lodsve.core.condition.OnWebApplicationCondition.java Source code

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Here is the source code for lodsve.core.condition.OnWebApplicationCondition.java

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/*
 * Copyright 2012-2014 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 lodsve.core.condition;

import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.type.AnnotatedTypeMetadata;
import org.springframework.util.ClassUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.StandardServletEnvironment;

/**
 * {@link Condition} that checks for the presence or absence of
 * {@link WebApplicationContext}.
 *
 * @author Dave Syer
 * @see ConditionalOnWebApplication
 * @see ConditionalOnNotWebApplication
 */
@Order(Ordered.HIGHEST_PRECEDENCE + 20)
class OnWebApplicationCondition extends SpringBootCondition {

    private static final String WEB_CONTEXT_CLASS = "org.springframework.web.context."
            + "support.GenericWebApplicationContext";

    @Override
    public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
        boolean webApplicationRequired = metadata.isAnnotated(ConditionalOnWebApplication.class.getName());
        ConditionOutcome webApplication = isWebApplication(context, metadata);

        if (webApplicationRequired && !webApplication.isMatch()) {
            return ConditionOutcome.noMatch(webApplication.getMessage());
        }

        if (!webApplicationRequired && webApplication.isMatch()) {
            return ConditionOutcome.noMatch(webApplication.getMessage());
        }

        return ConditionOutcome.match(webApplication.getMessage());
    }

    private ConditionOutcome isWebApplication(ConditionContext context, AnnotatedTypeMetadata metadata) {

        if (!ClassUtils.isPresent(WEB_CONTEXT_CLASS, context.getClassLoader())) {
            return ConditionOutcome.noMatch("web application classes not found");
        }

        if (context.getBeanFactory() != null) {
            String[] scopes = context.getBeanFactory().getRegisteredScopeNames();
            if (ObjectUtils.containsElement(scopes, "session")) {
                return ConditionOutcome.match("found web application 'session' scope");
            }
        }

        if (context.getEnvironment() instanceof StandardServletEnvironment) {
            return ConditionOutcome.match("found web application StandardServletEnvironment");
        }

        if (context.getResourceLoader() instanceof WebApplicationContext) {
            return ConditionOutcome.match("found web application WebApplicationContext");
        }

        return ConditionOutcome.noMatch("not a web application");
    }

}