Object Storage Service:Java upload callbacks

import com.aliyun.oss.ClientBuilderConfiguration;
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.Callback;
import com.aliyun.oss.model.PutObjectRequest;
import com.aliyun.oss.model.PutObjectResult;

import java.io.ByteArrayInputStream;

public class Demo {

    public static void main(String[] args) throws Exception{
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket.
        String bucketName = "examplebucket";
        // Specify the full path of the object. Example: exampledir/exampleobject.txt. The full path of the object cannot contain the bucket name.
        String objectName = "exampledir/exampleobject.txt";
        // Specify the address of the server to which the callback request is sent. Example: https://example.com:23450.
        String callbackUrl = "yourCallbackServerUrl";
        // Specify the region of the bucket. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance and configure the V4 signature version.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();
        
        try {
            String content = "Hello OSS";
            PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, objectName,new ByteArrayInputStream(content.getBytes()));

            // Specify the upload callback parameters
            Callback callback = new Callback();
            callback.setCallbackUrl(callbackUrl);
            // (Optional) Specify the Host field included in the callback request header.
            // callback.setCallbackHost("yourCallbackHost");
            
            // Specify the body content of the callback request in JSON format and define placeholder variables in the body.
            callback.setCalbackBodyType(Callback.CalbackBodyType.JSON);
            callback.setCallbackBody("{\\\"bucket\\\":${bucket},\\\"object\\\":${object},\\\"mimeType\\\":${mimeType},\\\"size\\\":${size},\\\"my_var1\\\":${x:var1},\\\"my_var2\\\":${x:var2}}");

            // Specify custom parameters for the callback request. Each custom parameter consists of a key and a value. The key must start with x:.
            callback.addCallbackVar("x:var1", "value1");
            callback.addCallbackVar("x:var2", "value2");
            putObjectRequest.setCallback(callback);

            // Perform the upload operation
            PutObjectResult putObjectResult = ossClient.putObject(putObjectRequest);

            // Read the response to the upload callback request.
            byte[] buffer = new byte[1024];
            putObjectResult.getResponse().getContent().read(buffer);
            // You must close the stream after the response is read. Otherwise, connection leaks may occur and cause exceptions and unavailability of connection.
            putObjectResult.getResponse().getContent().close();
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (Throwable ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.internal.Mimetypes;
import com.aliyun.oss.model.*;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

public class Demo {

    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket.
        String bucketName = "examplebucket";
        // Specify the full path of the object. Example: exampledir/exampleobject.txt. The full path of the object cannot contain the bucket name.
        String objectName = "exampledir/exampleobject.txt";
        // Specify the path of the local file that you want to upload.
        String filePath = "D:\\localpath\\examplefile.txt";
        // Specify the region of the bucket. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";
        // Specify the address of the server to which the callback request is sent. Example: https://example.com:23450.
        String callbackUrl = "https://example.com:23450";

        // Create an OSSClient instance and configure the V4 signature version.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
        OSS ossClient = OSSClientBuilder.create()
                .endpoint(endpoint)
                .credentialsProvider(credentialsProvider)
                .clientConfiguration(clientBuilderConfiguration)
                .region(region)
                .build();

        try {
            // Create an InitiateMultipartUploadRequest object.
            InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, objectName);

            // Specify the metadata of the object and obtain the Content-Type of the file.
            ObjectMetadata metadata = new ObjectMetadata();
            if (metadata.getContentType() == null) {
                metadata.setContentType(Mimetypes.getInstance().getMimetype(new File(filePath), objectName));
            }
            System.out.println("Content-Type: " + metadata.getContentType());

            // Bind the metadata to the upload request.
            request.setObjectMetadata(metadata);

            // Initiate the multipart upload task.
            InitiateMultipartUploadResult upresult = ossClient.initiateMultipartUpload(request);
            // Obtain the upload ID.
            String uploadId = upresult.getUploadId();

            // partETags is a set of PartETags. A PartETag consists of the part number and ETag of an uploaded part.
            List<PartETag> partETags = new ArrayList<PartETag>();
            // Specify the size of each part. The part size is used to calculate the number of parts of the object. Unit: bytes.
            // The minimum size of a part is 100 KB and the maximum size is 5 GB. The size of the last part can be less than 100 KB.
            // Set the part size to 1 MB.
            final long partSize = 1 * 1024 * 1024L;

