/*******************************************************************************
* Copyright 2013 SAP AG
*
* 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.
******************************************************************************/
package com.sap.core.odata.processor.core.jpa;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import com.sap.core.odata.api.edm.EdmException;
import com.sap.core.odata.api.edm.EdmLiteralKind;
import com.sap.core.odata.api.edm.EdmMapping;
import com.sap.core.odata.api.edm.EdmProperty;
import com.sap.core.odata.api.edm.EdmSimpleType;
import com.sap.core.odata.api.edm.EdmSimpleTypeException;
import com.sap.core.odata.api.edm.EdmSimpleTypeKind;
import com.sap.core.odata.api.exception.ODataException;
import com.sap.core.odata.api.exception.ODataNotImplementedException;
import com.sap.core.odata.api.uri.KeyPredicate;
import com.sap.core.odata.api.uri.expression.BinaryExpression;
import com.sap.core.odata.api.uri.expression.BinaryOperator;
import com.sap.core.odata.api.uri.expression.CommonExpression;
import com.sap.core.odata.api.uri.expression.ExpressionKind;
import com.sap.core.odata.api.uri.expression.FilterExpression;
import com.sap.core.odata.api.uri.expression.LiteralExpression;
import com.sap.core.odata.api.uri.expression.MemberExpression;
import com.sap.core.odata.api.uri.expression.MethodExpression;
import com.sap.core.odata.api.uri.expression.MethodOperator;
import com.sap.core.odata.api.uri.expression.OrderByExpression;
import com.sap.core.odata.api.uri.expression.OrderExpression;
import com.sap.core.odata.api.uri.expression.PropertyExpression;
import com.sap.core.odata.api.uri.expression.SortOrder;
import com.sap.core.odata.api.uri.expression.UnaryExpression;
import com.sap.core.odata.processor.api.jpa.exception.ODataJPARuntimeException;
import com.sap.core.odata.processor.api.jpa.jpql.JPQLStatement;
/**
* This class contains utility methods for parsing the filter expressions built by core library from user OData Query.
*
* @author SAP AG
*
*/
public class ODataExpressionParser {
public static final String EMPTY = ""; //$NON-NLS-1$
public static Integer methodFlag = 0;
/**
* This method returns the parsed where condition corresponding to the filter input in the user query.
*
* @param whereExpression
*
* @return Parsed where condition String
* @throws ODataException
*/
public static String parseToJPAWhereExpression(final CommonExpression whereExpression, final String tableAlias) throws ODataException {
switch (whereExpression.getKind()) {
case UNARY:
final UnaryExpression unaryExpression = (UnaryExpression) whereExpression;
final String operand = parseToJPAWhereExpression(unaryExpression.getOperand(), tableAlias);
switch (unaryExpression.getOperator()) {
case NOT:
return JPQLStatement.Operator.NOT + "(" + operand + ")"; //$NON-NLS-1$ //$NON-NLS-2$
case MINUS:
if (operand.startsWith("-")) {
return operand.substring(1);
}
else {
return "-" + operand; //$NON-NLS-1$
}
default:
throw new ODataNotImplementedException();
}
case FILTER:
return parseToJPAWhereExpression(((FilterExpression) whereExpression).getExpression(), tableAlias);
case BINARY:
final BinaryExpression binaryExpression = (BinaryExpression) whereExpression;
if ((binaryExpression.getLeftOperand().getKind() == ExpressionKind.METHOD) && ((binaryExpression.getOperator() == BinaryOperator.EQ) || (binaryExpression.getOperator() == BinaryOperator.NE)) && (((MethodExpression) binaryExpression.getLeftOperand()).getMethod() == MethodOperator.SUBSTRINGOF)) {
methodFlag = 1;
}
final String left = parseToJPAWhereExpression(binaryExpression.getLeftOperand(), tableAlias);
final String right = parseToJPAWhereExpression(binaryExpression.getRightOperand(), tableAlias);
switch (binaryExpression.getOperator()) {
case AND:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.AND + JPQLStatement.DELIMITER.SPACE + right;
case OR:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.OR + JPQLStatement.DELIMITER.SPACE + right;
