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Node: get{Parent,Data}: return item or throw exception

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Previous, Optional, implementations have been renamed as find{Parent,Data}
This commit is contained in:
Paul Campbell 2017-02-18 18:29:36 +00:00
parent 4c4d3a9012
commit 543c91f611
10 changed files with 247 additions and 90 deletions
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42
src/main/java/net/kemitix/node/EmptyNodeException.java Normal file
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@ -0,0 +1,42 @@
/*
The MIT License (MIT)
Copyright (c) 2016 Paul Campbell
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
package net.kemitix.node;
/**
* Raised when an attempt is made to get the data from an empty node.
*
* @author Paul Campbell (pcampbell@kemitix.net)
*/
public class EmptyNodeException extends NodeException {
/**
* Constructor with message.
*
* @param message the message
*/
public EmptyNodeException(final String message) {
super(message);
}
}

18
src/main/java/net/kemitix/node/Node.java
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@ -59,7 +59,14 @@ public interface Node<T> {
*
* @return an Optional containing the node's data, or empty if the node has none
*/
Optional<T> getData();
Optional<T> findData();
/**
* Fetch the data held within the node.
*
* @return the node's data, or throws an {@link EmptyNodeException}
*/
T getData();
/**
* Set the data held within the node.
@ -80,7 +87,14 @@ public interface Node<T> {
*
* @return an Optional contain the parent node, or empty if a root node
*/
Optional<Node<T>> getParent();
Optional<Node<T>> findParent();
/**
* Fetch the parent node.
*
* @return the parent node, or throws an {@link OrphanedNodeException}
*/
Node<T> getParent();
/**
* Make the current node a direct child of the parent.

39
src/main/java/net/kemitix/node/NodeItem.java
View file

@ -42,7 +42,8 @@ import java.util.stream.Stream;
*
* @author Paul Campbell (pcampbell@kemitix.net)
*/
@ToString(exclude = "children")
@ToString(exclude = {"children", "data", "parent"})
@SuppressWarnings("methodcount")
class NodeItem<T> implements Node<T> {
private final Set<Node<T>> children = new HashSet<>();
@ -61,9 +62,7 @@ class NodeItem<T> implements Node<T> {
* @param parent the parent of the node, or null for a root node
* @param children the children of the node - must not be null
*/
NodeItem(
final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children
) {
NodeItem(final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children) {
this.data = data;
this.name = name;
if (parent != null) {
@ -92,10 +91,18 @@ class NodeItem<T> implements Node<T> {
}
@Override
public Optional<T> getData() {
public Optional<T> findData() {
return Optional.ofNullable(data);
}
@Override
public T getData() {
if (isEmpty()) {
throw new EmptyNodeException(getName());
}
return data;
}
@Override
public void setData(final T data) {
this.data = data;
@ -107,10 +114,18 @@ class NodeItem<T> implements Node<T> {
}
@Override
public Optional<Node<T>> getParent() {
public Optional<Node<T>> findParent() {
return Optional.ofNullable(parent);
}
@Override
public Node<T> getParent() {
if (parent == null) {
throw new OrphanedNodeException(getName());
}
return parent;
}
/**
* Make the current node a direct child of the parent.
*
@ -155,9 +170,9 @@ class NodeItem<T> implements Node<T> {
}
children.add(child);
// update the child's parent if they don't have one or it is not this
val childParent = child.getParent();
if (!childParent.isPresent() || !childParent.get()
.equals(this)) {
if (!child.findParent()
.filter(this::equals)
.isPresent()) {
child.setParent(this);
}
}
@ -214,8 +229,8 @@ class NodeItem<T> implements Node<T> {
@Override
public Optional<Node<T>> findChild(@NonNull final T child) {
return children.stream()
.filter(node -> child.equals(node.getData()
.orElseGet(() -> null)))
.filter(node -> child.equals(node.findData()
.orElse(null)))
.findFirst();
}
@ -283,7 +298,7 @@ class NodeItem<T> implements Node<T> {
val existing = childByName.get();
if (existing.isEmpty()) {
// place any data in the new node into the existing empty node
nodeItem.getData()
nodeItem.findData()
.ifPresent(existing::setData);
} else {
throw new NodeException("A non-empty node named '" + nodeItem.getName() + "' already exists here");

