiner("-"); 

 // Joining multiple strings by using add() method 
 mystring.add("Logan"); 
 mystring.add("Magneto"); 
 mystring.add("Rogue"); 
 mystring.add("Storm"); 

 System.out.println(mystring);
</code></pre>
</blockquote>

Output:

<blockquote>
 Logan-Magneto-Rogue-Storm
</blockquote>

Example with suffix and prefix:

<blockquote>
<pre><code> StringJoiner mystring = new StringJoiner(",", "(", ")"); 

 // Joining multiple strings by using add() method 
 mystring.add("Negan"); 
 mystring.add("Rick"); 
 mystring.add("Maggie"); 
 mystring.add("Daryl"); 

 System.out.println(mystring);
</code></pre>
</blockquote>

Output

<blockquote>
 (Negan,Rick,Maggie,Daryl)
</blockquote>

blocks|key|301084|text|在这种情况下，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|301085|sb.setLength(sb.length()+-+1);|code-block|syntax|javascript|301086|更可取，因为它只将最后一个值赋给'\0'，而删除最后一个字符则为System.arraycopy|offset|length|style|CODE|301087|entityMap^0|0|0|G|4|W|G|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

In this case,

<pre><code>sb.setLength(sb.length() - 1);
</code></pre>

is preferable as it just assign the last value to <code>'\0'</code> whereas deleting last character does <code>System.arraycopy</code>

blocks|key|3030533|text|通过Java-8，您可以使用String类静态方法，|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3030534|String#join(CharSequence+delimiter,Iterable+elements).|3030535|3030536|public+class+Test+{

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

++++++++List<String>+names+=+new+ArrayList<>();
++++++++names.add("James");
++++++++names.add("Harry");
++++++++names.add("Roy");
++++++++System.out.println(String.join(",",+names));
++++}
}|code-block|syntax|javascript|3030537|输出|BOLD|3030538|James,Harry,Roy|3030539|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#join-java.lang.CharSequence-java.lang.Iterable-^0|2|6|E|6|0|0|1H|0|1I|0|0|0|0|0|2|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|H|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]|$1|I|3|J|5|K|7|1C|8|@]|D|@]|E|$L|M]]|$1|N|3|O|5|6|7|1D|8|@$9|1E|A|1F|B|P]]|D|@]|E|$]]|$1|Q|3|R|5|K|7|1G|8|@]|D|@]|E|$L|M]]|$1|S|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]]]

With <code>Java-8</code> you can use static method of <code>String</code> class,

<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#join-java.lang.CharSequence-java.lang.Iterable-" rel="noreferrer"><code>String#join(CharSequence delimiter,Iterable&lt;? extends CharSequence&gt; elements)</code>.</a>

<hr>

<pre><code>public class Test {

 public static void main(String[] args) {

 List&lt;String&gt; names = new ArrayList&lt;&gt;();
 names.add("James");
 names.add("Harry");
 names.add("Roy");
 System.out.println(String.join(",", names));
 }
}
</code></pre>

OUTPUT

<pre><code>James,Harry,Roy
</code></pre>

blocks|key|3244559|text|另一种选择|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3244560|for(String+serverId+:+serverIds)+{
+++sb.append(",");
+++sb.append(serverId);+
}
sb.deleteCharAt(0);|code-block|syntax|javascript|3244561|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|$]]

Another alternative

<pre><code>for(String serverId : serverIds) {
 sb.append(",");
 sb.append(serverId); 
}
sb.deleteCharAt(0);
</code></pre>

blocks|key|3244521|text|或者，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3244522|StringBuilder+result+=+new+StringBuilder();
for(String+string+:+collection)+{
++++result.append(string);
++++result.append(',');
}
return+result.substring(0,+result.length()+-+1)+;|code-block|syntax|javascript|3244523|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|$]]

Alternatively,

<pre><code>StringBuilder result = new StringBuilder();
for(String string : collection) {
 result.append(string);
 result.append(',');
}
return result.substring(0, result.length() - 1) ;
</code></pre>

blocks|key|3030311|text|StringBuilder+sb+=+new+StringBuilder();
sb.append("abcdef");
sb.deleteCharAt(sb.length()+-+1);
assertEquals("abcde",sb.toString());
//+true|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3030312|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>StringBuilder sb = new StringBuilder();
sb.append("abcdef");
sb.deleteCharAt(sb.length() - 1);
assertEquals("abcde",sb.toString());
// true
</code></pre>

blocks|key|3244553|text|还有另一种选择：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3244554|public+String+join(Collection<String>+collection,+String+seperator)+{
++++if+(collection.isEmpty())+return+"";

++++Iterator<String>+iter+=+collection.iterator();
++++StringBuilder+sb+=+new+StringBuilder(iter.next());
++++while+(iter.hasNext())+{
++++++++sb.append(seperator);
++++++++sb.append(iter.next());
++++}

