org.argeo.api.acr/src/org/argeo/api/acr/ContentUtils.java

   1 package org.argeo.api.acr;
   2
   3 import java.io.PrintStream;
   4 import java.net.URI;
   5 import java.net.URISyntaxException;
   6 import java.util.Arrays;
   7 import java.util.Base64;
   8 import java.util.List;
   9 import java.util.function.BiConsumer;
  10
  11 import javax.xml.namespace.QName;
  12
  13 public class ContentUtils {
  14         public static void traverse(Content content, BiConsumer<Content, Integer> doIt) {
  15                 traverse(content, doIt, 0);
  16         }
  17
  18         public static void traverse(Content content, BiConsumer<Content, Integer> doIt, int currentDepth) {
  19                 doIt.accept(content, currentDepth);
  20                 int nextDepth = currentDepth + 1;
  21                 for (Content child : content) {
  22                         traverse(child, doIt, nextDepth);
  23                 }
  24         }
  25
  26         public static void print(Content content, PrintStream out, int depth, boolean printText) {
  27                 StringBuilder sb = new StringBuilder();
  28                 for (int i = 0; i < depth; i++) {
  29                         sb.append("  ");
  30                 }
  31                 String prefix = sb.toString();
  32                 out.println(prefix + content.getName());
  33                 for (QName key : content.keySet()) {
  34                         out.println(prefix + " " + key + "=" + content.get(key));
  35                 }
  36                 if (printText) {
  37                         if (content.hasText()) {
  38                                 out.println("<![CDATA[" + content.getText().trim() + "]]>");
  39                         }
  40                 }
  41         }
  42
  43         public static URI bytesToDataURI(byte[] arr) {
  44                 String base64Str = Base64.getEncoder().encodeToString(arr);
  45                 try {
  46                         final String PREFIX = "data:application/octet-stream;base64,";
  47                         return new URI(PREFIX + base64Str);
  48                 } catch (URISyntaxException e) {
  49                         throw new IllegalStateException("Cannot serialize bytes a Base64 data URI", e);
  50                 }
  51
  52         }
  53
  54         public static byte[] bytesFromDataURI(URI uri) {
  55                 if (!"data".equals(uri.getScheme()))
  56                         throw new IllegalArgumentException("URI must have 'data' as a scheme");
  57                 String schemeSpecificPart = uri.getSchemeSpecificPart();
  58                 int commaIndex = schemeSpecificPart.indexOf(',');
  59                 String prefix = schemeSpecificPart.substring(0, commaIndex);
  60                 List<String> info = Arrays.asList(prefix.split(";"));
  61                 if (!info.contains("base64"))
  62                         throw new IllegalArgumentException("URI must specify base64");
  63
  64                 String base64Str = schemeSpecificPart.substring(commaIndex + 1);
  65                 return Base64.getDecoder().decode(base64Str);
  66
  67         }
  68
  69         public static <T> boolean isString(T t) {
  70                 return t instanceof String;
  71         }
  72
  73         /** Singleton. */
  74         private ContentUtils() {
  75
  76         }
  77 }