Request signing

The following code provides a complete Java example of how to sign a request that uses the `MakeSuperResolutionImage` action for image super resolution.

import java.net.URI;
import java.util.HashMap;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class SignDemo {
    // Use the POST method.
    static final String API_HTTP_METHOD = "POST";
    // The API endpoint is related to the category. For the API endpoint of a specific category, see https://help.aliyun.com/document_detail/143103.html
    static final String API_ENDPOINT = "imageenhan.cn-shanghai.aliyuncs.com";
    // The API version is related to the category. For the API version of a specific category, see https://help.aliyun.com/document_detail/464194.html
    static final String API_VERSION = "2019-09-30";
    static final java.text.SimpleDateFormat DF = new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
    public static void main(String[] args) throws Exception {
        // To create an AccessKey ID and AccessKey secret, see https://help.aliyun.com/document_detail/175144.html
        // If you use the AccessKey of a RAM user, you must grant the AliyunVIAPIFullAccess permission to the RAM user. For more information, see https://help.aliyun.com/document_detail/145025.html
        // Read the AccessKey ID and AccessKey secret from environment variables. Before you run the sample code, you must configure the environment variables.
        String accessKeyId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
        String accessSecret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
        DF.setTimeZone(new java.util.SimpleTimeZone(0, "GMT"));// You must set the time zone to GMT.
        // Business parameter names are in UpperCamelCase.
        Map<String, String> params = new HashMap<>();
        // Note: When you use the signing mechanism to make a call, file parameters currently only support OSS URLs in the China (Shanghai) region. You can store files in OSS in the China (Shanghai) region. For more information, see https://help.aliyun.com/document_detail/175142.html. For other cases, such as local files or other URLs, you must first explicitly transform them into OSS URLs in the China (Shanghai) region. For more information, see Method 2 in https://help.aliyun.com/document_detail/155645.html. However, this solution does not support direct calls from a web frontend environment.
        params.put("Url", "http://viapi-test.oss-cn-shanghai.aliyuncs.com/viapi-3.0domepic/imageenhan/MakeSuperResolutionImage/MakeSuperResolutionImage1.png");
        // The API action is the capability name. For the Action parameter, see the product page of the specific algorithm. This example uses image super resolution: https://help.aliyun.com/document_detail/151947.html
        String action = "MakeSuperResolutionImage";
        execute(action, accessKeyId, accessSecret, params);
    }
    public static void execute(String action, String accessKeyId, String accessSecret, Map<String, String> bizParams) throws Exception {
        java.util.Map<String, String> params = new java.util.HashMap<String, String>();
        // 1. System parameters
        params.put("SignatureMethod", "HMAC-SHA1");
        params.put("SignatureNonce", java.util.UUID.randomUUID().toString());// Prevents replay attacks.
        params.put("AccessKeyId", accessKeyId);
        params.put("SignatureVersion", "1.0");
        params.put("Timestamp", DF.format(new java.util.Date()));
        params.put("Format", "JSON");
        // 2. Business API parameters
        params.put("RegionId", "cn-shanghai");
        params.put("Version", API_VERSION);
        params.put("Action", action);
        if (bizParams != null && !bizParams.isEmpty()) {
            params.putAll(bizParams);
        }
        // 3. Remove the signature keyword key
        if (params.containsKey("Signature")) {
            params.remove("Signature");
        }
        // 4. Sort the parameters by key
        java.util.TreeMap<String, String> sortParams = new java.util.TreeMap<String, String>();
        sortParams.putAll(params);
        // 5. Construct the string to be signed
        java.util.Iterator<String> it = sortParams.keySet().iterator();
        StringBuilder sortQueryStringTmp = new StringBuilder();
        while (it.hasNext()) {
            String key = it.next();
            sortQueryStringTmp.append("&").append(specialUrlEncode(key)).append("=").append(specialUrlEncode(params.get(key)));
        }
        String sortedQueryString = sortQueryStringTmp.substring(1);// Remove the extra ampersand (&) at the beginning.
        StringBuilder stringToSign = new StringBuilder();
        stringToSign.append(API_HTTP_METHOD).append("&");
        stringToSign.append(specialUrlEncode("/")).append("&");
        stringToSign.append(specialUrlEncode(sortedQueryString));
        String sign = sign(accessSecret + "&", stringToSign.toString());
        // 6. The signature must also be specially URL-encoded at the end.
        String signature = specialUrlEncode(sign);
        System.out.println(params.get("SignatureNonce"));
        System.out.println("\r\n=========\r\n");
        System.out.println(params.get("Timestamp"));
        System.out.println("\r\n=========\r\n");
        System.out.println(sortedQueryString);
        System.out.println("\r\n=========\r\n");
        System.out.println(stringToSign.toString());
        System.out.println("\r\n=========\r\n");
        System.out.println(sign);
        System.out.println("\r\n=========\r\n");
        System.out.println(signature);
        System.out.println("\r\n=========\r\n");
        // The final valid request URL is generated.
        System.out.println("http://" + API_ENDPOINT + "/?Signature=" + signature + sortQueryStringTmp);

