1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.compatibility.common.util;
18 
19 import com.google.common.io.Closeables;
20 
21 import java.io.ByteArrayOutputStream;
22 import java.io.IOException;
23 import java.io.InputStream;
24 import java.io.OutputStream;
25 import java.io.Reader;
26 import java.nio.charset.StandardCharsets;
27 
28 
29 public class StreamUtil {
30 
31     // 16K buffer size
32     private static final int BUFFER_SIZE = 16 * 1024;
33     /**
34      * Copies contents of origStream to destStream.
35      * <p/>
36      * Recommended to provide a buffered stream for input and output
37      *
38      * @param inStream the {@link InputStream}
39      * @param outStream the {@link OutputStream}
40      * @throws IOException
41      */
copyStreams(InputStream inStream, OutputStream outStream)42     public static void copyStreams(InputStream inStream, OutputStream outStream)
43             throws IOException {
44         byte[] buf = new byte[BUFFER_SIZE];
45         int size = -1;
46         while ((size = inStream.read(buf)) != -1) {
47             outStream.write(buf, 0, size);
48         }
49     }
50 
51     /**
52      * Reads {@code inputStream} converting it into a string. Does NOT close it.
53      *
54      * @throws IOException
55      */
readInputStream(InputStream inputStream)56     public static String readInputStream(InputStream inputStream) throws IOException {
57         ByteArrayOutputStream result = new ByteArrayOutputStream();
58         byte[] buffer = new byte[1024];
59         int length;
60         while ((length = inputStream.read(buffer)) != -1) {
61             result.write(buffer, 0, length);
62         }
63         return result.toString(StandardCharsets.UTF_8.name());
64     }
65 
drainAndClose(Reader reader)66     public static void drainAndClose(Reader reader) {
67         try {
68             while (reader.read() >= 0) {}
69         } catch (IOException ignored) {}
70         Closeables.closeQuietly(reader);
71     }
72 }
73