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authorLiam Fallon <liam.fallon@est.tech>2019-03-05 21:03:06 +0000
committerGerrit Code Review <gerrit@onap.org>2019-03-05 21:03:06 +0000
commit23a3dc4ece2f1533fe1d6b627b5db05e7754a70c (patch)
tree007a918e60dfe15b022a5f637af2270eaa379b4d /utils/src/main
parentb25889ce1871ca2ad4f231666fbeaa6de6598a5c (diff)
parentfabde091ed5589552885265f8ed91bc1d72a9a6e (diff)
Merge "Add bean configurator"
Diffstat (limited to 'utils/src/main')
-rw-r--r--utils/src/main/java/org/onap/policy/common/utils/properties/BeanConfigurator.java567
-rw-r--r--utils/src/main/java/org/onap/policy/common/utils/properties/Property.java59
2 files changed, 626 insertions, 0 deletions
diff --git a/utils/src/main/java/org/onap/policy/common/utils/properties/BeanConfigurator.java b/utils/src/main/java/org/onap/policy/common/utils/properties/BeanConfigurator.java
new file mode 100644
index 00000000..9d02819a
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/properties/BeanConfigurator.java
@@ -0,0 +1,567 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP - Common Modules
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.properties;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.Properties;
+import org.apache.commons.lang3.StringUtils;
+import org.onap.policy.common.utils.properties.exception.PropertyAccessException;
+import org.onap.policy.common.utils.properties.exception.PropertyException;
+import org.onap.policy.common.utils.properties.exception.PropertyInvalidException;
+import org.onap.policy.common.utils.properties.exception.PropertyMissingException;
+
+/**
+ * Configurator for beans whose fields are initialized by reading from a set of
+ * {@link Properties}, as directed by the {@link Property} annotations that appear on
+ * fields within the bean. The values of the fields are set via <i>setXxx()</i> methods.
+ * As a result, if a field is annotated and there is no corresponding <i>setXxx()</i>
+ * method, then an exception will be thrown.
+ *
+ * <p>It is possible that an invalid <i>defaultValue</i> is specified via the
+ * {@link Property} annotation. This could remain undetected until an optional property is
+ * left out of the {@link Properties}. Consequently, this class will always validate a
+ * {@link Property}'s default value, if the <i>defaultValue</i> is not empty or if
+ * <i>accept</i> includes the "empty" option.
+ */
+public class BeanConfigurator {
+
+ /**
+ * The "empty" option that may appear within the {@link Property}'s <i>accept</i>
+ * attribute.
+ */
+ public static final String ACCEPT_EMPTY = "empty";
+
+ /**
+ * Walks the class hierarchy of the bean, populating fields defined in each class,
+ * using values extracted from the given property set.
+ *
+ * @param bean bean whose fields are to be configured from the properties
+ * @param props properties from which to extract the values
+ * @throws PropertyException if an error occurs
+ */
+ public <T> T configureFromProperties(T bean, Properties props) throws PropertyException {
+ Class<?> clazz = bean.getClass();
+
+ while (clazz != Object.class) {
+ for (Field field : clazz.getDeclaredFields()) {
+ setValue(bean, field, props);
+ }
+
+ clazz = clazz.getSuperclass();
+ }
+
+ return bean;
+ }
+
+ /**
+ * Sets a field's value, within an object, based on what's in the properties.
+ *
+ * @param bean bean whose fields are to be configured from the properties
+ * @param field field whose value is to be set
+ * @param props properties from which to get the value
+ * @return {@code true} if the property's value was set, {@code false} otherwise
+ * @throws PropertyException if an error occurs
+ */
+ protected boolean setValue(Object bean, Field field, Properties props) throws PropertyException {
+ Property prop = field.getAnnotation(Property.class);
+ if (prop == null) {
+ return false;
+ }
+
+ checkModifiable(field, prop);
+
+ Method setter = getSetter(field, prop);
+ checkMethod(setter, prop);
+
+ if (setValue(bean, setter, field, props, prop)) {
+ return true;
+ }
+
+ throw new PropertyAccessException(prop.name(), field.getName(), "unsupported field type");
+ }
+
+ /**
+ * Sets a field's value from a particular property.
