从 Java 字符串中去除前导和尾随空格

你可以试试 trim() 方法。

String newString = oldString.trim();

看看javadocs

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使用 String#trim() 方法或 String allRemoved = myString.replaceAll("^\\s+|\\s+$", "") 修剪两端。

对于左装饰：

String leftRemoved = myString.replaceAll("^\\s+", "");

对于右修剪：

String rightRemoved = myString.replaceAll("\\s+$", "");

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从 docs：

String.trim();

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trim() 是您的选择，但如果您想使用 replace 方法——这可能更灵活，您可以尝试以下方法：

String stripppedString = myString.replaceAll("(^ )|( $)", "");

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对于 Java-11 及更高版本，您可以使用 String.strip API 返回一个字符串，其值为该字符串，并删除所有前导和尾随空格。相同的 javadoc 内容如下：

/**
 * Returns a string whose value is this string, with all leading
 * and trailing {@link Character#isWhitespace(int) white space}
 * removed.
 * <p>
 * If this {@code String} object represents an empty string,
 * or if all code points in this string are
 * {@link Character#isWhitespace(int) white space}, then an empty string
 * is returned.
 * <p>
 * Otherwise, returns a substring of this string beginning with the first
 * code point that is not a {@link Character#isWhitespace(int) white space}
 * up to and including the last code point that is not a
 * {@link Character#isWhitespace(int) white space}.
 * <p>
 * This method may be used to strip
 * {@link Character#isWhitespace(int) white space} from
 * the beginning and end of a string.
 *
 * @return  a string whose value is this string, with all leading
 *          and trailing white space removed
 *
 * @see Character#isWhitespace(int)
 *
 * @since 11
 */
public String strip()

这些示例案例可能是：-

System.out.println("  leading".strip()); // prints "leading"
System.out.println("trailing  ".strip()); // prints "trailing"
System.out.println("  keep this  ".strip()); // prints "keep this"

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要修剪特定的字符，您可以使用：

String s = s.replaceAll("^(,|\\s)*|(,|\\s)*$", "")

这里将去掉前导和尾随空格和逗号。

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s.strip() 您可以从 java 11 开始使用。

s.trim() 你可以使用。

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private void capitaliseEveryWordInASentence() {

    String mm = "Hello there, this is the cluster";

    String[] words = mm.split(" ");
    String outt = "";

    for (String w : words) {

        outt = outt + Character.toUpperCase(w.charAt(0)) + w.substring(1) + " ";
    }

    System.out.println(outt.trim());
}

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