Clob，Blob，InputStream，byte 互转

一、byte[]=>Blob

我们可以通过Hibernate提供的表态方法来实现如：

org.hibernate.Hibernate.Hibernate.createBlob(new byte[1024]);

二、Blob=>byte[]

/**
* 把Blob类型转换为byte数组类型
* @param blob
* @return
*/
private byte [] blobToBytes(Blob blob) {

  BufferedInputStream is = null ;
  try {
    is = new BufferedInputStream(blob.getBinaryStream());
    byte [] bytes = new byte [( int ) blob.length()];
    int len = bytes.length;
    int offset = 0 ;
    int read = 0 ;
    while (offset < len && (read = is.read(bytes, offset, len offset)) >= 0 ) {
      offset += read;
    }
    return bytes;
  } catch (Exception e) {
    return null ;
  } finally {
    try {
      is.close();
      is = null ;
    } catch (IOException e) {
      return null ;
    }
  }
}

三、InputStream=>byte[]

private byte [] InputStreamToByte(InputStream is) throws IOException {

  ByteArrayOutputStream bytestream = new ByteArrayOutputStream();
  int ch;
  while ((ch = is.read()) != - 1 ) {
    bytestream.write(ch);
  }
  byte imgdata[] = bytestream.toByteArray();
  bytestream.close();

  return imgdata;
}

四、byte[]  => InputStream 

InputStream is = new ByteArrayInputStream(new byte[1024]);




五、InputStream => Blob


可通过Hibernate提供的API：


Hibernate.createBlob(new FileInputStream(" 可以为图片/文件等路径 "));





六、Blob => InputStream


Blog转流，可通过提供的API直接调用：


new Blob().getBinaryStream();





转：http://my.oschina.net/zimingforever/blog/81691