com.b2international.snowowl.datastore.oplock.impl.DatastoreOperationLockException.java Source code

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Here is the source code for com.b2international.snowowl.datastore.oplock.impl.DatastoreOperationLockException.java

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/*
 * Copyright 2011-2015 B2i Healthcare Pte Ltd, http://b2i.sg
 * 
 * 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.b2international.snowowl.datastore.oplock.impl;

import java.util.Map;

import javax.annotation.Nullable;

import com.b2international.snowowl.datastore.oplock.IOperationLockTarget;
import com.b2international.snowowl.datastore.oplock.OperationLockException;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableMap;

/**
 * Thrown when reporting issues related to locking any terminology store.
 * 
 */
public class DatastoreOperationLockException extends OperationLockException {

    private static final long serialVersionUID = 1L;

    private final Map<IOperationLockTarget, DatastoreLockContext> targetMap;

    /**
     * Creates a new instance with the specified detail message.
     * 
     * @param message the detail message
     */
    public DatastoreOperationLockException(final @Nullable String message) {
        this(message, ImmutableMap.<IOperationLockTarget, DatastoreLockContext>of());
    }

    /**
     * Creates a new instance with the specified detail message and lock targets which could not be acquired or released.
     * 
     * @param message the detail message
     * @param targetMap a map keyed by lock targets with issues; the corresponding values are the lock contexts
     * currently holding the requested lock, or a conflicting lock (may not be {@code null})
     */
    public DatastoreOperationLockException(final @Nullable String message,
            final Map<IOperationLockTarget, DatastoreLockContext> targetMap) {
        super(message);
        Preconditions.checkNotNull(targetMap, "Lock target map may not be null.");
        this.targetMap = ImmutableMap.copyOf(targetMap);
    }

    /**
     * Returns the current owner of the requested lock target, or {@code null} if no issue has been recorded for this target.
     * 
     * @param target the lock target to check (may not be {@code null})
     * @return the current owner for the specified target, or {@code null}
     */
    public DatastoreLockContext getContext(final IOperationLockTarget target) {
        Preconditions.checkNotNull(target, "Lock target to check may not be null.");
        return targetMap.get(target);
    }

    @Override
    public String getMessage() {
        final FluentIterable<DatastoreLockContext> contexts = FluentIterable.from(targetMap.values());
        final Optional<DatastoreLockContext> rootContext = contexts
                .firstMatch(new Predicate<DatastoreLockContext>() {
                    @Override
                    public boolean apply(DatastoreLockContext input) {
                        return DatastoreLockContextDescriptions.ROOT.equals(input.getParentDescription());
                    }
                });

        DatastoreLockContext context = null;
        if (rootContext.isPresent()) {
            context = rootContext.get();
        } else {
            if (contexts.first().isPresent()) {
                context = contexts.first().get();
            } else {
                return super.getMessage();
            }
        }

        return String.format("%s %s is %s.", super.getMessage(), context.getUserId(), context.getDescription());
    }
}