simplecascadetest.java

《基于Eclipse的开源框架技术与实战》[第8章]随书源码

package com.free.hibernate.cascade;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.util.*;

import org.hibernate.*;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.*;

import com.free.hibernate.bo.Event;
import com.free.hibernate.bo.Location;
import com.free.hibernate.util.HibernateUtil;

/**
 * <p>Title: Eclipse Plugin Development</p>
 * <p>Description: Free download</p>
 * <p>Copyright: Copyright (c) 2006</p>
 * <p>Company: Free</p>
 * @author gan.shu.man
 * @version 1.0
 */

public class SimpleCascadeTest {

	static Connection conn;
	static Statement st;
	
	public static void main(String[] args) {
		setup("create table events(uid bigint(20) PRIMARY KEY not null,name varchar(255),start_date date,duration int(11),location_id bigint(20));");
		setup("create table locations(uid bigint(20) PRIMARY KEY not null,name varchar(255),street_address varchar(255),city varchar(255),state varchar(255),zip_code varchar(255));");
		
		HibernateUtil.buildSessionFactory();
		
		Session session = HibernateUtil.currentSession();
		Transaction tx = session.beginTransaction();

        Location location = new Location();
        location.setName("USA");
        location.getAddress().setStreetAddress("St.");
        location.getAddress().setCity("Regina");
        location.getAddress().setState("SK");
        location.getAddress().setZipCode("22204");

        Event event = new Event();
        event.setName("Annual Meeting");
        event.setDuration(60);
        event.setStartDate(createDate(2004, 11, 1));
        //设置event关联的主键
        event.setLocation(location);

        session.save(event);

        tx.commit();
        session.flush();
        session.close();
        
		HibernateUtil.sessionFactory.close();
        checkData("select * from events");
        checkData("select * from locations");
	}
    private static Date createDate(int year, int month, int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month, day);
        return calendar.getTime();
    }
    
	/**
	 * 为使用JDBC连接初始化，并执行Sql语句
	 * */
	public static void setup(String sql) {
		try {
			//加载JDBC驱动
			Class.forName("com.mysql.jdbc.Driver");
			System.out.println("Driver Loaded.");
			
			//和数据库建立连接
			String url = "jdbc:mysql://localhost/hibernate";
			conn = DriverManager.getConnection(url, "root", "");
			System.out.println("Got Connection.");

			//执行Sql语句
			st = conn.createStatement();
			st.executeUpdate(sql);
		} catch (Exception e) {
			System.err.println("Got an exception! ");
			e.printStackTrace();
		}
	}

	/**
	 * 检查Sql语句的返回值
	 * */
	public static void checkData(String sql) {
		try {
			outputResultSet(st.executeQuery(sql));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 打印ResultSet的值
	 * */
	public static void outputResultSet(ResultSet rs) throws Exception {
		ResultSetMetaData metadata = rs.getMetaData();

		int numcols = metadata.getColumnCount();
		String[] labels = new String[numcols];
		int[] colwidths = new int[numcols];
		int[] colpos = new int[numcols];
		int linewidth;

		//计算列宽和总宽度
		linewidth = 1;
		for (int i = 0; i < numcols; i++) {
			colpos[i] = linewidth;
			//列名
			labels[i] = metadata.getColumnLabel(i + 1);
			int size = metadata.getColumnDisplaySize(i + 1);
			if (size > 30 || size == -1)
				size = 30;
			int labelsize = labels[i].length();
			if (labelsize > size)
				size = labelsize;
			//列宽
			colwidths[i] = size + 1; 
			//总宽度
			linewidth += colwidths[i] + 2; 
		}

		StringBuffer divider = new StringBuffer(linewidth);
		StringBuffer blankline = new StringBuffer(linewidth);
		for (int i = 0; i < linewidth; i++) {
			divider.insert(i, '-');
			blankline.insert(i, " ");
		}
		for (int i = 0; i < numcols; i++)
			divider.setCharAt(colpos[i] - 1, '+');
		divider.setCharAt(linewidth - 1, '+');

		//打印输出线
		System.out.println(divider);

		
		StringBuffer line = new StringBuffer(blankline.toString());
		line.setCharAt(0, '|');
		for (int i = 0; i < numcols; i++) {
			int pos = colpos[i] + 1 + (colwidths[i] - labels[i].length()) / 2;
			overwrite(line, pos, labels[i]);
			overwrite(line, colpos[i] + colwidths[i], " |");
		}
        //打印列头
		System.out.println(line);
		System.out.println(divider);

		while (rs.next()) {
			line = new StringBuffer(blankline.toString());
			line.setCharAt(0, '|');
			for (int i = 0; i < numcols; i++) {
				Object value = rs.getObject(i + 1);
				overwrite(line, colpos[i] + 1, value.toString().trim());
				overwrite(line, colpos[i] + colwidths[i], " |");
			}
			//输出数据
			System.out.println(line);
		}
		//打印最后一行
		System.out.println(divider);

	}

	static void overwrite(StringBuffer b, int pos, String s) {
		int len = s.length();
		for (int i = 0; i < len; i++)
			b.setCharAt(pos + i, s.charAt(i));
	}
}