Java 几个类或者方法的用法

String separetor = File.separator;
// 获取系统的文件分隔符

System.getProperty("user.dir")
// 得到当前的工做路径

//编码
ByteBuffer buffer = cset.encode("dafafe");
byte[] bytes = buffer.array();
//转码
byte[] byt={1,2};
ByteBuffer bbuf = ByteBuffer.wrap(byt);
CharBuffer cbuf = cset.decode(bbuf);
String str = cbuf.toString();

StringTokenizer t = new StringTokenizer(s, "|"); // 分隔符工具
//文件过滤
public class ExtensionFilter implements FilenameFilter {

	private String extension;
	public ExtensionFilter(String ext){
		extension = "."+ext;
	}
	@Override
	public boolean accept(File dir, String name) {
		return name.endsWith(extension);
	}

}

//使用
 File directory=new File(filename);   
 String[] files = directory.list(new ExtensionFilter());