com.blazebit.persistence.impl.function.tostringjson.AbstractToStringJsonFunction Maven / Gradle / Ivy
/*
* Copyright 2014 - 2020 Blazebit.
*
* 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.blazebit.persistence.impl.function.tostringjson;
import com.blazebit.persistence.impl.util.JpqlFunctionUtil;
import com.blazebit.persistence.impl.util.SqlUtils;
import com.blazebit.persistence.parser.JsonParser;
import com.blazebit.persistence.spi.FunctionRenderContext;
import com.blazebit.persistence.spi.JpqlFunction;
/**
* @author Christian Beikov
* @since 1.5.0
*/
public abstract class AbstractToStringJsonFunction implements JpqlFunction {
public static final String FUNCTION_NAME = "to_string_json";
@Override
public boolean hasArguments() {
return true;
}
@Override
public boolean hasParenthesesIfNoArguments() {
return true;
}
@Override
public Class getReturnType(Class firstArgumentType) {
return String.class;
}
@Override
public void render(FunctionRenderContext context) {
if (context.getArgumentsSize() < 2) {
throw new RuntimeException("The to_string_json function needs at least two arguments , , ..., ! args=" + context);
}
String subquery = context.getArgument(0);
int fromIndex = SqlUtils.indexOfFrom(subquery, 1);
String[] selectItemExpressions = SqlUtils.getSelectItemExpressions(subquery, SqlUtils.indexOfSelect(subquery));
String[] fields = new String[context.getArgumentsSize() - 1];
if (selectItemExpressions.length < fields.length) {
throw new RuntimeException("The to_string_json function argument must have at least as many select items as keys are given! args=" + context);
}
for (int i = 0; i < fields.length; i++) {
fields[i] = JpqlFunctionUtil.unquote(context.getArgument(i + 1));
}
render(context, fields, selectItemExpressions, subquery, fromIndex);
}
public Object process(CharSequence result, String[] fields) {
if (result == null) {
return null;
}
return JsonParser.parseStringOnly(result, fields);
}
public abstract void render(FunctionRenderContext context, String[] fields, String[] selectItemExpressions, String subquery, int fromIndex);
}