com.google.inject.servlet.ServletSpiVisitor.java Source code

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Here is the source code for com.google.inject.servlet.ServletSpiVisitor.java

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/**
 * Copyright (C) 2010 Google Inc.
 *
 * 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 com.google.inject.servlet;

import com.google.common.base.Objects;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.inject.Binding;
import com.google.inject.Injector;
import com.google.inject.Stage;
import com.google.inject.spi.DefaultBindingTargetVisitor;

import junit.framework.AssertionFailedError;

import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;

import javax.servlet.Filter;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * A visitor for testing the servlet SPI extension.
 *
 * @author sameb@google.com (Sam Berlin)
 */
class ServletSpiVisitor extends DefaultBindingTargetVisitor<Object, Integer>
        implements ServletModuleTargetVisitor<Object, Integer> {

    int otherCount = 0;
    int currentCount = 0;
    List<Params> actual = Lists.newArrayList();

    /* The set of classes that are allowed to be "other" bindings. */
    Set<Class> allowedClasses;

    ServletSpiVisitor(boolean forInjector) {
        ImmutableSet.Builder<Class> builder = ImmutableSet.builder();
        // always ignore these things...
        builder.add(ServletRequest.class, ServletResponse.class, ManagedFilterPipeline.class,
                ManagedServletPipeline.class, FilterPipeline.class, ServletContext.class, HttpServletRequest.class,
                Filter.class, HttpServletResponse.class, HttpSession.class, Map.class, HttpServlet.class,
                InternalServletModule.BackwardsCompatibleServletContextProvider.class, GuiceFilter.class);
        if (forInjector) {
            // only ignore these if this is for the live injector, any other time it'd be an error!
            builder.add(Injector.class, Stage.class, Logger.class);
        }
        this.allowedClasses = builder.build();
    }

    public Integer visit(InstanceFilterBinding binding) {
        actual.add(new Params(binding, binding.getFilterInstance()));
        return currentCount++;
    }

    public Integer visit(InstanceServletBinding binding) {
        actual.add(new Params(binding, binding.getServletInstance()));
        return currentCount++;
    }

    public Integer visit(LinkedFilterBinding binding) {
        actual.add(new Params(binding, binding.getLinkedKey()));
        return currentCount++;
    }

    public Integer visit(LinkedServletBinding binding) {
        actual.add(new Params(binding, binding.getLinkedKey()));
        return currentCount++;
    }

    @Override
    protected Integer visitOther(Binding<? extends Object> binding) {
        if (!allowedClasses.contains(binding.getKey().getTypeLiteral().getRawType())) {
            throw new AssertionFailedError("invalid other binding: " + binding);
        }
        otherCount++;
        return currentCount++;
    }

    static class Params {
        private final String pattern;
        private final Object keyOrInstance;
        private final Map<String, String> params;
        private final UriPatternType patternType;

        Params(ServletModuleBinding binding, Object keyOrInstance) {
            this.pattern = binding.getPattern();
            this.keyOrInstance = keyOrInstance;
            this.params = binding.getInitParams();
            this.patternType = binding.getUriPatternType();
        }

        Params(String pattern, Object keyOrInstance, Map params, UriPatternType patternType) {
            this.pattern = pattern;
            this.keyOrInstance = keyOrInstance;
            this.params = params;
            this.patternType = patternType;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj instanceof Params) {
                Params o = (Params) obj;
                return Objects.equal(pattern, o.pattern) && Objects.equal(keyOrInstance, o.keyOrInstance)
                        && Objects.equal(params, o.params) && Objects.equal(patternType, o.patternType);
            } else {
                return false;
            }
        }

        @Override
        public int hashCode() {
            return Objects.hashCode(pattern, keyOrInstance, params, patternType);
        }

        @Override
        public String toString() {
            return Objects.toStringHelper(Params.class).add("pattern", pattern).add("keyOrInstance", keyOrInstance)
                    .add("initParams", params).add("patternType", patternType).toString();
        }
    }
}