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Merge pull request #20 from kemitix/merge-nodeitem-into-abstract

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Make ImmutableNodeItem an extension of NodeItem
This commit is contained in:
Paul Campbell 2016-09-20 23:23:16 +01:00 committed by GitHub
commit e61f6db9cf
8 changed files with 64 additions and 363 deletions
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183
src/main/java/net/kemitix/node/AbstractNodeItem.java
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@ -1,183 +0,0 @@
/*
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;
import lombok.NonNull;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
/**
* An abstract node item, providing default implementations for most read-only
* operations.
*
* @param <T> the type of data stored in each node
*
* @author Paul Campbell (pcampbell@kemitix.net)
*/
abstract class AbstractNodeItem<T> implements Node<T> {
private final Set<Node<T>> children;
private T data;
private String name;
private Node<T> parent;
/**
* Constructor.
*
* @param data the data of the node
* @param name the name of the node
* @param parent the parent of the node, or null for a root node
* @param children the children of the node - must not be null
*/
protected AbstractNodeItem(
final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children
) {
this.data = data;
this.name = name;
this.parent = parent;
this.children = children;
}
@Override
public String getName() {
return name;
}
@Override
public Optional<T> getData() {
return Optional.ofNullable(data);
}
@Override
public boolean isEmpty() {
return data == null;
}
@Override
public Optional<Node<T>> getParent() {
return Optional.ofNullable(parent);
}
@Override
public Set<Node<T>> getChildren() {
return new HashSet<>(children);
}
/**
* Fetches the node for the child if present.
*
* @param child the child's data to search for
*
* @return an {@link Optional} containing the child node if found
*/
@Override
public Optional<Node<T>> findChild(@NonNull final T child) {
return children.stream()
.filter(node -> {
final Optional<T> d = node.getData();
return d.isPresent() && d.get()
.equals(child);
})
.findAny();
}
@Override
public Node<T> getChild(final T child) {
return findChild(child).orElseThrow(() -> new NodeException("Child not found"));
}
/**
* Checks if the node is an ancestor.
*
* @param node the potential ancestor
*
* @return true if the node is an ancestor
*/
@Override
public boolean isDescendantOf(final Node<T> node) {
return parent != null && (node.equals(parent) || parent.isDescendantOf(node));
}
/**
* Walks the node tree using the path to select each child.
*
* @param path the path to the desired child
*
* @return the child or null
*/
@Override
public Optional<Node<T>> findInPath(@NonNull final List<T> path) {
if (path.isEmpty()) {
return Optional.empty();
}
Node<T> current = this;
for (int i = 0, pathSize = path.size(); i < pathSize && current != null; i++) {
current = current.findChild(path.get(i))
.orElse(null);
}
return Optional.ofNullable(current);
}
@Override
public Optional<Node<T>> findChildByName(@NonNull final String named) {
return children.stream()
.filter(n -> n.getName()
.equals(named))
.findAny();
}
@Override
public Node<T> getChildByName(final String named) {
return findChildByName(named).orElseThrow(() -> new NodeException("Named child not found"));
}
@Override
public String drawTree(final int depth) {
final StringBuilder sb = new StringBuilder();
final String unnamed = "(unnamed)";
if (isNamed()) {
sb.append(formatByDepth(name, depth));
} else if (!children.isEmpty()) {
sb.append(formatByDepth(unnamed, depth));
}
getChildren().forEach(c -> sb.append(c.drawTree(depth + 1)));
return sb.toString();
}
private String formatByDepth(final String value, final int depth) {
return String.format("[%1$" + (depth + value.length()) + "s]\n", value);
}
@Override
public boolean isNamed() {
return name != null && name.length() > 0;
}
}

11
src/main/java/net/kemitix/node/ImmutableNodeItem.java
View file

@ -39,14 +39,15 @@ import java.util.Set;
*
* @author Paul Campbell (pcampbell@kemitix.net)
*/
final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
final class ImmutableNodeItem<T> extends NodeItem<T> {
private static final String IMMUTABLE_OBJECT = "Immutable object";
private ImmutableNodeItem(
final T data, final String name, final Node<T> parent, final Set<Node<T>> children
) {
super(data, name, parent, children);
super(data, name, null, children);
forceParent(parent);
}
/**
@ -117,11 +118,6 @@ final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
}
@Override
public Node<T> findOrCreateChild(final T child) {
return findChild(child).orElseThrow(() -> new UnsupportedOperationException(IMMUTABLE_OBJECT));
}
@Override
public void insertInPath(final Node<T> node, final String... path) {
throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
@ -136,5 +132,4 @@ final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
public void removeParent() {
throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
}
}

13
src/main/java/net/kemitix/node/Node.java
View file

@ -129,19 +129,6 @@ public interface Node<T> {
*/
void createDescendantLine(List<T> descendants);
/**
* Looks for a child node and returns it, creating a new child node if one
* isn't found.
*
* @param child the child's data to search or create with
*
* @return the found or created child node
*
* @deprecated use {@code node.findChild(child).orElseGet(() -> node.createChild(child))};
*/
@Deprecated
Node<T> findOrCreateChild(T child);
/**
* Fetches the node for the child if present.
*

