com.vaadin.data.SimpleResult Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.data;
import java.util.Objects;
import java.util.Optional;
import com.vaadin.server.SerializableConsumer;
import com.vaadin.server.SerializableFunction;
/**
* An internal implementation of {@code Result}.
*
* @param
* the result value type
*
* @since 8.0
*/
class SimpleResult implements Result {
private final R value;
private final String message;
/**
* Creates a new {@link Result} instance using {@code value} for a non error
* {@link Result} and {@code message} for an error {@link Result}.
*
* If {@code message} is null then {@code value} is ignored and result is an
* error.
*
* @param value
* the value of the result, may be {@code null}
* @param message
* the error message of the result, may be {@code null}
*/
SimpleResult(R value, String message) {
// value != null => message == null
assert value == null
|| message == null : "Message must be null if value is provided";
this.value = value;
this.message = message;
}
@Override
@SuppressWarnings("unchecked")
public Result flatMap(SerializableFunction> mapper) {
Objects.requireNonNull(mapper, "mapper cannot be null");
if (isError()) {
// Safe cast; valueless
return (Result) this;
} else {
return mapper.apply(value);
}
}
@Override
public void handle(SerializableConsumer ifOk,
SerializableConsumer ifError) {
Objects.requireNonNull(ifOk, "ifOk cannot be null");
Objects.requireNonNull(ifError, "ifError cannot be null");
if (isError()) {
ifError.accept(message);
} else {
ifOk.accept(value);
}
}
@Override
public Optional getMessage() {
return Optional.ofNullable(message);
}
@Override
public boolean isError() {
return message != null;
}
@Override
public String toString() {
if (isError()) {
return "error(" + message + ")";
} else {
return "ok(" + value + ")";
}
}
@Override
public R getOrThrow(
SerializableFunction exceptionSupplier)
throws X {
Objects.requireNonNull(exceptionSupplier,
"Exception supplier cannot be null");
if (isError()) {
throw exceptionSupplier.apply(message);
} else {
return value;
}
}
}