case EQ:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.EQ + JPQLStatement.DELIMITER.SPACE + right;
case NE:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.NE + JPQLStatement.DELIMITER.SPACE + right;
case LT:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.LT + JPQLStatement.DELIMITER.SPACE + right;
case LE:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.LE + JPQLStatement.DELIMITER.SPACE + right;
case GT:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.GT + JPQLStatement.DELIMITER.SPACE + right;
case GE:
return left + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.GE + JPQLStatement.DELIMITER.SPACE + right;
case PROPERTY_ACCESS:
throw new ODataNotImplementedException();
default:
throw new ODataNotImplementedException();
}
case PROPERTY:
String returnStr = tableAlias + JPQLStatement.DELIMITER.PERIOD + ((EdmProperty) ((PropertyExpression) whereExpression).getEdmProperty()).getMapping().getInternalName();
return returnStr;
case MEMBER:
String memberExpStr = EMPTY;
int i = 0;
MemberExpression member = null;
CommonExpression tempExp = whereExpression;
while (tempExp != null && tempExp.getKind() == ExpressionKind.MEMBER) {
member = (MemberExpression) tempExp;
if (i > 0) {
memberExpStr = JPQLStatement.DELIMITER.PERIOD + memberExpStr;
}
i++;
memberExpStr = ((EdmProperty) ((PropertyExpression) member.getProperty()).getEdmProperty()).getMapping().getInternalName() + memberExpStr;
tempExp = member.getPath();
}
memberExpStr = ((EdmProperty) ((PropertyExpression) tempExp).getEdmProperty()).getMapping().getInternalName() + JPQLStatement.DELIMITER.PERIOD + memberExpStr;
return tableAlias + JPQLStatement.DELIMITER.PERIOD + memberExpStr;
case LITERAL:
final LiteralExpression literal = (LiteralExpression) whereExpression;
final EdmSimpleType literalType = (EdmSimpleType) literal.getEdmType();
String value = literalType.valueToString(literalType.valueOfString(literal.getUriLiteral(), EdmLiteralKind.URI, null, literalType.getDefaultType()), EdmLiteralKind.DEFAULT, null);
return evaluateComparingExpression(value, literalType);
case METHOD:
final MethodExpression methodExpression = (MethodExpression) whereExpression;
String first = parseToJPAWhereExpression(methodExpression.getParameters().get(0), tableAlias);
final String second = methodExpression.getParameterCount() > 1 ?
parseToJPAWhereExpression(methodExpression.getParameters().get(1), tableAlias) : null;
String third = methodExpression.getParameterCount() > 2 ?
parseToJPAWhereExpression(methodExpression.getParameters().get(2), tableAlias) : null;
switch (methodExpression.getMethod()) {
case SUBSTRING:
third = third != null ? ", " + third : "";
return String.format("SUBSTRING(%s, %s + 1 %s)", first, second, third);
case SUBSTRINGOF:
first = first.substring(1, first.length() - 1);
if (methodFlag == 1) {
methodFlag = 0;
return String.format("(CASE WHEN (%s LIKE '%%%s%%') THEN TRUE ELSE FALSE END)", second, first);
}
else {
return String.format("(CASE WHEN (%s LIKE '%%%s%%') THEN TRUE ELSE FALSE END) = true", second, first);
}
case TOLOWER:
return String.format("LOWER(%s)", first);
default:
throw new ODataNotImplementedException();
}
default:
throw new ODataNotImplementedException();
}
}
/**
* This method parses the select clause
*
* @param tableAlias
* @param selectedFields
* @return
*/
public static String parseToJPASelectExpression(final String tableAlias, final ArrayList<String> selectedFields) {
if ((selectedFields == null) || (selectedFields.size() == 0)) {
return tableAlias;
}
String selectClause = EMPTY;
Iterator<String> itr = selectedFields.iterator();
int count = 0;
while (itr.hasNext()) {
selectClause = selectClause + tableAlias + JPQLStatement.DELIMITER.PERIOD + itr.next();
count++;
if (count < selectedFields.size()) {
selectClause = selectClause + JPQLStatement.DELIMITER.COMMA + JPQLStatement.DELIMITER.SPACE;
}
}
return selectClause;
}
/**
* This method parses the order by condition in the query.
