Java Query类代码示例

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns number of albums according to the specified language.
 *
 * @param language language code.
 * @return number of albums with specified language code.
 */
public long getTotalNumByLanguage(String language) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();

        QueryCondition languageEqualsCondition = connection.newCondition()
                .is("language", QueryCondition.Op.EQUAL, language)
                .build();

        Query query = connection.newQuery()
                .select("_id")
                .where(languageEqualsCondition)
                .build();

        DocumentStream documentStream = store.findQuery(query);
        long totalNum = 0;
        for (Document ignored : documentStream) {
            totalNum++;
        }

        log.debug("Counting '{}' albums by language '{}' took {}", totalNum, language, stopwatch);

        return totalNum;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns list of Artist rates by user identifier.
 *
 * @param userId user's identifier.
 * @return list of Artist rates.
 */
public List<ArtistRate> getByUserId(String userId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();
        Query query = connection.newQuery().where(
                connection.newCondition()
                        .is("user_id", QueryCondition.Op.EQUAL, userId)
                        .build()
        ).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        List<ArtistRate> rates = new ArrayList<>();
        for (Document document : documentStream) {
            ArtistRate rate = mapOjaiDocument(document);
            if (rate != null) {
                rates.add(rate);
            }
        }

        log.debug("Get '{}' rates by user id '{}' took {}", rates.size(), userId, stopwatch);

        return rates;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns list of Artist rates by artist identifier.
 *
 * @param artistId artist's identifier.
 * @return list of Artist rates.
 */
public List<ArtistRate> getByArtistId(String artistId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();
        Query query = connection.newQuery().where(
                connection.newCondition()
                        .is("document_id", QueryCondition.Op.EQUAL, artistId)
                        .build()
        ).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        List<ArtistRate> rates = new ArrayList<>();
        for (Document document : documentStream) {
            ArtistRate rate = mapOjaiDocument(document);
            if (rate != null) {
                rates.add(rate);
            }
        }

        log.debug("Get '{}' rates by artist id '{}' took {}", rates.size(), artistId, stopwatch);

        return rates;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Finds albums, which titles start with the specified name entry.
 *
 * @param nameEntry specifies query criteria.
 * @param limit     specified limit.
 * @param fields    specifies fields that will be fetched.
 * @return list of albums which titles start with the specified name entry.
 */
public List<Album> getByNameStartsWith(String nameEntry, long limit, String... fields) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();
        Query query = connection.newQuery();

        // Select only specified field
        if (fields != null && fields.length > 0) {
            query.select(fields);
        } else {
            query.select("*");
        }

        // Build Query Condition to fetch documents by name entry
        String nameStartsWithPattern = nameEntry + "%";
        QueryCondition nameStartsWithCondition = connection.newCondition()
                .like("name", nameStartsWithPattern)
                .build();

        // Add Condition and specified limit to the Query
        query.where(nameStartsWithCondition)
                .limit(limit)
                .build();

        DocumentStream documentStream = store.findQuery(query);
        List<Album> albums = new ArrayList<>();
        for (Document doc : documentStream) {
            albums.add(mapOjaiDocument(doc));
        }

        log.debug("Get '{}' albums by name entry: '{}' with limit: '{}', fields: '{}'. Elapsed time: {}",
                albums.size(), nameEntry, limit, (fields != null) ? Arrays.asList(fields) : "[]", stopwatch);

        return albums;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns Artist rate according to the specified user identifier and artist identifier.
 *
 * @param userId   user identifier.
 * @param artistId artist identifier.
 * @return artist rate.
 */
public ArtistRate getRate(String userId, String artistId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();
        QueryCondition condition = connection.newCondition()
                .and()
                .is("user_id", QueryCondition.Op.EQUAL, userId)
                .is("document_id", QueryCondition.Op.EQUAL, artistId)
                .close()
                .build();

        Query query = connection.newQuery().where(condition).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        Iterator<Document> documentIterator = documentStream.iterator();

        if (!documentIterator.hasNext()) {
            return null;
        }

        log.debug("Get rate by artist id '{}' and user id '{}' took {}", artistId, userId, stopwatch);

        return mapOjaiDocument(documentIterator.next());
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Finds artists, which names start with the specified name entry.
 *
 * @param nameEntry specifies query criteria.
 * @param limit     specified limit.
 * @param fields    specifies fields that will be fetched.
 * @return list of artists which names start with the specified name entry.
 */
public List<Artist> getByNameStartsWith(String nameEntry, long limit, String... fields) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();
        Query query = connection.newQuery();

        // Select only specified field
        if (fields != null && fields.length > 0) {
            query.select(fields);
        } else {
            query.select("*");
        }

        // Build Query Condition to fetch documents by name entry
        String nameStartsWithPattern = nameEntry + "%";
        QueryCondition nameStartsWithCondition = connection.newCondition()
                .like("name", nameStartsWithPattern)
                .build();

        // Add Condition and specified limit to the Query
        query.where(nameStartsWithCondition)
                .limit(limit)
                .build();

