資源簡介
最簡單粗暴的mysql數據庫訪問,實現簡單用戶名和密碼登錄功能,最直接的演示 操作jsp+servlet+mysql

代碼片段和文件信息
package?com.test;
import?java.io.IOException;
import?java.io.PrintWriter;
import?java.sql.DriverManager;
import?java.sql.PreparedStatement;
import?java.sql.ResultSet;
import?java.sql.SQLException;
import?javax.servlet.ServletException;
import?javax.servlet.http.HttpServlet;
import?javax.servlet.http.HttpServletRequest;
import?javax.servlet.http.HttpServletResponse;
import?com.mysql.jdbc.Connection;
/**
?*?Servlet?implementation?class?LoginServlet
?*/
//如果在web.xml中聲明過servlet?就把這一句注釋掉
//@WebServlet(“/LoginServlet“)
public?class?LoginServlet?extends?HttpServlet?{
private?static?final?long?serialVersionUID?=?1L;
???????
????/**
?????*?@see?HttpServlet#HttpServlet()
?????*/
????public?LoginServlet()?{
????????super();
????????//?TODO?Auto-generated?constructor?stub
????}
/**
?*?@see?HttpServlet#doGet(HttpServletRequest?request?HttpServletResponse?response)
?*/
protected?void?doGet(HttpServletRequest?request?HttpServletResponse?response)?throws?ServletException?IOException?{
//?TODO?Auto-generated?method?stub
response.getWriter().append(“Served?at:?“).append(request.getContextPath());
}
/**
?*?@see?HttpServlet#doPost(HttpServletRequest?request?HttpServletResponse?response)
?*/
protected?void?doPost(HttpServletRequest?request?HttpServletResponse?response)?throws?ServletException?IOException?{
request.setCharacterEncoding(“utf-8“);
response.setCharacterEncoding(“utf-8“);
response.setContentType(“text/html;?charset=UTF-8“);
//mysql數據庫驅動
String?driver?=?“com.mysql.jdbc.Driver“;
//鏈接數據庫的url?test為數據庫名
String?url?=?“jdbc:mysql://127.0.0.1:3306/test“;
//數據庫用戶
String?user?=?“root“;
//數據庫密碼
String?password?=?“yanglong123“;
//從前臺讀取到的用戶名
String?username?=?request.getParameter(“username“);
//從前臺讀取到的密碼
String?pwd?=?request.getParameter(“pwd“);
//數據庫鏈接成功時返回的實例
Connection?conn?=?null;
//查詢成功時返回的記錄集
ResultSet?rs?=?null;
try{
//加載驅動
Class.forName(driver);
//獲取鏈接
conn?=?(Connection)?DriverManager.getConnection(url?user?password);
//準備sql查詢
String?sql?=?“select?*?from?User?where?username=??and?pwd=?“;
//使用PreparedStatement,可以防止sql注入
PreparedStatement?ps?=?conn.prepareStatement(sql);
ps.setString(1?username);
ps.setString(2?pwd);
//執行查詢返回記錄集?
rs?=?ps.executeQuery();
//如果查詢到用戶名和密碼,則允許用戶登錄
if?(rs.next()){
System.out.println(“login?ok!!“);
PrintWriter?out?=?response.getWriter();
out.flush();
out.println(“ript>“);
out.println(“alert(‘恭喜,登錄成功‘);“);
out.println(“history.back();“);
out.println(“ ript>“);
out.close();
}else{
System.out.println(“login?fail!!“);
PrintWriter?out?=?response.getWriter();
out.flush();
out.println(“ript>“);
out.println(“alert(‘很遺憾,用戶名或密碼錯誤‘);“);
out.println(“history.back();“);
out.println(“ ript>“);
out.close();
}
//關閉PreparedStatement
ps.close();
?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????838??2017-06-25?11:45??javaweb\mysql數據庫\test.sql
?????文件????????483??2019-05-22?09:46??javaweb\readme.txt
?????文件????????937??2017-06-25?10:13??javaweb\sourcecode\mysqlTest\.classpath
?????文件???????1042??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.project
?????文件????????567??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\.jsdtscope
?????文件????????364??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\org.eclipse.jdt.core.prefs
?????文件????????479??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\org.eclipse.wst.common.component
?????文件????????345??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\org.eclipse.wst.common.project.facet.core.xm
?????文件?????????49??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\org.eclipse.wst.jsdt.ui.superType.container
?????文件??????????6??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\.settings\org.eclipse.wst.jsdt.ui.superType.name
?????文件???????3877??2017-06-25?11:33??javaweb\sourcecode\mysqlTest\build\classes\com\test\LoginServlet.class
?????文件???????3647??2017-06-25?11:33??javaweb\sourcecode\mysqlTest\src\com\test\LoginServlet.java
?????文件?????141182??2017-06-25?10:19??javaweb\sourcecode\mysqlTest\WebContent\css\bootstrap.css
?????文件???????1676??2017-06-25?11:26??javaweb\sourcecode\mysqlTest\WebContent\index.jsp
?????文件??????70843??2017-06-25?10:19??javaweb\sourcecode\mysqlTest\WebContent\js\jquery.js
?????文件?????????39??2017-06-25?10:12??javaweb\sourcecode\mysqlTest\WebContent\me
?????文件?????536609??2017-06-02?09:08??javaweb\sourcecode\mysqlTest\WebContent\WEB-INF\lib\mysql-connector-java-5.0.7-bin.jar
?????文件???????1012??2017-06-25?10:47??javaweb\sourcecode\mysqlTest\WebContent\WEB-INF\web.xm
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\build\classes\com\test
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\build\classes\com
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\src\com\test
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\WebContent\WEB-INF\lib
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\build\classes
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\src\com
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\WebContent\css
?????目錄??????????0??2017-06-25?10:19??javaweb\sourcecode\mysqlTest\WebContent\img
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\WebContent\js
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\WebContent\me
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\WebContent\WEB-INF
?????目錄??????????0??2017-06-25?11:44??javaweb\sourcecode\mysqlTest\.settings
............此處省略10個文件信息
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