本文档主要介绍 AWS SDK for Java 的程序样例。用户可以下载 AWS 的开发工具包，利用工具包中的接口更快捷地发送 S3 请求。

Java的AWS开发工具包链接，建议下载 v1.11.x 版本：https://aws.amazon.com/cn/sdk-for-java

以下样例示范了如何连接 SequoiaS3 数据库实例，并对桶和对象进行操作。
连接过程中，需要提供正确的认证密钥 access_key、secret_key 和服务器地址。

创建代码

在 IDE 编辑器新建 Java 或 Maven 工程，将以下代码复制粘贴到 class 源文件中，并引入依赖包，添加 AWS SDK for Java 的依赖。

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.ClientConfiguration;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.*;

public class AWSClient {
	static AmazonS3 s3;
	private static void init() throws Exception {
		AWSCredentials credentials = new BasicAWSCredentials("access_key",
				"secret_key");

		ClientConfiguration configuration = new ClientConfiguration();
		configuration.setUseExpectContinue(false);

		String endPoint = "127.0.0.1:8002";
		AwsClientBuilder.EndpointConfiguration endpointConfiguration = new AwsClientBuilder.EndpointConfiguration(
				endPoint, null);

		s3 = AmazonS3ClientBuilder.standard().withEndpointConfiguration(endpointConfiguration)
				.withClientConfiguration(configuration).withCredentials(new AWSStaticCredentialsProvider(credentials))
				//.withChunkedEncodingDisabled(true)
				.withPathStyleAccessEnabled(true).build();
	}
    
	public static void deleteObject(String bucket, String object) {
		try {
			s3.deleteObject(bucket, object);
		} catch (AmazonServiceException e) {
			System.out.println("status code:" + e.getStatusCode());
		} catch (AmazonClientException e2) {
			System.out.println("status code:" + e2.getMessage());
		}
	}
    
	public static void putObject(String bucket, String object) {
		try {
			PutObjectRequest request = new PutObjectRequest(bucket, object,
					new File("C:\\Users\\C\\Desktop\\files\\\\testfile.png"));
			s3.putObject(request);
		} catch (AmazonServiceException e) {
			System.out.println("status code:" + e.getStatusCode());
		} catch (AmazonClientException e2) {
			System.out.println("status code:" + e2.getMessage());
		}
	}
    
	public static void getObject(String bucket, String object) {
		try {
			GetObjectRequest request = new GetObjectRequest(bucket, object, null);
			System.out.println(object.toString());
			S3Object result = s3.getObject(request);

			S3ObjectInputStream s3is = result.getObjectContent();
			FileOutputStream fos = new FileOutputStream(new File("C:\\Users\\C\\Desktop\\files\\" + object));
			byte[] read_buf = new byte[1024 * 34];
			int read_len = 0;
			while ((read_len = s3is.read(read_buf)) > 0) {
				fos.write(read_buf, 0, read_len);
			}
			s3is.close();
			fos.close();
		} catch (AmazonServiceException e) {
			System.err.println(e.getErrorMessage());
		} catch (FileNotFoundException e) {
			System.err.println(e.getMessage());
		} catch (IOException e) {
			System.err.println(e.getMessage());
		}
	}
    
	public static void listObjects(String bucket) {
		try {
			ListObjectsV2Request request = new ListObjectsV2Request();
			request.setBucketName(bucket);
			ListObjectsV2Result result = s3.listObjectsV2(request);

			List<String> commonPrefix = result.getCommonPrefixes();
			for (int i = 0; i < commonPrefix.size(); i++) {
				System.out.println("commonPrefix:" + commonPrefix.get(i));
			}
			List<S3ObjectSummary> objectList = result.getObjectSummaries();
			for (int i = 0; i < objectList.size(); i++) {
				System.out.println("key:" + objectList.get(i).getKey());
			}
		} catch (AmazonServiceException e) {
			System.out.println("status code:" + e.getStatusCode());
		} catch (AmazonClientException e2) {
			System.out.println("status code:" + e2.getMessage());
		}
	}
    
	public static void putBucket(String bucket) {
		try {
			s3.createBucket(bucket);
		} catch (AmazonServiceException e) {
			System.err.println(e.getStatusCode());
			System.err.println(e.getErrorCode());
			System.err.println(e.getErrorMessage());
		}
	}
    //运行主函数
	public static void main(String[] args) throws Exception {
		String bucketName = "mybucket";
		String keyName = "example.png";
		//初始化连接
		init();
		//创建桶
		putBucket(bucketName);
		//添加对象
		putObject(bucketName, keyName);
		//获取对象
		getObject(bucketName, keyName);
		//删除对象
		deleteObject(bucketName, keyName);
		//枚举对象列表
		listObjects(bucketName);
	}
}

将工程打成 jar 包。

执行程序

$ java -jar s3-client.jar

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