/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.eval;
import java.beans.BeanInfo;
import java.beans.IndexedPropertyDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.MethodDescriptor;
import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.io.Reader;
import java.lang.ref.Reference;
import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;
import javax.script.AbstractScriptEngine;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import org.teiid.core.util.LRUCache;
import org.teiid.core.util.ObjectConverterUtil;
import org.teiid.query.function.FunctionMethods;
import org.teiid.runtime.client.Messages;
/**
* A simplistic script engine that supports root variable access and 0-ary methods on the subsequent objects.
*/
public final class TeiidScriptEngine extends AbstractScriptEngine implements Compilable {
private static Reference<Map<Class<?>, Map<String, Method>>> properties;
private static Pattern splitter = Pattern.compile("\\."); //$NON-NLS-1$
@Override
public Bindings createBindings() {
return new SimpleBindings();
}
@Override
public CompiledScript compile(String script) throws ScriptException {
final String[] parts = splitter.split(script);
final int[] indexes = new int[parts.length];
for (int i = 1; i < parts.length; i++) {
String string = parts[i];
for (int j = 0; j < string.length(); j++) {
if (!Character.isJavaIdentifierPart(string.charAt(j))) {
throw new ScriptException(Messages.gs(Messages.TEIID.TEIID30431,string, string.charAt(j)));
}
}
try {
indexes[i] = Integer.parseInt(string);
} catch (NumberFormatException e) {
indexes[i] = -1;
}
}
return new CompiledScript() {
@Override
public ScriptEngine getEngine() {
return TeiidScriptEngine.this;
}
@Override
public Object eval(ScriptContext sc) throws ScriptException {
if (sc == null) {
throw new NullPointerException();
}
Object obj = null;
if (parts.length > 0) {
obj = sc.getAttribute(parts[0]);
}
for (int i = 1; i < parts.length; i++) {
if (obj == null) {
return null;
}
String part = parts[i];
Map<String, Method> methodMap = getMethodMap(obj.getClass());
Method m = methodMap.get(part);
if (m == null) {
int index = indexes[i];
if (index > 0) { //assume it's a list/array
if (obj instanceof List) {
try {
obj = ((List<?>)obj).get(index - 1);
} catch (IndexOutOfBoundsException e) {
obj = null;
}
continue;
}
try {
obj = FunctionMethods.array_get(obj, index);
continue;
} catch (Exception e) {
throw new ScriptException(e);
}
}
throw new ScriptException(Messages.gs(Messages.TEIID.TEIID31111, part, obj.getClass()));
}
try {
obj = m.invoke(obj);
} catch (IllegalAccessException e) {
throw new ScriptException(e);
} catch (InvocationTargetException e) {
if (e.getCause() instanceof Exception) {
throw new ScriptException((Exception) e.getCause());
}
throw new ScriptException(e);
}
}
return obj;
}
};
}
public Map<String, Method> getMethodMap(Class<?> clazz) throws ScriptException {
Map<Class<?>, Map<String, Method>> clazzMaps = null;
Map<String, Method> methodMap = null;
if (properties != null) {
clazzMaps = properties.get();
if (clazzMaps != null) {
methodMap = clazzMaps.get(clazz);
if (methodMap != null) {
return methodMap;
}
}
}
try {
BeanInfo info = Introspector.getBeanInfo(clazz);
PropertyDescriptor[] pds = info.getPropertyDescriptors();
methodMap = new LinkedHashMap<String, Method>();
if (pds != null) {
for (int j = 0; j < pds.length; j++) {
PropertyDescriptor pd = pds[j];
if (pd.getReadMethod() == null || pd instanceof IndexedPropertyDescriptor) {
continue;
}
String name = pd.getName();
Method m = pd.getReadMethod();
methodMap.put(name, m);
}
}
MethodDescriptor[] mds = info.getMethodDescriptors();
if (pds != null) {
for (int j = 0; j < mds.length; j++) {
MethodDescriptor md = mds[j];
if (md.getMethod() == null || md.getMethod().getParameterTypes().length > 0 || md.getMethod().getReturnType() == Void.class || md.getMethod().getReturnType() == void.class) {
continue;
}
String name = md.getName();
Method m = md.getMethod();
methodMap.put(name, m);
}
}
if (clazzMaps == null) {
clazzMaps = Collections.synchronizedMap(new LRUCache<Class<?>, Map<String,Method>>(100));
properties = new SoftReference<Map<Class<?>,Map<String,Method>>>(clazzMaps);
}
clazzMaps.put(clazz, methodMap);
} catch (IntrospectionException e) {
throw new ScriptException(e);
}
return methodMap;
}
@Override
public CompiledScript compile(Reader script) throws ScriptException {
try {
return compile(ObjectConverterUtil.convertToString(script));
} catch (IOException e) {
throw new ScriptException(e);
}
}
@Override
public ScriptEngineFactory getFactory() {
throw new UnsupportedOperationException();
}
public Object eval(Reader reader, ScriptContext sc)
throws ScriptException {
throw new UnsupportedOperationException();
}
@Override
public Object eval(String script, ScriptContext sc)
throws ScriptException {
throw new UnsupportedOperationException();
}
}