diff options
Diffstat (limited to 'utils/src/main/java')
| -rw-r--r-- | utils/src/main/java/org/onap/policy/common/utils/properties/BeanConfigurator.java | 567 | ||||
| -rw-r--r-- | utils/src/main/java/org/onap/policy/common/utils/properties/Property.java | 59 |
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 ""; +} |