XmlTag.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.Text;

public class XmlTag {
    private String tagName;
    private Collection<XmlTag> children;
    private String value;
    private boolean ignoreBlank = false;
    private boolean isTextNode = false;

    private XmlTag() {
    }

    public static XmlTag empty() {
        return new XmlTag();
    }

    public static XmlTag text(String tagName, String value) {
        return new XmlTag(tagName, value, true, true);
    }

    public static XmlTag textDontIgnoreBlank(String tagName, String value) {
        return new XmlTag(tagName, value, true, false);
    }

    public static XmlTag nested(String tagName, Collection<XmlTag> children) {
        return new XmlTag(tagName, children);
    }

    public static XmlTag nested(String tagName, XmlTag... children) {
        return new XmlTag(tagName, Arrays.asList(children));
    }

    private XmlTag(String tagName, String value, boolean isTextNode, boolean ignoreBlank) {
        this.tagName = tagName;
        this.value = value;
        this.isTextNode = isTextNode;
        this.ignoreBlank = ignoreBlank;
    }

    private XmlTag(String tagName, Collection<XmlTag> children) {
        this.tagName = tagName;
        this.children = children;
    }

    public Node appendToDoc(Document doc) {
        return appendToRoot(doc, doc);
    }

    public Node appendToRoot(Document creator, Node root) {
        if (tagName == null) {
            return null;
        }

        Node childRoot = creator.createElement(tagName);
        if (isTextNode) {
            return createTextNode(creator, root, childRoot);
        }

        return createNodes(creator, root, childRoot);
    }

    private Node createNodes(Document creator, Node root, Node childRoot) {
        Collection<Node> childNodes = createChildNodes(creator, childRoot);

        for (Node node : childNodes) {
            childRoot.appendChild(node);
        }

        if(childNodes.size() != 0) {
            root.appendChild(childRoot);
            return childRoot;
        }
        
        return null;
    }

    private Collection<Node> createChildNodes(Document creator, Node root) {
        if (children == null) {
            return Collections.emptyList();
        }

        List<Node> list = new ArrayList<Node>();

        for (XmlTag child : children) {
            Node childNode = child.appendToRoot(creator, root);
            if (childNode != null) {
                list.add(childNode);
            }
        }

        return list;
    }

    private Node createTextNode(Document creator, Node root, Node childRoot) {
        if (appendTextNode(creator, childRoot)) {
            root.appendChild(childRoot);
            return childRoot;
        }

        return null;
    }

    private boolean appendTextNode(Document creator, Node root) {
        if (!isTextAvailable()) {
            return false;
        }

        Text text = creator.createTextNode(value);
        root.appendChild(text);
        return true;
    }

    private boolean isTextAvailable() {
        if (ignoreBlank) {
            return StringUtils.isNotBlank(value);
        }

        return value != null;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((children == null) ? 0 : children.hashCode());
        result = prime * result + (ignoreBlank ? 1231 : 1237);
        result = prime * result + (isTextNode ? 1231 : 1237);
        result = prime * result + ((tagName == null) ? 0 : tagName.hashCode());
        result = prime * result + ((value == null) ? 0 : value.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        XmlTag other = (XmlTag) obj;
        if (children == null) {
            if (other.children != null) {
                return false;
            }
        } else if (!children.equals(other.children)) {
            return false;
        }
        if (ignoreBlank != other.ignoreBlank) {
            return false;
        }
        if (isTextNode != other.isTextNode) {
            return false;
        }
        if (tagName == null) {
            if (other.tagName != null) {
                return false;
            }
        } else if (!tagName.equals(other.tagName)) {
            return false;
        }
        if (value == null) {
            if (other.value != null) {
                return false;
            }
        } else if (!value.equals(other.value)) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("XmlTag [tagName=").append(tagName);
        builder.append(", value=").append(value);
        builder.append(", ignoreBlank=").append(ignoreBlank);
        builder.append(", isTextNode=").append(isTextNode);
        builder.append(", children=").append(children);
        builder.append("]");
        return builder.toString();
    }
}