como chamar uma API usando Java - Direct Mail: Central de Documentação do Alibaba Cloud

Esta página apresenta um exemplo completo em Java para chamar a API SingleSendMail do Direct Mail por meio de solicitações HTTP brutas com assinatura HMAC-SHA1.

Antes de começar

Antes de executar o exemplo, conclua as etapas a seguir:

Obtenha um AccessKey ID e um AccessKey Secret no console do Alibaba Cloud. Armazene-os nas variáveis de ambiente ALIBABA_CLOUD_ACCESS_KEY_ID e ALIBABA_CLOUD_ACCESS_KEY_SECRET.
Verifique um endereço de remetente no console do Direct Mail e defina-o como valor de AccountName.
Adicione as dependências abaixo ao arquivo pom.xml:

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.15</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.14</version>
</dependency>

Nota

Para mais informações sobre como configurar o AccessKeySecret e o AccessKeyId como variáveis de ambiente, consulte Configure um AccessKey para verificação de identidade em uma variável de ambiente.

Para obter detalhes sobre os RegionIds de outras regiões, veja Endpoints da API.

Como funciona

O exemplo executa as seguintes etapas:

Reúne todos os parâmetros necessários da API em um TreeMap ordenado.
Codifica os parâmetros em URL, calcula uma assinatura HMAC-SHA1 e a anexa à solicitação.
Envia a solicitação assinada para https://dm.aliyuncs.com via HTTP POST.
Imprime a resposta da API para confirmar o sucesso da operação.

Exemplo de solicitação

package com.aliyun.test;

import codec.Base64;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.junit.Test;
import org.springframework.http.HttpMethod;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Map;
import java.util.TreeMap;
import java.util.UUID;

public class SampleAPI {
    /**
     * https://dm.aliyuncs.com/?Action=SingleSendMail
     * &AccountName=test***@example.net
     * &ReplyToAddress=true
     * &AddressType=1
     * &ToAddress=test1***@example.net
     * &Subject=Subject
     * &HtmlBody=body
     * &<Common request parameters>
     */
    @Test
    public void testSingleSendMail() {
        Map<String, Object> params = new TreeMap<String, Object>();
        params.put("AccessKeyId", AccessKeyId);
        params.put("Action", "SingleSendMail");
        params.put("Format", Format);
        params.put("RegionId", RegionId);
        params.put("SignatureMethod", SignatureMethod);
        params.put("SignatureNonce", UUID.randomUUID().toString());
        params.put("SignatureVersion", SignatureVersion);
        params.put("Timestamp", getUTCTimeStr());
        params.put("Version", Version);
        params.put("AccountName", AccountName);
        params.put("AddressType", AddressType);
        params.put("HtmlBody", HtmlBody);
        params.put("ReplyToAddress", ReplyToAddress);
        params.put("Subject", Subject);
        params.put("TagName", TagName);
        params.put("ToAddress", ToAddress);

        Long start = System.currentTimeMillis();
        String result = httpRequestSendEmail(params);
        System.out.println("Response: " + result);
        System.out.println("Time elapsed: " + (System.currentTimeMillis() - start) + " ms");
    }

    public String httpRequestSendEmail(Map<String, Object> params) {
        String result = null;
        try {
            params.put("Signature", getSignature(prepareParamStrURLEncoder(params), method));
            String param = prepareParamStrURLEncoder(params);
            String url = protocol + "://" + host + "/?" + param;

            HttpClient httpClient = HttpClientBuilder.create().build();
            HttpResponse response = null;
            if (method.equals(HttpMethod.GET)) {
                HttpGet request = new HttpGet(url);
                response = httpClient.execute(request);
            } else {
                HttpPost request = new HttpPost(url);
                response = httpClient.execute(request);
            }
            System.out.println("Status: " + response.getStatusLine().getStatusCode());
            if (null != response){
                result = EntityUtils.toString(response.getEntity());
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return result;
    }

    private final static String protocol = "https";
    private final static String host = "dm.aliyuncs.com";
    private final static String AccessKeyId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
    private final static String AccessKeySecret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
    // Sender address (must be verified in the Direct Mail console)
    private final static String AccountName = "test***@example.net";
    // Recipient address
    private final static String ToAddress = "test1***@example.net";
    private final static String Format = "JSON";
    private final static String SignatureMethod = "HMAC-SHA1";
    private final static String SignatureVersion = "1.0";
    private final static String Version = "2015-11-23";
    private final static String AddressType = "1";
    private final static String RegionId = "cn-hangzhou";
    private final static Boolean ReplyToAddress = Boolean.TRUE;
    private final static String HtmlBody = "<html><body><h3>Test send to email! </h3></body></html>";
    private final static String Subject = "Test subject";
    private final static String TagName = "Test tag";
    private final static HttpMethod method = HttpMethod.POST;

    public String prepareParamStrURLEncoder(Map<String, Object> params) {
        try {
            StringBuffer param = new StringBuffer();
            for (Map.Entry<String, Object> entry : params.entrySet()) {
                if (StringUtils.isBlank(entry.getKey()) || null == entry.getValue()) {
                    continue;
                }
                param.append(getUtf8Encoder(entry.getKey()) + "=" + getUtf8Encoder(entry.getValue().toString()) + "&");