        // Add a method to directly make a POST request.
        try {
            // Create a POST request using the generated URL.
            URIBuilder builder = new URIBuilder("http://" + API_ENDPOINT + "/?Signature=" + signature + sortQueryStringTmp);
            URI uri = builder.build();
            HttpPost request = new HttpPost(uri);
            HttpClient httpclient = HttpClients.createDefault();
            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
    public static String specialUrlEncode(String value) throws Exception {
        return java.net.URLEncoder.encode(value, "UTF-8").replace("+", "%20").replace("*", "%2A").replace("%7E", "~");
    }
    public static String sign(String accessSecret, String stringToSign) throws Exception {
        javax.crypto.Mac mac = javax.crypto.Mac.getInstance("HmacSHA1");
        mac.init(new javax.crypto.spec.SecretKeySpec(accessSecret.getBytes("UTF-8"), "HmacSHA1"));
        byte[] signData = mac.doFinal(stringToSign.getBytes("UTF-8"));
        return new sun.misc.BASE64Encoder().encode(signData);
    }
}              

The following code provides a complete Java example of how to sign a request that uses the `DetectLivingFace` action for face liveness detection.

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.net.URI;
import java.util.HashMap;
import java.util.Map;

public class SignDemo {

    // Use the POST method.
    static final String API_HTTP_METHOD = "POST";
    // The API endpoint is related to the category. For the API endpoint of a specific category, see https://help.aliyun.com/document_detail/143103.html
    static final String API_ENDPOINT = "facebody.cn-shanghai.aliyuncs.com";
    // The API version is related to the category. For the API version of a specific category, see https://help.aliyun.com/document_detail/464194.html
    static final String API_VERSION = "2019-12-30";
    static final java.text.SimpleDateFormat DF = new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
    public static void main(String[] args) throws Exception {
        // To create an AccessKey ID and AccessKey secret, see https://help.aliyun.com/document_detail/175144.html
        // If you use the AccessKey of a RAM user, you must grant the AliyunVIAPIFullAccess permission to the RAM user. For more information, see https://help.aliyun.com/document_detail/145025.html
        // Read the AccessKey ID and AccessKey secret from environment variables. Before you run the sample code, you must configure the environment variables.
        String accessKeyId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
        String accessSecret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
        DF.setTimeZone(new java.util.SimpleTimeZone(0, "GMT"));// You must set the time zone to GMT.
        // Business parameter names are in UpperCamelCase.
        Map<String, String> params = new HashMap<>();
        // Note: When you use the signing mechanism to make a call, file parameters currently only support OSS URLs in the China (Shanghai) region. You can store files in OSS in the China (Shanghai) region. For more information, see https://help.aliyun.com/document_detail/175142.html. For other cases, such as local files or other URLs, you must first explicitly transform them into OSS URLs in the China (Shanghai) region. For more information, see Method 2 in https://help.aliyun.com/document_detail/155645.html. However, this solution does not support direct calls from a web frontend environment.
        // For array fields, you must replace N in the parameter with a specific consecutive number starting from 1. For example, to input two images for the Tasks.N.ImageURL parameter, use the following:
        params.put("Tasks.1.ImageURL", "http://viapi-test.oss-cn-shanghai.aliyuncs.com/viapi-3.0domepic/facebody/DetectLivingFace/DetectLivingFace11.jpg");
        params.put("Tasks.2.ImageURL", "http://viapi-test.oss-cn-shanghai.aliyuncs.com/viapi-3.0domepic/facebody/DetectLivingFace/DetectLivingFace13.jpg");
        // The API action is the capability name. For the Action parameter, see the product page of the specific algorithm. This example uses face liveness detection: https://help.aliyun.com/document_detail/151947.html
