java字符串的各种编码转换

import java.io.UnsupportedEncodingException;


public class ChangeCharset {


public static final String US_ASCII = "US-ASCII";


public static final String ISO_8859_1 = "ISO-8859-1";


public static final String UTF_8 = "UTF-8";


public static final String UTF_16BE = "UTF-16BE";


public static final String UTF_16LE = "UTF-16LE";


public static final String UTF_16 = "UTF-16";


public static final String GBK = "GBK";


public String toASCII(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, US_ASCII);
}


public String toISO_8859_1(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, ISO_8859_1);
}


public String toUTF_8(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, UTF_8);
}


public String toUTF_16BE(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, UTF_16BE);
}


public String toUTF_16LE(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, UTF_16LE);
}


public String toUTF_16(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, UTF_16);
}


public String toGBK(String str) throws UnsupportedEncodingException {
return this.changeCharset(str, GBK);
}


public String changeCharset(String str, String newCharset)
throws UnsupportedEncodingException {
if (str != null) {
// 用默认字符编码解码字符串。
byte[] bs = str.getBytes();
// 用新的字符编码生成字符串
return new String(bs, newCharset);
}
return null;
}


public String changeCharset(String str, String oldCharset, String newCharset)
throws UnsupportedEncodingException {
if (str != null) {
// 用旧的字符编码解码字符串。解码可能会出现异常。
byte[] bs = str.getBytes(oldCharset);
// 用新的字符编码生成字符串
return new String(bs, newCharset);
}
return null;
}


public static void main(String[] args) throws UnsupportedEncodingException {
ChangeCharset test = new ChangeCharset();
String str = "This is a 中文的 String!";
System.out.println("str: " + str);
String gbk = test.toGBK(str);
System.out.println("转换成GBK码: " + gbk);
System.out.println();


String ascii = test.toASCII(str);
System.out.println("转换成US-ASCII码: " + ascii);
gbk = test.changeCharset(ascii, ChangeCharset.US_ASCII, ChangeCharset.GBK);
System.out.println("再把ASCII码的字符串转换成GBK码: " + gbk);
System.out.println();


String iso88591 = test.toISO_8859_1(str);
System.out.println("转换成ISO-8859-1码: " + iso88591);
gbk = test.changeCharset(iso88591, ChangeCharset.ISO_8859_1, ChangeCharset.GBK);
System.out.println("再把ISO-8859-1码的字符串转换成GBK码: " + gbk);
System.out.println();


String utf8 = test.toUTF_8(str);
System.out.println("转换成UTF-8码: " + utf8);
gbk = test.changeCharset(utf8, ChangeCharset.UTF_8, ChangeCharset.GBK);
System.out.println("再把UTF-8码的字符串转换成GBK码: " + gbk);
System.out.println();


String utf16be = test.toUTF_16BE(str);
System.out.println("转换成UTF-16BE码:" + utf16be);
gbk = test.changeCharset(utf16be, ChangeCharset.UTF_16BE, ChangeCharset.GBK);
System.out.println("再把UTF-16BE码的字符串转换成GBK码: " + gbk);
System.out.println();


String utf16le = test.toUTF_16LE(str);
System.out.println("转换成UTF-16LE码:" + utf16le);
gbk = test.changeCharset(utf16le, ChangeCharset.UTF_16LE, ChangeCharset.GBK);
System.out.println("再把UTF-16LE码的字符串转换成GBK码: " + gbk);
System.out.println();


String utf16 = test.toUTF_16(str);
System.out.println("转换成UTF-16码:" + utf16);
gbk = test.changeCharset(utf16, ChangeCharset.UTF_16LE, ChangeCharset.GBK);
System.out.println("再把UTF-16码的字符串转换成GBK码: " + gbk);
String s = new String("中文".getBytes("UTF-8"), "UTF-8");
System.out.println(s);
}
}