            }
            return param.substring(0, param.lastIndexOf("&"));

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * Get the signature
     *
     * @param param
     * @param method
     * @return
     * @throws Exception
     */
    private String getSignature(String param, HttpMethod method) throws Exception {
        String toSign = method + "&" + URLEncoder.encode("/", "utf8") + "&"
                + getUtf8Encoder(param);
        byte[] bytes = HmacSHA1Encrypt(toSign, AccessKeySecret + "&");
        return Base64.encode(bytes);
    }

    private String getUtf8Encoder(String param) throws UnsupportedEncodingException {
        return URLEncoder.encode(param, "utf8")
                .replaceAll("\\+", "%20")
                .replaceAll("\\*", "%2A")
                .replaceAll("%7E", "~");
    }

    private static final String MAC_NAME = "HmacSHA1";
    private static final String ENCODING = "UTF-8";

    /**
     * Use the HMAC-SHA1 signature method to sign encryptText
     *
     * @param encryptText The string to be signed
     * @param encryptKey  The key
     * @return
     * @throws Exception
     */
    public static byte[] HmacSHA1Encrypt(String encryptText, String encryptKey) throws Exception {
        byte[] data = encryptKey.getBytes(ENCODING);
        // Construct a key from the given byte array. The second parameter specifies the name of a key algorithm.
        SecretKey secretKey = new SecretKeySpec(data, MAC_NAME);
        // Generate a Mac object for a specified Mac algorithm.
        Mac mac = Mac.getInstance(MAC_NAME);
        // Initialize the Mac object with the given key.
        mac.init(secretKey);

        byte[] text = encryptText.getBytes(ENCODING);
        // Complete the Mac operation.
        return mac.doFinal(text);
    }

    private static DateFormat daetFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    /**
     * Get the UTC time as a string in the "yyyy-MM-dd HH:mm" format.<br />
     * If the operation fails, null is returned.
     *
     * @return
     */
    public static String getUTCTimeStr() {
        // 1. Get the local time.
        Calendar cal = Calendar.getInstance();
        // 2. Get the time zone offset.
        int zoneOffset = cal.get(Calendar.ZONE_OFFSET);
        // 3. Get the daylight saving time offset.
        int dstOffset = cal.get(Calendar.DST_OFFSET);
        // 4. Subtract these offsets from the local time to get the UTC time.
        cal.add(Calendar.MILLISECOND, -(zoneOffset + dstOffset));
        String date = daetFormat.format(cal.getTime());
        String[] strs = date.split(" ");
        return strs[0] + "T" + strs[1] + "Z";
    }

}

Veja a seguir um exemplo de solicitação com URL assinada, enviada da região China (Hangzhou).

https://dm.aliyuncs.com/?AccessKeyId=xxxxxxx&AccountName=noreply%40xxxxxxxx.club&Action=SingleSendMail&AddressType=1&Format=JSON&HtmlBody=%3Chtml%3E%3Cbody%3E%3Cimg%20alt%3D%22Go%20Language%20Chinese%20Website%22%20src%3D%22https%3A%2F%2Fstatic.studygolang.com%2Fimg%2Flogo1.png%22%20%3E%3Cimg%20alt%3D%22%22%20src%3D%22https%3A%2F%2Fgoss4.vcg.com%2Fcreative%2Fvcg%2F400%2Fnew%2FVCG211173951082.jpg%22%20%3E%3Ch3%3ETest%20send%20to%20email%20()!%3C%2Fh3%3E%3C%2Fbody%3E%3C%2Fhtml%3E%20%3Ca%25b%27%20%2B%20%2A%20%257E%3E%20Test%20email%20body.%20Your%20verification%20code%20for%20this%20registration%20is%3A%20123456&RegionId=cn-hangzhou&ReplyToAddress=true&Signature=1PysI0HsZeOEHqQ%3D&SignatureMethod=HMAC-SHA1&SignatureNonce=37161234-7747-419f-b433-bc4719504b01&SignatureVersion=1.0&Subject=Test%20subject&TagName=Test%20tag&Timestamp=2018-11-07T09%3A40%3A13Z&ToAddress=xxxxx%40example.net&Version=2015-11-23