The Prelude Java SDK provides convenient access to the Prelude REST API from applications written in Java.
It is generated with Stainless.
The REST API documentation can be found on docs.prelude.so. Javadocs are available on javadoc.io.
implementation("so.prelude.sdk:prelude-java:0.5.0")
<dependency>
<groupId>so.prelude.sdk</groupId>
<artifactId>prelude-java</artifactId>
<version>0.5.0</version>
</dependency>
This library requires Java 8 or later.
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
import so.prelude.sdk.models.VerificationCreateParams;
import so.prelude.sdk.models.VerificationCreateResponse;
// Configures using the `API_TOKEN` and `PRELUDE_BASE_URL` environment variables
PreludeClient client = PreludeOkHttpClient.fromEnv();
VerificationCreateParams params = VerificationCreateParams.builder()
.target(VerificationCreateParams.Target.builder()
.type(VerificationCreateParams.Target.Type.PHONE_NUMBER)
.value("+30123456789")
.build())
.build();
VerificationCreateResponse verification = client.verification().create(params);
Configure the client using environment variables:
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
// Configures using the `API_TOKEN` and `PRELUDE_BASE_URL` environment variables
PreludeClient client = PreludeOkHttpClient.fromEnv();
Or manually:
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
.apiToken("My API Token")
.build();
Or using a combination of the two approaches:
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
// Configures using the `API_TOKEN` and `PRELUDE_BASE_URL` environment variables
.fromEnv()
.apiToken("My API Token")
.build();
See this table for the available options:
Setter | Environment variable | Required | Default value |
---|---|---|---|
apiToken |
API_TOKEN |
true | - |
baseUrl |
PRELUDE_BASE_URL |
true | "https://api.prelude.dev" |
Tip
Don't create more than one client in the same application. Each client has a connection pool and thread pools, which are more efficient to share between requests.
To send a request to the Prelude API, build an instance of some Params
class and pass it to the corresponding client method. When the response is received, it will be deserialized into an instance of a Java class.
For example, client.verification().create(...)
should be called with an instance of VerificationCreateParams
, and it will return an instance of VerificationCreateResponse
.
Each class in the SDK has an associated builder or factory method for constructing it.
Each class is immutable once constructed. If the class has an associated builder, then it has a toBuilder()
method, which can be used to convert it back to a builder for making a modified copy.
Because each class is immutable, builder modification will never affect already built class instances.
The default client is synchronous. To switch to asynchronous execution, call the async()
method:
import java.util.concurrent.CompletableFuture;
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
import so.prelude.sdk.models.VerificationCreateParams;
import so.prelude.sdk.models.VerificationCreateResponse;
// Configures using the `API_TOKEN` and `PRELUDE_BASE_URL` environment variables
PreludeClient client = PreludeOkHttpClient.fromEnv();
VerificationCreateParams params = VerificationCreateParams.builder()
.target(VerificationCreateParams.Target.builder()
.type(VerificationCreateParams.Target.Type.PHONE_NUMBER)
.value("+30123456789")
.build())
.build();
CompletableFuture<VerificationCreateResponse> verification = client.async().verification().create(params);
Or create an asynchronous client from the beginning:
import java.util.concurrent.CompletableFuture;
import so.prelude.sdk.client.PreludeClientAsync;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClientAsync;
import so.prelude.sdk.models.VerificationCreateParams;
import so.prelude.sdk.models.VerificationCreateResponse;
// Configures using the `API_TOKEN` and `PRELUDE_BASE_URL` environment variables
PreludeClientAsync client = PreludeOkHttpClientAsync.fromEnv();
VerificationCreateParams params = VerificationCreateParams.builder()
.target(VerificationCreateParams.Target.builder()
.type(VerificationCreateParams.Target.Type.PHONE_NUMBER)
.value("+30123456789")
.build())
.build();
CompletableFuture<VerificationCreateResponse> verification = client.verification().create(params);
The asynchronous client supports the same options as the synchronous one, except most methods return CompletableFuture
s.
