/*
* Copyright 2002-2016 the original author or authors.
*
* 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.springframework.test.util;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;
import org.springframework.util.MethodInvoker;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
/**
* {@code ReflectionTestUtils} is a collection of reflection-based utility
* methods for use in unit and integration testing scenarios.
*
* <p>There are often times when it would be beneficial to be able to set a
* non-{@code public} field, invoke a non-{@code public} setter method, or
* invoke a non-{@code public} <em>configuration</em> or <em>lifecycle</em>
* callback method when testing code involving, for example:
*
* <ul>
* <li>ORM frameworks such as JPA and Hibernate which condone the usage of
* {@code private} or {@code protected} field access as opposed to
* {@code public} setter methods for properties in a domain entity.</li>
* <li>Spring's support for annotations such as
* {@link org.springframework.beans.factory.annotation.Autowired @Autowired},
* {@link javax.inject.Inject @Inject}, and
* {@link javax.annotation.Resource @Resource} which provides dependency
* injection for {@code private} or {@code protected} fields, setter methods,
* and configuration methods.</li>
* <li>Use of annotations such as {@link javax.annotation.PostConstruct @PostConstruct}
* and {@link javax.annotation.PreDestroy @PreDestroy} for lifecycle callback
* methods.</li>
* </ul>
*
* <p>In addition, several methods in this class provide support for {@code static}
* fields — for example, {@link #setField(Class, String, Object)},
* {@link #getField(Class, String)}, etc.
*
* @author Sam Brannen
* @author Juergen Hoeller
* @since 2.5
* @see ReflectionUtils
* @see AopTestUtils
*/
public class ReflectionTestUtils {
private static final String SETTER_PREFIX = "set";
private static final String GETTER_PREFIX = "get";
private static final Log logger = LogFactory.getLog(ReflectionTestUtils.class);
/**
* Set the {@linkplain Field field} with the given {@code name} on the
* provided {@code targetObject} to the supplied {@code value}.
* <p>This method delegates to {@link #setField(Object, String, Object, Class)},
* supplying {@code null} for the {@code type} argument.
* @param targetObject the target object on which to set the field; never {@code null}
* @param name the name of the field to set; never {@code null}
* @param value the value to set
*/
public static void setField(Object targetObject, String name, Object value) {
setField(targetObject, name, value, null);
}
/**
* Set the {@linkplain Field field} with the given {@code name}/{@code type}
* on the provided {@code targetObject} to the supplied {@code value}.
* <p>This method delegates to {@link #setField(Object, Class, String, Object, Class)},
* supplying {@code null} for the {@code targetClass} argument.
* @param targetObject the target object on which to set the field; never {@code null}
* @param name the name of the field to set; may be {@code null} if
* {@code type} is specified
* @param value the value to set
* @param type the type of the field to set; may be {@code null} if
* {@code name} is specified
*/
public static void setField(Object targetObject, String name, Object value, Class<?> type) {
setField(targetObject, null, name, value, type);
}
/**
* Set the static {@linkplain Field field} with the given {@code name} on
* the provided {@code targetClass} to the supplied {@code value}.
* <p>This method delegates to {@link #setField(Object, Class, String, Object, Class)},
* supplying {@code null} for the {@code targetObject} and {@code type} arguments.
* @param targetClass the target class on which to set the static field;
* never {@code null}
* @param name the name of the field to set; never {@code null}
* @param value the value to set
* @since 4.2
*/
public static void setField(Class<?> targetClass, String name, Object value) {
setField(null, targetClass, name, value, null);
}
/**
* Set the static {@linkplain Field field} with the given
* {@code name}/{@code type} on the provided {@code targetClass} to
* the supplied {@code value}.
* <p>This method delegates to {@link #setField(Object, Class, String, Object, Class)},
* supplying {@code null} for the {@code targetObject} argument.
* @param targetClass the target class on which to set the static field;
* never {@code null}
* @param name the name of the field to set; may be {@code null} if
* {@code type} is specified
* @param value the value to set
* @param type the type of the field to set; may be {@code null} if
* {@code name} is specified
* @since 4.2
*/
public static void setField(Class<?> targetClass, String name, Object value, Class<?> type) {
setField(null, targetClass, name, value, type);
}
/**
* Set the {@linkplain Field field} with the given {@code name}/{@code type}
* on the provided {@code targetObject}/{@code targetClass} to the supplied
* {@code value}.
