La carga mediante formulario es un método que utiliza un formulario HTML para cargar un objeto en un bucket específico. El tamaño máximo del archivo es de 5 GB.
Notas de uso
En este tema se utiliza el endpoint público de la región China (Hangzhou). Para acceder a OSS desde otros servicios de Alibaba Cloud en la misma región, use un endpoint interno. Para obtener más información sobre las regiones y los endpoints compatibles, consulte Regions and endpoints.
Este tema muestra cómo crear una instancia de OSSClient con un endpoint de OSS. Para conocer configuraciones alternativas, como usar un dominio personalizado o autenticarse con credenciales de Security Token Service (STS), consulte Client configuration.
Para cargar un archivo mediante formulario, debe contar con el permiso
oss:PutObject. Para obtener más información, consulte Grant a custom policy.
Código de ejemplo
A continuación se muestra un código de ejemplo que indica cómo cargar un archivo mediante formulario:
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 to upload.
private String localFilePath = "yourLocalFile";
// The endpoint of the China (Hangzhou) region is used as an example. Specify the actual endpoint.
private String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
// An AccessKey pair of an Alibaba Cloud account has permissions on all API operations. Using an AccessKey pair 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 bucket name.
private String bucketName = "yourBucketName";
// Specify the full path of the object. Do not include the bucket name.
private String objectName = "yourObjectName";
// Set the URL of the callback server. Example: http://oss-demo.oss-cn-hangzhou.aliyuncs.com:23450 or http://127.0.0.1:9090.
private String callbackServerUrl = "yourCallbackServerUrl";
// Set the value of the Host header in the callback request. Example: oss-cn-hangzhou.aliyuncs.com.
private String callbackServerHost = "yourCallbackServerHost";
/**
* 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 the form map.
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 callback server. Example: http://oss-demo.oss-cn-hangzhou.aliyuncs.com:23450 or http://127.0.0.1:9090.
// callback.setCallbackUrl(callbackServerUrl);
// Set the value of the Host header in the callback request, such as oss-cn-hangzhou.aliyuncs.com.
// callback.setCallbackHost(callbackServerHost);
// Set the value of the request body for the callback.
// callback.setCallbackBody("{\\\"mimeType\\\":${mimeType},\\\"size\\\":${size}}");
// Set the Content-Type of the callback request.
// callback.setCalbackBodyType(Callback.CalbackBodyType.JSON);
// Set custom parameters for the callback request. Each parameter is 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 parameters in the form map.
// 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 the form map, read the data, 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 upload 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();
}
}Referencias
Para obtener más información sobre la operación de API correspondiente a la carga mediante formulario, consulte PostObject.