112
src/main/java/net/kemitix/node/NodeItem.java
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@ -51,47 +51,31 @@ class NodeItem<T> implements Node<T> {
private String name;
/**
* Create named root node.
* Constructor.
*
* @param data the data or null
* @param name the name
* @param data the data of the node
* @param name the name of the node
* @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) {
this(data);
this.name = name;
}
/**
* Create unnamed root node.
*
* @param data the data or null
*/
NodeItem(final T data) {
this.data = data;
}
/**
* Creates a node with a parent.
*
* @param data the data or null
* @param parent the parent node
*/
NodeItem(final T data, final Node<T> parent) {
this.data = data;
setParent(parent);
}
/**
* Creates a named node with a parent.
*
* @param data the data or null
* @param name the name
* @param parent the parent node
*/
NodeItem(final T data, final String name, final Node<T> parent) {
NodeItem(
final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children
) {
this.data = data;
this.name = name;
setParent(parent);
if (parent != null) {
doSetParent(parent);
}
this.children.addAll(children);
}
/**
* Sets the parent of a node without updating the parent in the process as {@link #setParent(Node)} does.
*
* @param newParent The new parent node
*/
protected void forceParent(final Node<T> newParent) {
this.parent = newParent;
}
@Override
@ -130,16 +114,20 @@ class NodeItem<T> implements Node<T> {
* @param parent the new parent node
*/
@Override
public final void setParent(@NonNull final Node<T> parent) {
if (this.equals(parent) || parent.isDescendantOf(this)) {
public void setParent(@NonNull final Node<T> parent) {
doSetParent(parent);
}
private void doSetParent(@NonNull final Node<T> newParent) {
if (this.equals(newParent) || newParent.isDescendantOf(this)) {
throw new NodeException("Parent is a descendant");
}
if (this.parent != null) {
this.parent.getChildren()
.remove(this);
}
this.parent = parent;
parent.addChild(this);
this.parent = newParent;
newParent.addChild(this);
}
@Override
@ -191,7 +179,7 @@ class NodeItem<T> implements Node<T> {
*/
@Override
public Node<T> createChild(@NonNull final T child) {
return new NodeItem<>(child, this);
return new NodeItem<>(child, "", this, new HashSet<>());
}
@Override
@ -211,26 +199,13 @@ class NodeItem<T> implements Node<T> {
@Override
public void createDescendantLine(@NonNull final List<T> descendants) {
if (!descendants.isEmpty()) {
findOrCreateChild(descendants.get(0)).createDescendantLine(descendants.subList(1, descendants.size()));
val child = descendants.get(0);
val remainingLine = descendants.subList(1, descendants.size());
findChild(child).orElseGet(() -> createChild(child))
.createDescendantLine(remainingLine);
}
}
/**
* Looks for a child node and returns it, creating a new child node if one
* isn't found.
*
* @param child the child's data to search or create with
*
* @return the found or created child node
*
* @deprecated use node.findChild(child).orElseGet(() -> node.createChild (child));
*/
@Override
@Deprecated
public Node<T> findOrCreateChild(@NonNull final T child) {
return findChild(child).orElseGet(() -> createChild(child));
}
/**
* Fetches the node for the child if present.
*
@ -241,21 +216,14 @@ class NodeItem<T> implements Node<T> {
@Override
public Optional<Node<T>> findChild(@NonNull final T child) {
return children.stream()
.filter(node -> {
final Optional<T> d = node.getData();
return d.isPresent() && d.get()
.equals(child);
})
.findAny();
.filter(node -> child.equals(node.getData()
.orElseGet(() -> null)))
.findFirst();
}
@Override
public Node<T> getChild(final T child) {
Optional<Node<T>> optional = findChild(child);
if (optional.isPresent()) {
return optional.get();
}
throw new NodeException("Child not found");
return findChild(child).orElseThrow(() -> new NodeException("Child not found"));
}
/**
@ -295,8 +263,8 @@ class NodeItem<T> implements Node<T> {
if (path.length == 0) {
insertChild(nodeItem);
} else {
val item = path[0];
findChildByName(item).orElseGet(() -> new NodeItem<>(null, item, this))
val nextInPath = path[0];
findChildByName(nextInPath).orElseGet(() -> new NodeItem<>(null, nextInPath, this, new HashSet<>()))
.insertInPath(nodeItem, Arrays.copyOfRange(path, 1, path.length));
}
}

