java通过Servlet连接mysql数据库

第一步：创建Servletimport java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sq...

龙游有方

7235人浏览 · 2018-12-05 09:42:47

龙游有方 · 2018-12-05 09:42:47 发布

第一步：创建Servlet

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ConnectionServlet
 */
public class ConnectionServlet extends HttpServlet {
	Connection con;
	public void init() {
		String driver = getInitParameter("driver");
		String url = getInitParameter("url");
		String name = getInitParameter("user");
		String pass = getInitParameter("password");
		try {
			Class.forName(driver);
			con=DriverManager.getConnection(url,name,pass);
		}catch(ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}
	}
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public ConnectionServlet() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */

		// TODO Auto-generated method stub
		//response.getWriter().append("Served at: ").append(request.getContextPath());
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException,ServletException{
			request.setCharacterEncoding("UTF-8");
			response.setContentType("text/html;charset=UTF-8");
			PrintWriter out=response.getWriter();
			String bookName=request.getParameter("bookName");
			ResultSet rst=getBook(bookName);
			out.println("<table border=1><tr><td>图书名</td><td>出版社</td><td>价格</td></tr>");
			try {
				while(rst.next()) {
					out.println("<tr>");
					out.println("<td>"+rst.getString("bookname")+"</td>");
					out.println("<td>"+rst.getString("publisher")+"</td>");
					out.println("<td>"+rst.getString("price")+"</td>");
					out.println("</tr>");
				}
				out.println("</table>");
				rst.close();
			}catch(Exception e) {
				
			}
		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException,ServletException{
		// TODO Auto-generated method stub
		//init();
		doGet(request, response);
	}
	public ResultSet getBook(String bookName) {
		try {
			Statement stm=con.createStatement();
			ResultSet result=stm.executeQuery("select * from books where bookname='"+bookName+"'");
			return result;
		}catch(Exception e) {
			return null;
		}
	}

}

第二步：配置xml文件

在eclipse中找到该项目的xml文件
在这里插入图片描述

修改xml

在这里插入图片描述

第三步：编写一个html来测试servlet

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<hr><center>输入图书名，点击按钮操作.<br>
  <form action="ConnectionServlet" method="post">
     <table>
        <tr><td>图书名：<input type="text" name="bookName"></td></tr>
        <tr><td><input type="submit" name="action" value="查询"></td></tr>
     </table>
  </form></center>
</body>
</html>