        DocumentStream documentStream = store.findQuery(query);
        List<Artist> artists = new ArrayList<>();
        for (Document doc : documentStream) {
            artists.add(mapOjaiDocument(doc));
        }

        log.debug("Get '{}' artists by name entry: '{}' with limit: '{}', fields: '{}'. Elapsed time: {}",
                artists.size(), nameEntry, limit, (fields != null) ? Arrays.asList(fields) : "[]", stopwatch);

        return artists;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns Album rate according to the specified user identifier and album identifier.
 *
 * @param userId  user identifier.
 * @param albumId album identifier.
 * @return album rate.
 */
public AlbumRate getRate(String userId, String albumId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();

        QueryCondition condition = connection.newCondition()
                .and()
                .is("user_id", QueryCondition.Op.EQUAL, userId)
                .is("document_id", QueryCondition.Op.EQUAL, albumId)
                .close()
                .build();

        Query query = connection.newQuery().where(condition).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        Iterator<Document> documentIterator = documentStream.iterator();

        if (!documentIterator.hasNext()) {
            return null;
        }

        log.debug("Get rate by album id '{}' and user id '{}' took {}", albumId, userId, stopwatch);

        return mapOjaiDocument(documentIterator.next());
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns list of Album rates by user identifier.
 *
 * @param userId user's identifier.
 * @return list of Album rates.
 */
public List<AlbumRate> getByUserId(String userId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();

        Query query = connection.newQuery().where(
                connection.newCondition()
                        .is("user_id", QueryCondition.Op.EQUAL, userId)
                        .build()
        ).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        List<AlbumRate> rates = new ArrayList<>();
        for (Document document : documentStream) {
            AlbumRate rate = mapOjaiDocument(document);
            if (rate != null) {
                rates.add(rate);
            }
        }

        log.debug("Get '{}' rates by user id '{}' took {}", rates.size(), userId, stopwatch);

        return rates;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns list of Album rates by album identifier.
 *
 * @param albumId album's identifier.
 * @return list of Album rates.
 */
public List<AlbumRate> getByAlbumId(String albumId) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();

        Query query = connection.newQuery().where(
                connection.newCondition()
                        .is("document_id", QueryCondition.Op.EQUAL, albumId)
                        .build()
        ).build();

        // Fetch all OJAI Documents from this store according to the built query
        DocumentStream documentStream = store.findQuery(query);
        List<AlbumRate> rates = new ArrayList<>();
        for (Document document : documentStream) {
            AlbumRate rate = mapOjaiDocument(document);
            if (rate != null) {
                rates.add(rate);
            }
        }

        log.debug("Get '{}' rates by album id '{}' took {}", rates.size(), albumId, stopwatch);

        return rates;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
/**
 * Returns list of albums by language code.
 *
 * @param offset  offset value.
 * @param limit   limit value.
 * @param options define the order of documents.
 * @param lang    language code.
 * @param fields  list of fields that will present in document.
 * @return list of albums with specified language code.
 */
public List<Album> getByLanguage(long offset, long limit, List<SortOption> options, String lang, String... fields) {
    return processStore((connection, store) -> {

        Stopwatch stopwatch = Stopwatch.createStarted();

        Query query = connection.newQuery();

        // Select only specified field
        if (fields != null && fields.length > 0) {
            query.select(fields);
        } else {
            query.select("*");
        }

        // Build Query Condition to fetch documents by specified language
        QueryCondition languageEqualsCondition = connection.newCondition()
                .is("language", QueryCondition.Op.EQUAL, lang)
                .build();

        // Add Condition to the Query
        query.where(languageEqualsCondition);

        // Add ordering if sort options specified
        if (options != null && !options.isEmpty()) {
            for (SortOption opt : options) {
                SortOrder ojaiOrder = (SortOption.Order.DESC == opt.getOrder()) ? SortOrder.DESC : SortOrder.ASC;
                for (String field : opt.getFields()) {
                    query = query.orderBy(field, ojaiOrder);
                }
            }
        }

        // Add specified offset and limit to the Query
        query.offset(offset)
                .limit(limit)
                .build();

        DocumentStream documentStream = store.findQuery(query);
        List<Album> albums = new ArrayList<>();
        for (Document doc : documentStream) {
            albums.add(mapOjaiDocument(doc));
        }

        log.debug("Get list of '{}' documents from '{}' table by language: '{}' with offset: '{}', limit: '{}', " +
                        "sortOptions: '{}', fields: '{}'. Elapsed time: {}", albums.size(), tablePath, lang, offset,
                limit, options, (fields != null) ? Arrays.asList(fields) : "[]", stopwatch);

        return albums;
    });
}
 

import org.ojai.store.Query; //导入依赖的package包/类
@Override
public Query newQuery() {
  throw new UnsupportedOperationException();
}
 

import org.ojai.store.Query; //导入依赖的package包/类
@Override
public Query newQuery() {
  return driver.newQuery();
}