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mac2025-01-10 7

JavaWeb+JDBC+登录验证

登录界面

js

CSS

body { padding-top: 40px; padding-bottom: 40px; background-color: #eee; } .form-signin { max-width: 330px; padding: 15px; margin: 0 auto; } .form-signin .form-signin-heading, .form-signin .checkbox { margin-bottom: 10px; } .form-signin .checkbox { font-weight: normal; } .form-signin .form-control { position: relative; height: auto; -webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box; padding: 10px; font-size: 16px; } .form-signin .form-control:focus { z-index: 2; } .form-signin input[type="email"] { margin-bottom: -1px; border-bottom-right-radius: 0; border-bottom-left-radius: 0; } .form-signin input[type="password"] { margin-bottom: 10px; border-top-left-radius: 0; border-top-right-radius: 0; }

##c3po配置文件

<?xml version="1.0" encoding="UTF-8" ?> <![CDATA[ jdbc:mysql://localhost:3306/mes?useUnicode=true&characterEncoding=UTF-8&useServerPrepStmts=true&prepStmtCacheSqlLimit=256&cachePrepStmts=true&prepStmtCacheSize=256&rewriteBatchedStatements=true ]]> com.mysql.jdbc.Driver root root <property name="acquireIncrement">3</property> <property name="initialPoolSize">10</property> <property name="minPoolSize">2</property> <property name="maxPoolSize">10</property> </default-config> ## dao.propertice

userDao=com.mes.dao.impl.UserDaoImpl

注解类： *package com.mes.annotaion;

import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface MyTransaction {

String value() default "openTransaction";

}

base baseDao package com.mes.base;

import java.sql.Connection;

import org.apache.commons.dbutils.handlers.BeanHandler;

import com.mes.common.ConnectionContext; import com.mes.utils.MyQueryRunner; import com.mes.utils.ReflectUtil; //UserDaoImpl extends BaseDao public class BaseDao implements Dao {

private Class<T> clazz; protected MyQueryRunner queryRunner=new MyQueryRunner(); public BaseDao() { this.clazz = ReflectUtil.getSupserGenericType(getClass());//使用�?个reflect工具类，返回T的类�? } @Override public T queryForBean(String sql, Object... args) { Connection conn=null; try { //获取连接 conn=ConnectionContext.getInstance().get(); return queryRunner.query(conn,sql,args,new BeanHandler<T>(clazz)); } catch (Exception e) { e.printStackTrace(); throw new RuntimeException("查询出现问题！！"); } }

}

BaseServlet package com.mes.base;

import java.io.IOException; import java.lang.reflect.Method;

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

import com.google.gson.Gson; import com.mes.common.JsonData;

/**

BaseServlet用来作为其它Servlet的父类

一个类多个请求处理方法，每个请求处理方法的原型与service相同！原型 = 返回值类型 + 方法名称 + 参数列表 / public class BaseServlet extends HttpServlet { @Override public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /* * 1. 获取method参数，它是用户想调用的方法 2. 把方法名称变成Method类的实例对象 3. 通过invoke()来调用这个方法 / String methodName = request.getParameter(“method”); Method method = null; /* * 2. 通过方法名称获取Method对象 */ try { method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class); } catch (Exception e) { throw new RuntimeException(“您要调用的方法：” + methodName + “它不存在！”, e); }

/** * 3. 通过method对象来调用它 */ try {//returnResult Object resultObj=method.invoke(this, request, response); //如果是json字符串，就直接写回数据给页面 if(resultObj!=null&&resultObj instanceof JsonData) { //这里要把resultobj也转换成json格式 JsonData jsonData=(JsonData) resultObj; Gson gson = new Gson(); String jsonStr = gson.toJson(jsonData,JsonData.class); //"{“success”:“true”,“result”:"{"":"","":""}",“message”:“info—”}" response.getWriter().print(jsonStr); return ; }

//如果不是json封装类，则得到跳转路径 String result=(String)resultObj; //"r:/WEB-INF/jsp/index.jsp" if(result != null && !result.trim().isEmpty()) {//如果请求处理方法返回不为空 int index = result.indexOf(":");//获取第一个冒号的位置 if(index == -1) {//如果没有冒号，使用转发 request.getRequestDispatcher(result).forward(request, response); } else {//如果存在冒号 String start = result.substring(0, index);//分割出前缀 String path = result.substring(index + 1);//分割出路径 if(start.equals("f")) {//前缀为f表示转发 request.getRequestDispatcher(path).forward(request, response); } else if(start.equals("r")) {//前缀为r表示重定向 response.sendRedirect(request.getContextPath() + path); } } }

} catch (Exception e) { throw new RuntimeException(e); } } }

Dao package com.mes.base;

public interface Dao {

T queryForBean(String sql,Object... args);

