步骤 1：创建新分类账 - Amazon Quantum Ledger Database (Amazon QLDB)

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步骤 1：创建新分类账

在此步骤中，您将创建一个名为 vehicle-registration 的新 Amazon QLDB 分类账。

创建新的分类账

  1. 查看以下文件 (Constants.java)，其包含本教程中所有其他程序使用的常量值。

    2.x
    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazon.ion.IonSystem;
import com.amazon.ion.system.IonSystemBuilder;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.dataformat.ion.IonObjectMapper;
import com.fasterxml.jackson.dataformat.ion.ionvalue.IonValueMapper;

/**
 * Constant values used throughout this tutorial.
 */
public final class Constants {
    public static final int RETRY_LIMIT = 4;
    public static final String LEDGER_NAME = "vehicle-registration";
    public static final String STREAM_NAME = "vehicle-registration-stream";
    public static final String VEHICLE_REGISTRATION_TABLE_NAME = "VehicleRegistration";
    public static final String VEHICLE_TABLE_NAME = "Vehicle";
    public static final String PERSON_TABLE_NAME = "Person";
    public static final String DRIVERS_LICENSE_TABLE_NAME = "DriversLicense";
    public static final String VIN_INDEX_NAME = "VIN";
    public static final String PERSON_GOV_ID_INDEX_NAME = "GovId";
    public static final String VEHICLE_REGISTRATION_LICENSE_PLATE_NUMBER_INDEX_NAME = "LicensePlateNumber";
    public static final String DRIVER_LICENSE_NUMBER_INDEX_NAME = "LicenseNumber";
    public static final String DRIVER_LICENSE_PERSONID_INDEX_NAME = "PersonId";
    public static final String JOURNAL_EXPORT_S3_BUCKET_NAME_PREFIX = "qldb-tutorial-journal-export";
    public static final String USER_TABLES = "information_schema.user_tables";
    public static final String LEDGER_NAME_WITH_TAGS = "tags";
    public static final IonSystem SYSTEM = IonSystemBuilder.standard().build();
    public static final IonObjectMapper MAPPER = new IonValueMapper(SYSTEM);

    private Constants() { }

    static {
        MAPPER.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    }
}
    1.x
    重要

    对于 Amazon Ion 软件包，您必须在应用程序中使用命名空间com.amazon.ion。AWS SDK for Java 依赖于命名空间software.amazon.ion下的另一个 Ion 包，但这是一个与 QLDB 驱动程序不兼容的旧包。

    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazon.ion.IonSystem;
import com.amazon.ion.system.IonSystemBuilder;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.dataformat.ion.IonObjectMapper;
import com.fasterxml.jackson.dataformat.ion.ionvalue.IonValueMapper;

/**
 * Constant values used throughout this tutorial.
 */
public final class Constants {
    public static final int RETRY_LIMIT = 4;
    public static final String LEDGER_NAME = "vehicle-registration";
    public static final String STREAM_NAME = "vehicle-registration-stream";
    public static final String VEHICLE_REGISTRATION_TABLE_NAME = "VehicleRegistration";
    public static final String VEHICLE_TABLE_NAME = "Vehicle";
    public static final String PERSON_TABLE_NAME = "Person";
    public static final String DRIVERS_LICENSE_TABLE_NAME = "DriversLicense";
    public static final String VIN_INDEX_NAME = "VIN";
    public static final String PERSON_GOV_ID_INDEX_NAME = "GovId";
    public static final String VEHICLE_REGISTRATION_LICENSE_PLATE_NUMBER_INDEX_NAME = "LicensePlateNumber";
    public static final String DRIVER_LICENSE_NUMBER_INDEX_NAME = "LicenseNumber";
    public static final String DRIVER_LICENSE_PERSONID_INDEX_NAME = "PersonId";
    public static final String JOURNAL_EXPORT_S3_BUCKET_NAME_PREFIX = "qldb-tutorial-journal-export";
    public static final String USER_TABLES = "information_schema.user_tables";
    public static final String LEDGER_NAME_WITH_TAGS = "tags";
    public static final IonSystem SYSTEM = IonSystemBuilder.standard().build();
    public static final IonObjectMapper MAPPER = new IonValueMapper(SYSTEM);

    private Constants() { }

    static {
        MAPPER.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    }
}
    注意

