com.wealdtech.hawk.HawkClient.java Source code

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Here is the source code for com.wealdtech.hawk.HawkClient.java

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/*
 *    Copyright 2012 Weald Technology Trading Limited
 *
 *   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.wealdtech.hawk;

import static com.wealdtech.Preconditions.*;

import java.net.URI;

import com.google.common.base.Objects;
import com.google.common.collect.ComparisonChain;
import com.google.inject.Inject;
import com.wealdtech.DataError;
import com.wealdtech.utils.StringUtils;

public final class HawkClient implements Comparable<HawkClient> {
    private final HawkClientConfiguration configuration;
    private final HawkCredentials credentials;

    @Inject
    private HawkClient(final HawkClientConfiguration configuration, final HawkCredentials credentials) {
        if (configuration == null) {
            this.configuration = new HawkClientConfiguration();
        } else {
            this.configuration = configuration;
        }
        this.credentials = credentials;
        validate();
    }

    private void validate() {
        checkNotNull(this.configuration, "The client configuration is required");
        checkNotNull(this.credentials, "The credentials are required");
    }

    /**
     * Generate the value for the Hawk authorization header.
     *
     * @param uri the URI for the request
     * @param method the request for the method
     * @param hash a hash of the request's payload, or <code>null</code> if payload authentication is not required
     * @param ext extra data, or <code>null</code> if none
     * @param app application ID, or <code>null</code> if none
     * @param dlg delegator, or <code>null</code> if none
     * @return The value for the Hawk authorization header.
     * @throws DataError If there is a problem with the data passed in which makes it impossible to generate a valid authorization header
     */
    public String generateAuthorizationHeader(final URI uri, final String method, final String hash,
            final String ext, final String app, final String dlg) {
        long timestamp = System.currentTimeMillis() / Hawk.MILLISECONDS_IN_SECONDS;
        final String nonce = StringUtils.generateRandomString(6);
        final String mac = Hawk.calculateMAC(this.credentials, Hawk.AuthType.HEADER, timestamp, uri, nonce, method,
                hash, ext, app, dlg);

        final StringBuilder sb = new StringBuilder(1024);
        sb.append("Hawk id=\"");
        sb.append(this.credentials.getKeyId());
        sb.append("\", ts=\"");
        sb.append(timestamp);
        sb.append("\", nonce=\"");
        sb.append(nonce);
        if (hash != null) {
            sb.append("\", hash=\"");
            sb.append(hash);
        }
        if ((ext != null) && (!"".equals(ext))) {
            sb.append("\", ext=\"");
            sb.append(ext);
        }
        sb.append("\", mac=\"");
        sb.append(mac);
        sb.append('"');

        return sb.toString();
    }

    public boolean isValidFor(final String path) {
        return ((this.configuration.getPathPrefix() == null)
                || ((path == null) || (path.startsWith(this.configuration.getPathPrefix()))));
    }

    // Standard object methods follow
    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("configuration", this.configuration)
                .add("credentials", this.credentials).toString();
    }

    @Override
    public boolean equals(final Object that) {
        return (that instanceof HawkClient) && (this.compareTo((HawkClient) that) == 0);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(this.configuration, this.credentials);
    }

    @Override
    public int compareTo(final HawkClient that) {
        return ComparisonChain.start().compare(this.configuration, that.configuration)
                .compare(this.credentials, that.credentials).result();
    }

    public static class Builder {
        private HawkClientConfiguration configuration;
        private HawkCredentials credentials;

        /**
         * Generate a new builder.
         */
        public Builder() {
        }

        /**
         * Generate build with all values set from a prior object.
         * @param prior the prior object
         */
        public Builder(final HawkClient prior) {
            this.configuration = prior.configuration;
            this.credentials = prior.credentials;
        }

        /**
         * Override the existing configuration.
         * @param configuration the new configuration
         * @return The builder
         */
        public Builder configuration(final HawkClientConfiguration configuration) {
            this.configuration = configuration;
            return this;
        }

        /**
         * Override the existing credentials.
         * @param credentials the new credentials
         * @return The builder
         */
        public Builder credentials(final HawkCredentials credentials) {
            this.credentials = credentials;
            return this;
        }

        /**
         * Build the client
         * @return a new client
         */
        public HawkClient build() {
            return new HawkClient(this.configuration, this.credentials);
        }
    }
}