查看支持哪些字符编码：
package com.nio;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
/**
* 字符集：charset
* 编码：字符串->字节数组
* 解码：字节数组->字符串
*/
public class TestCharset {
public static void main(String[] args) {
//查看Charset支持的字符编码
SortedMap<String, Charset> map = Charset.availableCharsets();
Set<Map.Entry<String, Charset>> entries = map.entrySet();
for (Map.Entry<String, Charset> entry : entries) {
System.out.println(entry.getKey()+"="+entry.getValue());
}
}
}
运行结果：
Big5=Big5 Big5-HKSCS=Big5-HKSCS CESU-8=CESU-8 EUC-JP=EUC-JP EUC-KR=EUC-KR GB18030=GB18030 GB2312=GB2312 GBK=GBK IBM-Thai=IBM-Thai IBM00858=IBM00858 IBM01140=IBM01140 IBM01141=IBM01141 IBM01142=IBM01142 IBM01143=IBM01143 IBM01144=IBM01144 IBM01145=IBM01145 IBM01146=IBM01146 IBM01147=IBM01147 IBM01148=IBM01148 IBM01149=IBM01149 IBM037=IBM037 IBM1026=IBM1026 IBM1047=IBM1047 IBM273=IBM273 IBM277=IBM277 IBM278=IBM278 IBM280=IBM280 IBM284=IBM284 IBM285=IBM285 IBM290=IBM290 IBM297=IBM297 IBM420=IBM420 IBM424=IBM424 IBM437=IBM437 IBM500=IBM500 IBM775=IBM775 IBM850=IBM850 IBM852=IBM852 IBM855=IBM855 IBM857=IBM857 IBM860=IBM860 IBM861=IBM861 IBM862=IBM862 IBM863=IBM863 IBM864=IBM864 IBM865=IBM865 IBM866=IBM866 IBM868=IBM868 IBM869=IBM869 IBM870=IBM870 IBM871=IBM871 IBM918=IBM918 ISO-2022-CN=ISO-2022-CN ISO-2022-JP=ISO-2022-JP ISO-2022-JP-2=ISO-2022-JP-2 ISO-2022-KR=ISO-2022-KR ISO-8859-1=ISO-8859-1 ISO-8859-13=ISO-8859-13 ISO-8859-15=ISO-8859-15 ISO-8859-2=ISO-8859-2 ISO-8859-3=ISO-8859-3 ISO-8859-4=ISO-8859-4 ISO-8859-5=ISO-8859-5 ISO-8859-6=ISO-8859-6 ISO-8859-7=ISO-8859-7 ISO-8859-8=ISO-8859-8 ISO-8859-9=ISO-8859-9 JIS_X0201=JIS_X0201 JIS_X0212-1990=JIS_X0212-1990 KOI8-R=KOI8-R KOI8-U=KOI8-U Shift_JIS=Shift_JIS TIS-620=TIS-620 US-ASCII=US-ASCII UTF-16=UTF-16 UTF-16BE=UTF-16BE UTF-16LE=UTF-16LE UTF-32=UTF-32 UTF-32BE=UTF-32BE UTF-32LE=UTF-32LE UTF-8=UTF-8 windows-1250=windows-1250 windows-1251=windows-1251 windows-1252=windows-1252 windows-1253=windows-1253 windows-1254=windows-1254 windows-1255=windows-1255 windows-1256=windows-1256 windows-1257=windows-1257 windows-1258=windows-1258 windows-31j=windows-31j x-Big5-HKSCS-2001=x-Big5-HKSCS-2001 x-Big5-Solaris=x-Big5-Solaris x-euc-jp-linux=x-euc-jp-linux x-EUC-TW=x-EUC-TW x-eucJP-Open=x-eucJP-Open x-IBM1006=x-IBM1006 x-IBM1025=x-IBM1025 x-IBM1046=x-IBM1046 x-IBM1097=x-IBM1097 x-IBM1098=x-IBM1098 x-IBM1112=x-IBM1112 x-IBM1122=x-IBM1122 x-IBM1123=x-IBM1123 x-IBM1124=x-IBM1124 x-IBM1166=x-IBM1166 