Java 程序样例

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。建议用户下载 v1.11.x 版本的 Java AWS 开发工具包。

示例

以下样例将展示如何连接 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。

1. 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);
       }
   }

2. 将工程打成 jar 包

3. 执行程序

   $ java -jar s3-client.jar