import java.io.InputStream;
import java.io.UnsupportedEncodingException;
+/**
+ * This {@link InputStream} will replace some of its content by replacing it
+ * with something else.
+ *
+ * @author niki
+ */
public class ReplaceInputStream extends BufferedInputStream {
private byte[] from;
private byte[] to;
private int spos;
private int slen;
+ /**
+ * Create a {@link ReplaceInputStream} that will replace <tt>from</tt> with
+ * <tt>to</tt>.
+ *
+ * @param in
+ * the under-laying {@link InputStream}
+ * @param from
+ * the {@link String} to replace
+ * @param to
+ * the {@link String} to replace with
+ */
public ReplaceInputStream(InputStream in, String from, String to) {
this(in, bytes(from), bytes(to));
}
+ /**
+ * Create a {@link ReplaceInputStream} that will replace <tt>from</tt> with
+ * <tt>to</tt>.
+ *
+ * @param in
+ * the under-laying {@link InputStream}
+ * @param from
+ * the value to replace
+ * @param to
+ * the value to replace with
+ */
public ReplaceInputStream(InputStream in, byte[] from, byte[] to) {
super(in);
this.from = from;
@Override
protected int read(InputStream in, byte[] buffer) throws IOException {
- if (buffer.length < to.length) {
+ if (buffer.length < to.length || source.length < to.length * 2) {
throw new IOException(
- "Underlaying buffer is too small to contain the replace String");
+ "An underlaying buffer is too small for this replace value");
}
if (spos >= slen) {
// Note: very simple, not efficient implementation, sorry.
int count = 0;
- int i = spos;
- while (i < slen && count < buffer.length - to.length) {
- if (from.length > 0 && startsWith(from, source, spos)) {
+ 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;
- i += to.length;
- spos += to.length;
+ spos += from.length;
} else {
- buffer[count++] = source[i++];
- spos++;
+ buffer[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");