java字符串的各种编码转换

java字符串的各种编码转换 
import java.io.UnsupportedEncodingException;

/**
 * 转换字符串的编码
 */
public class ChangeCharset {
 /** 7位ASCII字符，也叫作ISO646-US、Unicode字符集的基本拉丁块 */
 public static final String US_ASCII = "US-ASCII";

 /** ISO 拉丁字母表 No.1，也叫作 ISO-LATIN-1 */
 public static final String ISO_8859_1 = "ISO-8859-1";

 /** 8 位 UCS 转换格式 */
 public static final String UTF_8 = "UTF-8";

 /** 16 位 UCS 转换格式，Big Endian（最低地址存放高位字节）字节顺序 */
 public static final String UTF_16BE = "UTF-16BE";

 /** 16 位 UCS 转换格式，Little-endian（最高地址存放低位字节）字节顺序 */
 public static final String UTF_16LE = "UTF-16LE";

 /** 16 位 UCS 转换格式，字节顺序由可选的字节顺序标记来标识 */
 public static final String UTF_16 = "UTF-16";

 /** 中文超大字符集 */
 public static final String GBK = "GBK";

 /**
  * 将字符编码转换成US-ASCII码

  */
 public String toASCII(String str) throws UnsupportedEncodingException{
  return this.changeCharset(str, US_ASCII);
 }
 /**
  * 将字符编码转换成ISO-8859-1码
  */
 public String toISO_8859_1(String str) throws UnsupportedEncodingException{
  return this.changeCharset(str, ISO_8859_1);
 }
 /**
  * 将字符编码转换成UTF-8码
  */
 public String toUTF_8(String str) throws UnsupportedEncodingException{
  return this.changeCharset(str, UTF_8);
 }
 /**
  * 将字符编码转换成UTF-16BE码
  */
 public String toUTF_16BE(String str) throws UnsupportedEncodingException{
  return this.changeCharset(str, UTF_16BE);
 }
 /**
  * 将字符编码转换成UTF-16LE码
  */
 public String toUTF_16LE(String str) throws UnsupportedEncodingException{
  return this.changeCharset(str, UTF_16LE);
 }
 /**
  * 将字符编码转换成UTF-16码