Create methods for creating temp files

Created utility methods to create temp files and set default
permissions.  These can be used in other repos to satisfy sonar.
Also added code to close streams and clean up temp files created
by some junit tests.
Modified to use IOUtils to read a stream.

Issue-ID: POLICY-3289
Change-Id: Ic83e4f4d7745be7b37ebb42bf1d81e303d8dadc9
Signed-off-by: Jim Hahn <jrh3@att.com>

3 files changed, 102 insertions, 14 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/resources/DirectoryUtils.java b/utils/src/main/java/org/onap/policy/common/utils/resources/DirectoryUtils.java
new file mode 100644
index 00000000..35a13138
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/resources/DirectoryUtils.java
@@ -0,0 +1,63 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.resources;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.apache.commons.io.FileUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Utilities for manipulating directories.
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class DirectoryUtils {
+    private static final Logger logger = LoggerFactory.getLogger(DirectoryUtils.class);
+
+    /**
+     * Creates a directory file, only accessible by the owner.
+     *
+     * @param prefix file name prefix
+     * @return a new, temporary directory
+     * @throws IOException if an error occurs
+     */
+    public static Path createTempDirectory(String prefix) throws IOException {
+        /*
+         * Disabling sonar, as the code below sets the permissions, just as sonar
+         * suggests it be fixed.
+         */
+        var path = Files.createTempDirectory(prefix);           // NOSONAR
+        logger.info("created temporary directory, {}", path);
+
+        var file = path.toFile();
+
+        TextFileUtils.setDefaultPermissions(file);
+
+        // ensure nothing has been written to it yet
+        FileUtils.cleanDirectory(file);
+
+        return path;
+    }
+}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/resources/ResourceUtils.java b/utils/src/main/java/org/onap/policy/common/utils/resources/ResourceUtils.java
index 83d41fb3..001c9f06 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/resources/ResourceUtils.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/resources/ResourceUtils.java
@@ -23,11 +23,11 @@
 package org.onap.policy.common.utils.resources;
 
 import com.google.re2j.Pattern;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.Set;
@@ -36,6 +36,7 @@ import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
+import org.apache.commons.io.IOUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,9 +51,6 @@ public final class ResourceUtils {
 
     private static final Pattern SLASH_PAT = Pattern.compile("/");
 
-    // The length of byte buffers used to read resources into strings
-    private static final int BYTE_BUFFER_LENGH = 1024;
-
     // Resource types
     private static final String FILE_PROTOCOL = "file";
     private static final String JAR_PROTOCOL = "jar";
@@ -90,20 +88,13 @@ public final class ResourceUtils {
             return null;
         }
 
-        // Read the stream contents in to an output stream
-        final var resourceOutputStreamBuffer = new ByteArrayOutputStream();
-        final var resourceBuffer = new byte[BYTE_BUFFER_LENGH];
-        int length;
-        try {
-            while ((length = resourceStream.read(resourceBuffer)) != -1) {
-                resourceOutputStreamBuffer.write(resourceBuffer, 0, length);
-            }
+        // Read the stream contents, closing when done
+        try (var streamCloser = resourceStream) {
+            return IOUtils.toString(resourceStream, StandardCharsets.UTF_8);
         } catch (final IOException e) {
             LOGGER.debug("error reading resource stream {}", resourceName, e);
             return null;
         }
-
-        return resourceOutputStreamBuffer.toString();
     }
 
     /**
diff --git a/utils/src/main/java/org/onap/policy/common/utils/resources/TextFileUtils.java b/utils/src/main/java/org/onap/policy/common/utils/resources/TextFileUtils.java
index 9df98801..7701eae9 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/resources/TextFileUtils.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/resources/TextFileUtils.java
@@ -31,6 +31,8 @@ import java.nio.file.Files;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import org.apache.commons.io.IOUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * The Class TextFileUtils is class that provides useful functions for handling text files. Functions to read and write
@@ -40,6 +42,7 @@ import org.apache.commons.io.IOUtils;
  */
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
 public final class TextFileUtils {
+    private static final Logger logger = LoggerFactory.getLogger(TextFileUtils.class);
 
     /**
      * Method to return the contents of a text file as a string.
@@ -101,4 +104,35 @@ public final class TextFileUtils {
     public static String getReaderAsString(final Reader textReader) throws IOException {
         return IOUtils.toString(textReader);
     }
+
+    /**
+     * Creates a temporary file, only accessible by the owner.
+     *
+     * @param prefix file name prefix
+     * @param suffix file name suffix
+     * @return a new, temporary file
+     * @throws IOException if an error occurs
+     */
+    public static File createTempFile(String prefix, String suffix) throws IOException {
+        /*
+         * Disabling sonar, because setDefaultPermissions() will set the permissions of
+         * the file.
+         */
+        var file = File.createTempFile(prefix, suffix); // NOSONAR
+
+        setDefaultPermissions(file);
+
+        return file;
+    }
+
+    /**
+     * Sets permissions on a file or directory so that only the owner can access it.
+     *
+     * @param file file or directory on which permissions are to be set
+     */
+    public static void setDefaultPermissions(File file) {
+        if (!file.setReadable(true, true) || !file.setWritable(true, true) || !file.setExecutable(true, true)) {
+            logger.warn("cannot set permissions for {}", file);
+        }
+    }
 }