@@ -58,8 +58,7 @@ import java.io.InputStream;
import java.io.StringReader; import java.io.StringReader;
/** /**
* Wraps a String as an InputStream. Note that data will be lost for
* characters not in ISO Latin 1, as a simple char->byte mapping is assumed.
* Wraps a String as an InputStream.
* *
* @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a> * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
*/ */
@@ -68,9 +67,15 @@ public class StringInputStream
/** Source string, stored as a StringReader */ /** Source string, stored as a StringReader */
private StringReader in; private StringReader in;
private String encoding;
private byte[] slack;
private int begin;
/** /**
* Composes a stream from a String * Composes a stream from a String
*
*
* @param source The string to read from. Must not be <code>null</code>. * @param source The string to read from. Must not be <code>null</code>.
*/ */
public StringInputStream(String source) { public StringInputStream(String source) {
@@ -78,32 +83,88 @@ public class StringInputStream
} }
/** /**
* Reads from the Stringreader, returning the same value. Note that
* data will be lost for characters not in ISO Latin 1. Clients
* assuming a return value in the range -1 to 255 may even fail on
* such input.
*
* @return the value of the next character in the StringReader
*
* @exception IOException if the original StringReader fails to be read
* Composes a stream from a String with the specified encoding
*
* @param source The string to read from. Must not be <code>null</code>.
* @param encoding The encoding scheme.
*/ */
public int read() throws IOException {
return in.read();
public StringInputStream(String source, String encoding) {
in = new StringReader(source);
this.encoding = encoding;
} }
/** /**
* Closes the Stringreader.
*
* @exception IOException if the original StringReader fails to be closed
* Reads from the Stringreader, returning the same value.
*
* @return the value of the next character in the StringReader
*
* @exception IOException if the original StringReader fails to be read
*/ */
public void close() throws IOException {
in.close();
public synchronized int read() throws IOException {
if (in == null) {
throw new IOException("Stream Closed");
}
byte result;
if (slack != null && begin < slack.length) {
result = slack[begin];
if (++begin == slack.length) {
slack = null;
}
} else {
byte[] buf = new byte[1];
if (read(buf, 0, 1) <= 0) {
return -1;
}
result = buf[0];
}
if (result < 0) {
return 256 + result;
} else {
return result;
}
}
public synchronized int read(byte[] b, int off, int len)
throws IOException {
if (in == null) {
throw new IOException("Stream Closed");
}
while (slack == null) {
char[] buf = new char[len]; // might read too much
int n = in.read(buf);
if (n == -1) {
return -1;
}
if (n > 0) {
String s = new String(buf, 0, n);
if (encoding == null) {
slack = s.getBytes();
} else {
slack = s.getBytes(encoding);
}
begin = 0;
}
}
if (len > slack.length - begin) {
len = slack.length - begin;
}
System.arraycopy(slack, begin, b, off, len);
if ((begin += len) >= slack.length) {
slack = null;
}
return len;
} }
/** /**
* Marks the read limit of the StringReader. * Marks the read limit of the StringReader.
*
* @param limit the maximum limit of bytes that can be read before the
*
* @param limit the maximum limit of bytes that can be read before the
* mark position becomes invalid * mark position becomes invalid
*/ */
public synchronized void mark(final int limit) { public synchronized void mark(final int limit) {
@@ -114,20 +175,46 @@ public class StringInputStream
} }
} }
public synchronized int available() throws IOException {
if (in == null) {
throw new IOException("Stream Closed");
}
if (slack != null) {
return slack.length - begin;
}
if (in.ready()) {
return 1;
} else {
return 0;
}
}
public boolean markSupported () {
return false; // would be imprecise
}
/** /**
* Resets the StringReader. * Resets the StringReader.
*
*
* @exception IOException if the StringReader fails to be reset * @exception IOException if the StringReader fails to be reset
*/ */
public synchronized void reset() throws IOException { public synchronized void reset() throws IOException {
if (in == null) {
throw new IOException("Stream Closed");
}
slack = null;
in.reset(); in.reset();
} }
/** /**
* @see InputStream#markSupported
* Closes the Stringreader.
*
* @exception IOException if the original StringReader fails to be closed
*/ */
public boolean markSupported() {
return in.markSupported();
public synchronized void close() throws IOException {
in.close();
slack = null;
in = null;
} }
} }
Magesh Umasankar