如何在Java中将yyyymm数据格式解析为Month、YYYY格式？

Question

我有一个等于 的字符串值"202004"。我怎样才能将它转换为"April, 2020" Java？

Answer 1

我会用于java.time这样的任务。

您可以定义两个java.time.format.DateTimeFormatter实例（一个用于将输入字符串解析为java.time.YearMonth，另一个用于将获得的字符串格式化YearMonth为所需格式的字符串）。

定义一个像这样的方法：

public static String convert(String monthInSomeYear, Locale locale) {
    // create something that is able to parse such input
    DateTimeFormatter inputParser = DateTimeFormatter.ofPattern("uuuuMM");
    // then use that formatter in order to create an object of year and month
    YearMonth yearMonth = YearMonth.parse(monthInSomeYear, inputParser);
    /*
     * the output format is different, so create another formatter
     * with a different pattern. Please note that you need a Locale
     * in order to define the language used for month names in the output.
     */
    DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern(
                                            "MMMM, uuuu",
                                            Locale.ENGLISH
                                        );
    // then return the desired format
    return yearMonth.format(outputFormatter);
}

然后使用它，例如在main方法中：

public static void main(String[] args) {
    // your example input
    String monthInAYear = "202004";
    // use the method
    String sameMonthInAYear = convert(monthInAYear, Locale.ENGLISH);
    // and print the result
    System.out.println(sameMonthInAYear);
}

输出将是这样的：

April, 2020