9
src/main/java/net/kemitix/node/Nodes.java
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@ -24,6 +24,7 @@ SOFTWARE.
package net.kemitix.node;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
@ -47,7 +48,7 @@ public final class Nodes {
* @return the new node
*/
public static <T> Node<T> unnamedRoot(final T data) {
return new NodeItem<>(data);
return new NodeItem<>(data, "", null, new HashSet<>());
}
/**
@ -60,7 +61,7 @@ public final class Nodes {
* @return the new node
*/
public static <T> Node<T> namedRoot(final T data, final String name) {
return new NodeItem<>(data, name);
return new NodeItem<>(data, name, null, new HashSet<>());
}
/**
@ -73,7 +74,7 @@ public final class Nodes {
* @return the new node
*/
public static <T> Node<T> unnamedChild(final T data, final Node<T> parent) {
return new NodeItem<>(data, parent);
return new NodeItem<>(data, "", parent, new HashSet<>());
}
/**
@ -89,7 +90,7 @@ public final class Nodes {
public static <T> Node<T> namedChild(
final T data, final String name, final Node<T> parent
) {
return new NodeItem<>(data, name, parent);
return new NodeItem<>(data, name, parent, new HashSet<>());
}
/**

35
src/test/java/net/kemitix/node/ImmutableNodeItemTest.java
View file

@ -126,7 +126,7 @@ public class ImmutableNodeItemTest {
immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("subject"));
expectImmutableException();
//when
immutableNode.setParent(null);
immutableNode.setParent(Nodes.unnamedRoot("child"));
}
@Test
@ -222,19 +222,6 @@ public class ImmutableNodeItemTest {
}
}
/**
* Test that if we pass null we get an exception.
*/
@Test
public void findOrCreateChildShouldThrowNPEFWhenChildIsNull() {
//given
immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("subject"));
exception.expect(NullPointerException.class);
exception.expectMessage("child");
//when
immutableNode.findOrCreateChild(null);
}
/**
* Test that we throw an exception when passed null.
*/
@ -431,24 +418,4 @@ public class ImmutableNodeItemTest {
//when
immutableNode.insertInPath(null, "");
}
@Test
public void findOrCreateChildShouldReturnChildWhenChildIsFound() {
//given
val root = Nodes.unnamedRoot("");
Nodes.namedChild("child", "child", root);
immutableNode = Nodes.asImmutable(root);
//when
val found = immutableNode.findOrCreateChild("child");
assertThat(found).extracting(Node::getName).contains("child");
}
@Test
public void findOrCreateChildShouldThrowExceptionWhenChildNotFound() {
//given
immutableNode = Nodes.asImmutable(Nodes.unnamedRoot(""));
expectImmutableException();
//when
immutableNode.findOrCreateChild("child");
}
}

58
src/test/java/net/kemitix/node/NodeItemTest.java
View file

@ -10,6 +10,7 @@ import org.junit.rules.ExpectedException;
import java.util.Arrays;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;
import static org.assertj.core.api.Assertions.assertThat;
@ -84,6 +85,17 @@ public class NodeItemTest {
.contains(parent);
}
@Test
public void shouldAddAsChildWhenCreatedWithParent() {
//given
final Node<String> root = Nodes.namedRoot("root data", "root name");
//when
final Node<String> child = Nodes.namedChild("child data", "child name", root);
//then
final Set<Node<String>> children = root.getChildren();
assertThat(children).containsExactly(child);
}
/**
* Test that setting the parent on a node where the proposed parent is a
* child of the node throws an exception.
@ -457,52 +469,6 @@ public class NodeItemTest {
+ "is created").isEmpty();
}
/**
* Test that we can find a child of a node.
*/
@Test
public void shouldFindExistingChildNode() {
//given
node = Nodes.unnamedRoot("subject");
val childData = "child";
val child = Nodes.unnamedChild(childData, node);
//when
val found = node.findOrCreateChild(childData);
//then
assertThat(found).as(
"when searching for a child by data, the matching child is "
+ "found").isSameAs(child);
}
/**
* Test that we create a missing child of a node.
*/
@Test
public void shouldFindCreateNewChildNode() {
//given
node = Nodes.unnamedRoot("subject");
val childData = "child";
//when
val found = node.findOrCreateChild(childData);
//then
assertThat(found.getData()).as(
"when searching for a non-existent child by data, a new node "
+ "is created").contains(childData);
}
/**
* Test that if we pass null we get an exception.
*/
@Test
public void findOrCreateChildShouldThrowNPEFWhenChildIsNull() {
//given
node = Nodes.unnamedRoot("subject");
exception.expect(NullPointerException.class);
exception.expectMessage("child");
//when
node.findOrCreateChild(null);
}
/**
* Test that we can get the node for a child.
*/

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

@ -24,7 +24,7 @@ public class NodesTest {
val node = Nodes.unnamedRoot("data");
SoftAssertions softly = new SoftAssertions();
softly.assertThat(node.getData()).contains("data");
softly.assertThat(node.getName()).isNull();
softly.assertThat(node.getName()).isEmpty();
softly.assertAll();
}
@ -43,7 +43,7 @@ public class NodesTest {
val node = Nodes.unnamedChild("data", parent);
SoftAssertions softly = new SoftAssertions();
softly.assertThat(node.getData()).contains("data");
softly.assertThat(node.getName()).isNull();
softly.assertThat(node.getName()).isEmpty();
softly.assertThat(node.getParent()).contains(parent);
softly.assertAll();
}