dbconnectmysql.java

JAVA案例开发集锦源代码 袁然 郑自国编

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.net.*;
import java.sql.*;
import java.text.DateFormat;
import java.util.Locale;

public class DBConnectSample extends HttpServlet {

  public void init() throws ServletException {
    try {
      Class.forName("org.gjt.mm.mysql.Driver").newInstance();
    }
	//创建实例
    catch (Exception e) {
    }
  }

  public void doPost(HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException {
    ServletOutputStream out = res.getOutputStream();
    // 用户名
    String userName = req.getParameter("username");
	//SQL语句
    String sqlStr = "select * from person where username= '" + userName + "'";
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    try {
      // 数据库连接
      conn = getConnection();
      stmt = conn.createStatement();
      // 执行查询操作
      rs = stmt.executeQuery(sqlStr);
      res.setContentType("text/html");
	//输出用户相关信息
      if (rs.next()) {
        out.println("<TABLE WIDTH=\"50%\" ALIGN=\"CENTER\" BORDER=\"1\">");
        out.println("<TR><TD COLSPAN=\"2\">User " + userName + " Info: </TD></TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Name:</TD><TD>" + rs.getString("TRUENAME") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Birthday:</TD><TD>" + rs.getString("BIRTHDAY") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Identity No:</TD><TD>" + rs.getString("IDENTITY_NO") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Office Telephone:</TD><TD>" + rs.getString("OFFICEPHONE") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Home Telephone:</TD><TD>" + rs.getString("HOMEPHONE") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Mobilephone:</TD><TD>" + rs.getString("MOBILEPHONE") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Email:</TD><TD>" + rs.getString("EMAIL") + "</TD>");
        out.println("</TR>");
        out.println("<TR ALIGN=\"LEFT\">");
        out.println("<TD>Address:</TD><TD>" + rs.getString("ADDRESS") + "</TD>");
        out.println("</TR>");
        out.println("</TABLE>");
      }
    }
    catch (SQLException se) {
      System.out.println("查询数据库记录时出现异常.");
    }
    finally {
      try {
        if (conn != null)
          conn.close();
        if (stmt != null)
          stmt.close();
        if (rs != null)
          rs.close();
      } catch (Exception e) {
      }//如果创建了连接，则关闭所有连接

    }
  }

  private Connection getConnection() {
    Connection conn = null;
    String dbUrl = "jdbc:mysql://10.21.88.88/mysql3235";
	//数据库的JDBC URL
    String dbUser = "root";
	//数据库帐号
    String dbPassword = "yyoa2";
	//数据密码
    try {
      conn = DriverManager.getConnection(dbUrl, dbUser, dbPassword);
	//数据库连接
    }
    catch (SQLException sqlexception) {
      System.out.println("数据库连接异常.");
    }
    return conn;
	//返回一个数据库连接
  }

}