        String action = "DetectLivingFace";
        execute(action, accessKeyId, accessSecret, params);
    }
    public static void execute(String action, String accessKeyId, String accessSecret, Map<String, String> bizParams) throws Exception {
        java.util.Map<String, String> params = new java.util.HashMap<String, String>();
        // 1. System parameters
        params.put("SignatureMethod", "HMAC-SHA1");
        params.put("SignatureNonce", java.util.UUID.randomUUID().toString());// Prevents replay attacks.
        params.put("AccessKeyId", accessKeyId);
        params.put("SignatureVersion", "1.0");
        params.put("Timestamp", DF.format(new java.util.Date()));
        params.put("Format", "JSON");
        // 2. Business API parameters
        params.put("RegionId", "cn-shanghai");
        params.put("Version", API_VERSION);
        params.put("Action", action);
        if (bizParams != null && !bizParams.isEmpty()) {
            params.putAll(bizParams);
        }
        // 3. Remove the signature keyword key
        if (params.containsKey("Signature")) {
            params.remove("Signature");
        }
        // 4. Sort the parameters by key
        java.util.TreeMap<String, String> sortParams = new java.util.TreeMap<String, String>();
        sortParams.putAll(params);
        // 5. Construct the string to be signed
        java.util.Iterator<String> it = sortParams.keySet().iterator();
        StringBuilder sortQueryStringTmp = new StringBuilder();
        while (it.hasNext()) {
            String key = it.next();
            sortQueryStringTmp.append("&").append(specialUrlEncode(key)).append("=").append(specialUrlEncode(params.get(key)));
        }
        String sortedQueryString = sortQueryStringTmp.substring(1);// Remove the extra ampersand (&) at the beginning.
        StringBuilder stringToSign = new StringBuilder();
        stringToSign.append(API_HTTP_METHOD).append("&");
        stringToSign.append(specialUrlEncode("/")).append("&");
        stringToSign.append(specialUrlEncode(sortedQueryString));
        String sign = sign(accessSecret + "&", stringToSign.toString());
        // 6. The signature must also be specially URL-encoded at the end.
        String signature = specialUrlEncode(sign);
        System.out.println(params.get("SignatureNonce"));
        System.out.println("\r\n=========\r\n");
        System.out.println(params.get("Timestamp"));
        System.out.println("\r\n=========\r\n");
        System.out.println(sortedQueryString);
        System.out.println("\r\n=========\r\n");
        System.out.println(stringToSign.toString());
        System.out.println("\r\n=========\r\n");
        System.out.println(sign);
        System.out.println("\r\n=========\r\n");
        System.out.println(signature);
        System.out.println("\r\n=========\r\n");
        // The final valid request URL is generated.
        System.out.println("http://" + API_ENDPOINT + "/?Signature=" + signature + sortQueryStringTmp);

        // Add a method to directly make a POST request.
        try {
            // Create a POST request using the generated URL.
            URIBuilder builder = new URIBuilder("http://" + API_ENDPOINT + "/?Signature=" + signature + sortQueryStringTmp);
            URI uri = builder.build();
            HttpPost request = new HttpPost(uri);
            HttpClient httpclient = HttpClients.createDefault();
            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
    public static String specialUrlEncode(String value) throws Exception {
        return java.net.URLEncoder.encode(value, "UTF-8").replace("+", "%20").replace("*", "%2A").replace("%7E", "~");
    }
    public static String sign(String accessSecret, String stringToSign) throws Exception {
        javax.crypto.Mac mac = javax.crypto.Mac.getInstance("HmacSHA1");
        mac.init(new javax.crypto.spec.SecretKeySpec(accessSecret.getBytes("UTF-8"), "HmacSHA1"));
        byte[] signData = mac.doFinal(stringToSign.getBytes("UTF-8"));
        return new sun.misc.BASE64Encoder().encode(signData);
    }

}