package org.drools.decisiontable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import org.drools.builder.DecisionTableConfiguration;
import org.drools.compiler.DecisionTableProvider;
import org.drools.core.util.StringUtils;
public class DecisionTableProviderImpl
implements
DecisionTableProvider {
public String loadFromInputStream(InputStream is,
DecisionTableConfiguration configuration) {
return compileStream( is,
configuration );
}
private String compileStream(InputStream is,
DecisionTableConfiguration configuration) {
SpreadsheetCompiler compiler = new SpreadsheetCompiler();
switch ( configuration.getInputType() ) {
case XLS : {
if ( StringUtils.isEmpty( configuration.getWorksheetName() ) ) {
return compiler.compile( is,
InputType.XLS );
} else {
return compiler.compile( is,
configuration.getWorksheetName() );
}
}
case CSV : {
return compiler.compile( is,
InputType.CSV );
}
}
return null;
}
/**
* Adapts a <code>Reader</code> as an <code>InputStream</code>.
* Adapted from <CODE>StringInputStream</CODE>.
*
*/
public static class ReaderInputStream extends InputStream {
/** Source Reader */
private Reader in;
private String encoding = System.getProperty( "file.encoding" );
private byte[] slack;
private int begin;
/**
* Construct a <CODE>ReaderInputStream</CODE>
* for the specified <CODE>Reader</CODE>.
*
* @param reader <CODE>Reader</CODE>. Must not be <code>null</code>.
*/
public ReaderInputStream(Reader reader) {
in = reader;
}
/**
* Construct a <CODE>ReaderInputStream</CODE>
* for the specified <CODE>Reader</CODE>,
* with the specified encoding.
*
* @param reader non-null <CODE>Reader</CODE>.
* @param encoding non-null <CODE>String</CODE> encoding.
*/
public ReaderInputStream(Reader reader,
String encoding) {
this( reader );
if ( encoding == null ) {
throw new IllegalArgumentException( "encoding must not be null" );
} else {
this.encoding = encoding;
}
}
/**
* Reads from the <CODE>Reader</CODE>, returning the same value.
*
* @return the value of the next character in the <CODE>Reader</CODE>.
*
* @exception IOException if the original <code>Reader</code> fails to be read
*/
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 ) {
result = -1;
}
result = buf[0];
}
if ( result < -1 ) {
result += 256;
}
return result;
}
/**
* Reads from the <code>Reader</code> into a byte array
*
* @param b the byte array to read into
* @param off the offset in the byte array
* @param len the length in the byte array to fill
* @return the actual number read into the byte array, -1 at
* the end of the stream
* @exception IOException if an error occurs
*/
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 ) {
slack = new String( buf,
0,
n ).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.
*
* @param limit the maximum limit of bytes that can be read before the
* mark position becomes invalid
*/
public synchronized void mark(final int limit) {
try {
in.mark( limit );
} catch ( IOException ioe ) {
throw new RuntimeException( ioe.getMessage() );
}
}
/**
* @return the current number of bytes ready for reading
* @exception IOException if an error occurs
*/
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;
}
}
/**
* @return false - mark is not supported
*/
public boolean markSupported() {
return false; // would be imprecise
}
/**
* Resets the StringReader.
*
* @exception IOException if the StringReader fails to be reset
*/
public synchronized void reset() throws IOException {
if ( in == null ) {
throw new IOException( "Stream Closed" );
}
slack = null;
in.reset();
}
/**
* Closes the Stringreader.
*
* @exception IOException if the original StringReader fails to be closed
*/
public synchronized void close() throws IOException {
if ( in != null ) {
in.close();
slack = null;
in = null;
}
}
}
}