*
* @param orderByExpression
* @return
* @throws ODataJPARuntimeException
*/
public static HashMap<String, String> parseToJPAOrderByExpression(final OrderByExpression orderByExpression, final String tableAlias) throws ODataJPARuntimeException {
HashMap<String, String> orderByMap = new HashMap<String, String>();
if (orderByExpression != null && orderByExpression.getOrders() != null) {
List<OrderExpression> orderBys = orderByExpression.getOrders();
String orderByField = null;
String orderByDirection = null;
for (OrderExpression orderBy : orderBys) {
try {
orderByField = ((EdmProperty) ((PropertyExpression) orderBy.getExpression()).getEdmProperty()).getMapping().getInternalName();
orderByDirection = (orderBy.getSortOrder() == SortOrder.asc) ? EMPTY : "DESC"; //$NON-NLS-1$
orderByMap.put(tableAlias + JPQLStatement.DELIMITER.PERIOD + orderByField, orderByDirection);
} catch (EdmException e) {
throw ODataJPARuntimeException.throwException(
ODataJPARuntimeException.GENERAL.addContent(e
.getMessage()), e);
}
}
}
return orderByMap;
}
/**
* This method evaluated the where expression for read of an entity based on the keys specified in the query.
*
* @param keyPredicates
* @return the evaluated where expression
*/
public static String parseKeyPredicates(final List<KeyPredicate> keyPredicates, final String tableAlias) throws ODataJPARuntimeException {
String literal = null;
String propertyName = null;
EdmSimpleType edmSimpleType = null;
StringBuilder keyFilters = new StringBuilder();
int i = 0;
for (KeyPredicate keyPredicate : keyPredicates) {
if (i > 0) {
keyFilters.append(JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.AND + JPQLStatement.DELIMITER.SPACE);
}
i++;
literal = keyPredicate.getLiteral();
try {
EdmMapping mapping = keyPredicate.getProperty().getMapping();
if (mapping != null) {
propertyName = keyPredicate.getProperty().getMapping().getInternalName();
}
else {
propertyName = keyPredicate.getProperty().getName(); // Get external Name
}
edmSimpleType = (EdmSimpleType) keyPredicate.getProperty().getType();
} catch (EdmException e) {
throw ODataJPARuntimeException.throwException(
ODataJPARuntimeException.GENERAL.addContent(e
.getMessage()), e);
}
literal = evaluateComparingExpression(literal, edmSimpleType);
if (edmSimpleType == EdmSimpleTypeKind.DateTime.getEdmSimpleTypeInstance()
|| edmSimpleType == EdmSimpleTypeKind.DateTimeOffset.getEdmSimpleTypeInstance()) {
literal = literal.substring(literal.indexOf('\''), literal.indexOf('}'));
}
keyFilters.append(tableAlias + JPQLStatement.DELIMITER.PERIOD + propertyName + JPQLStatement.DELIMITER.SPACE + JPQLStatement.Operator.EQ + JPQLStatement.DELIMITER.SPACE + literal);
}
if (keyFilters.length() > 0) {
return keyFilters.toString();
} else {
return null;
}
}
/**
* This method evaluates the expression based on the type instance. Used for adding escape characters where necessary.