* <p>If the supplied {@code targetObject} is a <em>proxy</em>, it will
* be {@linkplain AopTestUtils#getUltimateTargetObject unwrapped} allowing
* the field to be set on the ultimate target of the proxy.
* <p>This method traverses the class hierarchy in search of the desired
* field. In addition, an attempt will be made to make non-{@code public}
* fields <em>accessible</em>, thus allowing one to set {@code protected},
* {@code private}, and <em>package-private</em> fields.
* @param targetObject the target object on which to set the field; may be
* {@code null} if the field is static
* @param targetClass the target class on which to set the field; may
* be {@code null} if the field is an instance field
* @param name the name of the field to set; may be {@code null} if
* {@code type} is specified
* @param value the value to set
* @param type the type of the field to set; may be {@code null} if
* {@code name} is specified
* @since 4.2
* @see ReflectionUtils#findField(Class, String, Class)
* @see ReflectionUtils#makeAccessible(Field)
* @see ReflectionUtils#setField(Field, Object, Object)
* @see AopTestUtils#getUltimateTargetObject(Object)
*/
public static void setField(Object targetObject, Class<?> targetClass, String name, Object value, Class<?> type) {
Assert.isTrue(targetObject != null || targetClass != null,
"Either targetObject or targetClass for the field must be specified");
Object ultimateTarget = (targetObject != null ? AopTestUtils.getUltimateTargetObject(targetObject) : null);
if (targetClass == null) {
targetClass = ultimateTarget.getClass();
}
Field field = ReflectionUtils.findField(targetClass, name, type);
if (field == null) {
throw new IllegalArgumentException(String.format(
"Could not find field '%s' of type [%s] on %s or target class [%s]", name, type,
safeToString(ultimateTarget), targetClass));
}
if (logger.isDebugEnabled()) {
logger.debug(String.format(
"Setting field '%s' of type [%s] on %s or target class [%s] to value [%s]", name, type,
safeToString(ultimateTarget), targetClass, value));
}
ReflectionUtils.makeAccessible(field);
ReflectionUtils.setField(field, ultimateTarget, value);
}
/**
* Get the value of the {@linkplain Field field} with the given {@code name}
* from the provided {@code targetObject}.
* <p>This method delegates to {@link #getField(Object, Class, String)},
* supplying {@code null} for the {@code targetClass} argument.
* @param targetObject the target object from which to get the field;
* never {@code null}
* @param name the name of the field to get; never {@code null}
* @return the field's current value
* @see #getField(Class, String)
*/
public static Object getField(Object targetObject, String name) {
return getField(targetObject, null, name);
}
/**
* Get the value of the static {@linkplain Field field} with the given
* {@code name} from the provided {@code targetClass}.
* <p>This method delegates to {@link #getField(Object, Class, String)},
* supplying {@code null} for the {@code targetObject} argument.
* @param targetClass the target class from which to get the static field;
* never {@code null}
* @param name the name of the field to get; never {@code null}
* @return the field's current value
* @since 4.2
* @see #getField(Object, String)
*/
public static Object getField(Class<?> targetClass, String name) {
return getField(null, targetClass, name);
}
/**
* Get the value of the {@linkplain Field field} with the given {@code name}
* from the provided {@code targetObject}/{@code targetClass}.
* <p>If the supplied {@code targetObject} is a <em>proxy</em>, it will
* be {@linkplain AopTestUtils#getUltimateTargetObject unwrapped} allowing
* the field to be retrieved from the ultimate target of the proxy.
* <p>This method traverses the class hierarchy in search of the desired
* field. In addition, an attempt will be made to make non-{@code public}
* fields <em>accessible</em>, thus allowing one to get {@code protected},
* {@code private}, and <em>package-private</em> fields.
