亚马逊云计算平台---------AWS(三) S3 存储桶中 上传下载删除文件 Java代码实现_java 通过s3协议上传下载

    上一篇由于时间仓促，写了一个在S3上上传下载文件的客户端说明。但是在实际的开发中我们肯定不需要手动操作，要通过代码来进行实现。

Java 在S3上传文件的前提

1. 已经创建aws账号

2. 已经在aws中创建用户， 并同时获得 AWS_ACCESS_KEY 和AWS_SECRET_KEY

3. 在S3中已经创建好桶，不过没有创建好，代码中也有提现。

Java在S3上操作的工具代码

 
 
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
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.zip.GZIPInputStream;
 
import com.amazonaws.AmazonClientException;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
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.ObjectListing;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectSummary;
import com.amazonaws.services.s3.transfer.TransferManager;
import com.amazonaws.services.s3.transfer.Upload;
 
 
/**
 * @author DELL
 * @Desc S3上传文件客户端
 */
public class S3AwsClient {
 
    private static String AWS_ACCESS_KEY = "自己是key";
    private static String AWS_SECRET_KEY = "自己的ID";
    private static final String bucketName = "自己创建的桶名称";
 
    private static AmazonS3   s3;
    private static TransferManager   tx;
 
    /**
     * 通过default方法连接aws
     * @throws Exception
     */
    private static void init() throws Exception {
        AWSCredentials credentials = null;
        try {
            credentials = new ProfileCredentialsProvider("default").getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException("Exception on credentials.", e);
        }
        s3 = new AmazonS3Client(credentials);
        //Region usWest2 = Region.getRegion(Regions.US_WEST_2);
        //s3.setRegion(usWest2);
        tx = new TransferManager(s3);
    }
 
    /**
     * 通过在代码中包含 access key id 和 secret access key 连接 aws
     * @throws Exception
     */
    private static void init_with_key() throws Exception {
        AWSCredentials credentials = null;
        credentials = new BasicAWSCredentials(AWS_ACCESS_KEY, AWS_SECRET_KEY);
        s3 = new AmazonS3Client(credentials);
        //Region usWest2 = Region.getRegion(Regions.US_WEST_2);
        //s3.setRegion(usWest2);
        tx = new TransferManager(s3);
    }
 
    /**
     * 用于创建一个名为bucketName的s3 bucket
     * @param bucketName
     */
    private static void createBucket(String bucketName) {
        if(s3.doesBucketExist(bucketName) == true) {
            System.out.println(bucketName + " already exist!");
            return;
        }
        System.out.println("creating " + bucketName + " ...");
        s3.createBucket(bucketName);
        System.out.println(bucketName + " has been created!");
    }
 
    /**
     * 列出名为bucketName的bucket里面的所有object
     * @param bucketName
     */
    private static void listObjects(String bucketName) {
        System.out.println("Listing objects of " + bucketName);
        ObjectListing objectListing = s3.listObjects(bucketName);
        int objectNum = 0;
        for(S3ObjectSummary objectSummary : objectListing.getObjectSummaries()) {
            System.out.println(" - " + objectSummary.getKey());
            objectNum ++;
        }
        System.out.println("total " + objectNum + " object(s).");
    }
 
    /**
     * 判断名为bucketName的bucket里面是否有一个名为key的object
     * @param bucketName
     * @param key
     * @return
     */
    private static boolean isObjectExit(String bucketName, String key) {
        int len = key.length();
        ObjectListing objectListing = s3.listObjects(bucketName);
        String s = new String();
        for(S3ObjectSummary objectSummary : objectListing.getObjectSummaries()) {
            s = objectSummary.getKey();
            int slen = s.length();
            if(len == slen) {
                int i;
                for(i=0;i<len;i++) {
                    if(s.charAt(i) != key.charAt(i)) {
                        break;
                    }
                }
                if(i == len) {
                    return true;
                }
            }
        }
        return false;
    }
 
    /**
     * 在本地创建一个名为filename的文件，输入一些信息后，将其传到名为bucketName的s3 bucket里面去
     * @param bucketName
     * @param filename
     * @throws IOException
     */
    private static void createSampleFile(String bucketName, String filename) throws IOException {
        if(isObjectExit(bucketName, filename) == true) {
            System.out.println(filename +" already exists in " + bucketName + "!");
            return;
        }
        System.out.println("creating file " + filename);
        File file = new File(filename);
        file.deleteOnExit();
 
        Writer writer = new OutputStreamWriter(new FileOutputStream(file));
        writer.write("abcdefghijklmnopqrstuvwxyz\n");
        writer.write("01234567890112345678901234\n");
        writer.write("!@#$%^&*()-=[]{};':',.<>/?\n");
        writer.write("01234567890112345678901234\n");
        writer.write("abcdefghijklmnopqrstuvwxyz\n");
        writer.close();
 
        s3.putObject(bucketName, filename, file);
        System.out.println("create sample file " + filename + " succeed!");
    }
 
