Add ValidationResult for arbitrary beans

Added implementations of ValidationResult for arbitrary objects and
for beans (i.e., containers of arbitrary objects).

Change-Id: I4c6f35bd19f1386062ce19125cbc648c399cc331
Issue-ID: POLICY-1542
Signed-off-by: Jim Hahn <jrh3@att.com>

3 files changed, 351 insertions, 0 deletions

diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/BeanValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/BeanValidationResult.java
new file mode 100644
index 00000000..f8eebcf1
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/BeanValidationResult.java
@@ -0,0 +1,166 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+
+/**
+ * This class holds the result of the validation of an arbitrary bean.
+ */
+public class BeanValidationResult extends ValidationResultImpl {
+
+    /**
+     * Validation results for each item in the bean.
+     */
+    private final List<ValidationResult> itemResults = new ArrayList<>();
+
+
+    /**
+     * Constructs the object.
+     *
+     * @param name name of the bean being validated
+     * @param object object being validated
+     */
+    public BeanValidationResult(String name, Object object) {
+        super(name, object);
+    }
+
+    /**
+     * Adds a result to this result.
+     *
+     * @param result the result to be added
+     * @return {@code true} if the result is {@code null} or valid, {@code false} if the
+     *         result is invalid
+     */
+    public boolean addResult(ValidationResult result) {
+        if (result == null) {
+            return true;
+        }
+
+        itemResults.add(result);
+        setResult(result.getStatus());
+
+        return result.isValid();
+    }
+
+    /**
+     * Validates that a sub-object within the bean is not {@code null}.
+     *
+     * @param subName name of the sub-object
+     * @param subObject the sub-object
+     * @return {@code true} if the value is not null, {@code false} otherwise
+     */
+    public boolean validateNotNull(String subName, Object subObject) {
+        ObjectValidationResult result = new ObjectValidationResult(subName, subObject);
+
+        if (result.validateNotNull()) {
+            return true;
+
+        } else {
+            addResult(result);
+            return false;
+        }
+    }
+
+    /**
+     * Validates the items in a list, after validating that the list, itself, is not null.
+     *
+     * @param listName name of the list
+     * @param list list whose items are to be validated, or {@code null}
+     * @param itemValidator function to validate an item in the list
+     * @return {@code true} if all items in the list are valid, {@code false} otherwise
+     */
+    public <T> boolean validateNotNullList(String listName, Collection<T> list,
+                    Function<T, ValidationResult> itemValidator) {
+
+        return validateNotNull(listName, list) && validateList(listName, list, itemValidator);
+    }
+
+    /**
+     * Validates the items in a list.
+     *
+     * @param listName name of the list
+     * @param list list whose items are to be validated, or {@code null}
+     * @param itemValidator function to validate an item in the list
+     * @return {@code true} if all items in the list are valid, {@code false} otherwise
+     */
+    public <T> boolean validateList(String listName, Collection<T> list, Function<T, ValidationResult> itemValidator) {
+        if (list == null) {
+            return true;
+        }
+
+        BeanValidationResult result = new BeanValidationResult(listName, null);
+        for (T item : list) {
+            if (item == null) {
+                result.addResult(new ObjectValidationResult("item", item, ValidationStatus.INVALID, "null"));
+            } else {
+                result.addResult(itemValidator.apply(item));
+            }
+        }
+
+        if (result.isValid()) {
+            return true;
+
+        } else {
+            addResult(result);
+            return false;
+        }
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the indentation to use on the main result output
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    @Override
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean) {
+        if (!showClean && getStatus() == ValidationStatus.CLEAN) {
+            return null;
+        }
+
+        StringBuilder builder = new StringBuilder();
+
+        builder.append(initialIndentation);
+        builder.append('"');
+        builder.append(getName());
+
+        builder.append("\" ");
+        builder.append(getStatus());
+        builder.append(", ");
+        builder.append(getMessage());
+        builder.append('\n');
+
+        for (ValidationResult itemResult : itemResults) {
+            String message = itemResult.getResult(initialIndentation + subIndentation, subIndentation, showClean);
+            if (message != null) {
