Java编码转换

java字符串应用之字符串编码转换

(2009-09-26 22:54:19)

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标签： 编码转换 it

无论是对程序的本地化还是国际化，都会涉及到字符编码的转换的问题。尤其在web应用中常常需要处理中文字符，这时就需要进行字符串的编码转换，将字符串编码转换为GBK或者GB2312。

一、关键技术点：
    1、当前流行的字符编码格式有：US-ASCII、ISO-8859-1、UTF-8、UTF-16BE、UTF-16LE、UTF-16、GBK、GB2312等，其中GBK、GB2312是专门处理中文编码的。
    2、String的getBytes方法用于按指定编码获取字符串的字节数组，参数指定了解码格式，如果没有指定解码格式，则按系统默认编码格式。
    3、String的“String(bytes[] bs, String charset)”构造方法用于把字节数组按指定的格式组合成一个字符串对象
   

二、实例演示：

 

 

package book.String;

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 static final String GB2312 = "GB2312";
   
   
    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 toGB2312(String str) throws UnsupportedEncodingException ...{
        return this.changeCharset(str,GB2312);
    }
   
   
    public String changeCharset(String str, String newCharset) throws UnsupportedEncodingException ...{
        if(str != null) ...{
            //用默认字符编码解码字符串。与系统相关，中文windows默认为GB2312
            byte[] bs = str.getBytes();
            return new String(bs, newCharset);    //用新的字符编码生成字符串
        }
        return null;
    }
   
   
    public String changeCharset(String str, String oldCharset, String newCharset) throws UnsupportedEncodingException ...{
        if(str != null) ...{
            //用源字符编码解码字符串
            byte[] bs = str.getBytes(oldCharset);
            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：" + ascii);
        System.out.println();
       
        String iso88591 = test.toISO_8859_1(str);
        System.out.println("转换成ISO-8859-1码：" + iso88591);
        System.out.println();
       
        gbk = test.changeCharset(iso88591, ISO_8859_1, 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();
        System.out.println("转换成UTF-8码：" + utf8);
        String utf16be = test.toUTF_16BE(str);
        System.out.println("转换成UTF-16BE码：" + utf16be);
        gbk = test.changeCharset(utf16be, UTF_16BE, GBK);
        System.out.println("再把UTF-16BE编码的字符转换成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, UTF_16LE, GBK);
        System.out.println("再把UTF-16LE编码的字符串转换成GBK码：" + gbk);
        System.out.println();
       
        String utf16 = test.toUTF_16(str);
        System.out.println("转换成UTF-16码：" + utf16);
        String gb2312 = test.changeCharset(utf16, UTF_16, GB2312);
        System.out.println("再把UTF-16编码的字符串转换成GB2312码：" + gb2312);
    }