/*
* Copyright 2008 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.wamblee.system.adapters;
+import org.wamblee.collections.CollectionFilter;
+
+import org.wamblee.conditions.Condition;
+
+import org.wamblee.system.core.RequiredInterface;
+import org.wamblee.system.core.Scope;
+import org.wamblee.system.core.SystemAssemblyException;
+
import java.lang.reflect.Constructor;
-import java.lang.reflect.Member;
import java.lang.reflect.Modifier;
+
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
-import org.wamblee.collections.CollectionFilter;
-import org.wamblee.conditions.Condition;
-import org.wamblee.system.core.RequiredInterface;
-import org.wamblee.system.core.Scope;
-import org.wamblee.system.core.SystemAssemblyException;
+/**
+ * Class that allows configuration of the constructor to use. In
+ * particular, it provides:
+ * <ul>
+ * <li>Selection of a constructor using explicit selection {@link
+ * #select(Class...)} or using the most greedy constructor {@link
+ * #greedy()}.</li>
+ * <li>Selection of methods to invoke to inject other objects into
+ * the object.</li>
+ * <li>Selection of fields to set.</li>
+ * </ul>
+ */
public class ConstructorConfiguration {
- private Class _class;
- private Constructor<?> _constructor;
- private ParameterValues _values;
- private boolean _publicOnly;
-
- /**
- * Constructs the configuration. By default no constructor is selected and
- * one of {@link #select(Class...)} or
- * {@link #greedy()} must be called.
- * @param aClass Class to construct.
- */
- public ConstructorConfiguration(Class aClass) {
- _class = aClass;
- _constructor = null;
- _publicOnly = true;
- }
-
- /**
- * Sets whether or no non public constructors are also considered.
- * Reset the choice of a constructor.
- * @param aNonPublic
- * @return
- */
- public ConstructorConfiguration setNonPublic(boolean aNonPublic) {
- _publicOnly = !aNonPublic;
- _constructor = null;
- _values = null;
- return this;
- }
-
- /**
- * Selects an explicit constructor.
- * @param aTypes Arguments of the constructor.
- * @return Return the injector to allow call chaining.
- */
- public ConstructorConfiguration select(Class... aTypes) {
- try {
- _constructor = _class.getDeclaredConstructor(aTypes);
- } catch (Exception e) {
- throw new SystemAssemblyException(e.getMessage(), e);
- }
- resetValues();
- return this;
- }
-
- /**
- * Selects the greediest constructor.
- * @return The injector to allow call chaining.
- * @throws SystemAssemblyException if the greediest constructor cannot be uniquely
- * identified.
- */
- public ConstructorConfiguration greedy() {
- Constructor<?>[] declared = _class.getDeclaredConstructors();
- if (declared.length == 0) {
- throw new SystemAssemblyException("Class '" + _class
- + " is an interface, primitive type, or array");
- }
- int max = -1;
- List<Constructor<?>> checked = new ArrayList<Constructor<?>>();
- CollectionFilter.filter(Arrays.asList(declared), checked,
- new Condition<Constructor<?>>() {
- @Override
- public boolean matches(Constructor<?> aObject) {
- if ( !_publicOnly ) {
- return true;
- } else {
- return Modifier.isPublic(aObject.getModifiers());
- }
- }
- });
- for (Constructor ctor : checked) {
- if (ctor.getParameterTypes().length > max) {
- max = ctor.getParameterTypes().length;
- }
- }
- final int max2 = max;
- List<Constructor<?>> ctors = checked;
- List<Constructor<?>> longest = new ArrayList<Constructor<?>>();
- CollectionFilter.filter(ctors, longest,
- new Condition<Constructor<?>>() {
- @Override
- public boolean matches(Constructor<?> aObject) {
- return aObject.getParameterTypes().length == max2;
- }
- });
- if (longest.size() > 1) {
- throw new SystemAssemblyException(
- "Greediest constructor cannot be uniquely determined");
- }
- _constructor = longest.get(0);
- resetValues();
- return this;
- }
-
- public ParameterValues getParameters() {
- getConstructor(); // initialize constructor if needed.
- return _values;
- }
-
- /**
- * Resets the values.
- */
- private void resetValues() {
- _constructor.setAccessible(true);
- _values = new ParameterValues(_constructor.getParameterTypes());
- }
-
- /**
- * Creates the object in the given scope.
- * @param aScope Scope containing required interfaces for this object.
- * @return object.
- */
- public Object create(Scope aScope) {
- Object[] values = _values.values(aScope);
- try {
- return getConstructor().newInstance(values);
- } catch (Exception e) {
- throw new SystemAssemblyException("Could not construct object "
- + getConstructor() + " " + Arrays.asList(values), e);
- }
- }
-
- public List<RequiredInterface> getRequiredInterfaces() {
- getConstructor(); // initialize constructor if needed.
