org.apache.openjpa.jdbc.kernel.exps.StringLength Maven / Gradle / Ivy
/*
* 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.jdbc.kernel.exps;
import org.apache.openjpa.jdbc.sql.DBDictionary;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
/**
* Returns the number of characters in a string.
*
* @author Marc Prud'hommeaux
*/
public class StringLength
extends StringFunction {
private Class _cast = null;
/**
* Constructor. Provide the string to operate on.
*/
public StringLength(Val val) {
super(val);
}
public Class getType() {
if (_cast != null)
return _cast;
return int.class;
}
public void setImplicitType(Class type) {
_cast = type;
}
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer buf, int index) {
DBDictionary dict = ctx.store.getDBDictionary();
String func = dict.stringLengthFunction;
dict.assertSupport(func != null, "StringLengthFunction");
func = dict.getCastFunction(getValue(), func);
int idx = func.indexOf("{0}");
buf.append(func.substring(0, idx));
getValue().appendTo(sel, ctx, state, buf, index);
buf.append(func.substring(idx + 3));
}
public int getId() {
return Val.LENGTH_VAL;
}
}