++++return+sb.toString();
}|code-block|syntax|javascript|3244555|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|$]]

Yet another alternative:

<pre><code>public String join(Collection&lt;String&gt; collection, String seperator) {
 if (collection.isEmpty()) return "";

 Iterator&lt;String&gt; iter = collection.iterator();
 StringBuilder sb = new StringBuilder(iter.next());
 while (iter.hasNext()) {
 sb.append(seperator);
 sb.append(iter.next());
 }

 return sb.toString();
}
</code></pre>

blocks|key|298830|text|要避免重新启动(影响性能)+prefix，请使用TextUtils.isEmpty：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|298831|++++++++++++String+prefix+=+"";
++++++++++++for+(String+item+:+list)+{
++++++++++++++++sb.append(prefix);
++++++++++++++++if+(TextUtils.isEmpty(prefix))
++++++++++++++++++++prefix+=+",";
++++++++++++++++sb.append(item);
++++++++++++}|code-block|syntax|javascript|298832|entityMap^0|E|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|$]]

To avoid reinit(affect performance) of <code>prefix</code> use TextUtils.isEmpty:

<pre><code> String prefix = "";
 for (String item : list) {
 sb.append(prefix);
 if (TextUtils.isEmpty(prefix))
 prefix = ",";
 sb.append(item);
 }
</code></pre>

blocks|key|298812|text|我正在做的事情如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|298813|++++StringBuilder+stringBuilder+=+new+StringBuilder();
++++for+(int+i+=+0;+i+<+value.length;+i%2B%2B)+{
++++++++stringBuilder.append(values[i]);
++++++++if+(value.length-1)+{
++++++++++++stringBuilder.append(",+");
++++++++}
++++}|code-block|syntax|javascript|298814|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|$]]

I am doing something like below:

<pre><code> StringBuilder stringBuilder = new StringBuilder();
 for (int i = 0; i &lt; value.length; i++) {
 stringBuilder.append(values[i]);
 if (value.length-1) {
 stringBuilder.append(", ");
 }
 }
</code></pre>

blocks|key|303913|text|您可以尝试使用“Joiner”类，而不是从生成的文本中删除最后一个字符；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|303914|++++++++++++++++List<String>+textList+=+new+ArrayList<>();
++++++++++++++++textList.add("text1");
++++++++++++++++textList.add("text2");
++++++++++++++++textList.add("text3");

++++++++++++++++Joiner+joiner+=+Joiner.on(",").useForNull("null");
++++++++++++++++String+output+=+joiner.join(textList);

+++++++++++++++//output+:+"text1,text2,text3"|code-block|syntax|javascript|303915|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 may try to use 'Joiner' class instead of removing the last character from your generated text;

<pre><code> List&lt;String&gt; textList = new ArrayList&lt;&gt;();
 textList.add("text1");
 textList.add("text2");
 textList.add("text3");

 Joiner joiner = Joiner.on(",").useForNull("null");
 String output = joiner.join(textList);

 //output : "text1,text2,text3"
</code></pre>

blocks|key|301850|text|这是另一个解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|301851|for(String+serverId+:+serverIds)+{
+++sb.append(",");
+++sb.append(serverId);+
}

String+resultingString+=+"";
if+(+sb.length()+>+1+)+{
++++resultingString+=+sb.substring(1);
}|code-block|syntax|javascript|301852|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 is another solution:

<pre><code>for(String serverId : serverIds) {
 sb.append(",");
 sb.append(serverId); 
}

String resultingString = "";
if ( sb.length() &gt; 1 ) {
 resultingString = sb.substring(1);
}
</code></pre>

blocks|key|301854|text|stringBuilder.Remove(stringBuilder.Length+-+1，1)；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|301855|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|$]]

stringBuilder.Remove(stringBuilder.Length - 1, 1);

When you have to loop through a collection and make a string of each data separated by a delimiter, you always end up with an extra delimiter at the end, e.g.

<pre><code>for (String serverId : serverIds) {
 sb.append(serverId);
 sb.append(",");
}
</code></pre>

Gives something like : serverId_1, serverId_2, serverId_3,

I would like to delete the last character in the StringBuilder (without converting it because I still need it after this loop).

Remove last character of a StringBuilder?

Storm

Java

当你必须遍历一个集合并用分隔符分隔每个数据的字符串时，你总是以一个额外的分隔符结尾，例如for (String serverId : serverIds) {  sb.append(serverId);   sb.append(",");}如下所示：serverId_1，serverId_2，serverId_3，我想删除StringBuilder中的最后一个字符(不转换它，因为在这个循环之后我仍

问是否删除StringBuilder的最后一个字符？
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问是否删除StringBuilder的最后一个字符？
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