如何在Java代码中使用SAP云平台CloudFoundry环境的环境变量

本文使用的例子源代码在我的github上。

让客户满意是我们工作的目标，不断超越客户的期望值来自于我们对这个行业的热爱。我们立志把好的技术通过有效、简单的方式提供给客户，将通过不懈努力成为客户在信息化领域值得信任、有价值的长期合作伙伴，公司提供的服务项目有：域名与空间、雅安服务器托管、营销软件、网站建设、平桂网站维护、网站推广。

在我的公众号文章在SAP云平台的CloudFoundry环境下消费ABAP On-Premise OData服务介绍了如何通过Cloud Connector连接ABAP On-Premise系统。

我创建了三个service的实例，详情如上图和下表：

这三个服务实例的名称维护在应用的manifest.xml中。

将应用使用cf push部署到CloudFoundry之后，在Cockpit里能观察到生成的系统变量VCAP_SERVICES:

在Java代码里，使用如下代码将该环境变量的值读取出来存储到字符串中。

 private static final String VCAP_SERVICES = System.getenv("VCAP_SERVICES"); 

该Json对象的具体字段通过getJSONObject读取出来。

下图是connectivity实例的credentials明细：

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附录

VCAP_SERVICES全部内容：

 { "VCAP_SERVICES": { "xsuaa": [
            { "name": "xsuaa-jerry-demo", "instance_name": "xsuaa-jerry-demo", "binding_name": null, "credentials": { "uaadomain": "authentication.eu10.hana.ondemand.com", "tenantmode": "dedicated", "sburl": "https://internal-xsuaa.authentication.eu10.hana.ondemand.com", "clientid": "sb-connectivity-jerry-demo!t3704", "verificationkey": "-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----", "xsappname": "connectivity-jerry-demo!t3704", "identityzone": "jerry", "identityzoneid": "f3bd7f84-ebf1-4c11-b7c7-a278ebd54dcb", "clientsecret": "WAxzZxYQCgB7Dkml8dFdU+kaLSE=", "tenantid": "f3bd7f84-ebf1-4c11-b7c7-a278ebd54dcb", "url": "https://jerry.authentication.eu10.hana.ondemand.com" }, "syslog_drain_url": null, "volume_mounts": [], "label": "xsuaa", "provider": null, "plan": "application", "tags": [ "xsuaa" ]
            }
        ], "connectivity": [
            { "name": "connectivity-jerry-demo", "instance_name": "connectivity-jerry-demo", "binding_name": null, "credentials": { "uaadomain": "authentication.eu10.hana.ondemand.com", "onpremise_proxy_port": "20003", "tenantmode": "dedicated", "clientid": "sb-clone5282c913c9164bb284239adcc4d74210!b3704|connectivity!b17", "verificationkey": "-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----", "xsappname": "clone5282c913c9164bb284239adcc4d74210!b3704|connectivity!b17", "identityzone": "jerry", "clientsecret": "nyiGD9QQSOZO+NTeEJdexWWjxYY=", "tenantid": "f3bd7f84-ebf1-4c11-b7c7-a278ebd54dcb", "url": "https://jerry.authentication.eu10.hana.ondemand.com", "onpremise_proxy_host": "10.0.85.1" }, "syslog_drain_url": null, "volume_mounts": [], "label": "connectivity", "provider": null, "plan": "lite", "tags": [ "connectivity", "conn", "connsvc" ]
            }
        ], "destination": [
            { "name": "jerry-destination-lite", "instance_name": "jerry-destination-lite", "binding_name": null, "credentials": { "uaadomain": "authentication.eu10.hana.ondemand.com", "tenantmode": "dedicated", "clientid": "sb-clone39a01503ac1845fbbda5d5ffccb1a469!b3704|destination-xsappname!b404", "instanceid": "39a01503-ac18-45fb-bda5-d5ffccb1a469", "verificationkey": "-----BEGIN PUBLIC KEY-----MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAwThn6OO9kj0bchkOGkqYBnV1dQ3zU/xtj7Kj7nDd8nyRMcEWCtVzrzjzhiisRhlrzlRIEY82wRAZNGKMnw7cvCwNixcfcDJnjzgr2pJ+5/yDZUc0IXXyIWPZD+XdL+0EogC3d4+fqyvg/BF/F0t2hKHWr/UTXE6zrGhBKaL0d8rKfYd6olGWigFd+3+24CKI14zWVxUBtC+P9Fhngc9DRzkXqhxOK/EKn0HzSgotf5duq6Tmk9DCNM4sLW4+ERc6xzrgbeEexakabvax/Az9WZ4qhwgw+fwIhKIC7WLwCEJaRsW4m7NKkv+eJR2LKYesuQ9SVAJ3EXV86RwdnH4uAv7lQHsKURPVAQBlranSqyQu0EXs2N9OlWTxe+FyNkIvyZvoLrZl/CdlYc8AKxRm5rn2/88nkrYQ0XZSrnICM5FRWgVF2hn5KfZGwtBN85/D4Yck6B3ocMfyX7e4URUm9lRPQFUJGTXaZnEIge0R159HUwhTN1HvyXrs6uT1ZZmW+c3p47dw1+LmUf/hIf8zd+uvHQjIeHEJqxjqfyA8yqAFKRHKVFrwnwdMHIsRap2EKBhHMfeVf0P2th6C9MggYoGCvdIaIUgMBX3TtCdvGrcWML7hnyS2zkrlA8SoKJnRcRF2KxWKs355FhpHpzqyZflO5l98+O8wOsFjGpL9d0ECAwEAAQ==-----END PUBLIC KEY-----", "xsappname": "clone39a01503ac1845fbbda5d5ffccb1a469!b3704|destination-xsappname!b404", "identityzone": "jerry", "clientsecret": "QCnO+2k8gvUkdTyiCZI5rhzylbQ=", "tenantid": "f3bd7f84-ebf1-4c11-b7c7-a278ebd54dcb", "uri": "https://destination-configuration.cfapps.eu10.hana.ondemand.com", "url": "https://jerry.authentication.eu10.hana.ondemand.com" }, "syslog_drain_url": null, "volume_mounts": [], "label": "destination", "provider": null, "plan": "lite", "tags": [ "destination", "document" ]
            }
        ], "application-logs": [
            { "name": "jerry-log", "instance_name": "jerry-log", "binding_name": null, "credentials": {}, "syslog_drain_url": "https://10.0.104.16: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", "volume_mounts": [], "label": "application-logs", "provider": null, "plan": "lite", "tags": []
            }
        ]
    }
}
{ "VCAP_APPLICATION": { "cf_api": "https://api.cf.eu10.hana.ondemand.com", "limits": { "fds": 16384, "mem": 512, "disk": 1024 }, "application_name": "connectivity-jerry-demo", "application_uris": [ "connectivity-jerry-demo-i042416.cfapps.eu10.hana.ondemand.com" ], "name": "connectivity-jerry-demo", "space_name": "dev", "space_id": "69abfd46-d228-4903-b245-de88ceff3642", "uris": [ "connectivity-jerry-demo-i042416.cfapps.eu10.hana.ondemand.com" ], "users": null, "application_id": "fa893f26-69ee-4a4a-aa04-8f8ae0676475", "version": "d964d7cc-e067-4810-b834-25c995fe1bc5", "application_version": "d964d7cc-e067-4810-b834-25c995fe1bc5" }
} 

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