[ONOS-4350] Inter Jar dependency implementation and code restructuring.

Change-Id: Iacac75e4187aed93ce1754c170a9c19707e5b8c3
diff --git a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java
new file mode 100644
index 0000000..0fcf663
--- /dev/null
+++ b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java
@@ -0,0 +1,288 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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.
+ */
+package org.onosproject.yangutils.datamodel;
+
+import java.io.Serializable;
+import java.util.Set;
+
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.utils.Parsable;
+import org.onosproject.yangutils.datamodel.utils.YangConstructType;
+
+import static org.onosproject.yangutils.datamodel.utils.DataModelUtils.findReferredNode;
+
+/*
+ *  Reference:RFC 6020.
+ *  The "import" statement makes definitions from one module available
+ *  inside another module or submodule.  The argument is the name of the
+ *  module to import, and the statement is followed by a block of
+ *  sub statements that holds detailed import information.
+ *  When a module is imported, the importing module may:
+ *  o  use any grouping and typedef defined at the top level in the
+ *     imported module or its submodules.
+ *
+ *  o  use any extension, feature, and identity defined in the imported
+ *     module or its submodules.
+ *
+ *  o  use any node in the imported module's schema tree in "must",
+ *     "path", and "when" statements, or as the target node in "augment"
+ *     and "deviation" statements.
+ *
+ *  The mandatory "prefix" sub statement assigns a prefix for the imported
+ *  module that is scoped to the importing module or submodule.  Multiple
+ *  "import" statements may be specified to import from different
+ *  modules.
+ *  When the optional "revision-date" sub-statement is present, any
+ *  typedef, grouping, extension, feature, and identity referenced by
+ *  definitions in the local module are taken from the specified revision
+ *  of the imported module.  It is an error if the specified revision of
+ *  the imported module does not exist.  If no "revision-date"
+ *  sub-statement is present, it is undefined from which revision of the
+ *  module they are taken.
+ *
+ *  Multiple revisions of the same module MUST NOT be imported.
+ *
+ *                       The import's Substatements
+ *
+ *                +---------------+---------+-------------+------------------+
+ *                | substatement  | section | cardinality |data model mapping|
+ *                +---------------+---------+-------------+------------------+
+ *                | prefix        | 7.1.4   | 1           | string           |
+ *                | revision-date | 7.1.5.1 | 0..1        | string           |
+ *                +---------------+---------+-------------+------------------+
+ */
+
+/**
+ * Represents the information about the imported modules.
+ */
+public class YangImport
+        implements Parsable, LocationInfo, Serializable {
+
+    private static final long serialVersionUID = 806201642L;
+
+    /**
+     * Name of the module that is being imported.
+     */
+    private String name;
+
+    /**
+     * Prefix used to identify the entities from the imported module.
+     */
+    private String prefixId;
+
+    /**
+     * Reference:RFC 6020.
+     * <p>
+     * The import's "revision-date" statement is used to specify the exact
+     * version of the module to import. The "revision-date" statement MUST match
+     * the most recent "revision" statement in the imported module. organization
+     * which defined the YANG module.
+     */
+    private String revision;
+
+    /**
+     * Reference to node which is imported.
+     */
+    private YangNode importedNode;
+
+    // Error Line number.
+    private transient int lineNumber;
+
+    // Error character position.
+    private transient int charPosition;
+
+    /**
+     * Creates a YANG import.
+     */
+    public YangImport() {
+    }
+
+    /**
+     * Returns the imported module name.
+     *
+     * @return the module name
+     */
+    public String getModuleName() {
+        return name;
+    }
+
+    /**
+     * Sets module name.
+     *
+     * @param moduleName the module name to set
+     */
+    public void setModuleName(String moduleName) {
+        name = moduleName;
+    }
+
+    /**
+     * Returns the prefix used to identify the entities from the imported module.
+     *
+     * @return the prefix used to identify the entities from the imported
+     * module
+     */
+    public String getPrefixId() {
+        return prefixId;
+    }
+
+    /**
+     * Sets prefix identifier.
+     *
+     * @param prefixId set the prefix identifier of the imported module
+     */
+    public void setPrefixId(String prefixId) {
+        this.prefixId = prefixId;
+    }
+
+    /**
+     * Returns the revision of the imported module.
+     *
+     * @return the revision of the imported module
+     */
+    public String getRevision() {
+        return revision;
+    }
+
+    /**
+     * Sets the revision of the imported module.
+     *
+     * @param rev set the revision of the imported module
+     */
+    public void setRevision(String rev) {
+        revision = rev;
+    }
+
+    /**
+     * Returns the type of the parsed data.
+     *
+     * @return returns IMPORT_DATA
+     */
+    @Override
+    public YangConstructType getYangConstructType() {
+        return YangConstructType.IMPORT_DATA;
+    }
+
+    /**
+     * Validates the data on entering the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules
+     */
+    @Override
+    public void validateDataOnEntry()
+            throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+
+    }
+
+    /**
+     * Validates the data on exiting the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules
+     */
+    @Override
+    public void validateDataOnExit()
+            throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+
+    }
+
+    /**
+     * Returns imported node.
+     *
+     * @return imported node
+     */
+    public YangNode getImportedNode() {
+        return importedNode;
+    }
+
+    /**
+     * Sets imported node.
+     *
+     * @param importedNode imported node
+     */
+    public void setImportedNode(YangNode importedNode) {
+        this.importedNode = importedNode;
+    }
+
+    @Override
+    public int getLineNumber() {
+        return lineNumber;
+    }
+
+    @Override
+    public int getCharPosition() {
+        return charPosition;
+    }
+
+    @Override
+    public void setLineNumber(int lineNumber) {
+        this.lineNumber = lineNumber;
+    }
+
+    @Override
+    public void setCharPosition(int charPositionInLine) {
+        charPosition = charPositionInLine;
+    }
+
+    /**
+     * Adds reference to an import.
+     *
+     * @param yangNodeSet YANG file info set
+     * @throws DataModelException a violation of data model rules
+     */
+    public void addReferenceToImport(Set<YangNode> yangNodeSet) throws DataModelException {
+        String importedModuleName = getModuleName();
+        String importedModuleRevision = getRevision();
+        YangNode moduleNode = null;
+        /*
+         * Find the imported module node for a given module name with a
+         * specified revision if revision is not null.
+         */
+        if (importedModuleRevision != null) {
+            String importedModuleNameWithRevision = importedModuleName + "@" + importedModuleRevision;
+            moduleNode = findReferredNode(yangNodeSet, importedModuleNameWithRevision);
+        }
+
+        /*
+         * Find the imported module node for a given module name without
+         * revision if can't find with revision.
+         */
+        if (moduleNode == null) {
+            moduleNode = findReferredNode(yangNodeSet, importedModuleName);
+        }
+
+        if (moduleNode != null) {
+            if (moduleNode instanceof YangModule) {
+                if (getRevision() == null || getRevision().isEmpty()) {
+                    setImportedNode(moduleNode);
+                    return;
+                }
+                // Match revision if import is with revision.
+                if (((YangModule) moduleNode).getRevision().getRevDate().equals(importedModuleRevision)) {
+                    setImportedNode(moduleNode);
+                    return;
+                }
+            }
+        }
+
+        // Exception if there is no match.
+        DataModelException exception = new DataModelException("YANG file error : Imported module "
+                + importedModuleName + " with revision " + importedModuleRevision + " is not found.");
+        exception.setLine(getLineNumber());
+        exception.setCharPosition(getCharPosition());
+        throw exception;
+    }
+}