Object Storage Service:Form upload (Java SDK)

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. To access OSS from other Alibaba Cloud services in the same region, use an internal endpoint. For details about supported regions and endpoints, see Regions and endpoints.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Configuration examples for common scenarios.

• To perform a form upload, you must have the oss:PutObject permission. For more information, see Attach a custom policy to a RAM user.

Examples

The following sample code provides an example on how to perform form upload:

import com.aliyun.oss.common.utils.BinaryUtil; 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.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; import com.aliyun.oss.ClientException; public class PostObjectSample { // Specify the full path of the local file that you want to upload. private String localFilePath = "yourLocalFile"; // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. private 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. String accessKeyId = System.getenv("OSS_ACCESS_KEY_ID"); String accessKeySecret = System.getenv("OSS_ACCESS_KEY_SECRET"); // Specify the name of the bucket. private String bucketName = "yourBucketName"; // Specify the full path of the object. Do not include the bucket name in the full path. private String objectName = "yourObjectName"; // Set 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 String callbackServerUrl = "yourCallbackServerUrl"; // Set the Host header in the callback request. Example: oss-cn-hangzhou.aliyuncs.com. private String callbackServerHost = "yourCallbackServerHost"; /** * Perform a 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+ "."); // Set Map for the form. Map<String, String> formFields = new LinkedHashMap<String, String>(); // Set the object name. formFields.put("key", this.objectName); // Set Content-Disposition. formFields.put("Content-Disposition", "attachment;filename=" + localFilePath); // Set callback parameters. // Callback callback = new Callback(); // Set 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); // Set the Host header in the callback request. Example: oss-cn-hangzhou.aliyuncs.com. // callback.setCallbackHost(callbackServerHost); // Set the value of the body field included in the callback request. // callback.setCallbackBody("{\\\"mimeType\\\":${mimeType},\\\"size\\\":${size}}"); // Set Content-Type in the callback request. // callback.setCalbackBodyType(Callback.CalbackBodyType.JSON); // Set the custom parameters in the callback request. Each custom parameter consists of a key-value pair. The key must start with x: and be in lowercase. // callback.addCallbackVar("x:var1", "value1"); // callback.addCallbackVar("x:var2", "value2"); // Set the callback parameter in Map for the form. // setCallBack(formFields, callback); // Set OSSAccessKeyId. formFields.put("OSSAccessKeyId", accessKeyId); String policy = "{\"expiration\": \"2120-01-01T12:00:00.000Z\",\"conditions\": [[\"content-length-range\", 0, 104857600]]}"; String encodePolicy = new String(Base64.encodeBase64(policy.getBytes())); // Set the policy. formFields.put("policy", encodePolicy); // Generate a signature. String signaturecom = com.aliyun.oss.common.auth.ServiceSignature.create().computeSignature(accessKeySecret, encodePolicy); // Set the signature. formFields.put("Signature", signaturecom); String ret = formUpload(urlStr, formFields, localFilePath); System.out.println("Post Object [" + this.objectName + "] to bucket [" + bucketName + "]"); System.out.println("post reponse:" + ret); } private static String formUpload(String urlStr, Map<String, String> formFields, String localFile) 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); OutputStream out = new DataOutputStream(conn.getOutputStream()); // Traverse and read the data in the form map, and write the data to the output stream. if (formFields != null) { StringBuffer strBuf = new StringBuffer(); 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=\"" + inputName + "\"\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 information and write the file to be uploaded to the output stream. File file = new File(localFile); 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()); } } } } public static void main(String[] args) throws Exception { PostObjectSample ossPostObject = new PostObjectSample(); ossPostObject.PostObject(); } }

References

For more information about the API operation that you can call to perform form upload, see PostObject.