StandardCharsets jdk自带的字符编码常量字段

￡神魔★判官ぃ 2022-02-25 04:20 595阅读 0赞

### ps jdk太神奇了 ###

以前写代码，用到UTF8，gbk 等需要转化字符编码时，为了优化常用，一般会自己写一个静态字段

public static final Charset UTF_8 = Charset.forName("UTF-8");

以前发现了apache的FileUtils包里面有几个这样的常量，还沾沾自喜，  
现在才发现jdk已经为我们提供了这些字符编码的静态常量，不得不说jdk太神奇了

### StandardCharsets ###

public final class StandardCharsets {
    
        private StandardCharsets() {
            throw new AssertionError("No java.nio.charset.StandardCharsets instances for you!");
        }
        /**
         * Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the
         * Unicode character set
         */
        public static final Charset US_ASCII = Charset.forName("US-ASCII");
        /**
         * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1
         */
        public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
        /**
         * Eight-bit UCS Transformation Format
         */
        public static final Charset UTF_8 = Charset.forName("UTF-8");
        /**
         * Sixteen-bit UCS Transformation Format, big-endian byte order
         */
        public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
        /**
         * Sixteen-bit UCS Transformation Format, little-endian byte order
         */
        public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
        /**
         * Sixteen-bit UCS Transformation Format, byte order identified by an
         * optional byte-order mark
         */
        public static final Charset UTF_16 = Charset.forName("UTF-16"); 
    }

### 怎么使用 ###

非常简单

@Test
        public void testUTF8() {
            System.err.println(StandardCharsets.UTF_8.name()); //UTF-8
        }