Add command line handler

Added a Handler for command line classes to share common strucutures.

Issue-ID: POLICY-3128
Change-Id: I662911c467faf5c39b8db018bb1a564fba7587a6
Signed-off-by: adheli.tavares <adheli.tavares@est.tech>

2 files changed, 327 insertions, 0 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineArgumentsHandler.java b/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineArgumentsHandler.java
new file mode 100644
index 00000000..37a9047b
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineArgumentsHandler.java
@@ -0,0 +1,273 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 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.cmd;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import lombok.Getter;
+import lombok.Setter;
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.DefaultParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+import org.apache.commons.lang3.StringUtils;
+import org.onap.policy.common.utils.resources.ResourceUtils;
+
+/**
+ * Class for command line common processing.
+ *
+ * @author Adheli Tavares (adheli.tavares@est.tech)
+ *
+ */
+public class CommandLineArgumentsHandler {
+    private static final String FILE_MESSAGE_PREAMBLE = " file \"";
+    private static final int HELP_LINE_LENGTH = 120;
+
+    private final Options options;
+
+    private final String helpClassName;
+    private final String component;
+
+    @Getter
+    @Setter
+    private String configurationFilePath = null;
+
+    @Getter
+    @Setter
+    private String propertyFilePath = null;
+
+    @Getter
+    private CommandLine commandLine = null;
+
+    /**
+     * Construct the options with default values for the CLI editor.
+     */
+    protected CommandLineArgumentsHandler(String helpClassName, String component) {
+        this.helpClassName = helpClassName;
+        this.component = component;
+        //@formatter:off
+        options = new Options();
+        options.addOption(Option.builder("h")
+                .longOpt("help")
+                .desc("outputs the usage of this command")
+                .required(false)
+                .type(Boolean.class)
+                .build());
+        options.addOption(Option.builder("v")
+                .longOpt("version")
+                .desc("outputs the version of " + this.component)
+                .required(false)
+                .type(Boolean.class)
+                .build());
+        options.addOption(Option.builder("c")
+                .longOpt("config-file")
+                .desc(String.format("the full path to the configuration file to use, "
+                        + "the configuration file must be a Json file containing the %s parameters", this.component))
+                .hasArg().argName("CONFIG_FILE")
+                .required(false)
+                .type(String.class)
+                .build());
+        //@formatter:on
+    }
+
+    /**
+     * Construct the options for the CLI editor with extra options.
+     */
+    public CommandLineArgumentsHandler(String helpClassName, String component, Option... customOptions) {
+        this(helpClassName, component);
+        if (customOptions != null && customOptions.length > 0) {
+            for (Option option : customOptions) {
+                options.addOption(option);
+            }
+        }
+    }
+
+    /**
+     * Construct the options with brand new options for the CLI editor.
+     */
+    public CommandLineArgumentsHandler(String helpClassName, String component, Options options) {
+        this.options = options;
+        this.helpClassName = helpClassName;
+        this.component = component;
+    }
+
+    /**
+     * Parse the command line options.
+     *
+     * @param args The command line arguments
+     * @return a string with a message for help and version, or null if there is no message
+     * @throws CommandLineException on command argument errors
+     */
+    public String parse(final String[] args) throws CommandLineException {
+        // Clear all our arguments
+        setConfigurationFilePath(null);
+        setPropertyFilePath(null);
+
+        try {
+            commandLine = new DefaultParser().parse(options, args);
+        } catch (final ParseException | NullPointerException e) {
+            throw new CommandLineException("invalid command line arguments specified", e);
+        }
+
+        // Arguments left over after Commons CLI does its stuff
+        final String[] remainingArgs = removeEmptyValues(commandLine.getArgs());
+
+        if (remainingArgs.length > 0) {
+            throw new CommandLineException("too many command line arguments specified: " + Arrays.toString(args));
+        }
+
+        if (commandLine.hasOption('h')) {
+            return help();
+        }
+
+        if (commandLine.hasOption('v')) {
+            return version();
+        }
+
+        if (commandLine.hasOption('c')) {
+            setConfigurationFilePath(commandLine.getOptionValue('c'));
+        }
+
+        if (commandLine.hasOption('p')) {
+            setPropertyFilePath(commandLine.getOptionValue('p'));
