一：inputStream轉換

1、inputStream轉為byte

//方法一  org.apache.commons.io.IOUtils包下的實現（建議）
IOUtils.toByteArray(inputStream);
//方法二  用java代碼實現（其實就是對上面方法一的解析）
public static byte[] toByteArray(InputStream input) throws IOException {
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    byte[] buffer = new
 
 byte[1024];
    int n = 0;
    while (-1 != (n = input.read(buffer))) {
        output.write(buffer, 0, n);
    }
    return output.toByteArray();
}

2、inputStream轉為file

    public static void inputstreamtofile(InputStream ins, File file) throws IOException {
        OutputStream os = new FileOutputStream(file);
        
 
int bytesRead;
        byte[] buffer = new byte[8192];
        while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
            os.write(buffer, 0, bytesRead);
        }
        os.close();
        ins.close();
    }

3、inputStream轉為String

//方法一  使用org.apache.commons.io.IOUtils包下的方法
IOUtils.toString(inputStream);

 
//方法二
    /**
     * 將InputStream轉換成某種字符編碼的String
     * 
     * @param in
     * @param encoding
     * @return
     * @throws Exception
     */
    public static String inputStreamToString(InputStream in, String encoding) {
        String string = null;
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] data = new byte[BUFFER_SIZE];
        int count = -1;
        try {
            while ((count = in.read(data, 0, BUFFER_SIZE)) != -1)
                outStream.write(data, 0, count);
        } catch (IOException e) {
            logger.error("io異常", e.fillInStackTrace());
        }

        try {
            string = new String(outStream.toByteArray(), encoding);
        } catch (UnsupportedEncodingException e) {
            logger.error("字符串編碼異常", e.fillInStackTrace());
        }
        return string;
    }

二：byte[]轉換

1、byte[]轉為inputStream

InputStream sbs = new ByteArrayInputStream(byte[] buf); 

2、byte[]轉為File

  public static void byte2File(byte[] buf, String filePath, String fileName)
    {
        BufferedOutputStream bos = null;
        FileOutputStream fos = null;
        File file = null;
        try
        {
            File dir = new File(filePath);
            if (!dir.exists() && dir.isDirectory())
            {
                dir.mkdirs();
            }
            file = new File(filePath + File.separator + fileName);
            fos = new FileOutputStream(file);
            bos = new BufferedOutputStream(fos);
            bos.write(buf);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (bos != null)
            {
                try
                {
                    bos.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            if (fos != null)
            {
                try
                {
                    fos.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }
    }

3、byte[]轉String

//先將byte[]轉為inputStream,然後在轉為String
InputStream is = new ByteArrayInputStream(byte[] byt);
//然後在根據上文提到的將inputStream轉為String的方法去轉換

三、File的轉換

1、file轉inputStream

FileInputStream fileInputStream = new FileInputStream(file);

inputStream、File、Byte、String等等之間的相互轉換