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

   1 package be.nikiroo.utils.serial;
   2
   3 import java.io.IOException;
   4 import java.io.NotSerializableException;
   5 import java.io.OutputStream;
   6 import java.util.HashMap;
   7 import java.util.Map;
   8
   9 import be.nikiroo.utils.StringUtils;
  10
  11 /**
  12  * A simple class to serialise objects to {@link String}.
  13  * <p>
  14  * This class does not support inner classes (it does support nested classes,
  15  * though).
  16  *
  17  * @author niki
  18  */
  19 public class Exporter {
  20         private Map<Integer, Object> map;
  21         private OutputStream out;
  22
  23         /**
  24          * Create a new {@link Exporter}.
  25          */
  26         public Exporter(OutputStream out) {
  27                 if (out == null) {
  28                         throw new NullPointerException(
  29                                         "Cannot create an be.nikiroo.utils.serials.Exporter that will export to NULL");
  30                 }
  31
  32                 this.out = out;
  33                 map = new HashMap<Integer, Object>();
  34         }
  35
  36         /**
  37          * Serialise the given object and add it to the list.
  38          * <p>
  39          * <b>Important: </b>If the operation fails (with a
  40          * {@link NotSerializableException}), the {@link Exporter} will be corrupted
  41          * (will contain bad, most probably not importable data).
  42          *
  43          * @param o
  44          *            the object to serialise
  45          * @return this (for easier appending of multiple values)
  46          *
  47          * @throws NotSerializableException
  48          *             if the object cannot be serialised (in this case, the
  49          *             {@link Exporter} can contain bad, most probably not
  50          *             importable data)
  51          * @throws IOException
  52          *             in case of I/O error
  53          */
  54         public Exporter append(Object o) throws NotSerializableException,
  55                         IOException {
  56                 SerialUtils.append(out, o, map);
  57                 return this;
  58         }
  59
  60         /**
  61          * Append the exported items in a serialised form into the given
  62          * {@link OutputStream}.
  63          *
  64          * @param out
  65          *            the {@link OutputStream}
  66          * @param b64
  67          *            TRUE to have BASE64-coded content, FALSE to have raw content,
  68          *            NULL to let the system decide
  69          * @param zip
  70          *            TRUE to zip the BASE64 output if the output is indeed in
  71          *            BASE64 format, FALSE not to
  72          */
  73         public void appendTo(OutputStream out, Boolean b64, boolean zip) {
  74                 if (b64 == null && out.length() < 128) {
  75                         b64 = false;
  76                 }
  77
  78                 if (b64 == null || b64) {
  79                         try {
  80                                 String zipped = StringUtils.base64(out.toString(), zip);
  81                                 if (b64 != null || zipped.length() < out.length() - 4) {
  82                                         SerialUtils.write(out, zip ? "ZIP:" : "B64:");
  83                                         SerialUtils.write(out, zipped);
  84                                         return;
  85                                 }
  86                         } catch (IOException e) {
  87                                 throw new RuntimeException(
  88                                                 "Base64 conversion of data failed, maybe not enough memory?",
  89                                                 e);
  90                         }
  91                 }
  92
  93                 out.append(out);
  94         }
  95 }