java String getBytes() 解析 平台处理

java的String类的getBytes()方法:

    public byte[] getBytes() {
 return StringCoding.encode(value, offset, count);
    }

StringCoding的encode方法

    static byte[] encode(char[] ca, int off, int len) {
 String csn = Charset.defaultCharset().name();
 try {
     return encode(csn, ca, off, len);
 } catch (UnsupportedEncodingException x) {
     warnUnsupportedCharset(csn);
 }
 try {
     return encode("ISO-8859-1", ca, off, len);
 } catch (UnsupportedEncodingException x) {
     // If this code is hit during VM initialization, MessageUtils is
     // the only way we will be able to get any kind of error message.
     MessageUtils.err("ISO-8859-1 charset not available: "
        + x.toString());
     // If we can not find ISO-8859-1 (a required encoding) then things
     // are seriously wrong with the installation.
     System.exit(1);
     return null;
 }
    }

由此可见，getBytes()方法是受JVM平台字符集限制的。

如果使用String.getBytes(“UTF8”), 也需要注意并不是所有的平台都支持utf-8字符集。

所以最好的方法就是自己封装一个toByteArray方法:

public static byte[] toByteArray(String string) {

byte[] bytes = new byte[string.length()];

char[] chars = string.toCharArray(); f

or (int i = 0; i != chars.length; i++)

{ bytes[i] = (byte)chars[i]; } return bytes; }

和toString方法:

public static String toString(byte[] bytes, int length) {

 char[] chars = new char[length];

for (int i = 0; i != chars.length; i++)

 { chars[i] = (char)(bytes[i] & 0xff); } return new String(chars); }