1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.maven.shared.invoker;
20
21 import java.io.PrintStream;
22
23 /**
24 * Offers an output handler that writes to a print stream like {@link java.lang.System#out}.
25 *
26 * @since 2.0.9
27 */
28 public class PrintStreamHandler implements InvocationOutputHandler {
29
30 /**
31 * The print stream to write to, never <code>null</code>.
32 */
33 private PrintStream out;
34
35 /**
36 * A flag whether the print stream should be flushed after each line.
37 */
38 private boolean alwaysFlush;
39
40 /**
41 * Creates a new output handler that writes to {@link java.lang.System#out}.
42 */
43 public PrintStreamHandler() {
44 this(System.out, false);
45 }
46
47 /**
48 * Creates a new output handler that writes to the specified print stream.
49 *
50 * @param out The print stream to write to, must not be <code>null</code>.
51 * @param alwaysFlush A flag whether the print stream should be flushed after each line.
52 */
53 public PrintStreamHandler(PrintStream out, boolean alwaysFlush) {
54 if (out == null) {
55 throw new NullPointerException("missing output stream");
56 }
57 this.out = out;
58 this.alwaysFlush = alwaysFlush;
59 }
60
61 /** {@inheritDoc} */
62 public void consumeLine(String line) {
63 if (line == null) {
64 out.println();
65 } else {
66 out.println(line);
67 }
68
69 if (alwaysFlush) {
70 out.flush();
71 }
72 }
73 }