org.apache.rocketmq.client.consumer.MessageSelector 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.rocketmq.client.consumer;
import org.apache.rocketmq.common.filter.ExpressionType;
/**
* Message selector: select message at server.
*
* Now, support:
*
Tag: {@link org.apache.rocketmq.common.filter.ExpressionType#TAG}
*
* SQL92: {@link org.apache.rocketmq.common.filter.ExpressionType#SQL92}
*
*
*/
public class MessageSelector {
/**
* @see org.apache.rocketmq.common.filter.ExpressionType
*/
private String type;
/**
* expression content.
*/
private String expression;
private MessageSelector(String type, String expression) {
this.type = type;
this.expression = expression;
}
/**
* Use SLQ92 to select message.
*
* @param sql if null or empty, will be treated as select all message.
*/
public static MessageSelector bySql(String sql) {
return new MessageSelector(ExpressionType.SQL92, sql);
}
/**
* Use tag to select message.
*
* @param tag if null or empty or "*", will be treated as select all message.
*/
public static MessageSelector byTag(String tag) {
return new MessageSelector(ExpressionType.TAG, tag);
}
public String getExpressionType() {
return type;
}
public String getExpression() {
return expression;
}
}