/* Copyright c 2005-2012.
* Licensed under GNU LESSER General Public License, Version 3.
* http://www.gnu.org/licenses
*/
package org.beangle.model.query.builder;
import java.util.List;
import java.util.Map;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang.StringUtils;
import org.beangle.commons.collection.CollectUtils;
import org.beangle.commons.collection.Order;
import org.beangle.commons.collection.page.PageLimit;
import org.beangle.model.query.Lang;
import org.beangle.model.query.Query;
import org.beangle.model.query.QueryBuilder;
public abstract class AbstractQueryBuilder<T> implements QueryBuilder<T> {
public static final String INNER_JOIN = " left join ";
public static final String OUTER_JOIN = " outer join ";
public static final String LEFT_OUTER_JOIN = " left outer join ";
public static final String RIGHT_OUTER_JOIN = " right outer join ";
/** query 查询语句 */
protected String statement;
/** 分页 */
protected PageLimit limit;
/** 参数 */
protected Map<String, Object> params;
protected String select;
protected String from;
/** 别名 */
protected String alias;
protected List<Condition> conditions = CollectUtils.newArrayList();
protected List<Order> orders = CollectUtils.newArrayList();
protected List<String> groups = CollectUtils.newArrayList();
/** 缓存查询结果 */
protected boolean cacheable = false;
public Map<String, Object> getParams() {
return (null == params) ? ConditionUtils.getParamMap(conditions) : CollectUtils.newHashMap(params);
}
/**
* @return
*/
public String getAlias() {
return alias;
}
public boolean isCacheable() {
return cacheable;
}
public PageLimit getLimit() {
return limit;
}
public Query<T> build() {
QueryBean<T> queryBean = new QueryBean<T>();
queryBean.setStatement(genStatement());
queryBean.setParams(getParams());
if (null != limit) {
queryBean.setLimit(new PageLimit(limit.getPageNo(), limit.getPageSize()));
}
queryBean.setCountStatement(genCountStatement());
queryBean.setCacheable(cacheable);
queryBean.setLang(getLang());
return queryBean;
}
abstract protected Lang getLang();
/**
* {@inheritDoc}
* <p>
* 生成查询语句（如果查询语句已经存在则不进行生成）
*/
protected String genStatement() {
if (StringUtils.isNotEmpty(statement)) {
return statement;
} else {
return genQueryStatement(true);
}
}
abstract protected String genCountStatement();
protected String genQueryStatement(final boolean hasOrder) {
if (null == from) { return statement; }
final StringBuilder buf = new StringBuilder(50);
buf.append((select == null) ? "" : select).append(' ').append(from);
if (!conditions.isEmpty()) {
buf.append(" where ").append(ConditionUtils.toQueryString(conditions));
}
if (!groups.isEmpty()) {
buf.append(" group by ");
for (final String groupBy : groups) {
buf.append(groupBy).append(',');
}
buf.deleteCharAt(buf.length() - 1);
}
if (hasOrder && !CollectionUtils.isEmpty(orders)) {
buf.append(' ').append(Order.toSortString(orders));
}
return buf.toString();
}
}