/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.openjpa.kernel;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.collections.map.LinkedMap;
import org.apache.commons.lang.StringUtils;
import org.apache.openjpa.lib.rop.ListResultObjectProvider;
import org.apache.openjpa.lib.rop.RangeResultObjectProvider;
import org.apache.openjpa.lib.rop.ResultObjectProvider;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.meta.ClassMetaData;
import org.apache.openjpa.util.Exceptions;
import org.apache.openjpa.util.ImplHelper;
import org.apache.openjpa.util.OpenJPAException;
import org.apache.openjpa.util.UserException;
/**
* A query that is executed by a user-defined method.
*
* @author Abe White
* @nojavadoc
*/
public class MethodStoreQuery
extends AbstractStoreQuery {
public static final String LANGUAGE = QueryLanguages.LANG_METHODQL;
private static final Class[] ARGS_DATASTORE = new Class[]{
StoreContext.class, ClassMetaData.class, boolean.class, Map.class,
FetchConfiguration.class
};
private static final Class[] ARGS_INMEM = new Class[]{
StoreContext.class, ClassMetaData.class, boolean.class,
Object.class, Map.class, FetchConfiguration.class
};
private static final int OBJ_INDEX = 3;
private static final Localizer _loc = Localizer.forPackage
(MethodStoreQuery.class);
private LinkedMap _params = null;
public void invalidateCompilation() {
if (_params != null)
_params.clear();
}
public Executor newInMemoryExecutor(ClassMetaData meta, boolean subs) {
return new MethodExecutor(this, meta, subs, true);
}
public Executor newDataStoreExecutor(ClassMetaData meta, boolean subs) {
return new MethodExecutor(this, meta, subs, false);
}
public boolean supportsInMemoryExecution() {
return true;
}
public boolean supportsDataStoreExecution() {
return true;
}
public boolean requiresCandidateType() {
return false;
}
/**
* Parse the parameter declarations.
*/
private LinkedMap bindParameterTypes() {
ctx.lock();
try {
if (_params != null)
return _params;
String params = ctx.getParameterDeclaration();
if (params == null)
return EMPTY_PARAMS;
List decs = Filters.parseDeclaration(params, ',', "parameters");
if (_params == null)
_params = new LinkedMap((int) (decs.size() / 2 * 1.33 + 1));
String name;
Class cls;
for (int i = 0; i < decs.size(); i += 2) {
name = (String) decs.get(i);
cls = ctx.classForName(name, null);
if (cls == null)
throw new UserException(_loc.get("bad-param-type", name));
_params.put(decs.get(i + 1), cls);
}
return _params;
} finally {
ctx.unlock();
}
}
/**
* Uses a user-defined method named by the filter string to execute the
* query.
*/
private static class MethodExecutor
extends AbstractExecutor
implements Executor {
private final ClassMetaData _meta;
private final boolean _subs;
private final boolean _inMem;
private Method _meth = null;
public MethodExecutor(MethodStoreQuery q, ClassMetaData candidate,
boolean subclasses, boolean inMem) {
_meta = candidate;
_subs = subclasses;
_inMem = inMem;
}
public ResultObjectProvider executeQuery(StoreQuery q,
Object[] params, Range range) {
// convert the parameters into a map
Map paramMap;
if (params.length == 0)
paramMap = Collections.EMPTY_MAP;
else {
Map paramTypes = q.getContext().getParameterTypes();
paramMap = new HashMap((int) (params.length * 1.33 + 1));
int idx = 0;
for (Iterator itr = paramTypes.keySet().iterator();
itr.hasNext(); idx++)
paramMap.put(itr.next(), params[idx]);
}
FetchConfiguration fetch = q.getContext().getFetchConfiguration();
StoreContext sctx = q.getContext().getStoreContext();
ResultObjectProvider rop;
Object[] args;
if (_inMem) {
args = new Object[]{ sctx, _meta, (_subs) ? Boolean.TRUE
: Boolean.FALSE, null, paramMap, fetch };
Iterator itr = null;
Collection coll = q.getContext().getCandidateCollection();
if (coll == null) {
Extent ext = q.getContext().getQuery().