9
src/main/java/net/kemitix/node/Nodes.java
View file

@ -101,12 +101,12 @@ public final class Nodes {
* @return the immutable copy of the tree
*/
public static <T> Node<T> asImmutable(final Node<T> root) {
if (root.getParent()
if (root.findParent()
.isPresent()) {
throw new IllegalArgumentException("source must be the root node");
}
final Set<Node<T>> children = getImmutableChildren(root);
return ImmutableNodeItem.newRoot(root.getData()
return ImmutableNodeItem.newRoot(root.findData()
.orElse(null), root.getName(), children);
}
@ -120,11 +120,10 @@ public final class Nodes {
private static <T> Node<T> asImmutableChild(
final Node<T> source
) {
return ImmutableNodeItem.newChild(source.getData()
.orElse(null), source.getName(), source.getParent()
return ImmutableNodeItem.newChild(source.findData()
.orElse(null), source.getName(), source.findParent()
.orElse(null),
getImmutableChildren(source)
);
}
}

42
src/main/java/net/kemitix/node/OrphanedNodeException.java Normal file
View file

@ -0,0 +1,42 @@
/*
The MIT License (MIT)
Copyright (c) 2016 Paul Campbell
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
package net.kemitix.node;
/**
* Raised when an attempt is made to access the parent of a root node.
*
* @author Paul Campbell (pcampbell@kemitix.net)
*/
public class OrphanedNodeException extends NodeException {
/**
* Constructor with message.
*
* @param message the message
*/
public OrphanedNodeException(final String message) {
super(message);
}
}

29
src/test/java/net/kemitix/node/EmptyNodeExceptionTest.java Normal file
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@ -0,0 +1,29 @@
package net.kemitix.node;
import lombok.val;
import org.junit.Test;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
/**
* Tests for {@link EmptyNodeException}.
*
* @author pcampbell
*/
public class EmptyNodeExceptionTest {
/**
* Test that message provided to constructor is returned.
*/
@Test
public void shouldReturnConstructorMessage() {
//given
val message = "this is the message";
//when
val nodeException = new EmptyNodeException(message);
//then
assertThat(nodeException.getMessage(), is(message));
}
}

8
src/test/java/net/kemitix/node/ImmutableNodeItemTest.java
View file

@ -74,8 +74,8 @@ public class ImmutableNodeItemTest {
//given
immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("data"));
//then
assertThat(immutableNode.getParent()).as("immutableNode created without a parent has no parent")
.isEmpty();
assertThat(immutableNode.findParent()).as("immutableNode created without a parent has no parent")
.isEmpty();
}
@Test
@ -101,11 +101,11 @@ public class ImmutableNodeItemTest {
//then
// get the immutable node's child's parent
val immutableChild = immutableNode.getChildByName("child");
final Optional<Node<String>> optionalParent = immutableChild.getParent();
final Optional<Node<String>> optionalParent = immutableChild.findParent();
if (optionalParent.isPresent()) {
val p = optionalParent.get();
assertThat(p).hasFieldOrPropertyWithValue("name", "root")
.hasFieldOrPropertyWithValue("data", Optional.of("parent"));
.hasFieldOrPropertyWithValue("data", "parent");
}
}