    该 Constants 类包括开源 Jackson IonValueMapper类实例。在执行读写事务时，您可以使用此映射器处理您的 Amazon Ion 数据。

    该 CreateLedger.java 文件还依赖于以下程序 (DescribeLedger.java)，该程序描述了分类账的当前状态。

    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazonaws.services.qldb.AmazonQLDB;
import com.amazonaws.services.qldb.model.DescribeLedgerRequest;
import com.amazonaws.services.qldb.model.DescribeLedgerResult;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Describe a QLDB ledger.
 *
 * This code expects that you have AWS credentials setup per:
 * http://docs.aws.amazon.com/java-sdk/latest/developer-guide/setup-credentials.html
 */
public final class DescribeLedger {
    public static AmazonQLDB client = CreateLedger.getClient();
    public static final Logger log = LoggerFactory.getLogger(DescribeLedger.class);

    private DescribeLedger() { }

    public static void main(final String... args) {
        try {

            describe(Constants.LEDGER_NAME);

        } catch (Exception e) {
            log.error("Unable to describe a ledger!", e);
        }
    }

    /**
     * Describe a ledger.
     *
     * @param name
     *              Name of the ledger to describe.
     * @return {@link DescribeLedgerResult} from QLDB.
     */
    public static DescribeLedgerResult describe(final String name) {
        log.info("Let's describe ledger with name: {}...", name);
        DescribeLedgerRequest request = new DescribeLedgerRequest().withName(name);
        DescribeLedgerResult result = client.describeLedger(request);
        log.info("Success. Ledger description: {}", result);
        return result;
    }
}

  2. 编译并运行 CreateLedger.java 程序以创建名为vehicle-registration的分类账。

    2.x
    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.services.qldb.AmazonQLDB;
import com.amazonaws.services.qldb.AmazonQLDBClientBuilder;
import com.amazonaws.services.qldb.model.CreateLedgerRequest;
import com.amazonaws.services.qldb.model.CreateLedgerResult;
import com.amazonaws.services.qldb.model.DescribeLedgerResult;
import com.amazonaws.services.qldb.model.LedgerState;
import com.amazonaws.services.qldb.model.PermissionsMode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Create a ledger and wait for it to be active.
 * <p>
 * This code expects that you have AWS credentials setup per:
 * http://docs.aws.amazon.com/java-sdk/latest/developer-guide/setup-credentials.html
 */
public final class CreateLedger {
    public static final Logger log = LoggerFactory.getLogger(CreateLedger.class);
    public static final Long LEDGER_CREATION_POLL_PERIOD_MS = 10_000L;
    public static String endpoint = null;
    public static String region = null;
    public static AmazonQLDB client = getClient();

    private CreateLedger() {
    }

    /**
     * Build a low-level QLDB client.
     *
     * @return {@link AmazonQLDB} control plane client.
     */
    public static AmazonQLDB getClient() {
        AmazonQLDBClientBuilder builder = AmazonQLDBClientBuilder.standard();
        if (null != endpoint && null != region) {
            builder.setEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(endpoint, region));
        }
        return builder.build();
    }

    public static void main(final String... args) throws Exception {
        try {
            client = getClient();

            create(Constants.LEDGER_NAME);

            waitForActive(Constants.LEDGER_NAME);

        } catch (Exception e) {
            log.error("Unable to create the ledger!", e);
            throw e;
        }
    }

    /**
     * Create a new ledger with the specified ledger name.
     *
     * @param ledgerName Name of the ledger to be created.
     * @return {@link CreateLedgerResult} from QLDB.
     */
    public static CreateLedgerResult create(final String ledgerName) {
        log.info("Let's create the ledger with name: {}...", ledgerName);
        CreateLedgerRequest request = new CreateLedgerRequest()
                .withName(ledgerName)
                .withPermissionsMode(PermissionsMode.ALLOW_ALL);
        CreateLedgerResult result = client.createLedger(request);
        log.info("Success. Ledger state: {}.", result.getState());
        return result;
    }

