Identity.java

package com.redhat.lightblue.migrator;

import java.util.List;
import java.util.StringTokenizer;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.NullNode;

public class Identity {

    private final Object[] values;

    public Identity(Object[] values) {
        this.values = values;
    }

    public Identity(JsonNode doc, List<String> identityFields) {
        values = new Object[identityFields.size()];
        int i = 0;
        for (String field : identityFields) {
            JsonNode n = getFieldValue(doc, field);
            if (n == null || n instanceof NullNode) {
                values[i] = null;
            } else {
                values[i] = n.asText();
            }
            i++;
        }
    }

    public Object get(int i) {
        return values[i];
    }

    public int hashCode() {
        int v = 37;
        for (Object x : values) {
            if (x != null) {
                v *= x.hashCode();
            }
        }
        return v;
    }

    public boolean equals(Object x) {
        if (x instanceof Identity) {
            Identity id = (Identity) x;
            if (id.values.length == values.length) {
                for (int i = 0; i < id.values.length; i++) {
                    if (!((values[i] == null && id.values[i] == null)
                            || (values[i] != null && values[i].equals(id.values[i])))) {
                        return false;
                    }
                }
                return true;
            }
        }
        return false;
    }

    public String toString() {
        StringBuilder bld = new StringBuilder();
        for (int i = 0; i < values.length; i++) {
            if (i > 0) {
                bld.append(',');
            }
            bld.append(values[i] == null ? "null" : values[i].toString());
        }
        return bld.toString();
    }

    /**
     * Ooes not do array index lookup!
     */
    public static JsonNode getFieldValue(JsonNode doc, String field) {
        StringTokenizer tkz = new StringTokenizer(field, ". ");
        JsonNode trc = doc;
        while (tkz.hasMoreTokens() && trc != null) {
            String tok = tkz.nextToken();
            trc = trc.get(tok);
        }
        return trc;
    }

}