}

common CommonUtils

package com.mes.common;

import java.util.Map; import java.util.UUID;

import org.apache.commons.beanutils.BeanUtils; import org.apache.commons.beanutils.ConvertUtils;

/**

包含string的处理 */ public class CommonUtils {

//返回一个不重复的字符串 public static String uuid() { return UUID.randomUUID().toString().replace("-","").toUpperCase(); }

//map转换成bean public static T toBean(Map map,Class clazz) { try { //通过clazz创建实例 T bean=clazz.newInstance(); //使用beanutils.populute封装map数据到bean中 //日期格式转换 ConvertUtils.register(new DateConverter(“yyyy-MM-dd”),java.util.Date.class); BeanUtils.populate(bean, map);//map.put(“date”,string); //bean-date:Date return bean; } catch (Exception e) { throw new RuntimeException(e+“封装bean出了问题”); }

} }

connectionContext package com.mes.common;

import java.sql.Connection;

//连接的上下文工具,提供全局使用,保证线程变量的安�? public class ConnectionContext {//想成�?个存放线程的容器//做成单例模式，保证线程安�?

//饿汉�? private ConnectionContext() {} private static ConnectionContext instance=new ConnectionContext(); public static ConnectionContext getInstance() { return instance; } //准备本地线程变量 private ThreadLocal<Connection> connectionThreadLocal=// new ThreadLocal<Connection>(); public void bind(Connection conn) { connectionThreadLocal.set(conn); } public Connection get() { return connectionThreadLocal.get(); } public void remove() { connectionThreadLocal.remove(); }

}

DateConberter package com.mes.common;

import java.text.SimpleDateFormat;

import org.apache.commons.beanutils.Converter;

public class DateConverter implements Converter{ private String format; public DateConverter(String format) { this.format=format; } @Override public Object convert(Class type, Object value) { try { //我们遇到的需要转换的值是null，直接返回null if(value==null) return null; //接受到值并且需要转换成date类型，这个值如果不是String，不转 if(!(value instanceof String)) { return value; } //把值转换成string String val=(String)value; //日期格式化 SimpleDateFormat sdf=new SimpleDateFormat(format); //返回转换了格式的日期 return sdf.parse(val); }catch(Exception e) { throw new RuntimeException(e); } }

}

JsonDatapackage com.mes.common;

public class JsonData {

private boolean success=false; private Object result; private String message; public JsonData() { } public JsonData(boolean success) { this.success = success; } public JsonData(boolean success, Object result) { this.success = success; this.result = result; } public JsonData(boolean success, Object result, String message) { this.success = success; this.result = result; this.message = message; } public boolean isSuccess() { return success; } public void setSuccess(boolean success) { this.success = success; } public Object getResult() { return result; } public void setResult(Object result){ this.result = result; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; }

}

comtroller DispatcherServlet package com.mes.controller; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.mes.base.BaseServlet;

//用来转发页面 public class DispatcherServlet extends BaseServlet{ private static String RPATH=“r:/WEB-INF/jsp/”; private static String FPATH=“f:/WEB-INF/jsp/”; // /DispatcherServlet？method=loginPage //登录页面 public String loginPage(HttpServletRequest request,HttpServletResponse response) { return FPATH+“login.html”; }

//欢迎页面 public String mainPage(HttpServletRequest request,HttpServletResponse response) { return FPATH+"main.html"; }

} UserServlet package com.mes.controller;

import java.util.HashMap; import java.util.List; import java.util.Map;

import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession;

import com.google.gson.Gson; import com.mes.base.BaseServlet; import com.mes.common.CommonUtils; import com.mes.common.JsonData; import com.mes.dao.UserDao; import com.mes.factory.DaoFactory; import com.mes.pojo.User; //@Controller public class UserServlet extends BaseServlet{

private static String RPATH="r:/WEB-INF/jsp/"; private static String FPATH="f:/WEB-INF/jsp/"; //@Resource //private UserDao<User> userDao; private UserDao<User> userDao=(UserDao<User>) DaoFactory.getInstance().getDaoByName("userDao"); //用户登录 public JsonData loginAjax(HttpServletRequest request,HttpServletResponse response) { //准备好一个json对象 JsonData result=new JsonData(); //web2bean 2-to User user=CommonUtils.toBean(request.getParameterMap(), User.class); //query4Login queryForLogin User dbUser=userDao.query4Login(user.getLoginacct()); //比对密码 if(dbUser!=null&&user.getUserpasswd().equals(dbUser.getUserpasswd())) { //在服务器搞一个空间，用来专门存储这个指定浏览器的登录用户状态 HttpSession session=request.getSession(); session.setAttribute("loginUser",dbUser); result.setSuccess(true); }else { result.setSuccess(false); } return result; }