* @param targetObject the target object from which to get the field; may be
* {@code null} if the field is static
* @param targetClass the target class from which to get the field; may
* be {@code null} if the field is an instance field
* @param name the name of the field to get; never {@code null}
* @return the field's current value
* @since 4.2
* @see #getField(Object, String)
* @see #getField(Class, String)
* @see ReflectionUtils#findField(Class, String, Class)
* @see ReflectionUtils#makeAccessible(Field)
* @see ReflectionUtils#getField(Field, Object)
* @see AopTestUtils#getUltimateTargetObject(Object)
*/
public static Object getField(Object targetObject, Class<?> targetClass, String name) {
Assert.isTrue(targetObject != null || targetClass != null,
"Either targetObject or targetClass for the field must be specified");
Object ultimateTarget = (targetObject != null ? AopTestUtils.getUltimateTargetObject(targetObject) : null);
if (targetClass == null) {
targetClass = ultimateTarget.getClass();
}
Field field = ReflectionUtils.findField(targetClass, name);
if (field == null) {
throw new IllegalArgumentException(String.format("Could not find field '%s' on %s or target class [%s]",
name, safeToString(ultimateTarget), targetClass));
}
if (logger.isDebugEnabled()) {
logger.debug(String.format("Getting field '%s' from %s or target class [%s]", name,
safeToString(ultimateTarget), targetClass));
}
ReflectionUtils.makeAccessible(field);
return ReflectionUtils.getField(field, ultimateTarget);
}
/**
* Invoke the setter method with the given {@code name} on the supplied
* target object with the supplied {@code value}.
* <p>This method traverses the class hierarchy in search of the desired
* method. In addition, an attempt will be made to make non-{@code public}
* methods <em>accessible</em>, thus allowing one to invoke {@code protected},
* {@code private}, and <em>package-private</em> setter methods.
* <p>In addition, this method supports JavaBean-style <em>property</em>
* names. For example, if you wish to set the {@code name} property on the
* target object, you may pass either "name" or
* "setName" as the method name.
* @param target the target object on which to invoke the specified setter
* method
* @param name the name of the setter method to invoke or the corresponding
* property name
* @param value the value to provide to the setter method
* @see ReflectionUtils#findMethod(Class, String, Class[])
* @see ReflectionUtils#makeAccessible(Method)
* @see ReflectionUtils#invokeMethod(Method, Object, Object[])
*/
public static void invokeSetterMethod(Object target, String name, Object value) {
invokeSetterMethod(target, name, value, null);
}
/**
* Invoke the setter method with the given {@code name} on the supplied
* target object with the supplied {@code value}.
* <p>This method traverses the class hierarchy in search of the desired
* method. In addition, an attempt will be made to make non-{@code public}
* methods <em>accessible</em>, thus allowing one to invoke {@code protected},
* {@code private}, and <em>package-private</em> setter methods.
* <p>In addition, this method supports JavaBean-style <em>property</em>
* names. For example, if you wish to set the {@code name} property on the
* target object, you may pass either "name" or
* "setName" as the method name.
* @param target the target object on which to invoke the specified setter
* method
* @param name the name of the setter method to invoke or the corresponding
* property name
* @param value the value to provide to the setter method
* @param type the formal parameter type declared by the setter method
* @see ReflectionUtils#findMethod(Class, String, Class[])
* @see ReflectionUtils#makeAccessible(Method)
* @see ReflectionUtils#invokeMethod(Method, Object, Object[])
*/
public static void invokeSetterMethod(Object target, String name, Object value, Class<?> type) {
Assert.notNull(target, "Target object must not be null");
Assert.hasText(name, "Method name must not be empty");
Class<?>[] paramTypes = (type != null ? new Class<?>[] {type} : null);
String setterMethodName = name;
if (!name.startsWith(SETTER_PREFIX)) {
setterMethodName = SETTER_PREFIX + StringUtils.capitalize(name);
}
Method method = ReflectionUtils.findMethod(target.getClass(), setterMethodName, paramTypes);
if (method == null && !setterMethodName.equals(name)) {
setterMethodName = name;
method = ReflectionUtils.findMethod(target.getClass(), setterMethodName, paramTypes);
}
if (method == null) {
throw new IllegalArgumentException(String.format(
"Could not find setter method '%s' on %s with parameter type [%s]", setterMethodName,
safeToString(target), type));
}
if (logger.isDebugEnabled()) {
logger.debug(String.format("Invoking setter method '%s' on %s with value [%s]", setterMethodName,
safeToString(target), value));
}
ReflectionUtils.makeAccessible(method);
ReflectionUtils.invokeMethod(method, target, value);
}
/**
* Invoke the getter method with the given {@code name} on the supplied
* target object with the supplied {@code value}.
