tablerowiterator.java

旅游自助系统

/**
 * 
 */
package org.tshs.storage.rdbms;

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author Administrator
 * 
 */
public class TableRowIterator {

	/**
	 * Results from a query
	 */
	private ResultSet results;

	/**
	 * Statement used to submit the query
	 */
	private Statement statement;

	/**
	 * The name of the RDBMS table
	 */
	private String table;

	private boolean hasNext;

	/** Record the column names of each results. */
	private List<String> columnName;

	/**
	 * @param set
	 * @param statement
	 */
	public TableRowIterator(ResultSet results, Statement statement) {
		this(results, statement, null);
	}

	/**
	 * @param results2
	 * @param statement2
	 * @param object
	 */
	public TableRowIterator(ResultSet results, Statement statement, String table) {
		this.results = results;
		this.statement = statement;
		this.table = table;

		if (results == null) {
			hasNext = false;
		} else {

			try {
				hasNext = results.next();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				hasNext = false;
			}
		}
	}

	public boolean hasNext() {

		return hasNext;
	}

	public TableRow next() throws Exception {
		
		if(!hasNext()){
			return null;
		}
		
		TableRow row = null;
		try {
			
			if (columnName == null) {
				columnName = DbManager.getColumnName(results);
			}
			row = convertToTableRow(results);

		} catch (SQLException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
			return null;
		}
		
		try {
			hasNext = results.next();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			hasNext = false;
		}
		
		return row;
	}

	private TableRow convertToTableRow(ResultSet results) throws Exception {

		Map<String, Object> columns = new HashMap<String, Object>();

		ResultSetMetaData meta = results.getMetaData();
		int size = meta.getColumnCount();

		List<String> columnList = new ArrayList<String>();
		List<Integer> typeList = new ArrayList<Integer>();
		
		String name = null;
		for(int i = 0; i<size; i++){
			
			name = meta.getColumnName(i+1);
			
			columnList.add(name);
			typeList.add(meta.getColumnType(i+1));
			
			columns.put(name, results.getObject(i+1));
		}
		
		ColumnInfo info = new ColumnInfo(columnList, typeList);		
		return new TableRow(table, columns, info);
	}

	/**
	 * 
	 */
	public void close() {
		if (results != null) {
			try {
				results.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			results = null;
		}

		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		statement = null;
	}

}