    /**
     * Wait for a newly created ledger to become active.
     *
     * @param ledgerName Name of the ledger to wait on.
     * @return {@link DescribeLedgerResult} from QLDB.
     * @throws InterruptedException if thread is being interrupted.
     */
    public static DescribeLedgerResult waitForActive(final String ledgerName) throws InterruptedException {
        log.info("Waiting for ledger to become active...");
        while (true) {
            DescribeLedgerResult result = DescribeLedger.describe(ledgerName);
            if (result.getState().equals(LedgerState.ACTIVE.name())) {
                log.info("Success. Ledger is active and ready to use.");
                return result;
            }
            log.info("The ledger is still creating. Please wait...");
            Thread.sleep(LEDGER_CREATION_POLL_PERIOD_MS);
        }
    }
}
    1.x
    /*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazonaws.services.qldb.AmazonQLDB;
import com.amazonaws.services.qldb.AmazonQLDBClientBuilder;
import com.amazonaws.services.qldb.model.CreateLedgerRequest;
import com.amazonaws.services.qldb.model.CreateLedgerResult;
import com.amazonaws.services.qldb.model.DescribeLedgerResult;
import com.amazonaws.services.qldb.model.LedgerState;
import com.amazonaws.services.qldb.model.PermissionsMode;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Create a ledger and wait for it to be active.
 *
 * This code expects that you have AWS credentials setup per:
 * http://docs.aws.amazon.com/java-sdk/latest/developer-guide/setup-credentials.html
 */
public final class CreateLedger {
    public static final Logger log = LoggerFactory.getLogger(CreateLedger.class);
    public static final Long LEDGER_CREATION_POLL_PERIOD_MS = 10_000L;
    public static AmazonQLDB client = getClient();

    private CreateLedger() { }

    /**
     * Build a low-level QLDB client.
     *
     * @return {@link AmazonQLDB} control plane client.
     */
    public static AmazonQLDB getClient() {
        return AmazonQLDBClientBuilder.standard().build();
    }

    public static void main(final String... args) throws Exception {
        try {

            create(Constants.LEDGER_NAME);

            waitForActive(Constants.LEDGER_NAME);

        } catch (Exception e) {
            log.error("Unable to create the ledger!", e);
            throw e;
        }
    }

    /**
     * Create a new ledger with the specified ledger name.
     *
     * @param ledgerName
     *              Name of the ledger to be created.
     * @return {@link CreateLedgerResult} from QLDB.
     */
    public static CreateLedgerResult create(final String ledgerName) {
        log.info("Let's create the ledger with name: {}...", ledgerName);
        CreateLedgerRequest request = new CreateLedgerRequest()
                .withName(ledgerName)
                .withPermissionsMode(PermissionsMode.ALLOW_ALL);
        CreateLedgerResult result = client.createLedger(request);
        log.info("Success. Ledger state: {}.", result.getState());
        return result;
    }

    /**
     * Wait for a newly created ledger to become active.
     *
     * @param ledgerName
     *              Name of the ledger to wait on.
     * @return {@link DescribeLedgerResult} from QLDB.
     * @throws InterruptedException if thread is being interrupted.
     */
    public static DescribeLedgerResult waitForActive(final String ledgerName) throws InterruptedException {
        log.info("Waiting for ledger to become active...");
        while (true) {
            DescribeLedgerResult result = DescribeLedger.describe(ledgerName);
            if (result.getState().equals(LedgerState.ACTIVE.name())) {
                log.info("Success. Ledger is active and ready to use.");
                return result;
            }
            log.info("The ledger is still creating. Please wait...");
            Thread.sleep(LEDGER_CREATION_POLL_PERIOD_MS);
        }
    }
}
    注意

    • 在 createLedger 调用中，您必须指定分类账名称和权限模式。我们建议使用 STANDARD 权限模式来最大限度地提高分类账数据的安全性。

    • 创建分类账时，将默认启用 删除保护。QLDB 中有一项功能，可防止分类账被任何用户删除。您可以选择使用 QLDB API 或 AWS Command Line Interface (AWS CLI) 在创建分类账时禁用删除保护。

    • 您还可选择指定要附加到分类账的标签。

要验证您与新分类账的连接，请继续 步骤 2：测试分类账的连接性。