*
* @param value
* @param edmSimpleType
* @return the evaluated expression
* @throws ODataJPARuntimeException
*/
private static String evaluateComparingExpression(String value, final EdmSimpleType edmSimpleType) throws ODataJPARuntimeException {
if (edmSimpleType == EdmSimpleTypeKind.String.getEdmSimpleTypeInstance()
|| edmSimpleType == EdmSimpleTypeKind.Guid.getEdmSimpleTypeInstance())
{
value = "\'" + value + "\'"; //$NON-NLS-1$ //$NON-NLS-2$
} else if (edmSimpleType == EdmSimpleTypeKind.DateTime.getEdmSimpleTypeInstance()
|| edmSimpleType == EdmSimpleTypeKind.DateTimeOffset.getEdmSimpleTypeInstance())
{
try {
Calendar datetime = (Calendar) edmSimpleType.valueOfString(value, EdmLiteralKind.DEFAULT, null, edmSimpleType.getDefaultType());
String year = String.format("%04d", datetime.get(Calendar.YEAR));
String month = String.format("%02d", datetime.get(Calendar.MONTH) + 1);
String day = String.format("%02d", datetime.get(Calendar.DAY_OF_MONTH));
String hour = String.format("%02d", datetime.get(Calendar.HOUR_OF_DAY));
String min = String.format("%02d", datetime.get(Calendar.MINUTE));
String sec = String.format("%02d", datetime.get(Calendar.SECOND));
value = JPQLStatement.DELIMITER.LEFT_BRACE + JPQLStatement.KEYWORD.TIMESTAMP + JPQLStatement.DELIMITER.SPACE + "\'" + year + JPQLStatement.DELIMITER.HYPHEN + month + JPQLStatement.DELIMITER.HYPHEN + day + JPQLStatement.DELIMITER.SPACE + hour + JPQLStatement.DELIMITER.COLON + min + JPQLStatement.DELIMITER.COLON + sec + JPQLStatement.KEYWORD.OFFSET + "\'" + JPQLStatement.DELIMITER.RIGHT_BRACE;
} catch (EdmSimpleTypeException e) {
throw ODataJPARuntimeException.throwException(
ODataJPARuntimeException.GENERAL.addContent(e
.getMessage()), e);
}
} else if (edmSimpleType == EdmSimpleTypeKind.Time.getEdmSimpleTypeInstance()) {
try {
Calendar time = (Calendar) edmSimpleType.valueOfString(value, EdmLiteralKind.DEFAULT, null, edmSimpleType.getDefaultType());
String hourValue = String.format("%02d", time.get(Calendar.HOUR_OF_DAY));
String minValue = String.format("%02d", time.get(Calendar.MINUTE));
String secValue = String.format("%02d", time.get(Calendar.SECOND));
value = "\'" + hourValue + JPQLStatement.DELIMITER.COLON + minValue + JPQLStatement.DELIMITER.COLON + secValue + "\'";
} catch (EdmSimpleTypeException e) {
throw ODataJPARuntimeException.throwException(
ODataJPARuntimeException.GENERAL.addContent(e
.getMessage()), e);
}
} else if (edmSimpleType == EdmSimpleTypeKind.Int64.getEdmSimpleTypeInstance()) {
value = value + JPQLStatement.DELIMITER.LONG; //$NON-NLS-1$
}
return value;
}
public static HashMap<String, String> parseKeyPropertiesToJPAOrderByExpression(final List<EdmProperty> edmPropertylist, final String tableAlias) throws ODataJPARuntimeException {
HashMap<String, String> orderByMap = new HashMap<String, String>();
String propertyName = null;
for (EdmProperty edmProperty : edmPropertylist) {
try {
EdmMapping mapping = edmProperty.getMapping();
if (mapping != null && mapping.getInternalName() != null) {
propertyName = mapping.getInternalName();// For embedded/complex keys
} else {
propertyName = edmProperty.getName();
}
} catch (EdmException e) {
throw ODataJPARuntimeException.throwException(
ODataJPARuntimeException.GENERAL.addContent(e
.getMessage()), e);
}
orderByMap.put(tableAlias + JPQLStatement.DELIMITER.PERIOD + propertyName, EMPTY);
}
return orderByMap;
}
}