The SDK defines methods that deserialize responses into instances of Java classes. However, these methods don't provide access to the response headers, status code, or the raw response body.
To access this data, prefix any HTTP method call on a client or service with withRawResponse()
:
import so.prelude.sdk.core.http.Headers;
import so.prelude.sdk.core.http.HttpResponseFor;
import so.prelude.sdk.models.VerificationCreateParams;
import so.prelude.sdk.models.VerificationCreateResponse;
VerificationCreateParams params = VerificationCreateParams.builder()
.target(VerificationCreateParams.Target.builder()
.type(VerificationCreateParams.Target.Type.PHONE_NUMBER)
.value("+30123456789")
.build())
.build();
HttpResponseFor<VerificationCreateResponse> verification = client.verification().withRawResponse().create(params);
int statusCode = verification.statusCode();
Headers headers = verification.headers();
You can still deserialize the response into an instance of a Java class if needed:
import so.prelude.sdk.models.VerificationCreateResponse;
VerificationCreateResponse parsedVerification = verification.parse();
The SDK throws custom unchecked exception types:
-
PreludeServiceException
: Base class for HTTP errors. See this table for which exception subclass is thrown for each HTTP status code:Status Exception 400 BadRequestException
401 UnauthorizedException
403 PermissionDeniedException
404 NotFoundException
422 UnprocessableEntityException
429 RateLimitException
5xx InternalServerException
others UnexpectedStatusCodeException
-
PreludeIoException
: I/O networking errors. -
PreludeInvalidDataException
: Failure to interpret successfully parsed data. For example, when accessing a property that's supposed to be required, but the API unexpectedly omitted it from the response. -
PreludeException
: Base class for all exceptions. Most errors will result in one of the previously mentioned ones, but completely generic errors may be thrown using the base class.
The SDK uses the standard OkHttp logging interceptor.
Enable logging by setting the PRELUDE_LOG
environment variable to info
:
$ export PRELUDE_LOG=info
Or to debug
for more verbose logging:
$ export PRELUDE_LOG=debug
The SDK depends on Jackson for JSON serialization/deserialization. It is compatible with version 2.13.4 or higher, but depends on version 2.18.2 by default.
The SDK throws an exception if it detects an incompatible Jackson version at runtime (e.g. if the default version was overridden in your Maven or Gradle config).
If the SDK threw an exception, but you're certain the version is compatible, then disable the version check using the checkJacksonVersionCompatibility
on PreludeOkHttpClient
or PreludeOkHttpClientAsync
.
Caution
We make no guarantee that the SDK works correctly when the Jackson version check is disabled.
The SDK automatically retries 2 times by default, with a short exponential backoff.
Only the following error types are retried:
- Connection errors (for example, due to a network connectivity problem)
- 408 Request Timeout
- 409 Conflict
- 429 Rate Limit
- 5xx Internal
The API may also explicitly instruct the SDK to retry or not retry a response.
To set a custom number of retries, configure the client using the maxRetries
method:
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
.fromEnv()
.maxRetries(4)
.build();
Requests time out after 1 minute by default.
To set a custom timeout, configure the method call using the timeout
method:
import so.prelude.sdk.models.VerificationCreateResponse;
VerificationCreateResponse verification = client.verification().create(
params, RequestOptions.builder().timeout(Duration.ofSeconds(30)).build()
);
Or configure the default for all method calls at the client level:
import java.time.Duration;
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
.fromEnv()
.timeout(Duration.ofSeconds(30))
.build();
To route requests through a proxy, configure the client using the proxy
method:
import java.net.InetSocketAddress;
import java.net.Proxy;
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
.fromEnv()
.proxy(new Proxy(
Proxy.Type.HTTP, new InetSocketAddress(
"https://example.com", 8080
)
))
.build();
The SDK consists of three artifacts:
prelude-java-core
- Contains core SDK logic
- Does not depend on OkHttp
- Exposes
PreludeClient
,PreludeClientAsync
,PreludeClientImpl
, andPreludeClientAsyncImpl
, all of which can work with any HTTP client
prelude-java-client-okhttp
- Depends on OkHttp
- Exposes
PreludeOkHttpClient
andPreludeOkHttpClientAsync
, which provide a way to constructPreludeClientImpl
andPreludeClientAsyncImpl
, respectively, using OkHttp
prelude-java
- Depends on and exposes the APIs of both
prelude-java-core
andprelude-java-client-okhttp
- Does not have its own logic
- Depends on and exposes the APIs of both
This structure allows replacing the SDK's default HTTP client without pulling in unnecessary dependencies.