+ *
+ * @param bean bean whose fields are to be configured from the properties
+ * @param setter method to be used to set the field's value
+ * @param field field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return {@code true} if the property's value was set, {@code false} otherwise
+ * @throws PropertyException if an error occurs
+ */
+ protected boolean setValue(Object bean, Method setter, Field field, Properties props, Property prop)
+ throws PropertyException {
+
+ try {
+ Object val = getValue(field, props, prop);
+ if (val == null) {
+ return false;
+
+ } else {
+ setter.invoke(bean, val);
+ return true;
+ }
+
+ } catch (IllegalArgumentException e) {
+ throw new PropertyInvalidException(prop.name(), field.getName(), e);
+
+ } catch (IllegalAccessException | InvocationTargetException e) {
+ throw new PropertyAccessException(prop.name(), setter.getName(), e);
+ }
+ }
+
+ /**
+ * Get the setter.
+ *
+ * @param field field whose value is to be set
+ * @param prop property of interest
+ * @return the method to be used to set the field's value
+ * @throws PropertyAccessException if a "set" method cannot be identified
+ */
+ private Method getSetter(Field field, Property prop) throws PropertyAccessException {
+ String nm = "set" + StringUtils.capitalize(field.getName());
+
+ try {
+ return field.getDeclaringClass().getMethod(nm, field.getType());
+
+ } catch (NoSuchMethodException | SecurityException e) {
+ throw new PropertyAccessException(prop.name(), nm, e);
+ }
+ }
+
+ /**
+ * Gets a property value, coercing it to the field's type.
+ *
+ * @param field field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property, or {@code null} if the field type is
+ * not supported
+ * @throws PropertyException if an error occurs
+ */
+ protected Object getValue(Field field, Properties props, Property prop) throws PropertyException {
+
+ Class<?> clazz = field.getType();
+ String fieldName = field.getName();
+
+ // can still add support for short, float, double, enum
+
+ if (clazz == String.class) {
+ return getStringValue(fieldName, props, prop);
+
+ } else if (clazz == Boolean.class || clazz == boolean.class) {
+ return getBooleanValue(fieldName, props, prop);
+
+ } else if (clazz == Integer.class || clazz == int.class) {
+ return getIntegerValue(fieldName, props, prop);
+
+ } else if (clazz == Long.class || clazz == long.class) {
+ return getLongValue(fieldName, props, prop);
+
+ } else {
+ return null;
+ }
+ }
+
+ /**
+ * Verifies that the field can be modified, i.e., it's neither <i>static</i>, nor
+ * <i>final</i>.
+ *
+ * @param field field whose value is to be set
+ * @param prop property of interest
+ * @throws PropertyAccessException if the field is not modifiable
+ */
+ protected void checkModifiable(Field field, Property prop) throws PropertyAccessException {
+ int mod = field.getModifiers();
+
+ if (Modifier.isStatic(mod)) {
+ throw new PropertyAccessException(prop.name(), field.getName(), "'static' variable cannot be modified");
+ }
+
+ if (Modifier.isFinal(mod)) {
+ throw new PropertyAccessException(prop.name(), field.getName(), "'final' variable cannot be modified");
+ }
+ }
+
+ /**
+ * Verifies that the method is not <i>static</i>.
+ *
+ * @param method method to be checked
+ * @param prop property of interest
+ * @throws PropertyAccessException if the method is static
+ */
+ private void checkMethod(Method method, Property prop) throws PropertyAccessException {
+ int mod = method.getModifiers();
+
+ if (Modifier.isStatic(mod)) {
+ throw new PropertyAccessException(prop.name(), method.getName(), "method is 'static'");
+ }
+ }
+
+ /**
+ * Gets a property value, coercing it to a String.
