方式一：

/**

* 将字符串的编码格式转换为utf-8

*

* @param str

* @return Name = new

* String(Name.getBytes("ISO-8859-1"), "utf-8");

*/

public static String toUTF8(String str) {

if (isEmpty(str)) {

return "";

}

try {

if (str.equals(new String(str.getBytes("GB2312"), "GB2312"))) {

str = new String(str.getBytes("GB2312"), "utf-8");

return str;

}

} catch (Exception exception) {

}

try {

if (str.equals(new String(str.getBytes("ISO-8859-1"), "ISO-8859-1"))) {

str = new String(str.getBytes("ISO-8859-1"), "utf-8");

return str;

}

} catch (Exception exception1) {

}

try {

if (str.equals(new String(str.getBytes("GBK"), "GBK"))) {

str = new String(str.getBytes("GBK"), "utf-8");

return str;

}

} catch (Exception exception3) {

}

return str;

}

/**

* 判断是否为空

*

* @param str

* @return

*/

public static boolean isEmpty(String str) {

// 如果字符串不为null，去除空格后值不与空字符串相等的话，证明字符串有实质性的内容

if (str != null && !str.trim().isEmpty()) {

return false;// 不为空

}

return true;// 为空

}

方式二：

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

*/

public String toUTF_16(String str) throws UnsupportedEncodingException{

return this.changeCharset(str, UTF_16);

}

/**

* 将字符编码转换成GBK码

*/

public String toGBK(String str) throws UnsupportedEncodingException{

return this.changeCharset(str, GBK);

}

/**

* 字符串编码转换的实现方法

* @param str 待转换编码的字符串

* @param newCharset 目标编码

* @return

* @throws UnsupportedEncodingException

*/

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;

}

/**

* 字符串编码转换的实现方法

* @param str 待转换编码的字符串

* @param oldCharset 原编码

* @param newCharset 目标编码

* @return

* @throws UnsupportedEncodingException

*/

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);

}

}