OutputChoice.java

/*
 * 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.maven.slf4j;

import java.io.PrintStream;

/**
 * This class encapsulates the user's choice of output target.
 *
 * @author Ceki Gülcü
 *
 */
class OutputChoice {

    enum OutputChoiceType {
        SYS_OUT,
        CACHED_SYS_OUT,
        SYS_ERR,
        CACHED_SYS_ERR,
        FILE
    }

    final OutputChoiceType outputChoiceType;
    final PrintStream targetPrintStream;

    OutputChoice(OutputChoiceType outputChoiceType) {
        if (outputChoiceType == OutputChoiceType.FILE) {
            throw new IllegalArgumentException();
        }
        this.outputChoiceType = outputChoiceType;
        if (outputChoiceType == OutputChoiceType.CACHED_SYS_OUT) {
            this.targetPrintStream = System.out;
        } else if (outputChoiceType == OutputChoiceType.CACHED_SYS_ERR) {
            this.targetPrintStream = System.err;
        } else {
            this.targetPrintStream = null;
        }
    }

    OutputChoice(PrintStream printStream) {
        this.outputChoiceType = OutputChoiceType.FILE;
        this.targetPrintStream = printStream;
    }

    PrintStream getTargetPrintStream() {
        return switch (outputChoiceType) {
            case SYS_OUT -> System.out;
            case SYS_ERR -> System.err;
            case CACHED_SYS_ERR, CACHED_SYS_OUT, FILE -> targetPrintStream;
        };
    }
}