2 * Copyright 2016-2017, Nokia Corporation
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 package org.onap.vfc.nfvo.driver.vnfm.svnfm.nokia.util;
18 import com.google.common.io.ByteStreams;
19 import java.io.InputStream;
20 import java.io.PrintStream;
21 import org.apache.http.impl.client.CloseableHttpClient;
22 import org.apache.http.impl.client.HttpClients;
25 * Wrapper class for static method calls to core or core libraries.
26 * Calls to static methods in core or core libraries are wrapped to be able to test
27 * the classes that uses static calls.
29 public class SystemFunctions {
30 private static SystemFunctions singletonInstance;
33 * @return singleton instance
35 public static SystemFunctions systemFunctions() {
36 if (singletonInstance != null) {
37 return singletonInstance;
39 synchronized (SystemFunctions.class) {
40 singletonInstance = new SystemFunctions();
42 return singletonInstance;
47 * Causes the currently executing thread to sleep (temporarily cease
48 * execution) for the specified number of milliseconds, subject to
49 * the precision and accuracy of system timers and schedulers. The thread
50 * does not lose ownership of any monitors.
52 * @param millis the length of time to sleep in milliseconds
54 public void sleep(long millis) {
57 } catch (InterruptedException e) {
58 Thread.currentThread().interrupt();
59 throw new UserInvisibleError("Interrupted while sleep", e);
64 * Returns the current time in milliseconds. Note that
65 * while the unit of time of the return value is a millisecond,
66 * the granularity of the value depends on the underlying
67 * operating system and may be larger. For example, many
68 * operating systems measure time in units of tens of
71 * <p> See the description of the class <code>Date</code> for
72 * a discussion of slight discrepancies that may arise between
73 * Unable to load /unittests/missing * "computer time" and coordinated universal time (UTC).
75 * @return the difference, measured in milliseconds, between
76 * the current time and midnight, January 1, 1970 UTC.
79 public long currentTimeMillis() {
80 return System.currentTimeMillis();
84 * Loads a file from the class path
86 * @param url the URL of the file
87 * @return the content of the file
89 public byte[] loadFile(String url) {
91 InputStream stream = SystemFunctions.class.getClassLoader().getResourceAsStream(url);
92 return ByteStreams.toByteArray(stream);
93 } catch (Exception e) {
94 throw new UserVisibleError("Unable to load " + url, e);
99 * The "standard" error output stream. This stream is already
100 * open and ready to accept output data.
102 * Typically this stream corresponds to display output or another
103 * output destination specified by the host environment or user. By
104 * convention, this output stream is used to display error messages
105 * or other information that should come to the immediate attention
106 * of a user even if the principal output stream, the value of the
107 * variable <code>out</code>, has been redirected to a file or other
108 * destination that is typically not continuously monitored.
110 @SuppressWarnings("squid:S106") // (intentional wrapping of system err)
111 public PrintStream err() {
116 * The "standard" output stream. This stream is already
117 * open and ready to accept output data. Typically this stream
118 * corresponds to display output or another output destination
119 * specified by the host environment or user.
121 * For simple stand-alone Java applications, a typical way to write
122 * a line of output data is:
124 * System.out.println(data)
125 * </pre></blockquote>
127 * See the <code>println</code> methods in class <code>PrintStream</code>.
129 * @see java.io.PrintStream#println()
130 * @see java.io.PrintStream#println(boolean)
131 * @see java.io.PrintStream#println(char)
132 * @see java.io.PrintStream#println(char[])
133 * @see java.io.PrintStream#println(double)
134 * @see java.io.PrintStream#println(float)
135 * @see java.io.PrintStream#println(int)
136 * @see java.io.PrintStream#println(long)
137 * @see java.io.PrintStream#println(java.lang.Object)
138 * @see java.io.PrintStream#println(java.lang.String)
140 @SuppressWarnings("squid:S106") // (intentional wrapping of system err)
141 public PrintStream out() {
146 * The "standard" input stream. This stream is already
147 * open and ready to supply input data. Typically this stream
148 * corresponds to keyboard input or another input source specified by
149 * the host environment or user.
151 public InputStream in() {
152 return System.in; //NO SONAR (intentional wrapping of system in)
156 * Wraps the static call (required for being able to test)
158 * @return the default HTTP client
160 public CloseableHttpClient getHttpClient() {
161 return HttpClients.createDefault();