+ *
+ * @param fieldName field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property
+ * @throws PropertyException if an error occurs
+ */
+ protected String getStringValue(String fieldName, Properties props, Property prop) throws PropertyException {
+
+ /*
+ * Note: the default value for a String type is always valid, thus no need to
+ * check it.
+ */
+
+ return getPropValue(fieldName, props, prop);
+ }
+
+ /**
+ * Gets a property value, coercing it to a Boolean.
+ *
+ * @param fieldName field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property
+ * @throws PropertyException if an error occurs
+ */
+ protected Boolean getBooleanValue(String fieldName, Properties props, Property prop) throws PropertyException {
+ // validate the default value
+ checkDefaultValue(fieldName, prop, () -> makeBoolean(fieldName, prop, prop.defaultValue()));
+
+ return makeBoolean(fieldName, prop, getPropValue(fieldName, props, prop));
+ }
+
+ /**
+ * Gets a property value, coercing it to an Integer.
+ *
+ * @param fieldName field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property
+ * @throws PropertyException if an error occurs
+ */
+ protected Integer getIntegerValue(String fieldName, Properties props, Property prop) throws PropertyException {
+ // validate the default value
+ checkDefaultValue(fieldName, prop, () -> makeInteger(fieldName, prop, prop.defaultValue()));
+
+ return makeInteger(fieldName, prop, getPropValue(fieldName, props, prop));
+ }
+
+ /**
+ * Gets a property value, coercing it to a Long.
+ *
+ * @param fieldName field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property
+ * @throws PropertyException if an error occurs
+ */
+ protected Long getLongValue(String fieldName, Properties props, Property prop) throws PropertyException {
+ // validate the default value
+ checkDefaultValue(fieldName, prop, () -> makeLong(fieldName, prop, prop.defaultValue()));
+
+ return makeLong(fieldName, prop, getPropValue(fieldName, props, prop));
+ }
+
+ /**
+ * Gets a value from the property set.
+ *
+ * @param fieldName field whose value is to be set
+ * @param props properties from which to get the value
+ * @param prop property of interest
+ * @return the value extracted from the property, or the <i>defaultValue</i> if the
+ * value does not exist
+ * @throws PropertyMissingException if the property does not exist and the
+ * <i>defaultValue</i> is empty and <i>emptyOk</i> is {@code false}
+ */
+ protected String getPropValue(String fieldName, Properties props, Property prop) throws PropertyMissingException {
+ String propnm = prop.name();
+
+ String val = props.getProperty(propnm);
+ if (val != null && isEmptyOk(prop, val)) {
+ return val;
+ }
+
+ val = prop.defaultValue();
+ if (val != null && isEmptyOk(prop, val)) {
+ return val;
+ }
+
+ throw new PropertyMissingException(prop.name(), fieldName);
+ }
+
+ /**
+ * Coerces a String value into a Boolean.
+ *
+ * @param fieldName field whose value is to be set
+ * @param prop property of interest
+ * @param value value to be coerced
+ * @return the Boolean value represented by the String value
+ * @throws PropertyInvalidException if the value does not represent a valid Boolean
+ */
+ private Boolean makeBoolean(String fieldName, Property prop, String value) throws PropertyInvalidException {
+ if ("true".equalsIgnoreCase(value)) {
+ return Boolean.TRUE;
+
+ } else if ("false".equalsIgnoreCase(value)) {
+ return Boolean.FALSE;
+
+ } else {
+ throw new PropertyInvalidException(prop.name(), fieldName, "expecting 'true' or 'false'");
+ }
+ }
+
+ /**
+ * Coerces a String value into an Integer.
+ *
+ * @param fieldName field whose value is to be set
+ * @param prop property of interest
+ * @param value value to be coerced
+ * @return the Integer value represented by the String value
+ * @throws PropertyInvalidException if the value does not represent a valid Integer
+ */
+ private Integer makeInteger(String fieldName, Property prop, String value) throws PropertyInvalidException {
+ try {
+ return Integer.valueOf(value);
+
+ } catch (NumberFormatException e) {
+ throw new PropertyInvalidException(prop.name(), fieldName, e);
+ }
+ }
+
+ /**
+ * Coerces a String value into a Long.