x-IBM1364=x-IBM1364 x-IBM1381=x-IBM1381 x-IBM1383=x-IBM1383 x-IBM300=x-IBM300 x-IBM33722=x-IBM33722 x-IBM737=x-IBM737 x-IBM833=x-IBM833 x-IBM834=x-IBM834 x-IBM856=x-IBM856 x-IBM874=x-IBM874 x-IBM875=x-IBM875 x-IBM921=x-IBM921 x-IBM922=x-IBM922 x-IBM930=x-IBM930 x-IBM933=x-IBM933 x-IBM935=x-IBM935 x-IBM937=x-IBM937 x-IBM939=x-IBM939 x-IBM942=x-IBM942 x-IBM942C=x-IBM942C x-IBM943=x-IBM943 x-IBM943C=x-IBM943C x-IBM948=x-IBM948 x-IBM949=x-IBM949 x-IBM949C=x-IBM949C x-IBM950=x-IBM950 x-IBM964=x-IBM964 x-IBM970=x-IBM970 x-ISCII91=x-ISCII91 x-ISO-2022-CN-CNS=x-ISO-2022-CN-CNS x-ISO-2022-CN-GB=x-ISO-2022-CN-GB x-iso-8859-11=x-iso-8859-11 x-JIS0208=x-JIS0208 x-JISAutoDetect=x-JISAutoDetect x-Johab=x-Johab x-MacArabic=x-MacArabic x-MacCentralEurope=x-MacCentralEurope x-MacCroatian=x-MacCroatian x-MacCyrillic=x-MacCyrillic x-MacDingbat=x-MacDingbat x-MacGreek=x-MacGreek x-MacHebrew=x-MacHebrew x-MacIceland=x-MacIceland x-MacRoman=x-MacRoman x-MacRomania=x-MacRomania x-MacSymbol=x-MacSymbol x-MacThai=x-MacThai x-MacTurkish=x-MacTurkish x-MacUkraine=x-MacUkraine x-MS932_0213=x-MS932_0213 x-MS950-HKSCS=x-MS950-HKSCS x-MS950-HKSCS-XP=x-MS950-HKSCS-XP x-mswin-936=x-mswin-936 x-PCK=x-PCK x-SJIS_0213=x-SJIS_0213 x-UTF-16LE-BOM=x-UTF-16LE-BOM X-UTF-32BE-BOM=X-UTF-32BE-BOM X-UTF-32LE-BOM=X-UTF-32LE-BOM x-windows-50220=x-windows-50220 x-windows-50221=x-windows-50221 x-windows-874=x-windows-874 x-windows-949=x-windows-949 x-windows-950=x-windows-950 x-windows-iso2022jp=x-windows-iso2022jp
编码解码小案例：
package com.nio;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
/**
* 字符集
* 编码和解码的小案例
*/
public class TestCharsetDemo {
public static void main(String[] args) throws CharacterCodingException {
Charset cs1 = Charset.forName("GBK");
//获取解码器
CharsetEncoder ce = cs1.newEncoder();
//获取解码器
CharsetDecoder cd = cs1.newDecoder();
CharBuffer cBuf = CharBuffer.allocate(1024);
cBuf.put("张家口加油！");
cBuf.flip();
//编码
ByteBuffer bBuf = ce.encode(cBuf);
for (int i=0;i<12;i++) {
System.out.println(bBuf.get());
}
//解码
bBuf.flip();
CharBuffer cBuf2 = cd.decode(bBuf);
System.out.println(cBuf2.toString());
//解码 使用utf-8进行解码
Charset cs2 = Charset.forName("UTF-8");
bBuf.flip();
CharBuffer cBuf3 = cs2.decode(bBuf);
System.out.println(cBuf3.toString());
}
}
运行结果：
-43 -59 -68 -46 -65 -38 -68 -45 -45 -51 -93 -95 张家口加油！ �żҿڼ��ͣ�
由此可见，当编码和解码的方式不同的时候，会出现乱码。这在实际项目开发过程中一定要注意。
当客户端向服务端发送一个读写请求的时候，服务端无法判断读写请求中信息真实有效的时候，就会陷入阻塞状态。