This article explains how to implement handling and validation of common parameter into the Policy Framework Components using Spring boot framework.
A component can use org.springframework.core.env.Environment component directly.
Environment component is not a good approach because there is not type conversion and error checking, but it could be useful when the name of the property you need to access changes dynamically.
@Component
@RequiredArgsConstructor
public class Example {
private Environment env;
....
public void method(String pathPropertyName) {
.....
String path = env.getProperty(pathPropertyName);
.....
}
A component can use org.springframework.beans.factory.annotation.Value, which reads from properties, performs a type conversion and injects the value into the filed. There is not error checking, but it can assign default value if the property is not defined.
@Value("${security.enable-csrf:true}")
private boolean csrfEnabled = true;
Other approach using property configuration.
@Scheduled(
fixedRateString = "${runtime.participantParameters.heartBeatMs}",
initialDelayString = "${runtime.participantParameters.heartBeatMs}")
public void schedule() {
}
@ConfigurationProperties can be used to map values from .properties( .yml also supported) to a POJO. It performs all type conversion and error checking using validation javax.validation.constraints
@Validated
@Getter
@Setter
@ConfigurationProperties(prefix = "runtime")
public class ClRuntimeParameterGroup {
@Min(100)
private long heartBeatMs;
@Valid
@Positive
private long reportingTimeIntervalMs;
@Valid
@NotNull
private ParticipantUpdateParameters updateParameters;
@NotBlank
private String description;
}
Convert org.onap.policy.common.parameters.BeanValidationResult to Spring validator using org.onap.policy.common.parameters.validation.ParameterGroupConstraint
@NotNull
@ParameterGroupConstraint
private TopicParameterGroup topicParameterGroup;
ClRuntimeParameterGroup defined before could be injected into components.
@Component
@RequiredArgsConstructor
public class Example {
private ClRuntimeParameterGroup parameters;
....
public void method() {
.....
long heartBeatMs = parameters.getHeartBeatMs();
.....
}