+                builder.append(message);
+            }
+        }
+
+        return builder.toString();
+    }
+}
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ObjectValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ObjectValidationResult.java
new file mode 100644
index 00000000..e5597206
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ObjectValidationResult.java
@@ -0,0 +1,65 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+/**
+ * This class holds the result of the validation of an object within a bean.
+ */
+public class ObjectValidationResult extends ValidationResultImpl {
+
+    /**
+     * Constructs the object.
+     *
+     * @param name name of the object of this result
+     * @param object object being validated
+     */
+    public ObjectValidationResult(String name, Object object) {
+        super(name, object);
+    }
+
+    /**
+     * Constructs the object.
+     *
+     * @param name name of the object of this result
+     * @param object object being validated
+     */
+    public ObjectValidationResult(String name, Object object, ValidationStatus status, String message) {
+        super(name, object, status, message);
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the result indentation
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    @Override
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean) {
+        if (!showClean && getStatus() == ValidationStatus.CLEAN) {
+            return null;
+        }
+
+        return initialIndentation + "item \"" + getName() + "\" value \"" + getObject() + "\" " + getStatus() + ", "
+                        + getMessage() + '\n';
+    }
+}
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResultImpl.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResultImpl.java
new file mode 100644
index 00000000..1d8aa239
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResultImpl.java
@@ -0,0 +1,120 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+import lombok.Getter;
+
+/**
+ * Basic implementation of a ValidationResult.
+ */
+@Getter
+public abstract class ValidationResultImpl implements ValidationResult {
+    public static final String ITEM_HAS_STATUS_MESSAGE = "item has status ";
+
+    /**
+     * Name of the object of this result.
+     */
+    private final String name;
+
+    /**
+     * Object being validated.
+     */
+    private final Object object;
+
+    /**
+     * Validation status of this object.
+     */
+    private ValidationStatus status = ValidationStatus.CLEAN;
+
+    /**
+     * Validation message.
+     */
+    private String message = ITEM_HAS_STATUS_MESSAGE + status.toString();
+
+
+    /**
+     * Constructs the object.
+     *
+     * @param name name of the object of this result
+     * @param object object being validated
+     */
+    public ValidationResultImpl(String name, Object object) {
+        this.name = name;
+        this.object = object;
+    }
+
+    /**
+     * Constructs the object.
+     *
+     * @param name name of the object of this result
+     * @param object object being validated
+     * @param status the validation status
+     * @param message the validation message explaining the validation status
+     */
+    public ValidationResultImpl(String name, Object object, ValidationStatus status, String message) {
+        this.name = name;
+        this.object = object;
+        this.status = status;
+        this.message = message;
+    }
+
+    /**
+     * Validates that the value is not {@code null}.
+     *
+     * @return {@code true} if the value is not null, {@code false} otherwise
+     */
+    public boolean validateNotNull() {
+        if (object == null) {
+            setResult(ValidationStatus.INVALID, "is null");
+            return false;
+
+        } else {
+            return true;
+        }
+    }
+
+    /**
+     * Set the validation result status. On a sequence of calls, the most serious
+     * validation status is recorded, assuming the status enum ordinals increase in order
+     * of severity.
+     *
+     * @param status validation status the bean is receiving
+     */
+    public void setResult(final ValidationStatus status) {
+        setResult(status, ITEM_HAS_STATUS_MESSAGE + status.toString());
+    }
+
+    /**
+     * Set the validation result status. On a sequence of calls, the most serious
+     * validation status is recorded, assuming the status enum ordinals increase in order
+     * of severity.
+     *
+     * @param status the validation status
+     * @param message the validation message explaining the validation status
+     */
+    @Override
+    public void setResult(final ValidationStatus status, final String message) {
+        if (this.status.ordinal() < status.ordinal()) {
+            this.status = status;
+            this.message = message;
+        }
+    }
+}