src/be/nikiroo/utils/serial/CustomSerializer.java

   1 package be.nikiroo.utils.serial;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.io.OutputStream;
   6
   7 import be.nikiroo.utils.IOUtils;
   8 import be.nikiroo.utils.streams.NextableInputStream;
   9 import be.nikiroo.utils.streams.NextableInputStreamStep;
  10
  11 public abstract class CustomSerializer {
  12
  13         protected abstract void toStream(OutputStream out, Object value)
  14                         throws IOException;
  15
  16         protected abstract Object fromStream(InputStream in) throws IOException;
  17
  18         protected abstract String getType();
  19
  20         /**
  21          * Encode the object into the given {@link OutputStream} if supported.
  22          *
  23          * @param out
  24          *            the builder to append to
  25          * @param value
  26          *            the object to encode
  27          *
  28          * @return FALSE if the value is not supported, TRUE if the operation was
  29          *         successful (if the value is supported by the operation was not
  30          *         successful, you will get an {@link IOException})
  31          *
  32          * @throws IOException
  33          *             in case of I/O error
  34          */
  35         public boolean encode(OutputStream out, Object value) throws IOException {
  36                 SerialUtils.write(out, "custom^");
  37                 SerialUtils.write(out, getType());
  38                 SerialUtils.write(out, "^");
  39                 // TODO: manage ENTER
  40                 toStream(out, value);
  41
  42                 return true;
  43         }
  44
  45         public Object decode(InputStream in) throws IOException {
  46                 // TODO: manage ENTER
  47                 NextableInputStream stream = new NextableInputStream(in,
  48                                 new NextableInputStreamStep('^'));
  49
  50                 try {
  51                         if (!stream.next()) {
  52                                 throw new IOException("Cannot find the first custom^ element");
  53                         }
  54
  55                         String custom = IOUtils.readSmallStream(stream);
  56                         if (!"custom".equals(custom)) {
  57                                 throw new IOException(
  58                                                 "Cannot find the first custom^ element, it is: "
  59                                                                 + custom + "^");
  60                         }
  61
  62                         if (!stream.next()) {
  63                                 throw new IOException("Cannot find the second custom^"
  64                                                 + getType() + " element");
  65                         }
  66
  67                         String type = IOUtils.readSmallStream(stream);
  68                         if (!getType().equals(type)) {
  69                                 throw new IOException("Cannot find the second custom^"
  70                                                 + getType() + " element, it is: custom^" + type + "^");
  71                         }
  72
  73                         if (!stream.nextAll()) {
  74                                 throw new IOException("Cannot find the third custom^"
  75                                                 + getType() + "^value element");
  76                         }
  77
  78                         // TODO: manage ENTER
  79                         return fromStream(stream);
  80                 } finally {
  81                         stream.close(false);
  82                 }
  83         }
  84
  85         public static boolean isCustom(String encodedValue) {
  86                 int pos1 = encodedValue.indexOf('^');
  87                 int pos2 = encodedValue.indexOf('^', pos1 + 1);
  88
  89                 return pos1 >= 0 && pos2 >= 0 && encodedValue.startsWith("custom^");
  90         }
  91
  92         public static String typeOf(String encodedValue) {
  93                 int pos1 = encodedValue.indexOf('^');
  94                 int pos2 = encodedValue.indexOf('^', pos1 + 1);
  95                 String type = encodedValue.substring(pos1 + 1, pos2);
  96
  97                 return type;
  98         }
  99
 100         public static String contentOf(String encodedValue) {
 101                 int pos1 = encodedValue.indexOf('^');
 102                 int pos2 = encodedValue.indexOf('^', pos1 + 1);
 103                 String encodedContent = encodedValue.substring(pos2 + 1);
 104
 105                 return encodedContent;
 106         }
 107 }