package joptsimple.examples.ant.filters;
import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;
import org.apache.tools.ant.filters.BaseFilterReader;
import org.apache.tools.ant.filters.ChainableReader;
/**
* Ant filter class that transforms HTML special characters into their equivalent entities.
*
* @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>
*/
public class HTMLEntitifier extends BaseFilterReader implements ChainableReader {
private static final Map<Integer, String> ENTITIES = new HashMap<>();
static {
ENTITIES.put( (int) '<', "<" );
ENTITIES.put( (int) '>', ">" );
ENTITIES.put( (int) '"', """ );
ENTITIES.put( (int) '&', "&" );
}
private String replacementData;
private int replacementIndex = -1;
/**
* Creates "dummy" instances.
*/
public HTMLEntitifier() {
// empty on purpose
}
/**
* @param source where the data to filter comes from
*/
public HTMLEntitifier( Reader source ) {
super( source );
}
/**
* {@inheritDoc}
*/
public Reader chain( Reader source ) {
HTMLEntitifier newFilter = new HTMLEntitifier( source );
newFilter.setInitialized( true );
return newFilter;
}
/**
* {@inheritDoc}
*/
@Override
public int read() throws IOException {
if ( !getInitialized() )
setInitialized( true );
if ( replacementIndex > -1 ) {
int ch = replacementData.charAt( replacementIndex++ );
if ( replacementIndex >= replacementData.length() )
replacementIndex = -1;
return ch;
}
int nextChar = in.read();
if ( ENTITIES.containsKey( nextChar ) ) {
replacementData = ENTITIES.get( nextChar );
replacementIndex = 1;
return replacementData.charAt( 0 );
}
return nextChar;
}
}