aws java sdk 访问ceph radosgw (hammer)

1. 安装maven[1]

$ wget http://mirrors.cnnic.cn/apache/maven/maven-3/3.3.9/binaries/apache-maven-3.3.9-bin.tar.gz[/code] 
- 解压

$ mkdir ~/install/
$ tar -zxf apache-maven-3.3.9-bin.tar.gz -C ~/install/


- 添加bin的路径到PATH

打开 ~/.bashrc 文件，添加如下内容

export PATH=/home/joseph/install/apache-maven-3.3.9/bin/:$PATH


- 修改maven的本地仓库路径

默认的路径是:

${user.home}/.m2/repository
可以在如下配置文件中修改
~/install/apache-maven-3.3.9/conf/settings.xml
- 添加中国区内的maven源

如果需要的所有java包都从国外网站下载会很慢。先添加ali的源。

还是修改 settings.xml 文件，添加mirrors相关的配置：

...
<mirrors>
... // 省略
<mirror>
<id>alimaven</id>
<mirrorOf>central</mirrorOf>
<name>aliyun maven</name>
<url>http://maven.aliyun.com/nexus/content/repositories/central/</url>
</mirror>
</mirrors>
...


2. 下载编译aws-java-sample[2]
- clone aws-java-sample 仓库

$ git clone https://github.com/awslabs/aws-java-sample.git
- 修改示例程序
// src/main/java/com/amazonaws/samples/S3Sample.java
/*
* Copyright 2010-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
*  http://aws.amazon.com/apache2.0 *
* or in the "license" file accompanying this file. This file 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.amazonaws.samples;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.UUID;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.Bucket;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ListObjectsRequest;
import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectSummary;

///////// add by Yang Honggang
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.ClientConfiguration;
import com.amazonaws.Protocol;
import com.amazonaws.services.s3.model.ObjectMetadata;
import java.util.List;

/**
* This sample demonstrates how to make basic requests to Amazon S3 using
* the AWS SDK for Java.
* <p>
* <b>Prerequisites:</b> You must have a valid Amazon Web Services developer
* account, and be signed up to use Amazon S3. For more information on
* Amazon S3, see http://aws.amazon.com/s3. * <p>
* <b>Important:</b> Be sure to fill in your AWS access credentials in
* ~/.aws/credentials (C:\Users\USER_NAME\.aws\credentials for Windows
* users) before you try to run this sample.
*/
public class S3Sample {

public static void main(String[] args) throws IOException {

String accessKey = "7VEMLNMNYRVGDDFL2XCO";
String secretKey = "MN4oaaTNNrxgoVVyYR1ptfssD1nZ0XYhDscpNnPf";
// 如果默认的端口不是80（假如是90）
// String endpoint = "10.41.25.35:90";
String endpoint = "10.41.25.35";

AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
ClientConfiguration clientConfig = new ClientConfiguration();
clientConfig.setSignerOverride("S3SignerType");
clientConfig.setProtocol(Protocol.HTTP);
AmazonS3 conn = new AmazonS3Client(credentials, clientConfig);
conn.setEndpoint(endpoint);

String name = "from-java";

// create buckets
Bucket bucket = conn.createBucket(name);
String bucketName = bucket.getName();
// list buckets
List<Bucket> buckets = conn.listBuckets();
for(Bucket b : buckets){
System.out.println("bucketName:"+b.getName());
}

// put Object
String objName = "firstobj";
conn.putObject(bucketName, objName, "my first object");
System.out.println(">>> put object: firstobj");

// get Object
conn.getObject(bucketName, objName);
ObjectMetadata se = conn.getObject(new GetObjectRequest(bucketName, objName), new File("/tmp/xx1"));
System.out.println(">>> get object");

// list objects in the bucket
ObjectListing objs = conn.listObjects(bucketName);

System.out.println(">>> list all objects in bucket:");
List<S3ObjectSummary> sums = objs.getObjectSummaries();
for(S3ObjectSummary s3 : sums){
System.out.println("\t" + s3.getKey());
}

System.out.println("all done!");
}
}


.. Note:: hammer版的rgw不支持awsv4签名，所以必须显式使用v2的签名。

          clientConfig.setSignerOverride("S3SignerType")

更多关于 aws sdk for java的 api的介绍，参见[4]。

- 第一次编译使用默认的 v1.9.6 的 aws java sdk

// pom.xml
<dependencies>
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.9.6</version>
</dependency>
</dependencies>
编译、运行命令:
mvn clean compile exec:java
效果：

...
[INFO] --- exec-maven-plugin:1.2.1:java (default-cli) @ aws-java-sample ---
bucketName:from-java
>>> put object: firstobj
>>> get object
>>> list all objects in bucket:
firstobj
all done!
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6.675 s
[INFO] Finished at: 2016-12-07T13:44:54+08:00
[INFO] Final Memory: 23M/220M
[INFO] ------------------------------------------------------------------------


- 使用新版 1.11.64

将 pom.xml 中的 1.9.6 修改为 1.11.64 后，重新执行编译、运行命令。

参考
[1] http://maven.apache.org/install.html 
[2] https://github.com/aws/aws-sdk-java 
[3] https://github.com/aws/aws-sdk-java/issues/372 
[4] http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/overview-summary.html 
[5] http://www.cnblogs.com/wuyouwulv/p/aws_java_sdk__jAWSClient.html