java 后端服务 调用 google api 直接获取access toekn

开发google api 的时候遇到的问题  需要维护google上的搜索商品    google  需要获取access token 才能正常调用

相关文档

google api 文档
请求示例和文档
https://developers.google.com/shopping-content/v2/quickstart

身份平台
https://developers.google.com/identity/protocols/OAuth2ServiceAccount

创建项目生成json和p12文件
https://console.cloud.google.com/projectselector2/iam-admin/serviceaccounts?supportedpurview=project

创建项目
https://console.developers.google.com/cloud-resource-manager

https://developers.google.com/identity/protocols/OpenIDConnect

google身份平台
https://developers.google.com/identity/protocols/OAuth2ServiceAccount

作用域
https://developers.google.com/identity/protocols/googlescopes

api请求 示例
https://developers.google.com/identity/protocols/OAuth2ServiceAccount

网上看了很多相关文章   没有直接获取access  token的   大部分都是需要  url  重定向  取URL里面的code  然后用code取access  token

服务端这样处理比较难   应该是直接调一个接口返回  access  token   这样处理比较方便   

 

前面的步骤简单说一下

1.创建服务项目  

2.生成加密文件  (json或者p12)

这两个步骤网上都有教程

获取access token

方式一  直接用google原生的api   

public static void main(String[] args) throws IOException {

        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();

        GoogleCredentials credential = GoogleCredentials.fromStream(Demo1.class.getResourceAsStream("加密的json文件路径"))
                .createScoped(Arrays.asList("https://www.googleapis.com/auth/userinfo.profile", "https://www.googleapis.com/auth/content"));//设置作用域
        credential.refresh();
        String accessToken = credential.getAccessToken().getTokenValue();
        System.out.println(accessToken);

        ComputeCredential computeCredential = new ComputeCredential(httpTransport,jsonFactory);
        computeCredential.setAccessToken(accessToken);

        ShoppingContent service = new ShoppingContent
                .Builder(httpTransport, jsonFactory, computeCredential)
                .build();
        ShoppingContent.Products.List productList = service.products().list(BigInteger.valueOf(110141822));
        ProductsListResponse page = productList.execute();
        List<Product> resources = page.getResources();
        System.out.println(page.toString());

        //插入和更新
//        service.products().insert(BigInteger.valueOf(110141822),new Product());
//
//        //批量插入和更新
//        ProductsCustomBatchRequest productsCustomBatchRequest = new ProductsCustomBatchRequest();
//        List<ProductsCustomBatchRequestEntry> updates = new ArrayList();
//        ProductsCustomBatchRequestEntry info = new ProductsCustomBatchRequestEntry();
//        info.setProduct(new Product());
//        productsCustomBatchRequest.setEntries(updates);
//        service.products().custombatch(productsCustomBatchRequest);
    }

方式二  生成jwt字符串  再掉接口取access  token

a.使用 jjwt 方式生成JWT

private static String getJwt() throws InvalidKeyException {
        String private_key = getPrivateKey(); //json文件中的private_key  记得删除 头和尾的不必要字符串
        long now = System.currentTimeMillis() / 1000;
        Map<String, Object> heads = new HashMap();
        heads.put("typ", "JWT");
        heads.put("alg", "RS256");

        System.out.println(JSON.toJSONString(heads));
        Claims claims = Jwts.claims();
        claims.put("iss", "[e-mail]");
        claims.put("scope", "https://www.googleapis.com/auth/content");
        claims.put("aud", "https://oauth2.googleapis.com/token");
        claims.put("exp", now + 3600 + "");
        claims.put("iat", now + "");
        System.out.println(JSON.toJSONString(claims));

        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.RS256;
        byte[] apikeys = DatatypeConverter.parseBase64Binary(private_key);
        Key key = RSAPrivateCrtKeyImpl.newKey(apikeys);

        String str = Jwts.builder()
                .setHeader(heads)
                .setClaims(claims)
                .setExpiration(new Date(System.currentTimeMillis() + 3600 * 1000)) //token保留的时间
                .signWith(signatureAlgorithm, key) //
                .compact();
        System.out.println(str);
        return str;
    }

 

public static String getPrivateKey(){

    String jsonStr = "";
    try {
        File jsonFile = new File("加密json问价路径");
        FileReader fileReader = new FileReader(jsonFile);
        Reader reader = new InputStreamReader(new FileInputStream(jsonFile),"utf-8");
        int ch = 0;
        StringBuffer sb = new StringBuffer();
        while ((ch = reader.read()) != -1) {
            sb.append((char) ch);
        }
        fileReader.close();
        reader.close();
        jsonStr = sb.toString();
        return JSON.parseObject(jsonStr).get("private_key").toString().replace("-----BEGIN PRIVATE KEY-----\n", "").replace("\n-----END PRIVATE KEY-----\n", "");

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

b.谷歌原生api生成jwt

 

private static String getJwt() throws GeneralSecurityException, IOException {
        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();

        GoogleCredential credential = GoogleCredential.fromStream(Demo3.class.getResourceAsStream("加密json文件路径"));
        credential.createScoped(Collections.singleton(ShoppingContentScopes.CONTENT));

        PrivateKey privateKey = credential.getServiceAccountPrivateKey();

        long now = System.currentTimeMillis() / 1000;

        JsonWebSignature.Header header = new JsonWebSignature.Header();
        header.put("typ", "JWT");
        header.put("alg", "RS256");

        System.out.println(JSON.toJSONString(header));

        JsonWebToken.Payload payload = new JsonWebSignature.Payload();
        payload.put("iss", "[e-mail]");
        payload.put("scope", "https://www.googleapis.com/auth/content");
        payload.put("aud", "https://oauth2.googleapis.com/token");
        payload.put("exp", now + 3600);
        payload.put("iat", now);

        System.out.println(JSON.toJSONString(payload));

        String s = JsonWebSignature.signUsingRsaSha256(privateKey, jsonFactory, header, payload);

        System.out.println(s);
        return s;
    }

google  根据jwt  生成  access  token 的接口

https://oauth2.googleapis.com/token

post请求  form表单形式提交参数

grant_type    urn:ietf:params:oauth:grant-type:jwt-bearer  (固定写法)

assertion   jwt字符串

pom相关

<dependencies>
        <dependency>
            <groupId>com.google.apis</groupId>
            <artifactId>google-api-services-oauth2</artifactId>
            <version>v2-rev20200213-1.30.9</version>
        </dependency>

        <dependency>
            <groupId>com.google.apis</groupId>
            <artifactId>google-api-services-content</artifactId>
            <version>v2.1-rev20200219-1.30.9</version>
        </dependency>

        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.10.0</version>
        </dependency>

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>

        <dependency>
            <groupId>com.google.http-client</groupId>
            <artifactId>google-http-client-jackson2</artifactId>
            <version>1.34.2</version>
        </dependency>
        <dependency>
            <groupId>com.google.oauth-client</groupId>
            <artifactId>google-oauth-client-jetty</artifactId>
            <version>1.30.6</version>
        </dependency>

        <dependency>
            <groupId>com.google.oauth-client</groupId>
            <artifactId>google-oauth-client-servlet</artifactId>
            <version>1.30.6</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>3.0-alpha-1</version>
        </dependency>
        <dependency>
            <groupId>com.google.api-client</groupId>
            <artifactId>google-api-client</artifactId>
            <version>1.30.9</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
        <dependency>
            <groupId>com.google.auth</groupId>
            <artifactId>google-auth-library-oauth2-http</artifactId>
            <version>0.20.0</version>
        </dependency>
    </dependencies>
 

千万注意账户对应权限   如果对应不上会导致很奇怪的问题