package org.drools.base.mvel;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
import org.drools.WorkingMemory;
import org.drools.rule.Declaration;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.Package;
import org.drools.spi.PredicateExpression;
import org.drools.spi.Tuple;
import org.mvel2.MVEL;
public class MVELPredicateExpression implements PredicateExpression, MVELCompileable, Externalizable {
private static final long serialVersionUID = 400L;
private MVELCompilationUnit unit;
private String id;
private Serializable expr;
private DroolsMVELFactory prototype;
public MVELPredicateExpression() {
}
public MVELPredicateExpression(final MVELCompilationUnit unit,
final String id) {
this.unit = unit;
this.id = id;
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
id = in.readUTF();
unit = ( MVELCompilationUnit ) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeUTF( id );
out.writeObject( unit );
}
public void compile(ClassLoader classLoader) {
expr = unit.getCompiledExpression( classLoader );
prototype = unit.getFactory( );
}
public Object createContext() {
return this.prototype.clone();
}
public boolean evaluate(final Object object,
final Tuple tuple,
final Declaration[] previousDeclarations,
final Declaration[] requiredDeclarations,
final WorkingMemory workingMemory,
final Object context ) throws Exception {
DroolsMVELFactory factory = (DroolsMVELFactory) context;
factory.setContext( tuple,
null,
object,
workingMemory,
null );
// do we have any functions for this namespace?
Package pkg = workingMemory.getRuleBase().getPackage( "MAIN" );
if ( pkg != null ) {
MVELDialectRuntimeData data = ( MVELDialectRuntimeData ) pkg.getDialectRuntimeRegistry().getDialectData( this.id );
factory.setNextFactory( data.getFunctionFactory() );
}
final Boolean result = (Boolean) MVEL.executeExpression( this.expr,
object,
factory );
return result.booleanValue();
}
}