org.simpleflatmapper.jdbc.impl.SelectQueryWhereFactory Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of sfm-jdbc Show documentation

Java library to map flat record - ResultSet, csv - to java object with minimum configuration and low footprint.

There is a newer version: 9.0.2

package org.simpleflatmapper.jdbc.impl;

import org.simpleflatmapper.jdbc.JdbcMapper;
import org.simpleflatmapper.jdbc.JdbcMapperFactory;
import org.simpleflatmapper.jdbc.QueryPreparer;
import org.simpleflatmapper.jdbc.named.NamedSqlQuery;

import java.lang.reflect.Type;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

public class SelectQueryWhereFactory {

    private final CrudMeta meta;
    private final JdbcMapperFactory jdbcMapperFactory;
    private final JdbcMapper jdbcMapper;

    private final ConcurrentMap> cache = new ConcurrentHashMap>();

    public SelectQueryWhereFactory(CrudMeta meta, JdbcMapper jdbcMapper, JdbcMapperFactory jdbcMapperFactory) {
        this.meta = meta;
        this.jdbcMapper = jdbcMapper;
        this.jdbcMapperFactory = jdbcMapperFactory;
    }

    @SuppressWarnings("unchecked")
    public  SelectQueryImpl where(String whereClause, Type paramClass) {
        SelectQueryKey key = new SelectQueryKey(whereClause, paramClass);

        SelectQueryImpl selectQuery = cache.get(key);

        if (selectQuery == null) {
            SelectQueryImpl newSelectQuery = newSelectQuery(whereClause, paramClass);
            selectQuery = cache.putIfAbsent(key, newSelectQuery);

            if (selectQuery == null) {
                selectQuery = newSelectQuery;
            }
        }

        return (SelectQueryImpl) selectQuery;
    }

    private 
 SelectQueryImpl newSelectQuery(String whereClause, Type paramClass) {
        String query = sqlQuery(whereClause);
        QueryPreparer
 queryPreparer = jdbcMapperFactory.from(paramClass).to(NamedSqlQuery.parse(query));
        return new SelectQueryImpl(queryPreparer, jdbcMapper);
    }

    private String sqlQuery(String whereClause) {
        StringBuilder sb = new StringBuilder("SELECT * FROM ");
        meta.appendTableName(sb);
        sb.append(" WHERE ");
        sb.append(whereClause);
        return sb.toString();
    }

    private static class SelectQueryKey {
        private final String query;
        private final Type type;

        private SelectQueryKey(String query, Type type) {
            this.query = query;
            this.type = type;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            SelectQueryKey that = (SelectQueryKey) o;

            if (!query.equals(that.query)) return false;
            return type.equals(that.type);

        }

        @Override
        public int hashCode() {
            int result = query.hashCode();
            result = 31 * result + type.hashCode();
            return result;
        }
    }
}