117
src/test/java/net/kemitix/node/NodeItemTest.java
View file

@ -72,8 +72,8 @@ public class NodeItemTest {
//given
node = Nodes.unnamedRoot("data");
//then
assertThat(node.getParent()).as("node created without a parent has no parent")
.isEmpty();
assertThat(node.findParent()).as("node created without a parent has no parent")
.isEmpty();
}
/**
@ -86,8 +86,8 @@ public class NodeItemTest {
//when
node = Nodes.unnamedChild("subject", parent);
//then
assertThat(node.getParent()).as("node created with a parent can return the parent")
.contains(parent);
assertThat(node.findParent()).as("node created with a parent can return the parent")
.contains(parent);
}
@Test
@ -144,8 +144,8 @@ public class NodeItemTest {
//when
node.setParent(parent);
//then
assertThat(node.getParent()).as("when a node is assigned a new parent that parent can be " + "returned")
.contains(parent);
assertThat(node.findParent()).as("when a node is assigned a new parent that parent can be " + "returned")
.contains(parent);
}
/**
@ -188,8 +188,8 @@ public class NodeItemTest {
//when
child.setParent(newParent);
//then
assertThat(child.getParent()).as("when a node is assigned a new parent, the old parent is " + "replaced")
.contains(newParent);
assertThat(child.findParent()).as("when a node is assigned a new parent, the old parent is " + "replaced")
.contains(newParent);
assertThat(node.findChild("child")
.isPresent()).as(
"when a node is assigned a new parent, the old parent no " + "longer has the node among it's children")
@ -209,9 +209,9 @@ public class NodeItemTest {
//when
newParent.addChild(child);
//then
assertThat(child.getParent()).as("when a node with an existing parent is added as a child " +
"to another node, then the old parent is replaced")
.contains(newParent);
assertThat(child.findParent()).as("when a node with an existing parent is added as a child " +
"to another node, then the old parent is replaced")
.contains(newParent);
assertThat(node.findChild("child")
.isPresent()).as("when a node with an existing parent is added as a child to " +
"another node, then the old parent no longer has " +
@ -316,8 +316,8 @@ public class NodeItemTest {
//when
node.addChild(child);
//then
assertThat(child.getParent()).as("when a node is added as a child, the child has the node as " + "its parent")
.contains(node);
assertThat(child.findParent()).as("when a node is added as a child, the child has the node as " + "its parent")
.contains(node);
}
/**
@ -338,10 +338,9 @@ public class NodeItemTest {
//then
assertThat(result.isPresent()).as("when we walk the tree to a node it is found")
.isTrue();
if (result.isPresent()) {
assertThat(result.get()).as("when we walk the tree to a node the correct node is found")
.isSameAs(node);
}
result.ifPresent(
stringNode -> assertThat(stringNode).as("when we walk the tree to a node the correct node is found")
.isSameAs(node));
}
/**
@ -408,31 +407,27 @@ public class NodeItemTest {
val alphaOptional = node.findChild(alphaData);
assertThat(alphaOptional.isPresent()).as("when creating a descendant line, the first element is found")
.isTrue();
if (alphaOptional.isPresent()) {
val alpha = alphaOptional.get();
assertThat(alpha.getParent()).as(
"when creating a descendant line, the first element has " + "the current node as its parent")
.contains(node);
alphaOptional.ifPresent(alpha -> {
assertThat(alpha.findParent()).as(
"when creating a descendant line, the first element has the current node as its parent")
.contains(node);
val betaOptional = alpha.findChild(betaData);
assertThat(betaOptional.isPresent()).as("when creating a descendant line, the second element is " + "found")
assertThat(betaOptional.isPresent()).as("when creating a descendant line, the second element is found")
.isTrue();
if (betaOptional.isPresent()) {
val beta = betaOptional.get();
assertThat(beta.getParent()).as(
"when creating a descendant line, the second element " + "has the first as its parent")
.contains(alpha);
betaOptional.ifPresent(beta -> {
assertThat(beta.findParent()).as(
"when creating a descendant line, the second element has the first as its parent")
.contains(alpha);
val gammaOptional = beta.findChild(gammaData);
assertThat(gammaOptional.isPresent()).as(
"when creating a descendant line, the third element " + "is found")
assertThat(gammaOptional.isPresent()).as("when creating a descendant line, the third element is found")
.isTrue();
if (gammaOptional.isPresent()) {
val gamma = gammaOptional.get();
assertThat(gamma.getParent()).as(
"when creating a descendant line, the third " + "element has the second as its parent")
.contains(beta);
}
}
}
gammaOptional.ifPresent(gamma -> {
assertThat(gamma.findParent()).as(
"when creating a descendant line, the third element has the second as its parent")
.contains(beta);
});
});
});
}
/**
@ -478,10 +473,9 @@ public class NodeItemTest {
//then
assertThat(found.isPresent()).as("when retrieving a child by its data, it is found")
.isTrue();
if (found.isPresent()) {
assertThat(found.get()).as("when retrieving a child by its data, it is the expected " + "node")
.isSameAs(child);
}
found.ifPresent(
stringNode -> assertThat(stringNode).as("when retrieving a child by its data, it is the expected node")
.isSameAs(child));
}
/**
@ -509,17 +503,14 @@ public class NodeItemTest {
//when
val child = node.createChild(childData);
//then
assertThat(child.getParent()).as(
"when creating a child node, the child has the current node " + "as its parent")
.contains(node);
assertThat(child.findParent()).as("when creating a child node, the child has the current node as its parent")
.contains(node);
val foundChild = node.findChild(childData);
assertThat(foundChild.isPresent()).as("when creating a child node, the child can be found by its " + "data")
assertThat(foundChild.isPresent()).as("when creating a child node, the child can be found by its data")
.isTrue();
if (foundChild.isPresent()) {
assertThat(foundChild.get()).as(
"when creating a child node, the correct child can be " + "found by its data")
.isSameAs(child);
}
foundChild.ifPresent(stringNode -> assertThat(stringNode).as(
"when creating a child node, the correct child can be found by its data")
.isSameAs(child));
}
/**
@ -538,7 +529,7 @@ public class NodeItemTest {
@Test
public void canCreateRootNodeWithoutData() {
node = Nodes.namedRoot(null, "empty");
assertThat(node.getData()).isEmpty();
assertThat(node.findData()).isEmpty();
}
@Test
@ -590,19 +581,15 @@ public class NodeItemTest {
//when
node.insertInPath(four, "one", "two", "three");
//then
val three = four.getParent()
.get();
val three = four.getParent();
assertThat(four.getParent()).as("add node to a tree")
.isNotNull();
assertThat(three.getName()).isEqualTo("three");
val two = three.getParent()
.get();
val two = three.getParent();
assertThat(two.getName()).isEqualTo("two");
val one = two.getParent()
.get();
val one = two.getParent();
assertThat(one.getName()).isEqualTo("one");
assertThat(one.getParent()
.get()).isSameAs(node);
assertThat(one.getParent()).isSameAs(node);
assertThat(node.getChildByName("one")
.getChildByName("two")
.getChildByName("three")
@ -662,7 +649,7 @@ public class NodeItemTest {
//when
child.removeParent();
//then
assertThat(child.getParent()).isEmpty();
assertThat(child.findParent()).isEmpty();
assertThat(node.getChildren()).isEmpty();
}
@ -703,7 +690,7 @@ public class NodeItemTest {
node.addChild(child);
child.addChild(target);
val addMe = Nodes.namedRoot("I'm new", "target");
assertThat(addMe.getParent()).isEmpty();
assertThat(addMe.findParent()).isEmpty();
assertThat(child.getChildByName("target")
.isEmpty()).as("target starts empty")
.isTrue();
@ -761,7 +748,7 @@ public class NodeItemTest {
node.removeChild(child);
//then
assertThat(node.getChildren()).isEmpty();
assertThat(child.getParent()).isEmpty();
assertThat(child.findParent()).isEmpty();
}
@Test
@ -803,7 +790,7 @@ public class NodeItemTest {
Node<String> child = node.createChild("child data", "child name");
//then
assertThat(child.getName()).isEqualTo("child name");
assertThat(child.getParent()).contains(node);
assertThat(child.findParent()).contains(node);
assertThat(node.getChildren()).containsExactly(child);
}
@ -836,7 +823,7 @@ public class NodeItemTest {
//when
val child = Nodes.unnamedChild("child data", node);
//then
assertThat(child.getParent()).contains(node);
assertThat(child.findParent()).contains(node);
assertThat(node.getChildren()).containsExactly(child);
}

