Application: gvSIG desktop

package org.gvsig.exportto.impl;

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import org.gvsig.fmap.dal.feature.FeatureAttributeDescriptor;

import org.gvsig.fmap.dal.feature.FeatureType;

public class AttributeNamesTranslator implements Iterable<String> {

    private final Map<String,String> sourceToTarget;

    private final Map<String,String> targetToSource;

    private final int maxNameLen;

    public AttributeNamesTranslator(FeatureType type, int maxNameLen) {

        this.maxNameLen = maxNameLen;

        this.sourceToTarget = new HashMap<>();

        this.targetToSource = new HashMap<>();

        for( FeatureAttributeDescriptor attr : type) {

            String source_name = attr.getName();

                          String target_name = buildTranslatedName(source_name, this.sourceToTarget.values());

            if( !source_name.equals(target_name) ) {

                this.sourceToTarget.put(source_name, target_name);

                this.targetToSource.put(target_name, source_name);

            }

        }

    }

    public String getTargetName(String name) {

         return this.sourceToTarget.getOrDefault(name, name);

    }

    public String getSourceName(String name) {

         return this.targetToSource.getOrDefault(name, name);

    }

    @Override

    public Iterator<String> iterator() {

        return this.sourceToTarget.keySet().iterator();

    }

    public boolean hasTranslations() {

        return !this.sourceToTarget.isEmpty();

    }

    public boolean hasTranslation(String name) {

        return this.sourceToTarget.get(name)!=null;

    }

        private String buildTranslatedName(String source_name, Collection<String> current_names) {

                int len = source_name.length();

                if (len <= this.maxNameLen) {

                        /*

                         * Should not happen

                         */

                        return source_name;

                }

                String target_name;

                /*

                 * GDAL field name truncation method (extended from 100 to 255)

                 * THISISAVERYLONGNAME => THISISAVER, THISISAV_1 ... THISISAV_9,

                 * THISISAV10 ... THISISAV99, THISISA100 ... THISISA255

                 * (255 = max number of fields in a SHP)

                 */

                for (int i=0; i<255; i++) {

                    if (i==0) {

                target_name = source_name.substring(0, 10);

            } else if (i<=9) {

                target_name = source_name.substring(0, 8) + "_" + i;

            } else if (i<=99) {

                target_name = source_name.substring(0, 8) + i;

            } else {

                target_name = source_name.substring(0, 7) + i;

            }

                    if (!current_names.contains(target_name)) {

                return target_name;

            }

                }

                /*

                 * Should not get here

                 */

                return source_name.substring(0, 4) + "_" + (System.currentTimeMillis() % 1000000);

        }    

}