org.glowroot.api.MessageSupplier Maven / Gradle / Ivy
/*
* Copyright 2011-2014 the original author or authors.
*
* 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 org.glowroot.api;
import javax.annotation.Nullable;
/**
* A (lazy) supplier of {@link Message} instances. Needs to be thread safe since transaction thread
* creates it, but trace storage (and live viewing) is done in a separate thread.
*/
public abstract class MessageSupplier {
/**
* Returns the {@code Message} for a {@link TraceEntry}.
*
* The {@code Message} does not need to be thread safe if it is instantiated by the
* implementation of this method.
*/
public abstract Message get();
protected MessageSupplier() {}
/**
* Creates a {@code MessageSupplier} for the specified {@code message}.
*/
public static MessageSupplier from(@Nullable final String message) {
return new MessageSupplier() {
@Override
public Message get() {
return Message.from(message);
}
};
}
/**
* Creates a {@code MessageSupplier} for the specified {@code template} and {@code args}.
*
* The {@code template} can contain one or more placeholders {} that will be
* substituted if/when the message text is needed by the specified {@code args}.
*/
public static MessageSupplier from(final String template, final @Nullable String... args) {
return new MessageSupplier() {
@Override
public Message get() {
return Message.from(template, args);
}
};
}
}