            // Calculate the number of parts based on the size of the uploaded data. In the following code, a local file is used as an example to show how to use the File.length() method to obtain the size of the uploaded data.
            final File sampleFile = new File(filePath);
            long fileLength = sampleFile.length();
            int partCount = (int) (fileLength / partSize);
            if (fileLength % partSize != 0) {
                partCount++;
            }
            // Upload each part until all parts are uploaded.
            for (int i = 0; i < partCount; i++) {
                long startPos = i * partSize;
                long curPartSize = (i + 1 == partCount) ? (fileLength - startPos) : partSize;
                UploadPartRequest uploadPartRequest = new UploadPartRequest();
                uploadPartRequest.setBucketName(bucketName);
                uploadPartRequest.setKey(objectName);
                uploadPartRequest.setUploadId(uploadId);

                // Specify the input stream of the multipart upload task.
                // In the following sample code, a local file is used as an example to describe how to create a FileInputStream object and use the InputStream.skip() method to skip the specified data.
                InputStream instream = new FileInputStream(sampleFile);
                instream.skip(startPos);
                uploadPartRequest.setInputStream(instream);
                // Specify the part size.
                uploadPartRequest.setPartSize(curPartSize);
                // Specify part numbers. Each part has a part number that ranges from 1 to 10,000. If the part number that you specify does not fall within the specified range, OSS returns the InvalidArgument error code.
                uploadPartRequest.setPartNumber(i + 1);
                // Parts are not necessarily uploaded in order. They can be uploaded from different OSS clients. OSS sorts the parts based on their part numbers and combines them into a complete object.
                UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
                // Each time a part is uploaded, OSS returns a result that contains a PartETag. The PartETag is stored in partETags.
                partETags.add(uploadPartResult.getPartETag());

                // Disable the input stream
                instream.close();
            }

            // Create a CompleteMultipartUploadRequest object.
            // When you call the CompleteMultipartUpload operation, you must provide all valid PartETags. After OSS receives the PartETags, OSS verifies all parts one by one. If all the parts pass the verification, OSS combines these parts together into a complete object.
            CompleteMultipartUploadRequest completeMultipartUploadRequest =
                    new CompleteMultipartUploadRequest(bucketName, objectName, uploadId, partETags);

            // Specify the upload callback parameters.
            Callback callback = new Callback();
            callback.setCallbackUrl(callbackUrl);
            // (Optional) Specify the Host field included in the callback request header.
            // callback.setCallbackHost("yourCallbackHost");

            // Specify the body content of the callback request in JSON format and define placeholder variables in the body.
            callback.setCalbackBodyType(Callback.CalbackBodyType.JSON);
            callback.setCallbackBody("{\\\"bucket\\\":${bucket},\\\"object\\\":${object},\\\"mimeType\\\":${mimeType},\\\"size\\\":${size},\\\"my_var1\\\":${x:var1},\\\"my_var2\\\":${x:var2}}");

            // Specify custom parameters for the callback request. Each custom parameter consists of a key and a value. The key must start with x:.
            callback.addCallbackVar("x:var1", "value1");
            callback.addCallbackVar("x:var2", "value2");
            completeMultipartUploadRequest.setCallback(callback);

            // Complete the multipart upload task.
            CompleteMultipartUploadResult completeMultipartUploadResult = ossClient.completeMultipartUpload(completeMultipartUploadRequest);
            System.out.println("Upload successful,ETag:" + completeMultipartUploadResult.getETag());

        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught a ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

import com.aliyun.oss.ClientException;
import com.aliyun.oss.common.auth.ServiceSignature;
import com.aliyun.oss.common.utils.BinaryUtil;
import com.aliyun.oss.common.utils.StringUtils;
import com.aliyun.oss.internal.OSSUtils;
import com.aliyun.oss.model.Callback;
import org.apache.commons.codec.binary.Base64;
import javax.activation.MimetypesFileTypeMap;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.*;

public class PostObjectCallbackV4Demo {
    // Specify the full path of the local file that you want to upload.
    private static final String localFilePath = "D:\\localpath\\examplefile.txt";
    // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
    private static final String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
    // The AccessKey pair of an Alibaba Cloud account has permissions on all API operations. Using these credentials to perform operations in OSS is a high-risk operation. We recommend that you use a RAM user to call API operations or perform routine O&M. To create a RAM user, log on to the RAM console.
    private static final String accessKeyId = System.getenv("OSS_ACCESS_KEY_ID");
    private static final String accessKeySecret = System.getenv("OSS_ACCESS_KEY_SECRET");
    // Specify the name of the bucket. Example: examplebucket.
    private static final String bucketName = "examplebucket";
    // Specify the full path of the object. Example: exampledir/exampleobject.txt. The full path of the object cannot contain the bucket name.
    private static final String objectName = "exampledir/exampleobject.txt";
    // Specify the URL of the server to which you want to send the callback request. Example: http://oss-demo.oss-cn-hangzhou.aliyuncs.com:23450 or http://127.0.0.1:9090.
    private static final String callbackServerUrl = "http://oss-demo.oss-cn-hangzhou.aliyuncs.com:23450";
    // Specify the Host header in the callback request. Example: oss-cn-hangzhou.aliyuncs.com.
    private static final String callbackServerHost = "";
    // Specify the region of the bucket. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
    private static final String region = "cn-hangzhou";
    private static Date requestDateTime = new Date();


