推荐接口（predict）

调用个性化推荐接口，传入用户id以及相关的上下文信息等，可以获得推荐结果列表。

请求方法

HTTP POST

URL

《URL相关名词解释》

如无申明，url 最后一段默认为 default。特殊情况有可能产生变化。

请求头

公共请求头部分详见《公共请求头说明》。
接口额外请求头：

请求体

参数

示例

{
    "user":{
        "uid":"uid1",
        "device":{
            "deviceId":"device_id",
            "platform":"ios"
        },
        "age":"30",
        "gender":"male",
        "province":"GuangDong",
        "city":"ShenZhen",
        "country":"China"
    },
    "context":{
        "spm":"A$##$B$##$C",
        "feature":{
            "stringFeature":{
                "key":"value"
            },
            "intFeature":{
                "key":2
            },
            "floatFeature":{
                "key":3.5
            },
            "doubleFeature":{
                "key":3.51231
            },
            "stringArrayFeature":{
                "key":{
                    "values":[
                        "values1",
                        "values2"
                    ]
                }
            },
            "intArrayFeature":{
                "key":{
                    "values":[
                        1,
                        2
                    ]
                }
            },
            "floatArrayFeature":{
                "key":{
                    "values":[
                        1.1,
                        2.2
                    ]
                }
            },
            "doubleArrayFeature":{
                "key":{
                    "values":[
                        1.11111,
                        2.22222
                    ]
                }
            }
        },
        "filter":{
            "stringFilter":{
                "key":"value"
            },
            "intFilter":{
                "key":2
            },
            "floatFilter":{
                "key":3.5
            },
            "doubleFilter":{
                "key":3.51231
            },
            "stringArrayFilter":{
                "key":{
                    "values":[
                        "value1",
                        "value2"
                    ]
                }
            },
            "intArrayFilter":{
                "key":{
                    "values":[
                        1,
                        2
                    ]
                }
            },
            "floatArrayFilter":{
                "key":{
                    "values":[
                        1.1,
                        2.2
                    ]
                }
            },
            "doubleArrayFilter":{
                "key":{
                    "values":[
                        1.11111,
                        2.22222
                    ]
                }
            }
        },
        "extra":{
            "key1":"value1",
            "key2":"value2"
        }
    },
    "candidateItems":[
        {
            "id":"item_id1"
        },
        {
            "id":"item_id2"
        }
    ],
    "parentItem":{
        "id":"item_id3"
    },
    "filterItems":[
        {
            "id":"item_id4"
        },
        {
            "id":"item_id5"
        }
    ]
}

返回体

参数

示例

{
    "code":200,
    "message":"OK",
    "value":{
        "items":[
            {
                "id":"12345789",
                "rank":1,
                "transData":"jJGJveDUifbABAMoBDHRlc3RfZ2FubGluMQ==",
                "extra":{
                    "score":"0.67912"
                }
            },
            {
                "id":"56479201",
                "rank":2,
                "transData":"25vbGl0aBUa4MW/jhjkdsa+kljlkjdsa==",
                "extra":{
                    "score":"0.45213"
                }
            },
            {
                "id":"12340987",
                "rank":3,
                "transData":"dsjkahiunfmn1231/dsafkl+23123adaasd==",
                "extra":{
                    "score":"0.33768"
                }
            }
        ]
    },
    "request_id":"sfbnbm-123sam-dsajkh",
    "success":true
}

代码示例

import com.alibaba.fastjson2.JSON;
import okhttp3.*;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.*;

public class Main {

    final static String token = "xxx"; // 替换为实际的token
    final static String tenantId = "xxx"; // 替换为实际的租户id
    final static String applicationId = "xxx"; // 替换为实际的应用id
    final static String predictUrl = "https://api.byteair.volces.com/predict/api/" + applicationId + "/default";

    public static void main(String[] args) {
        predict();
    }

    public static void predict() {
        String tenantTs = Integer.toString((int) (System.currentTimeMillis() / 1000)); // 当前时间戳
        String tenantNonce = UUID.randomUUID().toString().substring(0, 8); // 随机字符串
        byte[] httpBody = JSON.toJSONBytes(new HashMap<>() {{ // 示例用http body.真实请求请替换成实际使用的body.
            put("user", new HashMap<>() {{
                put("uid", "123");
            }});
            put("context", new HashMap<>() {{
                put("spm", "1$##$2$##$3");
            }});
        }});
        String sign = calSignature(token, tenantId, tenantTs, tenantNonce, httpBody);
        Headers.Builder builder = createHeader(tenantTs, tenantNonce, sign);
        builder.set("Enable-Spm-Route", "true");
        System.out.println(builder.build().toString());
        System.out.println(new String(httpBody));
        Request request = new Request.Builder()
                .url(predictUrl)
                .headers(builder.build())
                .post(RequestBody.create(httpBody))
                .build();

        OkHttpClient client = new OkHttpClient();
        Call call = client.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                System.out.println("action=predict`phase=failure");
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String body = response.body().string();
                System.out.println(body);
            }
        });
    }

    //根据token、tenant_id、tenantTs、tenantNonce、httpBody计算signature
    public static String calSignature(String token, String tenant_id, String tenantTs, String tenantNonce, byte[] httpBody) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            // 按照token、httpBody、tenant_id、ts、nonce的顺序拼接
            // 本身为字符串的字段，需要使用utf-8方式编码成字节数组
            // httpBody本身为bytes类型，因此无需编码
            digest.update(token.getBytes(StandardCharsets.UTF_8));
            digest.update(httpBody);
            digest.update(tenant_id.getBytes(StandardCharsets.UTF_8));
            digest.update(tenantTs.getBytes(StandardCharsets.UTF_8));
            digest.update(tenantNonce.getBytes(StandardCharsets.UTF_8));
            // 将得到sha256使用16进制字符串表示
            return bytes2Hex(digest.digest());
        } catch (NoSuchAlgorithmException ignored) {
            return "";
        }
    }

    public static String bytes2Hex(byte[] bts) {
        StringBuilder des = new StringBuilder();
        String hex;
        for (byte bt : bts) {
            // 剔除负数强转成int后补上的"ffffff"
            hex = (Integer.toHexString(bt & 0xff));
            // 始终用两个16进制代表一个byte，不够的在前面补“0”
            if (hex.length() == 1) {
                des.append("0");
            }
            des.append(hex);
        }
        return des.toString();
    }

    private static Headers.Builder createHeader(String tenantTs, String nonce, String signature) {
        Headers.Builder builder = new Headers.Builder();
        builder.add("Tenant-Id", tenantId);
        builder.add("Tenant-Ts", tenantTs);
        builder.add("Tenant-Nonce", nonce);
        builder.add("Tenant-Signature", signature);
        builder.add("Request-Id", String.valueOf(UUID.randomUUID()));
        builder.add("Content-Type", "application/json");
        return builder;
    }
}