src/be/nikiroo/utils/streams/StreamUtils.java

   1 package be.nikiroo.utils.streams;
   2
   3 import java.io.UnsupportedEncodingException;
   4
   5 /**
   6  * Some non-public utilities used in the stream classes.
   7  *
   8  * @author niki
   9  */
  10 class StreamUtils {
  11         /**
  12          * Check if the buffer starts with the given search term (given as an array,
  13          * a start position and an end position).
  14          * <p>
  15          * Note: the parameter <tt>stop</tt> is the <b>index</b> of the last
  16          * position, <b>not</b> the length.
  17          * <p>
  18          * Note: the search term size <b>must</b> be smaller or equal the internal
  19          * buffer size.
  20          *
  21          * @param search
  22          *            the term to search for
  23          * @param buffer
  24          *            the buffer to look into
  25          * @param start
  26          *            the offset at which to start the search
  27          * @param stop
  28          *            the maximum index of the data to check (this is <b>not</b> a
  29          *            length, but an index)
  30          *
  31          * @return TRUE if the search content is present at the given location and
  32          *         does not exceed the <tt>len</tt> index
  33          */
  34         static public boolean startsWith(byte[] search, byte[] buffer, int start,
  35                         int stop) {
  36
  37                 // Check if there even is enough space for it
  38                 if (search.length > (stop - start)) {
  39                         return false;
  40                 }
  41
  42                 boolean same = true;
  43                 for (int i = 0; i < search.length; i++) {
  44                         if (search[i] != buffer[start + i]) {
  45                                 same = false;
  46                                 break;
  47                         }
  48                 }
  49
  50                 return same;
  51         }
  52
  53         /**
  54          * Return the bytes array representation of the given {@link String} in
  55          * UTF-8.
  56          *
  57          * @param str
  58          *            the string to transform into bytes
  59          * @return the content in bytes
  60          */
  61         static public byte[] bytes(String str) {
  62                 try {
  63                         return str.getBytes("UTF-8");
  64                 } catch (UnsupportedEncodingException e) {
  65                         // All conforming JVM must support UTF-8
  66                         e.printStackTrace();
  67                         return null;
  68                 }
  69         }
  70 }