    /**
     * 输出"s3://"+bucketname+"/"key对应的object对应的信息
     * @param bucketName
     * @param key
     */
    private static void showContentOfAnObject(String bucketName, String key) {
        S3Object object = s3.getObject(new GetObjectRequest(bucketName, key));
        InputStream input = object.getObjectContent();
        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        try {
            while (true) {
                String line = reader.readLine();
                if (line == null) {
                    break;
                }
                System.out.println("    " + line);
            }
            System.out.println();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    /**
     * 输出"s3://"+bucketname+"/"key对应的object对应的信息(这个object对应的文件时gzip格式的)
     * @param bucketName
     * @param key
     */
    private static void showContentOfAnGzipObject(String bucketName, String key) {
        try {
            S3Object object = s3.getObject(new GetObjectRequest(bucketName, key));
            InputStream input = new GZIPInputStream(object.getObjectContent());
            BufferedReader reader = new BufferedReader(new InputStreamReader(input));
 
            while (true) {
                String line = reader.readLine();
                if (line == null) {
                    break;
                }
                System.out.println("    " + line);
            }
            System.out.println();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    /**
     * 列出我的s3上所有的bucket的名字
     */
    private static void listBuckets() {
        System.out.println("Listing buckets");
        int bucketNum = 0;
        for(Bucket bucket : s3.listBuckets()) {
            System.out.println(" - " + bucket.getName());
            bucketNum ++;
        }
        System.out.println("total " + bucketNum + " bucket(s).");
    }
 
    /**
     * 删除一个名为bucketName的bucket
     * @param bucketName
     */
    private static void deleteBucket(String bucketName) {
        if(s3.doesBucketExist(bucketName) == false) {
            System.out.println(bucketName + " does not exists!");
            return;
        }
        System.out.println("deleting " + bucketName + " ...");
        ObjectListing objectListing = s3.listObjects(bucketName);
        for(S3ObjectSummary objectSummary : objectListing.getObjectSummaries()) {
            String key = objectSummary.getKey();
            s3.deleteObject(bucketName, key);
        }
        s3.deleteBucket(bucketName);
        System.out.println(bucketName + " has been deleted!");
    }
 
    /**
     * 删除名为bucketName的bucket里面所有key的前缀和prefix匹配的object
     * @param bucketName
     * @param prefix
     */
    private static void deleteObjectsWithPrefix(String bucketName, String prefix) {
        if(s3.doesBucketExist(bucketName) == false) {
            System.out.println(bucketName + " does not exists!");
            return;
        }
        System.out.println("deleting " + prefix +"* in " + bucketName + " ...");
        int pre_len = prefix.length();
        ObjectListing objectListing = s3.listObjects(bucketName);
        for(S3ObjectSummary objectSummary : objectListing.getObjectSummaries()) {
            String key = objectSummary.getKey();
            int len = key.length();
            if(len < pre_len) {
                continue;
            }
            int i;
            for(i=0;i<pre_len;i++) {
                if(key.charAt(i) != prefix.charAt(i)) {
                    break;
                }
            }
            if(i < pre_len) {
                continue;
            }
            s3.deleteObject(bucketName, key);
        }
        System.out.println("All " + prefix + "* deleted!");
    }
 
    /**
     * 上传一个本地文件(对应位置为path)上传到名为bucketName的bucket
     * @param path
     * @param bucketName
     */
    private static void uploadFileToBucket(String path, String bucketName) {
        File fileToUpload = new File(path);
        if(fileToUpload.exists() == false) {
            System.out.println(path + " not exists!");
            return;
        }
        PutObjectRequest request = new PutObjectRequest(bucketName, fileToUpload.getName(), fileToUpload);
        Upload upload = tx.upload(request);
        while((int)upload.getProgress().getPercentTransferred() < 100) {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        System.out.println(path + " upload succeed!");
    }
 
    /**
     * 在aws上创建一个目录
     * @param bucketName
     * @param folderName
     */
    private static void createFolder(String bucketName, String folderName) {
        // Create metadata for my folder & set content-length to 0
        ObjectMetadata metadata = new ObjectMetadata();
        metadata.setContentLength(0);
        // Create empty content
        InputStream emptyContent = new ByteArrayInputStream(new byte[0]);
        // Create a PutObjectRequest passing the foldername suffixed by /
        PutObjectRequest putObjectRequest =
                new PutObjectRequest(bucketName, folderName+"/",
                        emptyContent, metadata);
        // Send request to S3 to create folder
        s3.putObject(putObjectRequest);
    }
 
    public static void main(String[] args) throws Exception {
 
        init_with_key();
 
        //uploadFileToBucket("E:\\111\\111\\Ki.mp3","test-us-mp3");
        showContentOfAnObject(bucketName,"Kty_Come.mp3.json");
        System.exit(0);
    }
}