Customized OkHttpClient
Tip
Try the available network options before replacing the default client.
To use a customized OkHttpClient
:
- Replace your
prelude-java
dependency withprelude-java-core
- Copy
prelude-java-client-okhttp
'sOkHttpClient
class into your code and customize it - Construct
PreludeClientImpl
orPreludeClientAsyncImpl
, similarly toPreludeOkHttpClient
orPreludeOkHttpClientAsync
, using your customized client
To use a completely custom HTTP client:
- Replace your
prelude-java
dependency withprelude-java-core
- Write a class that implements the
HttpClient
interface - Construct
PreludeClientImpl
orPreludeClientAsyncImpl
, similarly toPreludeOkHttpClient
orPreludeOkHttpClientAsync
, using your new client class
The SDK is typed for convenient usage of the documented API. However, it also supports working with undocumented or not yet supported parts of the API.
To set undocumented parameters, call the putAdditionalHeader
, putAdditionalQueryParam
, or putAdditionalBodyProperty
methods on any Params
class:
import so.prelude.sdk.core.JsonValue;
import so.prelude.sdk.models.VerificationCreateParams;
VerificationCreateParams params = VerificationCreateParams.builder()
.putAdditionalHeader("Secret-Header", "42")
.putAdditionalQueryParam("secret_query_param", "42")
.putAdditionalBodyProperty("secretProperty", JsonValue.from("42"))
.build();
These can be accessed on the built object later using the _additionalHeaders()
, _additionalQueryParams()
, and _additionalBodyProperties()
methods.
To set undocumented parameters on nested headers, query params, or body classes, call the putAdditionalProperty
method on the nested class:
import so.prelude.sdk.core.JsonValue;
import so.prelude.sdk.models.VerificationCreateParams;
VerificationCreateParams params = VerificationCreateParams.builder()
.target(VerificationCreateParams.Target.builder()
.putAdditionalProperty("secretProperty", JsonValue.from("42"))
.build())
.build();
These properties can be accessed on the nested built object later using the _additionalProperties()
method.
To set a documented parameter or property to an undocumented or not yet supported value, pass a JsonValue
object to its setter:
import so.prelude.sdk.core.JsonValue;
import so.prelude.sdk.models.VerificationCreateParams;
VerificationCreateParams params = VerificationCreateParams.builder()
.target(JsonValue.from(42))
.build();
The most straightforward way to create a JsonValue
is using its from(...)
method:
import java.util.List;
import java.util.Map;
import so.prelude.sdk.core.JsonValue;
// Create primitive JSON values
JsonValue nullValue = JsonValue.from(null);
JsonValue booleanValue = JsonValue.from(true);
JsonValue numberValue = JsonValue.from(42);
JsonValue stringValue = JsonValue.from("Hello World!");
// Create a JSON array value equivalent to `["Hello", "World"]`
JsonValue arrayValue = JsonValue.from(List.of(
"Hello", "World"
));
// Create a JSON object value equivalent to `{ "a": 1, "b": 2 }`
JsonValue objectValue = JsonValue.from(Map.of(
"a", 1,
"b", 2
));
// Create an arbitrarily nested JSON equivalent to:
// {
// "a": [1, 2],
// "b": [3, 4]
// }
JsonValue complexValue = JsonValue.from(Map.of(
"a", List.of(
1, 2
),
"b", List.of(
3, 4
)
));
Normally a Builder
class's build
method will throw IllegalStateException
if any required parameter or property is unset.