* <p>This method traverses the class hierarchy in search of the desired
* method. In addition, an attempt will be made to make non-{@code public}
* methods <em>accessible</em>, thus allowing one to invoke {@code protected},
* {@code private}, and <em>package-private</em> getter methods.
* <p>In addition, this method supports JavaBean-style <em>property</em>
* names. For example, if you wish to get the {@code name} property on the
* target object, you may pass either "name" or
* "getName" as the method name.
* @param target the target object on which to invoke the specified getter
* method
* @param name the name of the getter method to invoke or the corresponding
* property name
* @return the value returned from the invocation
* @see ReflectionUtils#findMethod(Class, String, Class[])
* @see ReflectionUtils#makeAccessible(Method)
* @see ReflectionUtils#invokeMethod(Method, Object, Object[])
*/
public static Object invokeGetterMethod(Object target, String name) {
Assert.notNull(target, "Target object must not be null");
Assert.hasText(name, "Method name must not be empty");
String getterMethodName = name;
if (!name.startsWith(GETTER_PREFIX)) {
getterMethodName = GETTER_PREFIX + StringUtils.capitalize(name);
}
Method method = ReflectionUtils.findMethod(target.getClass(), getterMethodName);
if (method == null && !getterMethodName.equals(name)) {
getterMethodName = name;
method = ReflectionUtils.findMethod(target.getClass(), getterMethodName);
}
if (method == null) {
throw new IllegalArgumentException(String.format(
"Could not find getter method '%s' on %s", getterMethodName, safeToString(target)));
}
if (logger.isDebugEnabled()) {
logger.debug(String.format("Invoking getter method '%s' on %s", getterMethodName, safeToString(target)));
}
ReflectionUtils.makeAccessible(method);
return ReflectionUtils.invokeMethod(method, target);
}
/**
* Invoke the method with the given {@code name} on the supplied target
* object with the supplied arguments.
* <p>This method traverses the class hierarchy in search of the desired
* method. In addition, an attempt will be made to make non-{@code public}
* methods <em>accessible</em>, thus allowing one to invoke {@code protected},
* {@code private}, and <em>package-private</em> methods.
* @param target the target object on which to invoke the specified method
* @param name the name of the method to invoke
* @param args the arguments to provide to the method
* @return the invocation result, if any
* @see MethodInvoker
* @see ReflectionUtils#makeAccessible(Method)
* @see ReflectionUtils#invokeMethod(Method, Object, Object[])
* @see ReflectionUtils#handleReflectionException(Exception)
*/
@SuppressWarnings("unchecked")
public static <T> T invokeMethod(Object target, String name, Object... args) {
Assert.notNull(target, "Target object must not be null");
Assert.hasText(name, "Method name must not be empty");
try {
MethodInvoker methodInvoker = new MethodInvoker();
methodInvoker.setTargetObject(target);
methodInvoker.setTargetMethod(name);
methodInvoker.setArguments(args);
methodInvoker.prepare();
if (logger.isDebugEnabled()) {
logger.debug(String.format("Invoking method '%s' on %s with arguments %s", name, safeToString(target),
ObjectUtils.nullSafeToString(args)));
}
return (T) methodInvoker.invoke();
}
catch (Exception ex) {
ReflectionUtils.handleReflectionException(ex);
throw new IllegalStateException("Should never get here");
}
}
private static String safeToString(Object target) {
try {
return String.format("target object [%s]", target);
}
catch (Exception ex) {
return String.format("target of type [%s] whose toString() method threw [%s]",
(target != null ? target.getClass().getName() : "unknown"), ex);
}
}
}