将图片文件流转换成base64字符串

/**

  * 将文件流转换成base64字符串

  * @param screenshot    文件流

  * @return

  */

 private String file2ImgStr(File screenshot){

  try {

   byte[] data = null;

   // 读取图片字节数组

   try {

    //得到输入流

    InputStream in = new FileInputStream(screenshot);

    data = new byte[in.available()];

    in.read(data);

    in.close();

   } catch (IOException e) {

    e.printStackTrace();

   }

   // 对字节数组Base64编码

   BASE64Encoder encoder = new BASE64Encoder();

   return encoder.encode(data);

  } catch (Exception e) {

   e.printStackTrace();

  }

  return null;

 }

public static File byteArrayToFile(String path, String FileName, Object byteArr){

  File directory = new File(path);

  //不是文件夹,就返回空

  if(!directory.isDirectory() || null == byteArr)return null;

  if(!directory.exists()){

   directory.mkdirs();

  }

  //文件

  File file = new File(path,FileName);

  if(!file.exists()){

   try {

    file.createNewFile();

   } catch (IOException e) {

    e.printStackTrace();

   }

  }

  FileOutputStream out = null;

  InputStream in = null;

  try {

   out = new FileOutputStream(file);

   out.write((byte[])byteArr);

   out.flush();

  } catch (Exception e) {

   Blob b = (Blob)byteArr;

   try {

    in = b.getBinaryStream();

    int len = 1024*8;

    int offset = 0;

    byte[] buf = new byte[len];

    while((offset=in.read(buf, 0, len))!=-1){

     out.write(buf, 0, offset);

    }

    out.flush();

   } catch (Exception e1) {

    e1.printStackTrace();

   }

  }finally{

   if(null != out){

    try {

     out.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

   if(null != in){

    try {

     in.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

  }

  return file;

 }

 

/**

  * 将File文件转换为byte数组

  * @param f  file文件

  * @return   字节数组

  */

 @SuppressWarnings("resource")

 public static byte[] FileToByteArray(File f){

  int len = 1024*8;

  byte[] buf = new byte[len];

  int offset = 0;

  FileInputStream in = null;

  ByteArrayOutputStream out = null;

  try {

   in = new FileInputStream(f);

   out = new ByteArrayOutputStream();

   while((offset=in.read(buf, 0, len))!=-1){

    out.write(buf, 0, offset);

   }

   return out.toByteArray();

  } catch (Exception e) {

   e.printStackTrace();

  }finally{

   if(null != in){

    try {

     in.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

   if(null != out){

    try {

     out.close();

    } catch (IOException e) {

     e.printStackTrace();

    }

   }

  }

  return null;

 }

public static void main(String[] args){

//将附件内容转换成流

  File f = (File)byteArrayToFile(保存图片的路径, “图片字符串” ，utf003);

  //将流转换为base64字符串

  String strBase64 = file2ImgStr(f);

  //获取图片流

  BufferedImage src = javax.imageio.ImageIO.read(new FileInputStream(f));

}