Add support for TOSCA JSON Parsing

Added a getter to allow the Gson object to be retrieved from a GSON
message body handler, useful for testing.

Moved the TextFileUtils utility class from APEX utilites to policy common
utils

Issue-ID: POLICY-1195
Change-Id: I7c8074e8177a90b292c6dfd6e7f0d352063818e7
Signed-off-by: liamfallon <liam.fallon@est.tech>

1 files changed, 110 insertions, 0 deletions

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
new file mode 100644
index 00000000..5aeacf26
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/resources/TextFileUtils.java
@@ -0,0 +1,110 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 Nordix Foundation.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.resources;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.file.Files;
+
+/**
+ * The Class TextFileUtils is class that provides useful functions for handling text files. Functions to read and write
+ * text files to strings and strings are provided.
+ *
+ * @author Liam Fallon (liam.fallon@est.tech)
+ */
+public abstract class TextFileUtils {
+    private static final String UTF_8 = "UTF-8";
+    private static final int READER_CHAR_BUFFER_SIZE_4096 = 4096;
+
+    private TextFileUtils() {
+        // This class cannot be initialized
+    }
+
+    /**
+     * Method to return the contents of a text file as a string.
+     *
+     * @param textFilePath The path to the file as a string
+     * @return A string containing the contents of the file
+     * @throws IOException on errors reading text from the file
+     */
+    public static String getTextFileAsString(final String textFilePath) throws IOException {
+        final File textFile = new File(textFilePath);
+        return new String(Files.readAllBytes(textFile.toPath()), UTF_8);
+    }
+
+    /**
+     * Method to write contents of a string to a text file.
+     *
+     * @param outString The string to write
+     * @param textFilePath The path to the file as a string
+     * @throws IOException on errors reading text from the file
+     */
+    public static void putStringAsTextFile(final String outString, final String textFilePath) throws IOException {
+        final File textFile = new File(textFilePath);
+        putStringAsFile(outString, textFile);
+    }
+
+    /**
+     * Method to write contents of a string to a text file.
+     *
+     * @param outString The string to write
+     * @param textFile The file to write the string to
+     * @throws IOException on errors reading text from the file
+     */
+    public static void putStringAsFile(final String outString, final File textFile) throws IOException {
+        Files.write(textFile.toPath(), outString.getBytes(UTF_8));
+    }
+
+    /**
+     * Method to return the contents of a text steam as a string.
+     *
+     * @param textStream The stream
+     * @return A string containing the output of the stream as text
+     * @throws IOException on errors reading text from the file
+     */
+    public static String getStreamAsString(final InputStream textStream) throws IOException {
+        return getReaderAsString(new InputStreamReader(textStream, UTF_8));
+    }
+
+    /**
+     * Method to return the contents of a reader steam as a string. This closes the reader after use
+     *
+     * @param textReader The reader
+     * @return A string containing the output of the reader as text
+     * @throws IOException on errors reading text from the file
+     */
+    public static String getReaderAsString(final Reader textReader) throws IOException {
+        final StringBuilder builder = new StringBuilder();
+        int charsRead = -1;
+        final char[] chars = new char[READER_CHAR_BUFFER_SIZE_4096];
+        do {
+            charsRead = textReader.read(chars);
+            if (charsRead > 0) {
+                builder.append(chars, 0, charsRead);
+            }
+        }
+        while (charsRead > 0);
+        return builder.toString();
+    }
+}