    /**
     * Perform form upload.
     * @throws Exception
     */
    private void PostObject() throws Exception {

        // Add the bucket name to the URL. The URL format is http://yourBucketName.oss-cn-hangzhou.aliyuncs.com.
        String urlStr = endpoint.replace("http://", "http://" + bucketName+ ".");
        // Construct form parameters
        Map<String, String> formFields = new LinkedHashMap<String, String>();
        formFields.put("key", objectName);
        formFields.put("Content-Disposition", "attachment;filename="
                + localFilePath);
        // Specify callback parameters.
        Callback callback = new Callback();
        // Specify the URL of the server to which you want to send the callback request. Example: http://oss-demo.oss-cn-hangzhou.aliyuncs.com:23450 or http://127.0.0.1:9090.
        callback.setCallbackUrl(callbackServerUrl);
        // Specify the Host header in the callback request. Example: oss-cn-hangzhou.aliyuncs.com.
        callback.setCallbackHost(callbackServerHost);

        // Specify the body content of the callback request in JSON format and define placeholder variables in the body.
        callback.setCalbackBodyType(Callback.CalbackBodyType.JSON);
        callback.setCallbackBody("{\\\"bucket\\\":${bucket},\\\"object\\\":${object},\\\"mimeType\\\":${mimeType},\\\"size\\\":${size},\\\"my_var1\\\":${x:var1},\\\"my_var2\\\":${x:var2}}");

        // Specify custom parameters for the callback request. Each custom parameter consists of a key-value pair. The key must start with x: and be in lower case.
        callback.addCallbackVar("x:var1", "value1");
        callback.addCallbackVar("x:var2", "value2");
        // Specify the callback parameter in Map for the form.
        setCallBack(formFields, callback);

        // Specify OSSAccessKeyId.
        formFields.put("OSSAccessKeyId", accessKeyId);
        String policy = "{\"expiration\": \"2120-01-01T12:00:00.000Z\",\"conditions\": [" +
                "  {\"x-oss-signature-version\": \"OSS4-HMAC-SHA256\"},\n" +
                "  {\"x-oss-credential\": \""+accessKeyId+"/"+getDate()+"/"+region+"/oss/aliyun_v4_request\"},\n" +
                "  {\"x-oss-date\": \""+getDateTime()+"\"},\n" +
                "  [\"content-length-range\", 0, 104857600]" +
                "]}";
        String encodePolicy = new String(Base64.encodeBase64(policy.getBytes()));
        // Specify the policy.
        formFields.put("policy", encodePolicy);
        System.out.println("policy:" + policy);
        // Generate a signature.
        formFields.put("x-oss-signature-version", "OSS4-HMAC-SHA256");
        formFields.put("x-oss-credential", accessKeyId+"/"+getDate()+"/"+region+"/oss/aliyun_v4_request");
        formFields.put("x-oss-date", getDateTime());

        String stringToSign = new String(Base64.encodeBase64(policy.getBytes()));
        System.out.println("stringToSign:" + stringToSign);
        byte[] signingKey = buildSigningKey();
        String signature = buildSignature(signingKey, stringToSign);
        formFields.put("x-oss-signature", signature);
        System.out.println("Signature:" + signature);

        // Perform the upload
        String ret = formUpload(urlStr, formFields);
        System.out.println("Post Object [" + objectName + "] to bucket [" + bucketName + "]");
        System.out.println("post reponse:" + ret);
    }

    private static String formUpload(String urlStr, Map<String, String> formFields)
            throws Exception {
        String res = "";
        HttpURLConnection conn = null;
        String boundary = "9431149156168";
        try {
            URL url = new URL(urlStr);
            conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5000);
            conn.setReadTimeout(30000);
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("User-Agent",
                    "Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");
            conn.setRequestProperty("Content-Type",
                    "multipart/form-data; boundary=" + boundary);