+        }
+
+        return null;
+    }
+
+    /**
+     * Validate the command line options.
+     *
+     * @throws CommandLineException on command argument validation errors
+     */
+    public void validate() throws CommandLineException {
+        validateReadableFile(this.component + " configuration", configurationFilePath);
+    }
+
+    /**
+     * Print version information for policy distribution.
+     *
+     * @return the version string
+     */
+    public String version() {
+        return ResourceUtils.getResourceAsString("version.txt");
+    }
+
+    /**
+     * Print help information for policy distribution.
+     *
+     * @return the help string
+     */
+    public String help() {
+        final HelpFormatter helpFormatter = new HelpFormatter();
+        final StringWriter stringWriter = new StringWriter();
+        final PrintWriter printWriter = new PrintWriter(stringWriter);
+        final String cmdLineSyntax = this.helpClassName + " [options...]";
+
+        helpFormatter.printHelp(printWriter, HELP_LINE_LENGTH, cmdLineSyntax, "options", options, 0, 0, "");
+
+        return stringWriter.toString();
+    }
+
+    /**
+     * Gets the full expanded configuration file path.
+     *
+     * @return the configuration file path
+     */
+    public String getFullConfigurationFilePath() {
+        return ResourceUtils.getFilePath4Resource(getConfigurationFilePath());
+    }
+
+    /**
+     * Check set configuration file path.
+     *
+     * @return true, if check set configuration file path
+     */
+    public boolean checkSetConfigurationFilePath() {
+        return StringUtils.isNotBlank(getConfigurationFilePath());
+    }
+
+    /**
+     * Gets the full expanded property file path.
+     *
+     * @return the property file path
+     */
+    public String getFullPropertyFilePath() {
+        return ResourceUtils.getFilePath4Resource(getPropertyFilePath());
+    }
+
+    /**
+     * Check set property file path.
+     *
+     * @return true, if check set property file path
+     */
+    public boolean checkSetPropertyFilePath() {
+        return StringUtils.isNotBlank(getPropertyFilePath());
+    }
+
+    /**
+     * Validate readable file.
+     *
+     * @param fileTag the file tag
+     * @param fileName the file name
+     * @throws CommandLineException on the file name passed as a parameter
+     */
+    protected void validateReadableFile(final String fileTag, final String fileName) throws CommandLineException {
+        if (StringUtils.isBlank(fileName)) {
+            throw new CommandLineException(fileTag + " file was not specified as an argument");
+        }
+
+        // The file name refers to a resource on the local file system
+        final URL fileUrl = ResourceUtils.getUrl4Resource(fileName);
+        if (fileUrl == null) {
+            throw new CommandLineException(fileTag + FILE_MESSAGE_PREAMBLE + fileName + "\" does not exist");
+        }
+
+        try {
+            Path path = Path.of(fileUrl.toURI());
+            if (!Files.isRegularFile(path)) {
+                throw new CommandLineException(fileTag + FILE_MESSAGE_PREAMBLE + fileName + "\" is not a normal file");
+            }
+            if (!Files.isReadable(path)) {
+                throw new CommandLineException(fileTag + FILE_MESSAGE_PREAMBLE + fileName + "\" is unreadable");
+            }
+        } catch (URISyntaxException e) {
+            throw new CommandLineException("Error parsing " + fileUrl.toString(), e);
+        }
+
+    }
+
+    /**
+     * Checks if args has any null or empty value after parsing.
+     *
+     * @param args remaining args from CLI parse.
+     */
+    private String[] removeEmptyValues(String[] args) {
+        return Arrays.stream(args).filter(StringUtils::isNotBlank).toArray(String[]::new);
+    }
+}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineException.java b/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineException.java
new file mode 100644
index 00000000..95870f75
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/cmd/CommandLineException.java
@@ -0,0 +1,54 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 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.cmd;
+
+/**
+ * Exception used for CommandLineArguments class.
+ *
+ * @author Adheli Tavares (adheli.tavares@est.tech)
+ *
+ */
+public class CommandLineException extends Exception {
+
+    /**
+     * Generated serialVersionUID.
+     */
+    private static final long serialVersionUID = -1200607308084606425L;
+
+    /**
+     * Instantiates a new exception with a message.
+     *
+     * @param message the message
+     */
+    public CommandLineException(final String message) {
+        super(message);
+    }
+
+    /**
+     * Instantiates a new exception with a message and a caused by exception.
+     *
+     * @param message the message
+     * @param exp the exception that caused this exception to be thrown
+     */
+    public CommandLineException(final String message, final Exception exp) {
+        super(message, exp);
+    }
+}