- return _values.getRequiredInterfaces();
- }
-
- private Constructor getConstructor() {
- if (_constructor == null ) {
- greedy();
- }
- return _constructor;
- }
+ /**
+ * DOCUMENT ME!
+ */
+ private Class clazz;
+
+ /**
+ * DOCUMENT ME!
+ */
+ private Constructor<?> constructor;
+
+ /**
+ * DOCUMENT ME!
+ */
+ private ParameterValues values;
+
+ /**
+ * DOCUMENT ME!
+ */
+ private boolean publicOnly;
+
+/**
+ * Constructs the configuration. By default the public constructor with the
+ * most arguments will be used.
+ * @param aClass Class to construct.
+ */
+ public ConstructorConfiguration(Class aClass) {
+ clazz = aClass;
+ constructor = null;
+ publicOnly = true;
+ }
+
+ /**
+ * Sets whether or no non public constructors are also considered.
+ * Reset the choice of a constructor to its default.
+ *
+ * @param aNonPublic
+ *
+ * @return
+ */
+ public ConstructorConfiguration setNonPublic(boolean aNonPublic) {
+ publicOnly = !aNonPublic;
+ constructor = null;
+ values = null;
+
+ return this;
+ }
+
+ /**
+ * Selects an explicit constructor.
+ *
+ * @return Return the injector to allow call chaining.
+ *
+ * @throws SystemAssemblyException DOCUMENT ME!
+ */
+ public ConstructorConfiguration select(Class... aTypes) {
+ try {
+ constructor = clazz.getDeclaredConstructor(aTypes);
+ } catch (Exception e) {
+ throw new SystemAssemblyException(e.getMessage(), e);
+ }
+
+ resetValues();
+
+ return this;
+ }
+
+ /**
+ * Selects the greediest constructor.
+ *
+ * @return The injector to allow call chaining.
+ *
+ * @throws SystemAssemblyException if the greediest constructor cannot be
+ * uniquely identified.
+ */
+ public ConstructorConfiguration greedy() {
+ Constructor<?>[] declared = clazz.getDeclaredConstructors();
+
+ if (declared.length == 0) {
+ throw new SystemAssemblyException("Class '" + clazz
+ + " is an interface, primitive type, or array");
+ }
+
+ int max = -1;
+ List<Constructor<?>> checked = new ArrayList<Constructor<?>>();
+ CollectionFilter.filter(Arrays.asList(declared), checked,
+ new Condition<Constructor<?>>() {
+ @Override
+ public boolean matches(Constructor<?> aObject) {
+ if (!publicOnly) {
+ return true;
+ } else {
+ return Modifier.isPublic(aObject.getModifiers());
+ }
+ }
+ });
+
+ for (Constructor ctor : checked) {
+ if (ctor.getParameterTypes().length > max) {
+ max = ctor.getParameterTypes().length;
+ }
+ }
+
+ final int max2 = max;
+ List<Constructor<?>> ctors = checked;
+ List<Constructor<?>> longest = new ArrayList<Constructor<?>>();
+ CollectionFilter.filter(ctors, longest,
+ new Condition<Constructor<?>>() {
+ @Override
+ public boolean matches(Constructor<?> aObject) {
+ return aObject.getParameterTypes().length == max2;
+ }
+ });
+
+ if (longest.size() > 1) {
+ throw new SystemAssemblyException(
+ "Greediest constructor cannot be uniquely determined");
+ }
+
+ constructor = longest.get(0);
+ resetValues();
+
+ return this;
+ }
+
+ public ParameterValues getParameters() {
+ getConstructor(); // initialize constructor if needed.
+
+ return values;
+ }
+
+ /**
+ * Resets the values.
+ */
+ private void resetValues() {
+ constructor.setAccessible(true);
+ values = new ParameterValues(constructor.getParameterTypes());
+ }
+
+ /**
+ * Creates the object in the given scope.
+ *
+ * @param aScope Scope containing required interfaces for this object.
+ *
+ * @return object.
+ *
+ * @throws SystemAssemblyException DOCUMENT ME!
+ */
+ public Object create(Scope aScope) {
+ Object[] valueArray = values.values(aScope);
+
+ try {
+ return getConstructor().newInstance(valueArray);
+ } catch (Exception e) {
+ throw new SystemAssemblyException("Could not construct object "
+ + getConstructor() + " " + Arrays.asList(valueArray), e);
+ }
+ }
+
+ public List<RequiredInterface> getRequiredInterfaces() {
+ getConstructor(); // initialize constructor if needed.
+
+ return values.getRequiredInterfaces();
+ }
+
+ private Constructor getConstructor() {
+ if (constructor == null) {
+ greedy();
+ }
+
+ return constructor;
+ }
}