            // Process form fields
            OutputStream out = new DataOutputStream(conn.getOutputStream());
            // Recursively read all Map data for the form and write the data to the output stream.
            if (formFields != null) {
                StringBuilder strBuf = new StringBuilder();
                Iterator<Map.Entry<String, String>> iter = formFields.entrySet().iterator();
                int i = 0;
                while (iter.hasNext()) {
                    Map.Entry<String, String> entry = iter.next();
                    String inputName = entry.getKey();
                    String inputValue = entry.getValue();
                    if (inputValue == null) {
                        continue;
                    }
                    if (i == 0) {
                        strBuf.append("--").append(boundary).append("\r\n");
                        strBuf.append("Content-Disposition: form-data; name=\"").append(inputName).append("\"\r\n\r\n");
                        strBuf.append(inputValue);
                    } else {
                        strBuf.append("\r\n").append("--").append(boundary).append("\r\n");
                        strBuf.append("Content-Disposition: form-data; name=\""
                                + inputName + "\"\r\n\r\n");
                        strBuf.append(inputValue);
                    }
                    i++;
                }
                out.write(strBuf.toString().getBytes());
            }
            // Read the file, and then write the file to the output stream.
            File file = new File(localFilePath);
            String filename = file.getName();
            String contentType = new MimetypesFileTypeMap().getContentType(file);
            if (contentType == null || contentType.equals("")) {
                contentType = "application/octet-stream";
            }
            StringBuffer strBuf = new StringBuffer();
            strBuf.append("\r\n").append("--").append(boundary)
                    .append("\r\n");
            strBuf.append("Content-Disposition: form-data; name=\"file\"; "
                    + "filename=\"" + filename + "\"\r\n");
            strBuf.append("Content-Type: " + contentType + "\r\n\r\n");
            out.write(strBuf.toString().getBytes());
            DataInputStream in = new DataInputStream(new FileInputStream(file));
            int bytes = 0;
            byte[] bufferOut = new byte[1024];
            while ((bytes = in.read(bufferOut)) != -1) {
                out.write(bufferOut, 0, bytes);
            }
            in.close();
            byte[] endData = ("\r\n--" + boundary + "--\r\n").getBytes();
            out.write(endData);
            out.flush();
            out.close();
            // Read the returned data.
            strBuf = new StringBuffer();
            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                strBuf.append(line).append("\n");
            }
            res = strBuf.toString();
            reader.close();
            reader = null;
        } catch (ClientException e) {
            System.err.println("Send post request exception: " + e);
            System.err.println(e.getErrorCode()+" msg="+e.getMessage());
            throw e;
        } finally {
            if (conn != null) {
                conn.disconnect();
                conn = null;
            }
        }
        return res;
    }
    private static void setCallBack(Map<String, String> formFields, Callback callback) {
        if (callback != null) {
            String jsonCb = OSSUtils.jsonizeCallback(callback);
            String base64Cb = BinaryUtil.toBase64String(jsonCb.getBytes());
            formFields.put("callback", base64Cb);
            if (callback.hasCallbackVar()) {
                Map<String, String> varMap = callback.getCallbackVar();
                for (Map.Entry<String, String> entry : varMap.entrySet()) {
                    formFields.put(entry.getKey(), entry.getValue());
                }
            }
        }
    }

    private static String getDateTime() {
        return getIso8601DateTimeFormat().format(requestDateTime);
    }

    private static DateFormat getIso8601DateTimeFormat() {
        SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'", Locale.US);
        df.setTimeZone(new SimpleTimeZone(0, "GMT"));
        return df;
    }

    private static DateFormat getIso8601DateFormat() {
        SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd", Locale.US);
        df.setTimeZone(new SimpleTimeZone(0, "GMT"));
        return df;
    }

    private static String getDate() {
        return getIso8601DateFormat().format(requestDateTime);
    }

    private String buildSignature(byte[] signingKey, String stringToSign) {
        byte[] result = ServiceSignature.create("HmacSHA256").computeHash(signingKey, stringToSign.getBytes(StringUtils.UTF8));
        return BinaryUtil.toHex(result);
    }

    private byte[] buildSigningKey() {
        ServiceSignature signature = ServiceSignature.create("HmacSHA256");
        byte[] signingSecret = ("aliyun_v4" + accessKeySecret).getBytes(StringUtils.UTF8);
        byte[] signingDate = signature.computeHash(signingSecret, getDate().getBytes(StringUtils.UTF8));
        byte[] signingRegion = signature.computeHash(signingDate, region.getBytes(StringUtils.UTF8));
        byte[] signingService = signature.computeHash(signingRegion, "oss".getBytes(StringUtils.UTF8));
        /*System.out.println("signingSecret:\n" + BinaryUtil.toHex(signingSecret));
        System.out.println("signingDate:\n" + BinaryUtil.toHex(signingDate));
        System.out.println("signingRegion:\n" + BinaryUtil.toHex(signingRegion));
        System.out.println("signingService:\n" + BinaryUtil.toHex(signingService));*/
        return signature.computeHash(signingService, "aliyun_v4_request".getBytes(StringUtils.UTF8));
    }

    public static void main(String[] args) throws Exception {
        PostObjectCallbackV4Demo ossPostObject = new PostObjectCallbackV4Demo();
        ossPostObject.PostObject();
    }
}