/*
* Copyright 2011-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.
*/
package com.amazonaws.services.stepfunctions.builder.states;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.stepfunctions.builder.internal.PropertyNames;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonUnwrapped;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
/**
* The Pass State simply passes its input to its output, performing no work. Pass States are useful when constructing and
* debugging state machines.
*
* <p>A Pass State MAY have a field named “Result”. If present, its value is treated as the output of a virtual task, and placed
* as prescribed by the “ResultPath” field, if any, to be passed on to the next state.</p>
*
* @see <a href="https://states-language.net/spec.html#pass-state">https://states-language.net/spec.html#pass-state</a>
*/
public final class PassState extends TransitionState {
/**
* Disable Jackson specific features like annotations. Support only
* basic POJO serialization to limit our coupling to Jackson.
*/
private static final ObjectMapper MAPPER = new ObjectMapper()
.disable(MapperFeature.USE_ANNOTATIONS)
.disable(MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS)
.disable(MapperFeature.AUTO_DETECT_FIELDS);
@JsonProperty(PropertyNames.COMMENT)
private final String comment;
@JsonProperty(PropertyNames.RESULT)
private final JsonNode result;
@JsonUnwrapped
private final PathContainer pathContainer;
@JsonUnwrapped
private final Transition transition;
private PassState(Builder builder) {
this.comment = builder.comment;
this.result = builder.result;
this.pathContainer = builder.pathContainer.build();
this.transition = builder.transition.build();
}
/**
* @return Type identifier of {@link PassState}.
*/
@Override
public String getType() {
return "Pass";
}
/**
* @return Human readable description for the state.
*/
public String getComment() {
return comment;
}
/**
* @return String containing JSON document of the state's "virtual" result.
*/
@JsonIgnore
public String getResult() {
try {
return result == null ? null : MAPPER.writeValueAsString(result);
} catch (JsonProcessingException e) {
throw new SdkClientException("Could not serialize result", e);
}
}
/**
* @return The input path expression that may optionally transform the input to this state.
*/
@JsonIgnore
public String getInputPath() {
return pathContainer.getInputPath();
}
/**
* @return The output path expression that may optionally transform the output to this state.
*/
@JsonIgnore
public String getOutputPath() {
return pathContainer.getOutputPath();
}
/**
* @return The result path expression that may optionally combine or replace the state's raw input with it's result.
*/
@JsonIgnore
public String getResultPath() {
return pathContainer.getResultPath();
}
/**
* @return The {@link Transition} for this state.
*/
public Transition getTransition() {
return transition;
}
@Override
public <T> T accept(StateVisitor<T> visitor) {
return visitor.visit(this);
}
/**
* @return Builder instance to construct a {@link PassState}.
*/
public static Builder builder() {
return new Builder();
}
/**
* Builder for a {@link PassState}.
*/
public static final class Builder extends TransitionStateBuilder implements InputOutputResultPathBuilder<Builder> {
@JsonProperty(PropertyNames.COMMENT)
private String comment;
@JsonProperty(PropertyNames.RESULT)
private JsonNode result;
private final PathContainer.Builder pathContainer = PathContainer.builder();
private Transition.Builder transition = Transition.NULL_BUILDER;
private Builder() {
}
/**
* OPTIONAL. Human readable description for the state.
*
* @param comment New comment.
* @return This object for method chaining.
*/
public Builder comment(String comment) {
this.comment = comment;
return this;
}
/**
* OPTIONAL. Sets the "virtual" result of the pass state. Must be a POJO that can be serialized into JSON.
*
* @param result Object that will be serialized into the JSON document representing this states result.
* @return This object for method chaining.
*/
public Builder result(Object result) {
this.result = MAPPER.valueToTree(result);
return this;
}
/**
* OPTIONAL. Sets the "virtual" result of the pass state. Must be a valid JSON document.
*
* @param result JSON result represented as a string.
* @return This object for method chaining.
*/
public Builder result(String result) {
try {
this.result = MAPPER.readTree(result);
} catch (IOException e) {
throw new SdkClientException("Result must be a JSON document", e);
}
return this;
}
@Override
public Builder inputPath(String inputPath) {
pathContainer.inputPath(inputPath);
return this;
}
@Override
public Builder outputPath(String outputPath) {
pathContainer.outputPath(outputPath);
return this;
}
@Override
public Builder resultPath(String resultPath) {
pathContainer.resultPath(resultPath);
return this;
}
/**
* REQUIRED. Sets the transition that will occur when this state completes successfully.
*
* @param transition New transition.
* @return This object for method chaining.
*/
public Builder transition(Transition.Builder transition) {
this.transition = transition;
return this;
}
/**
* @return An immutable {@link PassState} object.
*/
public PassState build() {
return new PassState(this);
}
}
}