String与Inputstream相互转换

package com.sinotrans.filesystem.util;

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

/**
 * 
 * @author Andy.Chen
 * @mail [email protected]
 * 
 */
public class InputStreamUtil {

	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);
	}
	
	public static void main(String args[]){
		InputStream readFile = FileUtil.readFile("D:/1.jpg");
		try {
			String inputStreamTOString = InputStreamTOString(readFile);
			System.out.println("input转String"+ inputStreamTOString);
			
			String encode = Base64Util.encode(inputStreamTOString);  // base64 加密
			System.out.println();
			System.out.println(encode);
			System.out.println();
			String decode = new String (Base64Util.decode(encode),"UTF-8");	// base64 解密
			
			InputStream stringTOInputStream = StringTOInputStream(decode);
			File saveFile = FileUtil.saveFile(stringTOInputStream, "D:/thu_1.jpg");
			
			System.out.println("写出去的文件名称"+ saveFile.getPath());
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}