functionbuilder.java

jboss规则引擎

package org.drools.semantics.java;

/*
 * Copyright 2005 JBoss Inc
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.InputStreamReader;

import org.antlr.stringtemplate.StringTemplate;
import org.antlr.stringtemplate.StringTemplateGroup;
import org.antlr.stringtemplate.language.AngleBracketTemplateLexer;
import org.drools.lang.descr.FunctionDescr;
import org.drools.rule.Package;

public class FunctionBuilder {
    private static final StringTemplateGroup functionGroup = new StringTemplateGroup( new InputStreamReader( FunctionBuilder.class.getResourceAsStream( "javaFunction.stg" ) ),
                                                                                AngleBracketTemplateLexer.class );

    public FunctionBuilder() {

    }

    public String build(final Package pkg,
                        final FunctionDescr functionDescr) {
        final StringTemplate st = FunctionBuilder.functionGroup.getInstanceOf( "function" );

        st.setAttribute( "package",
                         pkg.getName() );

        st.setAttribute( "imports",
                         pkg.getImports() );

        st.setAttribute( "className",
                         ucFirst( functionDescr.getName() ) );
        st.setAttribute( "methodName",
                         functionDescr.getName() );

        st.setAttribute( "returnType",
                         functionDescr.getReturnType() );

        st.setAttribute( "parameterTypes",
                         functionDescr.getParameterTypes() );

        st.setAttribute( "parameterNames",
                         functionDescr.getParameterNames() );

        st.setAttribute( "text",
                         functionDescr.getText() );

        return st.toString();

    }

    private String ucFirst(final String name) {
        return name.toUpperCase().charAt( 0 ) + name.substring( 1 );
    }
}