4
src/test/java/net/kemitix/node/NodesTest.java
View file

@ -44,7 +44,7 @@ public class NodesTest {
SoftAssertions softly = new SoftAssertions();
softly.assertThat(node.getData()).contains("data");
softly.assertThat(node.getName()).isEmpty();
softly.assertThat(node.getParent()).contains(parent);
softly.assertThat(node.findParent()).contains(parent);
softly.assertAll();
}
@ -55,7 +55,7 @@ public class NodesTest {
SoftAssertions softly = new SoftAssertions();
softly.assertThat(node.getData()).contains("data");
softly.assertThat(node.getName()).isEqualTo("child");
softly.assertThat(node.getParent()).contains(parent);
softly.assertThat(node.findParent()).contains(parent);
softly.assertAll();
}

29
src/test/java/net/kemitix/node/OrphanedNodeExceptionTest.java Normal file
View file

@ -0,0 +1,29 @@
package net.kemitix.node;
import lombok.val;
import org.junit.Test;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
/**
* Tests for {@link OrphanedNodeException}.
*
* @author pcampbell
*/
public class OrphanedNodeExceptionTest {
/**
* Test that message provided to constructor is returned.
*/
@Test
public void shouldReturnConstructorMessage() {
//given
val message = "this is the message";
//when
val nodeException = new OrphanedNodeException(message);
//then
assertThat(nodeException.getMessage(), is(message));
}
}