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Java > Open Source Codes > org > apache > tools > ant > input > GreedyInputHandler


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  */
18
19 package org.apache.tools.ant.input;
20
21 import java.io.InputStream JavaDoc;
22 import java.io.ByteArrayOutputStream JavaDoc;
23 import org.apache.tools.ant.BuildException;
24 import org.apache.tools.ant.taskdefs.StreamPumper;
25 import org.apache.tools.ant.util.FileUtils;
26
27 /**
28  * Prompts on System.err, reads input from System.in until EOF
29  *
30  * @since Ant 1.7
31  */
32 public class GreedyInputHandler extends DefaultInputHandler {
33
34     private static final int BUFFER_SIZE = 1024;
35
36     /**
37      * Empty no-arg constructor
38      */
39     public GreedyInputHandler() {
40     }
41
42     /**
43      * Prompts and requests input.
44      * @param request the request to handle
45      * @throws BuildException if not possible to read from console,
46      * or if input is invalid.
47      */
48     public void handleInput(InputRequest request) throws BuildException {
49         String JavaDoc prompt = getPrompt(request);
50         InputStream JavaDoc in = null;
51         try {
52             in = getInputStream();
53             System.err.println(prompt);
54             System.err.flush();
55             ByteArrayOutputStream JavaDoc baos = new ByteArrayOutputStream JavaDoc();
56             StreamPumper p = new StreamPumper(in, baos);
57             Thread JavaDoc t = new Thread JavaDoc(p);
58             t.start();
59             try {
60                 t.join();
61             } catch (InterruptedException JavaDoc e) {
62                 try {
63                     t.join();
64                 } catch (InterruptedException JavaDoc e2) {
65                     // Ignore
66 }
67             }
68             request.setInput(new String JavaDoc(baos.toByteArray()));
69             if (!(request.isInputValid())) {
70                 throw new BuildException(
71                     "Received invalid console input");
72             }
73             if (p.getException() != null) {
74                 throw new BuildException(
75                     "Failed to read input from console", p.getException());
76             }
77         } finally {
78             FileUtils.close(in);
79         }
80     }
81 }
82
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