LimitSqlExecutor.java

package cn.org.rapid_framework.ibatis.sqlmap.engine.execution;

import java.sql.Connection;
import java.sql.SQLException;

import cn.org.rapid_framework.jdbc.dialect.Dialect;

import com.ibatis.sqlmap.engine.execution.SqlExecutor;
import com.ibatis.sqlmap.engine.mapping.statement.RowHandlerCallback;
import com.ibatis.sqlmap.engine.scope.StatementScope;
/**
 * 结合dialect为ibatis提供使用数据库原生的分页
 * 请查看:http://pengfeng.javaeye.com/blog/200772
 * @author badqiu
 *
 */
public class LimitSqlExecutor extends SqlExecutor {

	private Dialect dialect;

	private boolean enableLimit = true;

	public Dialect getDialect() {
		return dialect;
	}

	public void setDialect(Dialect dialect) {
		if(dialect != null) {
			System.out.println("[iBATIS] set ibatis LimitSqlExecutor.dialect = "+dialect.getClass().getName());
		}
		this.dialect = dialect;
	}

	public boolean isEnableLimit() {
		return enableLimit;
	}

	public void setEnableLimit(boolean enableLimit) {
		this.enableLimit = enableLimit;
	}

	@Override
	public void executeQuery(StatementScope statementScope, Connection conn, String sql, Object[] parameters, int skipResults, int maxResults, RowHandlerCallback callback) throws SQLException {
		if (supportsLimit() && (skipResults != NO_SKIPPED_RESULTS || maxResults != NO_MAXIMUM_RESULTS)) {
			sql = sql.trim();
			if(dialect.supportsLimitOffset()) {
				sql = dialect.getLimitString(sql, skipResults, maxResults);
				skipResults = NO_SKIPPED_RESULTS;
			}else {
				sql = dialect.getLimitString(sql, 0, maxResults);
			}
			maxResults = NO_MAXIMUM_RESULTS;
		}
		super.executeQuery(statementScope, conn, sql, parameters, skipResults, maxResults, callback);
	}

	public boolean supportsLimit() {
		if (enableLimit && dialect != null) {
			return dialect.supportsLimit();
		}
		return false;
	}

}