getCandidateExtent();
itr = ext.iterator();
} else
itr = coll.iterator();
List results = new ArrayList();
try {
Object obj;
while (itr.hasNext()) {
obj = itr.next();
if (obj == null
|| !_meta.getDescribedType().isInstance(obj))
continue;
args[OBJ_INDEX] = obj;
if (((Boolean) invoke(q, args)).booleanValue())
results.add(obj);
}
}
finally {
ImplHelper.close(itr);
}
rop = new ListResultObjectProvider(results);
} else {
// datastore
args = new Object[]{ sctx, _meta, (_subs) ? Boolean.TRUE
: Boolean.FALSE, paramMap, fetch };
rop = (ResultObjectProvider) invoke(q, args);
}
if (range.start != 0 || range.end != Long.MAX_VALUE)
rop = new RangeResultObjectProvider(rop, range.start,range.end);
return rop;
}
/**
* Invoke the internal method with the given arguments, returning the
* result.
*/
private Object invoke(StoreQuery q, Object[] args) {
validate(q);
try {
return _meth.invoke(null, args);
} catch (OpenJPAException ke) {
throw ke;
} catch (Exception e) {
throw new UserException(_loc.get("method-error", _meth,
Exceptions.toString(Arrays.asList(args))), e);
}
}
public void validate(StoreQuery q) {
if (_meth != null)
return;
String methName = q.getContext().getQueryString();
if (StringUtils.isEmpty(methName))
throw new UserException(_loc.get("no-method"));
int dotIdx = methName.lastIndexOf('.');
Class cls;
if (dotIdx == -1)
cls = _meta.getDescribedType();
else {
cls = q.getContext().classForName(methName.substring(0, dotIdx),
null);
if (cls == null)
throw new UserException(_loc.get("bad-method-class",
methName.substring(0, dotIdx), methName));
methName = methName.substring(dotIdx + 1);
}
Method meth;
Class[] types = (_inMem) ? ARGS_INMEM : ARGS_DATASTORE;
try {
meth = cls.getMethod(methName, types);
} catch (Exception e) {
String msg = (_inMem) ? "bad-inmem-method"
: "bad-datastore-method";
throw new UserException(_loc.get(msg, methName, cls));
}
if (!Modifier.isStatic(meth.getModifiers()))
throw new UserException(_loc.get("method-not-static", meth));
if (!ResultObjectProvider.class.isAssignableFrom(
meth.getReturnType()))
throw new UserException(_loc.get("method-return-type-invalid",
meth, meth.getReturnType()));
_meth = meth;
}
public LinkedMap getParameterTypes(StoreQuery q) {
return ((MethodStoreQuery) q).bindParameterTypes();
}
public Object[] toParameterArray(StoreQuery q, Map userParams) {
if (userParams == null || userParams.isEmpty())
return StoreQuery.EMPTY_OBJECTS;
LinkedMap paramTypes = getParameterTypes(q);
Object[] arr = new Object[userParams.size()];
int base = positionalParameterBase(userParams.keySet());
for (Object key : paramTypes.keySet()) {
int idx = (key instanceof Integer)
? ((Integer)key).intValue() - base
: paramTypes.indexOf(key);
if (idx >= arr.length || idx < 0)
throw new UserException(_loc.get("gap-query-param",
new Object[]{q.getContext().getQueryString(), key,
userParams.size(), userParams}));
arr[idx] = userParams.get(key);
}
return arr;
}
/**
* Return the base (generally 0 or 1) to use for positional parameters.
*/
private static int positionalParameterBase(Collection params) {
int low = Integer.MAX_VALUE;
Object obj;
int val;
for (Iterator itr = params.iterator(); itr.hasNext();) {
obj = itr.next();
if (!(obj instanceof Number))
return 0; // use 0 base when params are mixed types
val = ((Number) obj).intValue();
if (val == 0)
return val;
if (val < low)
low = val;
}
return low;
}
}
}