To forcibly omit a required parameter or property, pass JsonMissing
:
import so.prelude.sdk.core.JsonMissing;
import so.prelude.sdk.models.VerificationCreateParams;
VerificationCreateParams params = VerificationCreateParams.builder()
.target(JsonMissing.of())
.build();
To access undocumented response properties, call the _additionalProperties()
method:
import java.util.Map;
import so.prelude.sdk.core.JsonValue;
Map<String, JsonValue> additionalProperties = client.verification().create(params)._additionalProperties();
JsonValue secretPropertyValue = additionalProperties.get("secretProperty");
String result = secretPropertyValue.accept(new JsonValue.Visitor<>() {
@Override
public String visitNull() {
return "It's null!";
}
@Override
public String visitBoolean(boolean value) {
return "It's a boolean!";
}
@Override
public String visitNumber(Number value) {
return "It's a number!";
}
// Other methods include `visitMissing`, `visitString`, `visitArray`, and `visitObject`
// The default implementation of each unimplemented method delegates to `visitDefault`, which throws by default, but can also be overridden
});
To access a property's raw JSON value, which may be undocumented, call its _
prefixed method:
import java.util.Optional;
import so.prelude.sdk.core.JsonField;
import so.prelude.sdk.models.VerificationCreateParams;
JsonField<VerificationCreateParams.Target> target = client.verification().create(params)._target();
if (target.isMissing()) {
// The property is absent from the JSON response
} else if (target.isNull()) {
// The property was set to literal null
} else {
// Check if value was provided as a string
// Other methods include `asNumber()`, `asBoolean()`, etc.
Optional<String> jsonString = target.asString();
// Try to deserialize into a custom type
MyClass myObject = target.asUnknown().orElseThrow().convert(MyClass.class);
}
In rare cases, the API may return a response that doesn't match the expected type. For example, the SDK may expect a property to contain a String
, but the API could return something else.
By default, the SDK will not throw an exception in this case. It will throw PreludeInvalidDataException
only if you directly access the property.
If you would prefer to check that the response is completely well-typed upfront, then either call validate()
:
import so.prelude.sdk.models.VerificationCreateResponse;
VerificationCreateResponse verification = client.verification().create(params).validate();
Or configure the method call to validate the response using the responseValidation
method:
import so.prelude.sdk.models.VerificationCreateResponse;
VerificationCreateResponse verification = client.verification().create(
params, RequestOptions.builder().responseValidation(true).build()
);
Or configure the default for all method calls at the client level:
import so.prelude.sdk.client.PreludeClient;
import so.prelude.sdk.client.okhttp.PreludeOkHttpClient;
PreludeClient client = PreludeOkHttpClient.builder()
.fromEnv()
.responseValidation(true)
.build();
Java enum
classes are not trivially forwards compatible. Using them in the SDK could cause runtime exceptions if the API is updated to respond with a new enum value.
Using JsonField<T>
enables a few features:
- Allowing usage of undocumented API functionality
- Lazily validating the API response against the expected shape
- Representing absent vs explicitly null values
Why don't you use data
classes?
It is not backwards compatible to add new fields to a data class and we don't want to introduce a breaking change every time we add a field to a class.
Checked exceptions are widely considered a mistake in the Java programming language. In fact, they were omitted from Kotlin for this reason.
Checked exceptions:
- Are verbose to handle
- Encourage error handling at the wrong level of abstraction, where nothing can be done about the error
- Are tedious to propagate due to the function coloring problem
- Don't play well with lambdas (also due to the function coloring problem)
This package generally follows SemVer conventions, though certain backwards-incompatible changes may be released as minor versions:
- Changes to library internals which are technically public but not intended or documented for external use. (Please open a GitHub issue to let us know if you are relying on such internals.)
- Changes that we do not expect to impact the vast majority of users in practice.
We take backwards-compatibility seriously and work hard to ensure you can rely on a smooth upgrade experience.
We are keen for your feedback; please open an issue with questions, bugs, or suggestions.