import java.io.IOException;
import java.io.InputStream;
-import java.io.UnsupportedEncodingException;
/**
- * This {@link InputStream} will replace some of its content by replacing it
- * with something else.
+ * This {@link InputStream} will change some of its content by replacing it with
+ * something else.
*
* @author niki
*/
public class ReplaceInputStream extends BufferedInputStream {
- private byte[] from;
- private byte[] to;
+ private byte[][] froms;
+ private byte[][] tos;
+ private int maxToSize;
private byte[] source;
private int spos;
* the {@link String} to replace with
*/
public ReplaceInputStream(InputStream in, String from, String to) {
- this(in, bytes(from), bytes(to));
+ this(in, StreamUtils.bytes(from), StreamUtils.bytes(to));
}
/**
* the value to replace with
*/
public ReplaceInputStream(InputStream in, byte[] from, byte[] to) {
+ this(in, new byte[][] { from }, new byte[][] { to });
+ }
+
+ /**
+ * Create a {@link ReplaceInputStream} that will replace all <tt>froms</tt>
+ * with <tt>tos</tt>.
+ * <p>
+ * Note that they will be replaced in order, and that for each <tt>from</tt>
+ * a <tt>to</tt> must correspond.
+ *
+ * @param in
+ * the under-laying {@link InputStream}
+ * @param froms
+ * the values to replace
+ * @param tos
+ * the values to replace with
+ */
+ public ReplaceInputStream(InputStream in, String[] froms, String[] tos) {
+ this(in, StreamUtils.bytes(froms), StreamUtils.bytes(tos));
+ }
+
+ /**
+ * Create a {@link ReplaceInputStream} that will replace all <tt>froms</tt>
+ * with <tt>tos</tt>.
+ * <p>
+ * Note that they will be replaced in order, and that for each <tt>from</tt>
+ * a <tt>to</tt> must correspond.
+ *
+ * @param in
+ * the under-laying {@link InputStream}
+ * @param froms
+ * the values to replace
+ * @param tos
+ * the values to replace with
+ */
+ public ReplaceInputStream(InputStream in, byte[][] froms, byte[][] tos) {
super(in);
- this.from = from;
- this.to = to;
+
+ if (froms.length != tos.length) {
+ throw new IllegalArgumentException(
+ "For replacing, each FROM must have a corresponding TO");
+ }
+
+ this.froms = froms;
+ this.tos = tos;
+
+ for (int i = 0; i < tos.length; i++) {
+ maxToSize = Math.max(maxToSize, tos[i].length);
+ }
source = new byte[4096];
spos = 0;
}
@Override
- protected int read(InputStream in, byte[] buffer) throws IOException {
- if (buffer.length < to.length || source.length < to.length * 2) {
+ protected int read(InputStream in, byte[] buffer, int off, int len)
+ throws IOException {
+ if (len < maxToSize || source.length < maxToSize * 2) {
throw new IOException(
- "An underlaying buffer is too small for this replace value");
+ "An underlaying buffer is too small for these replace values");
}
if (spos >= slen) {
// Note: very simple, not efficient implementation, sorry.
int count = 0;
- while (spos < slen && count < buffer.length - to.length) {
- if (from.length > 0 && startsWith(from, source, spos, slen)) {
- System.arraycopy(to, 0, buffer, spos, to.length);
- count += to.length;
- spos += from.length;
- } else {
- buffer[count++] = source[spos++];
+ while (spos < slen && count < len - maxToSize) {
+ boolean replaced = false;
+ for (int i = 0; i < froms.length; i++) {
+ if (froms[i] != null && froms[i].length > 0
+ && StreamUtils.startsWith(froms[i], source, spos, slen)) {
+ if (tos[i] != null && tos[i].length > 0) {
+ System.arraycopy(tos[i], 0, buffer, off + spos,
+ tos[i].length);
+ count += tos[i].length;
+ }
+
+ spos += froms[i].length;
+ replaced = true;
+ break;
+ }
+ }
+
+ if (!replaced) {
+ buffer[off + count++] = source[spos++];
}
}
return count;
}
-
- /**
- * Return the bytes array representation of the given {@link String} in
- * UTF-8.
- *
- * @param str
- * the string to transform into bytes
- * @return the content in bytes
- */
- static private byte[] bytes(String str) {
- try {
- return str.getBytes("UTF-8");
- } catch (UnsupportedEncodingException e) {
- // All conforming JVM must support UTF-8
- e.printStackTrace();
- return null;
- }
- }
}