}

dao UserDaoImpl package com.mes.dao.impl;

import java.util.List; import java.util.Map;

import com.mes.base.BaseDao; import com.mes.dao.UserDao; import com.mes.pojo.User;

public class UserDaoImpl extends BaseDao implements UserDao {

@Override public User query4Login(String loginacct) { String sql="select * from mes_user where loginacct=?"; Object[] params=new Object[] {loginacct}; User user=queryForBean(sql, params); return user; }

}

UserDao

package com.mes.dao;

import java.util.List; import java.util.Map;

import com.mes.annotaion.MyTransaction; import com.mes.base.Dao;

public interface UserDao extends Dao{

public User query4Login(String loginacct);

}

factory DaoFactory package com.mes.factory;

import java.io.IOException; import java.io.InputStream; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import java.sql.Connection; import java.util.Properties;

import com.mes.annotaion.MyTransaction; import com.mes.base.Dao; import com.mes.common.ConnectionContext; import com.mes.utils.JdbcUtil;

public class DaoFactory {

//private Object target; private DaoFactory() { throw new RuntimeException("不可以反射哟"); } private DaoFactory(int init) {} private static DaoFactory instance=new DaoFactory(1); public static DaoFactory getInstance() { if(instance==null) { synchronized(DaoFactory.class) { if(instance==null) { instance=new DaoFactory(); } } } return instance; } //产生一个dao userDao--userDaoImpl public Dao getDaoByName(String daoName) { //获取这个dao-使用properties Properties prop=new Properties(); InputStream in=DaoFactory.class.getClassLoader()// .getResourceAsStream("dao.properties");

// InputStream in=new FileInputStream(“dao.properties”); try { //加载输入流，读取文件内容 prop.load(in); //classPath=com.mes.dao.impl.UserDaoImpl String classPath=prop.getProperty(daoName); if(classPath==null) { throw new RuntimeException(“没有文件”); } //通过反射的方式将类的全路径名，实例化出一个类对象 Dao targetDao=(Dao) Class.forName(classPath).newInstance(); //this.target=targetDao; //事务处理-采用的是动态代理技术 targetDao=(Dao) getTransactionDao(targetDao); return targetDao; } catch (IOException e) { throw new RuntimeException(“加载properties出问题”); } catch (Exception e) { throw new RuntimeException(“初始化dao出问题”); } }

public Object getTransactionDao(Object target) { return Proxy.newProxyInstance(// target.getClass().getClassLoader(), // target.getClass().getInterfaces(), // new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { Object result = null; // 若方法上有事务注解，则执行开启事�? MyTransaction ann = method.getDeclaredAnnotation(MyTransaction.class); Connection conn=null; // 判断注解不为空，取�?? if (ann != null) { // �?启事�?,以下实现真正的开启事务和关闭事务 // conn.rollback conn.commit String value = ann.value(); if (value.equals("openTransaction")) { try { // 开启一个连接 conn = JdbcUtil.getConnection(); // 开启事务 conn.setAutoCommit(false);// begin; // connection上下文绑定连接 ConnectionContext.getInstance().bind(conn); result = method.invoke(target, args);// userDao.add update delete // int i=10/0;

// conn=ConnectionContext.getInstance().get(); conn.commit(); } catch (Exception e) { conn.rollback(); throw new RuntimeException(e + “sql执行出问题，执行数据回滚”); } finally { // 释放资源 // 接触connection上下文的绑定状�?? ConnectionContext.getInstance().remove(); // 将connection放回连接�? JdbcUtil.close(conn, null, null); return result; } } } //不需要开启事务的 try { // 开启一个连接 conn = JdbcUtil.getConnection(); // connection上下文绑定连接 statement-sql ConnectionContext.getInstance().bind(conn); result = method.invoke(target, args);// userDao.add update delete } catch (Exception e) { throw new RuntimeException(e + “sql执行出问题，执行数据回滚”); } finally { ConnectionContext.getInstance().remove(); JdbcUtil.close(conn, null, null); return result; } } }); }

}

poji

package com.mes.pojo;

import java.io.Serializable;

public class User implements Serializable{ private static final long serialVersionUID = 2900466913200185672L; private Integer id;//用户id private String username;//用户名 private String loginacct;//用户类型 private String userpasswd;//密码 private String email;//电子邮件

public User() { } public User(Integer id, String username, String loginacct, String userpasswd, String email) { super(); this.id = id; this.username = username; this.loginacct = loginacct; this.userpasswd = userpasswd; this.email = email; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getLoginacct() { return loginacct; } public void setLoginacct(String loginacct) { this.loginacct = loginacct; } public String getUserpasswd() { return userpasswd; } public void setUserpasswd(String userpasswd) { this.userpasswd = userpasswd; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } @Override public String toString() { return "MesUser [id=" + id + ", username=" + username + ", loginacct=" + loginacct + ", userpasswd=" + userpasswd + ", email=" + email + "]"; }

