Long.parseLong("+2013") 抛出 NumberFormatException

Question

我正在尝试使用外部 Java 库来处理 Android 但在处理日期时出现错误。

我已将范围缩小到这一行：

Long year = Long.parseLong("+2013");

抛出一个

Caused by: java.lang.NumberFormatException: Invalid long: "+2013"

但是，该代码是有效的并且可以在纯 Java 应用程序中运行。为什么 Long.parseLong() 在 Android 应用程序中的工作方式不同？

Android's documentation 声明“+”Ascii 符号被识别：

public static long parseLong (String string)
Parses the specified string as a signed decimal long value. The ASCII characters - ('-') and + ('+') are recognized as the minus and plus signs.

Answer 1

谢谢大家！设法找出问题所在。

似乎 API 17: Android 4.2 (Jelly Bean) 引起了问题。 API 没有正确处理 parseLong() 中的“+”号。

解决了将编译 SDK 更改为 API 21 及更高版本的问题。

API 20 parseLong()

    /**
 * Parses the specified string as a signed long value using the specified
 * radix. The ASCII character \u002d ('-') is recognized as the minus sign.
 *
 * @param string
 *            the string representation of a long value.
 * @param radix
 *            the radix to use when parsing.
 * @return the primitive long value represented by {@code string} using
 *         {@code radix}.
 * @throws NumberFormatException
 *             if {@code string} cannot be parsed as a long value, or
 *             {@code radix < Character.MIN_RADIX ||
 *             radix > Character.MAX_RADIX}.
 */
public static long parseLong(String string, int radix) throws NumberFormatException {
    if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
        throw new NumberFormatException("Invalid radix: " + radix);
    }
    if (string == null) {
        throw invalidLong(string);
    }
    int length = string.length(), i = 0;
    if (length == 0) {
        throw invalidLong(string);
    }
    boolean negative = string.charAt(i) == '-';
    if (negative && ++i == length) {
        throw invalidLong(string);
    }

    return parse(string, i, radix, negative);
}

API 21 parseLong()

    /**
 * Parses the specified string as a signed long value using the specified
 * radix. The ASCII characters \u002d ('-') and \u002b ('+') are recognized
 * as the minus and plus signs.
 *
 * @param string
 *            the string representation of a long value.
 * @param radix
 *            the radix to use when parsing.
 * @return the primitive long value represented by {@code string} using
 *         {@code radix}.
 * @throws NumberFormatException
 *             if {@code string} cannot be parsed as a long value, or
 *             {@code radix < Character.MIN_RADIX ||
 *             radix > Character.MAX_RADIX}.
 */
public static long parseLong(String string, int radix) throws NumberFormatException {
    if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
        throw new NumberFormatException("Invalid radix: " + radix);
    }
    if (string == null || string.isEmpty()) {
        throw invalidLong(string);
    }
    char firstChar = string.charAt(0);
    int firstDigitIndex = (firstChar == '-' || firstChar == '+') ? 1 : 0;
    if (firstDigitIndex == string.length()) {
        throw invalidLong(string);
    }

    return parse(string, firstDigitIndex, radix, firstChar == '-');
}

Long.parseLong("+2013") 抛出 NumberFormatException

Long.parseLong("+2013") throws NumberFormatException

android

numberformatexception