JarCastingValidation mapper
Powerful reflection-based data validator. Mostly used for mapping and validating network-layer models
Install
Base library 
implementation "ru.ztrap.tools:validate-mapper:${latestVersion}"
Common checks 
implementation "ru.ztrap.tools:validate-mapper-common:${latestVersion}"
Gson extension 
implementation "ru.ztrap.tools:validate-mapper-gson:${latestVersion}"
Usage
1. Basics
Let's imagine we have a simple Message model which contains id, senderId, text and attachmentUrl. Fields id and senderId should not be empty or blank, text and attachmentUrl are not required and can be null. In code, it will be represented like this:
data class MessageNetworkEntity(
@Checks(NotBlankStringCheck::class)
val id: String?,
@Checks(NotBlankStringCheck::class)
val senderId: String?,
@Checks(NotBlankStringCheck::class)
val text: String?,
@NotRequired
val attachmentUrl: String?
) {
companion object : ValidateMapper<MessageNetworkEntity, MessageDomainEntity>() {
override fun transform(raw: MessageNetworkEntity) = MessageDomainEntity(
id = requireNotNull(raw.id),
text = raw.text,
senderId = requireNotNull(raw.senderId),
attachmentUrl = raw.attachmentUrl
)
}
}
data class MessageDomainEntity(
val id: String,
val text: String,
val senderId: String,
val attachmentUrl: String?
)
We can validate this network model with:
val networkMessage = MessageNetworkEntity(
id = "7c0518f7-874d-4dd7-89b6-af0adf0699a1",
senderId = "347da584-9f8c-4b47-b912-f9f2af0a6417",
text = "Hello!",
attachmentUrl = "https://avatars.githubusercontent.com/u/18091396?s=460&u=72fb5fb2f4d8a2ef3b6195ee371a130532656095&v=4"
)
val domainMessage = networkMessage.validateMap(MessageNetworkEntity)
If some constraint is not met, validateMap will throw a FailedValidationException and provide detailed explanation of what is not met. Example:
val networkMessage = MessageNetworkEntity(
id = "",
senderId = " ",
text = null,
attachmentUrl = "https://avatars.githubusercontent.com/u/18091396?s=460&u=72fb5fb2f4d8a2ef3b6195ee371a130532656095&v=4"
)
val domainMessage = networkMessage.validateMap(MessageNetworkEntity)
Will throw exception with following message:
ru.ztrap.tools.validate.mapper.FailedValidationException: Failed validation of received object.
Object -> MessageNetworkEntity(id=, senderId= , text=null, attachmentUrl=https://avatars.githubusercontent.com/u/18091396?s=460&u=72fb5fb2f4d8a2ef3b6195ee371a130532656095&v=4)
Params -> id ------- Reasons -> [{reason="empty string"}],
senderId - Reasons -> [{reason="blank string"}],
text ----- Reasons -> [{reason="value is null"}]
...
2. Parametrized checks
You can provide named parameters into any ValidateChecker via any of this annotations
annotation class StringParameter(val name: String, val value: String)
annotation class ByteParameter(val name: String, val value: Byte)
annotation class ShortParameter(val name: String, val value: Short)
annotation class IntParameter(val name: String, val value: Int)
annotation class LongParameter(val name: String, val value: Long)
annotation class FloatParameter(val name: String, val value: Float)
annotation class DoubleParameter(val name: String, val value: Double)
annotation class KClassParameter(val name: String, val value: KClass<*>)
Let's add length checks to unique id fields:
private const val MAX_UUID_LENGTH = 36L
data class MessageNetworkEntity(
@CheckParametrized(
expressionClass = TrimmedStringLengthCheck::class,
long = [
CheckParametrized.LongParameter(TrimmedStringLengthCheck.MAX_LIMIT_LONG, MAX_UUID_LENGTH),
CheckParametrized.LongParameter(TrimmedStringLengthCheck.MIN_LIMIT_LONG, MAX_UUID_LENGTH)
]
)
val id: String?,
@CheckParametrized(
expressionClass = TrimmedStringLengthCheck::class,
long = [
CheckParametrized.LongParameter(TrimmedStringLengthCheck.MAX_LIMIT_LONG, MAX_UUID_LENGTH),
CheckParametrized.LongParameter(TrimmedStringLengthCheck.MIN_LIMIT_LONG, MAX_UUID_LENGTH)
]
)
val senderId: String?,
...
)
And validate:
val networkMessage = MessageNetworkEntity(
id = "52b1c9c5-3cb2-41f0", // invalid
senderId = "52b1c9c5-3cb2-41f0-adff-1b0da5cffeee",
text = null,
attachmentUrl = "https://avatars.githubusercontent.com/u/18091396?s=460&u=72fb5fb2f4d8a2ef3b6195ee371a130532656095&v=4"
)
val domainMessage = networkMessage.validateMap(MessageNetworkEntity)
As result, we get thrown exception with following message:
ru.ztrap.tools.validate.mapper.FailedValidationException: Failed validation of received object.
Object -> MessageNetworkEntity(id=52b1c9c5-3cb2-41f0, senderId=52b1c9c5-3cb2-41f0-adff-1b0da5cffeee, text=null, attachmentUrl=https://avatars.githubusercontent.com/u/18091396?s=460&u=72fb5fb2f4d8a2ef3b6195ee371a130532656095&v=4)
Params -> id - Reasons -> [{reason="length not in limits", values=[min_limit=36, max_limit=36, current_length=18]}]
...
3. Global configuration
You can define checks for all fields with provided type. For example, we expect all strings can't be blank.
ValidateMapper.addGlobalCheck(String::class, NotBlankStringCheck::class)
In some cases you may want to exclude checks from global pool for some field. You can simply do this with:
data class MessageNetworkEntity(
@ExcludeCkecks(NotBlankStringCheck::class)
val text: String?,
...
)
Also, you can provide field name extractor. Actual for models parsed from json. Example you can find here
Developed By
- Peter Gulko
- [email protected]
- paypal.me/zTrap
License
Copyright 2021 zTrap
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.