}

utils jdbcUtils package com.mes.utils;

import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

//使用连接池，采用的c3p0连接�? public class JdbcUtil {

//使用c3p0连接�? private static DataSource ds=new ComboPooledDataSource();//close--List.add(conn) public static DataSource getDataSource() { return ds; } //自定义一个获取连接池中的连接方法 public static Connection getConnection()throws SQLException{ return ds.getConnection(); } public static void close(Connection conn,Statement state,ResultSet rs) { if(rs!=null) { try { rs.close();//oop--conn.close()----pool.add(conn) } catch (SQLException e) { throw new RuntimeException("关闭返回结果集失败！！！"); }finally { rs=null; } } if(state!=null) { try { state.close();//pool.add(conn) } catch (SQLException e) { throw new RuntimeException("关闭statement失败！！�??"); }finally { state=null; } } if(conn!=null) {//oop try { conn.close();//pool.add(conn) } catch (SQLException e) { throw new RuntimeException("根本就没有要关闭的连接！！！"); } } }

}

MyQueryRunner package com.mes.utils;

import java.sql.Connection; import java.sql.SQLException;

import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.ResultSetHandler;

public class MyQueryRunner extends QueryRunner{

//批量数据操作 @Override public int[] batch(Connection conn, String sql, Object[][] params) throws SQLException { int[] result=super.batch(conn, sql, params); return result; } //查询操作,传参数的方法 @Override public <T> T query(Connection conn, String sql, Object[] params, ResultSetHandler<T> rsh) throws SQLException { T result=super.query(conn, sql, params, rsh); return result; } //查询不带参数的方�? @Override public <T> T query(Connection conn, String sql,ResultSetHandler<T> rsh) throws SQLException { T result=super.query(conn, sql,rsh); return result; } //dml语句-update insert delete @Override public int update(Connection conn, String sql, Object... params) throws SQLException { int result=super.update(conn, sql, params); return result; } @Override public int update(Connection conn, String sql, Object param) throws SQLException { int result=super.update(conn, sql, param); return result; } @Override public int update(Connection conn, String sql) throws SQLException { int result=super.update(conn, sql); return result; }

}

ReflectUtils package com.mes.utils;

import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type;

public class ReflectUtil { //获取的一个泛型类类型 public static Class getSuperClassGenericType(Class clazz,int index) { Type genType=clazz.getGenericSuperclass(); // if(!(genType instanceof ParameterizedType)) { return Object.class; }

Type[] params=((ParameterizedType)genType).getActualTypeArguments(); // if(index>params.length || index<0) { return Object.class; } if(!(params[index] instanceof Class)) { return Object.class; } return (Class) params[index]; } //获取basedao类似结构的子类传递上来的类型 //返回T类型的字节码 //泛型方法，返回的泛型类型等于定义的泛型类�?? public static <T> Class<T> getSupserGenericType(Class clazz){ return getSuperClassGenericType(clazz,0); }

}

创建一个自定义列表

Markdown Text-to- HTML conversion tool Authors John Luke

如何创建一个注脚

一个具有注脚的文本。¹

注释也是必不可少的

Markdown将文本转换为 HTML。

KaTeX数学公式

您可以使用渲染LaTeX数学表达式 KaTeX:

Gamma公式展示 $\Gamma(n) = (n-1)!\quad\forall n\in\mathbb N$ 是通过欧拉积分

$\Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.$

你可以找到更多关于的信息 LaTeX 数学表达式here.

新的甘特图功能，丰富你的文章

Mon 06 Mon 13 Mon 20 已完成进行中计划一计划二现有任务 Adding GANTT diagram functionality to mermaid 关于甘特图语法，参考这儿,

UML 图表

可以使用UML图表进行渲染。 Mermaid. 例如下面产生的一个序列图：

张三李四王五你好！李四, 最近怎么样? 你最近怎么样，王五？我很好，谢谢! 我很好，谢谢! 李四想了很长时间, 文字太长了不适合放在一行. 打量着王五... 很好... 王五, 你怎么样? 张三李四王五

这将产生一个流程图。:

链接长方形圆圆角长方形菱形关于 Mermaid 语法，参考这儿,

FLowchart流程图

我们依旧会支持flowchart的流程图：

Created with Raphaël 2.2.0 开始我的操作确认？结束 yes no 关于 Flowchart流程图语法，参考这儿.

导出与导入

导出

如果你想尝试使用此编辑器, 你可以在此篇文章任意编辑。当你完成了一篇文章的写作, 在上方工具栏找到文章导出，生成一个.md文件或者.html文件进行本地保存。

导入

如果你想加载一篇你写过的.md文件，在上方工具栏可以选择导入功能进行对应扩展名的文件导入，继续你的创作。

注脚的解释 ↩︎

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