Java NIO之Charset类字符编码对象

This class defines methods for creating decoders and encoders and for retrieving the various names associated with a charset.   
Instances of this class are immutable.


This class also defines static methods for testing whether a particular charset is supported, 
for locating charset instances by name, and for constructing a map that contains every charset  
for which support is available in the current Java virtual machine.

public static Charset forName(String charsetName)//通过编码类型获得Charset对象
public static SortedMap<String,Charset> availableCharsets()//获得系统支持的所有编码方式
public static Charset defaultCharset()//获得虚拟机默认的编码方式
public static boolean isSupported(String charsetName)//判断是否支持该编码类型

public final String name()//获得Charset对象的编码类型(String)
public abstract CharsetEncoder newEncoder()//获得编码器对象
public abstract CharsetDecoder newDecoder()//获得解码器对象
. . . 还有很多方法

public void testGetAvailableCharsets() {

    // 获得本机所有编码格式
    Map<String, Charset> charsets = Charset.availableCharsets();
    // 迭代遍历出编码方式
    for (Entry<String, Charset> entry : charsets.entrySet()) {
        System.out.println(entry.getKey() + " : " + entry.getValue().name());
    }

}

// 获得JVM默认编码方式
Charset charset=Charset.defaultCharset();

public void testEncoderAndDecoder() throws Exception{

    //使用Charset进行编码和解码
    CharsetEncoder encoder=Charset.forName("GBK").newEncoder();
    CharsetDecoder decoder=Charset.forName("GBK").newDecoder();

    ByteBuffer byteBuffer=encoder.encode(CharBuffer.wrap("中国编码".toCharArray()));

    CharBuffer charBuffer=decoder.decode(byteBuffer);
    String string=charBuffer.toString();

    System.out.println(string);

}