java中byte,String,InputStream之间的转换

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 
 * @author Andy.Chen
 * @mail Chenjunjun.ZJ@gmail.com
 *
 */
public class InputStreamUtils {
    
    final static int BUFFER_SIZE = 4096;
    
    /**
     * 将InputStream转换成String
     * @param in InputStream
     * @return String
     * @throws Exception
     * 
     */
    public static String InputStreamTOString(InputStream in) throws Exception{
        
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] data = new byte[BUFFER_SIZE];
        int count = -1;
        while((count = in.read(data,0,BUFFER_SIZE)) != -1)
            outStream.write(data, 0, count);
        
        data = null;
        return new String(outStream.toByteArray(),"ISO-8859-1");
    }
    
    /**
     * 将InputStream转换成某种字符编码的String
     * @param in
     * @param encoding
     * @return
     * @throws Exception
     */
         public static String InputStreamTOString(InputStream in,String encoding) throws Exception{
        
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] data = new byte[BUFFER_SIZE];
        int count = -1;
        while((count = in.read(data,0,BUFFER_SIZE)) != -1)
            outStream.write(data, 0, count);
        
        data = null;
        return new String(outStream.toByteArray(),"ISO-8859-1");
    }
    
    /**
     * 将String转换成InputStream
     * @param in
     * @return
     * @throws Exception
     */
    public static InputStream StringTOInputStream(String in) throws Exception{
        
        ByteArrayInputStream is = new ByteArrayInputStream(in.getBytes("ISO-8859-1"));
        return is;
    }
    
    /**
     * 将InputStream转换成byte数组
     * @param in InputStream
     * @return byte[]
     * @throws IOException
     */
    public static byte[] InputStreamTOByte(InputStream in) throws IOException{
        
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] data = new byte[BUFFER_SIZE];
        int count = -1;
        while((count = in.read(data,0,BUFFER_SIZE)) != -1)
            outStream.write(data, 0, count);
        
        data = null;
        return outStream.toByteArray();
    }
    
    /**
     * 将byte数组转换成InputStream
     * @param in
     * @return
     * @throws Exception
     */
    public static InputStream byteTOInputStream(byte[] in) throws Exception{
        
        ByteArrayInputStream is = new ByteArrayInputStream(in);
        return is;
    }
    
    /**
     * 将byte数组转换成String
     * @param in
     * @return
     * @throws Exception
     */
    public static String byteTOString(byte[] in) throws Exception{
        
        InputStream is = byteTOInputStream(in);
        return InputStreamTOString(is);
    }

}

摘自 http://blog.csdn.net/xinzhu1990/article/details/7055602