+ *
+ * @param fieldName field whose value is to be set
+ * @param prop property of interest
+ * @param value value to be coerced
+ * @return the Long value represented by the String value
+ * @throws PropertyInvalidException if the value does not represent a valid Long
+ */
+ private Long makeLong(String fieldName, Property prop, String value) throws PropertyInvalidException {
+ try {
+ return Long.valueOf(value);
+
+ } catch (NumberFormatException e) {
+ throw new PropertyInvalidException(prop.name(), fieldName, e);
+ }
+ }
+
+ /**
+ * Applies a function to check a property's default value. If the function throws an
+ * exception about an invalid property, then it's re-thrown as an exception about an
+ * invalid <i>defaultValue</i>.
+ *
+ * @param fieldName name of the field being checked
+ * @param prop property of interest
+ * @param func function to invoke to check the default value
+ */
+ private void checkDefaultValue(String fieldName, Property prop, CheckDefaultValueFunction func)
+ throws PropertyInvalidException {
+
+ if (isEmptyOk(prop, prop.defaultValue())) {
+ try {
+ func.apply();
+
+ } catch (PropertyInvalidException ex) {
+ throw new PropertyInvalidException(ex.getPropertyName(), fieldName, "defaultValue is invalid", ex);
+ }
+ }
+ }
+
+ /**
+ * Determines if a value is OK, even if it's empty.
+ *
+ * @param prop property specifying what's acceptable
+ * @param value value to be checked
+ * @return {@code true} if the value is not empty or empty is allowed, {@code false}
+ * otherwise
+ */
+ protected boolean isEmptyOk(Property prop, String value) {
+ return !value.isEmpty() || isEmptyOk(prop);
+ }
+
+ /**
+ * Determines if a {@link Property}'s <i>accept</i> attribute includes the "empty"
+ * option.
+ *
+ * @param prop property whose <i>accept</i> attribute is to be examined
+ * @return {@code true} if the <i>accept</i> attribute includes "empty"
+ */
+ protected boolean isEmptyOk(Property prop) {
+ for (String option : prop.accept().split(",")) {
+ if (ACCEPT_EMPTY.equals(option)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Copies the field values to a set of properties.
+ *
+ * @param bean bean whose fields are to be exported to the properties
+ * @param props properties into which the values should be added
+ * @param origPrefix prefix of the property names as they appear within the Property
+ * annotations
+ * @param finalPrefix prefix to use instead, when adding to the set of properties
+ * @throws PropertyException if an error occurs
+ */
+ public void addToProperties(Object bean, Properties props, String origPrefix, String finalPrefix)
+ throws PropertyException {
+
+ Class<?> clazz = bean.getClass();
+
+ String dottedOrig = (origPrefix.isEmpty() || origPrefix.endsWith(".") ? origPrefix : origPrefix + ".");
+ String dottedFinal = (finalPrefix.isEmpty() || finalPrefix.endsWith(".") ? finalPrefix : finalPrefix + ".");
+
+ while (clazz != Object.class) {
+ for (Field field : clazz.getDeclaredFields()) {
+ putProperty(bean, field, props, dottedOrig, dottedFinal);
+ }
+
+ clazz = clazz.getSuperclass();
+ }
+ }
+
+ /**
+ * Copies the field values to a set of properties.
+ *
+ * @param bean bean whose fields are to be exported to the properties
+ * @param field field whose value is to be copied
+ * @param props properties into which the values should be added
+ * @param origPrefix prefix of the property names as they appear within the Property
+ * annotations. Includes a trailing "." (if non-empty)
+ * @param finalPrefix prefix to use instead, when adding to the set of properties.
