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1   package ca.uhn.hl7v2.hoh.util;
2   
3   import java.io.ByteArrayOutputStream;
4   import java.io.File;
5   import java.io.IOException;
6   import java.io.InputStream;
7   import java.io.OutputStream;
8   import java.util.List;
9   
10  /**
11   * Utilities for dealing with IO
12   */
13  public class IOUtils {
14  
15  	public static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
16  	public static final String FILE_PATH_SEP = System.getProperty("file.separator");
17  
18  	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(IOUtils.class);
19  
20  	/**
21  	 * Non instantiable
22  	 */
23  	private IOUtils() {
24  		super();
25  	}
26  
27  	/**
28  	 * <p>
29  	 * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
30  	 * <code>OutputStream</code>.
31  	 * </p>
32  	 * <p>
33  	 * This method is based on an implementation from Apache Commons-IO
34  	 * </p>
35  	 * 
36  	 * @param input
37  	 *            the <code>InputStream</code> to read from
38  	 * @param output
39  	 *            the <code>OutputStream</code> to write to
40  	 * @return the number of bytes copied
41  	 * @throws NullPointerException
42  	 *             if the input or output is null
43  	 * @throws IOException
44  	 *             if an I/O error occurs
45  	 */
46  	public static long copy(InputStream input, OutputStream output) throws IOException {
47  		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
48  		long count = 0;
49  		int n = 0;
50  		while (-1 != (n = input.read(buffer))) {
51  			output.write(buffer, 0, n);
52  			count += n;
53  		}
54  		return count;
55  	}
56  
57  	public static long copyWhileDataAvailable(InputStream input, OutputStream output) throws IOException {
58  		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
59  		long count = 0;
60  		int n = 0;
61  		while (input.available() > 0 && -1 != (n = input.read(buffer))) {
62  			output.write(buffer, 0, n);
63  			count += n;
64  		}
65  		return count;
66  	}
67  
68  	public static void deleteAllFromDirectory(File theWorkfilesDir) {
69  		File[] listFiles = theWorkfilesDir.listFiles();
70  		if (listFiles.length == 0) {
71  			return;
72  		}
73  		ourLog.info("Deleting {} files from {}", listFiles.length, theWorkfilesDir.getAbsoluteFile());
74  		for (File next : listFiles) {
75  			ourLog.info("Deleting existing file: " + next);
76  			next.delete();
77  		}
78  	}
79  
80  	public static void deleteAllFromDirectoryExcept(File theDirectory, List<File> theExcept) throws IOException {
81  		File[] listFiles = theDirectory.listFiles();
82  		if (listFiles.length == 0) {
83  			return;
84  		}
85  		ourLog.info("Deleting unneeded files from {}", theDirectory.getAbsoluteFile());
86  		for (File nextFile : listFiles) {
87  			boolean keep = false;
88  			for (File nextExcept : theExcept) {
89  				if (nextFile.getCanonicalPath().equals(nextExcept.getCanonicalPath())) {
90  					keep = true;
91  					break;
92  				}
93  			}
94  			if (!keep) {
95  				ourLog.info("Deleting existing file: " + nextFile);
96  				nextFile.delete();
97  			}
98  		}
99  	}
100 
101 	/**
102 	 * Read a classpath resource into a byte array
103 	 */
104 	public static byte[] readClasspathIntoByteArray(String theString) throws IOException {
105 		InputStream res = IOUtils.class.getResourceAsStream(theString);
106 		return readInputStreamIntoByteArray(res);
107 	}
108 
109 	public static byte[] readInputStreamIntoByteArraWhileDataAvailable(InputStream res) throws IOException {
110 		java.io.ByteArrayOutputStream bos = new ByteArrayOutputStream();
111 		copyWhileDataAvailable(res, bos);
112 		return bos.toByteArray();
113 	}
114 
115 	/**
116 	 * Read an entire input stream into a byte array
117 	 */
118 	public static byte[] readInputStreamIntoByteArray(InputStream res) throws IOException {
119 		java.io.ByteArrayOutputStream bos = new ByteArrayOutputStream();
120 		copy(res, bos);
121 		return bos.toByteArray();
122 	}
123 
124 }