jetbrains.buildServer.server.rest.util.BeanFactory.java Source code

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Here is the source code for jetbrains.buildServer.server.rest.util.BeanFactory.java

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/*
 * Copyright 2000-2011 JetBrains s.r.o.
 *
 * 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 jetbrains.buildServer.server.rest.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import jetbrains.buildServer.server.rest.errors.OperationException;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.springframework.context.ApplicationContext;

/**
 * @author Yegor.Yarko
 *         Date: 09.08.2010
 */
public class BeanFactory {
    private ApplicationContext ctx;

    public BeanFactory(ApplicationContext ctx) {
        this.ctx = ctx;
    }

    @Nullable
    private <T> Constructor<T> findConstructor(@NotNull final Class<T> clazz, Class<?>[] argTypes) {
        try {
            return clazz.getConstructor(argTypes);
        } catch (NoSuchMethodException e) {
            //NOP
        }

        for (Constructor c : clazz.getConstructors()) {
            final Class[] reqTypes = c.getParameterTypes();
            if (checkParametersMatch(argTypes, reqTypes)) {
                //noinspection unchecked
                return (Constructor<T>) c;
            }
        }
        return null;
    }

    private <T> boolean checkParametersMatch(final Class<?>[] argTypes, final Class[] reqTypes) {
        if (reqTypes.length != argTypes.length)
            return false;
        for (int i = 0; i < argTypes.length; i++) {
            final Class<?> paramType = argTypes[i];
            final Class<?> reqType = reqTypes[i];

            if (!reqType.isAssignableFrom(paramType)) {
                return false;
            }
        }
        return true;
    }

    public <T> T create(Class<T> clazz, Object... params) {
        Class[] types = new Class[params.length];
        for (int i = 0; i < types.length; i++) {
            types[i] = params[i].getClass();
        }

        final Constructor<T> constructor = findConstructor(clazz, types);
        if (constructor == null) {
            throw new OperationException("Could not find contructor for class " + clazz.getName()
                    + " with parameters " + describe(params));
        }

        final T t;
        try {
            t = constructor.newInstance(params);
        } catch (InstantiationException e) {
            throw new OperationException(
                    "Could not instantiate class " + clazz.getName() + " with parameters " + describe(params), e);
        } catch (IllegalAccessException e) {
            throw new OperationException(
                    "Could not instantiate class " + clazz.getName() + " with parameters " + describe(params), e);
        } catch (InvocationTargetException e) {
            throw new OperationException(
                    "Could not instantiate class " + clazz.getName() + " with parameters " + describe(params), e);
        }
        return autowire(t);
    }

    public <T> T autowire(T t) {
        ctx.getAutowireCapableBeanFactory().autowireBean(t);
        return t;
    }

    private String describe(Object... params) {
        StringBuilder result = new StringBuilder();
        result.append("[");
        for (int i = 0; i < params.length; i++) {
            if (i != 0) {
                result.append(",");
            }
            final Object param = params[i];
            if (param == null) {
                result.append("null");
            } else {
                result.append(param.getClass().getName()).append("(").append(param.toString()).append(")");
            }
        }
        return result.append("]").toString();
    }
}