+ * Includes a trailing "." (if non-empty)
+ * @throws PropertyAccessException if an error occurs
+ */
+ private void putProperty(Object bean, Field field, Properties props, String origPrefix, String finalPrefix)
+ throws PropertyAccessException {
+
+ Property prop = field.getAnnotation(Property.class);
+ if (prop == null) {
+ return;
+ }
+
+ Method getter = getGetter(field, prop);
+ checkMethod(getter, prop);
+
+ Object value = getBeanValue(bean, field, getter, prop);
+ if (value == null) {
+ return;
+ }
+
+ String name = prop.name();
+ if (name.startsWith(origPrefix)) {
+ name = finalPrefix + name.substring(origPrefix.length());
+ }
+
+ props.setProperty(name, value.toString());
+ }
+
+ /**
+ * Get the getter.
+ *
+ * @param field field whose value is to be gotten
+ * @param prop property of interest
+ * @return the method to be used to get the field's value
+ * @throws PropertyAccessException if a "get" method cannot be identified
+ */
+ private Method getGetter(Field field, Property prop) throws PropertyAccessException {
+ String capnm = StringUtils.capitalize(field.getName());
+
+ try {
+ return getGetter(field, "get" + capnm);
+
+ } catch (NoSuchMethodException e) {
+ if (field.getType() == Boolean.class || field.getType() == boolean.class) {
+ // boolean - check for "isXxx" method, too
+ try {
+ return getGetter(field, "is" + capnm);
+
+ } catch (NoSuchMethodException | SecurityException e2) {
+ throw new PropertyAccessException(prop.name(), "is" + capnm, e2);
+ }
+ }
+
+ throw new PropertyAccessException(prop.name(), "get" + capnm, e);
+
+ } catch (SecurityException e) {
+ // problem with "get" method
+ throw new PropertyAccessException(prop.name(), "get" + capnm, e);
+ }
+ }
+
+ /**
+ * Get the getter. This may be overridden by junit tests.
+ *
+ * @param field field whose value is to be gotten
+ * @param methodName name of the method to return
+ * @return the method to be used to get the field's value
+ * @throws NoSuchMethodException if the method does not exist
+ * @throws SecurityException if the method cannot be accessed
+ */
+ protected Method getGetter(Field field, String methodName) throws NoSuchMethodException, SecurityException {
+ return field.getDeclaringClass().getMethod(methodName);
+ }
+
+ /**
+ * Gets a field's value for a particular property.
+ *
+ * @param bean bean whose fields are to be configured from the properties
+ * @param getter method to be used to get the field's value
+ * @param field field whose value is to be gotten
+ * @param prop property of interest
+ * @throws PropertyAccessException if an error occurs
+ */
+ private Object getBeanValue(Object bean, Field field, Method getter, Property prop)
+ throws PropertyAccessException {
+ try {
+ return getter.invoke(bean);
+
+ } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+ throw new PropertyAccessException(prop.name(), field.getName(), e);
+ }
+ }
+
+ /**
+ * Functions to check a default value.
+ */
+ @FunctionalInterface
+ private static interface CheckDefaultValueFunction {
+
+ /**
+ * Checks the default value.
+ *
+ * @throws PropertyInvalidException if an error occurs
+ */
+ public void apply() throws PropertyInvalidException;
+ }
+}
diff --git a/utils/src/main/java/org/onap/policy/common/utils/properties/Property.java b/utils/src/main/java/org/onap/policy/common/utils/properties/Property.java
new file mode 100644
index 00000000..bacedef9
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/properties/Property.java
@@ -0,0 +1,59 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.properties;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.Properties;
+
+
+/**
+ * Annotation that declares a variable to be configured via {@link Properties}.
+ */
+@Target(ElementType.FIELD)
+@Retention(RetentionPolicy.RUNTIME)
+
+public @interface Property {
+
+ /**
+ * Name of the property.
+ *
+ * @return the property name
+ */
+ public String name();
+
+ /**
+ * Default value, used when the property does not exist.
+ *
+ * @return the default value
+ */
+ public String defaultValue() default "";
+
+ /**
+ * Comma-separated options identifying what's acceptable. The word, "empty",
+ * indicates that an empty string, "", is an acceptable value.
+ *
+ * @return options identifying what's acceptable
+ */
+ public String accept() default "";
+}