你可以用正则表达式来使用replace和replaceAll。

String[] strings = {"a", "b", "c"};

String result = Arrays.asList(strings).toString().replaceAll("(^\\[|\\]$)", "").replace(", ", ",");

因为Arrays.asList(). tostring()生成:"[a, b, c]"，我们执行replaceAll来删除第一个和最后一个括号，然后(可选地)您可以更改"，"序列为"，"(您的新分隔符)。

精简版(字符数更少):

String[] strings = {"a", "b", "c"};

String result = ("" + Arrays.asList(strings)).replaceAll("(^.|.$)", "").replace(", ", "," );

正则表达式非常强大，特别是字符串方法“replaceFirst”和“replaceAll”。试一试吧。

这个小函数总是会派上用场。

public static String join(String[] strings, int startIndex, String separator) {
    StringBuffer sb = new StringBuffer();
    for (int i=startIndex; i < strings.length; i++) {
        if (i != startIndex) sb.append(separator);
        sb.append(strings[i]);
    }
    return sb.toString();
}

“我相信有一种经过认证的、有效的方法来做到这一点(Apache Commons?)”

是的，很明显

StringUtils.join(array, separator)

http://www.java2s.com/Code/JavaAPI/org.apache.commons.lang/StringUtilsjoinObjectarrayStringseparator.htm

更简单的是，你可以使用数组，所以你会得到一个字符串，数组的值由"，"隔开

String concat = Arrays.toString(myArray);

所以你会得到这样的结果:concat = "[a,b,c]"

更新

然后，您可以使用Jeff建议的子字符串来消除括号

concat = concat.substring(1, concat.length() -1);

所以你得到concat = "a,b,c"

如果你想使用Kotlin:

 val concat = myArray.joinToString(separator = ",") //"a,b,c"

The approach that I've taken has evolved since Java 1.0 to provide readability and maintain reasonable options for backward-compatibility with older Java versions, while also providing method signatures that are drop-in replacements for those from apache commons-lang. For performance reasons, I can see some possible objections to the use of Arrays.asList but I prefer helper methods that have sensible defaults without duplicating the one method that performs the actual work. This approach provides appropriate entry points to a reliable method that does not require array/list conversions prior to calling.

Java版本兼容性的可能变化包括用StringBuffer (Java 1.0)代替StringBuilder (Java 1.5)，切换出Java 1.5迭代器，并从集合(Java 1.2)中删除通用通配符(Java 1.5)。如果想进一步提高向后兼容性，可以删除使用Collection的方法，并将逻辑移到基于数组的方法中。

public static String join(String[] values)
{
    return join(values, ',');
}

public static String join(String[] values, char delimiter)
{
    return join(Arrays.asList(values), String.valueOf(delimiter));
}

// To match Apache commons-lang: StringUtils.join(values, delimiter)
public static String join(String[] values, String delimiter)
{
    return join(Arrays.asList(values), delimiter);
}

public static String join(Collection<?> values)
{
    return join(values, ',');
}

public static String join(Collection<?> values, char delimiter)
{
    return join(values, String.valueOf(delimiter));
}

public static String join(Collection<?> values, String delimiter)
{
    if (values == null)
    {
        return new String();
    }

    StringBuffer strbuf = new StringBuffer();

    boolean first = true;

    for (Object value : values)
    {
        if (!first) { strbuf.append(delimiter); } else { first = false; }
        strbuf.append(value.toString());
    }

    return strbuf.toString();
}

对于这个特殊的问题，我更喜欢Guava而不是Apache StringUtils:

Joiner.on(separator).join(array)

与StringUtils相比，Joiner API具有流畅的设计，并且更加灵活，例如，null元素可以被跳过或被占位符替换。此外，Joiner还有一个特性，用于在键和值之间使用分隔符连接映射。