Java连接数据库的例子

import java.sql.*;

public class Jdbc {
private Connection con;
private Statement ste;
private ResultSet rs;
private String driver;
private String url;

/**
 * 空的构造函数
 */
public Jdbc() {
}

/**
 *
 * @param driver
 * @param url
 * @param username
 * @param userpwd
 * @throws Exception
 */
public Jdbc(String driver, String url, String username, String userpwd)
throws Exception {
try {
Class.forName(driver);
con = DriverManager.getConnection(url, username, userpwd);
ste = con.createStatement();
} catch (Exception e) {
System.out.println("出错了");
e.printStackTrace();
}
}

/**
 * 设置数据库连接驱动
 * @param driver
 * @return
 */
public boolean setDriver(String driver) {
try {
Class.forName(driver);
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}

/**
 * 按URL,DatabaseUserName,DatabasePassword连接数据库
 * @param url
 * @param userName
 * @param userPWD
 * @return
 */
public boolean setConnection(String url, String userName, String userPWD) {
try {
con = DriverManager.getConnection(url, userName, userPWD);
ste = con.createStatement();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}

/**
 * 通过SQL语句查询数据库
 * @param sql
 * @return
 */
public ResultSet sendQuery(String sql)
{
try {
ste =con.createStatement(
 ResultSet.TYPE_SCROLL_INSENSITIVE,
 ResultSet.CONCUR_READ_ONLY);
rs = ste.executeQuery(sql);
return rs;
} catch (SQLException e) {
e.printStackTrace();
    return null;
                  }
}

    /**
     * 处理数据更新
     * @param sql
     * @return
     */
public int sendUpdate(String sql)
{
try {
return ste.executeUpdate(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
        //更新出错
}

    /**
     * 关闭相关流操作
     */
public void close()
{
try {
rs.close();
ste.close();
con.close();
} catch (Exception e) {
    //e.printStackTrace();
//System.out.println("关闭数据库出错。");
}
}

    /**
     * 测试数据库是否成功连接
     * @param args
     */
public static void main(String[] args) {
Jdbc db = new Jdbc();
db.setDriver("sun.jdbc.odbc.JdbcOdbcDriver");
db.setConnection("jdbc:odbc:Archives", "用户名", "密码");
ResultSet res = db.sendQuery("测试SQA代码");
try {
while (res.next())
System.out.println(res.getString(1));
} catch (SQLException e) {
e.printStackTrace();
}
}
}