Servlet案例4：用户注册

数据库准备：

CREATE DATABASE web;
USE web;
CREATE TABLE `user` (
  `uid` VARCHAR(64) NOT NULL,
  `username` VARCHAR(20) DEFAULT NULL,
  `password` VARCHAR(20) DEFAULT NULL,
  `name` VARCHAR(20) DEFAULT NULL,
  `email` VARCHAR(30) DEFAULT NULL,
  `telephone` VARCHAR(20) DEFAULT NULL,
  `birthday` VARCHAR(20) DEFAULT NULL,
  `sex` VARCHAR(10) DEFAULT NULL,
  `state` INT(11) DEFAULT NULL,
  `code` VARCHAR(64) DEFAULT NULL,
  PRIMARY KEY (`uid`)
)

对应的类：

package register;

public class User {
    private String uid;
    private String username;
    private String password;
    private String name;
    private String email;
    private String sex;
    private String birthday;

    public String getUid() {
        return uid;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getBirthday() {
        return birthday;
    }

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }

    @Override
    public String toString() {
        return "User [uid=" + uid + ", username=" + username + ", password=" + password + ", name=" + name + ", email="
                + email + ", sex=" + sex + ", birthday=" + birthday + "]";
    }

}

注册登录页面很简单，一个表单即可，这里省略

servlet:

package register;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.sql.SQLException;
import java.util.Map;
import java.util.UUID;

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

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.dbutils.QueryRunner;

public class RegisterServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //中文乱码的解决
        request.setCharacterEncoding("UTF-8");

        //中文乱码的解决原理
        /*
        String username = request.getParameter("username");
        username = new String(username.getBytes("iso8859-1"),"UTF-8");
        */

        // 获取数据
        // 将数据封装（使用BeanUtils自动封装）
        Map<String, String[]> properties = request.getParameterMap();
        User user = new User();
        try {
            BeanUtils.populate(user, properties);
        } catch (IllegalAccessException | InvocationTargetException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        // users对象封装完毕，手动封装主键uid(使用uuid)
        user.setUid(UUID.randomUUID().toString());
        // 注册的方法
        regist(user);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    public void regist(User user) {
        QueryRunner runner = new QueryRunner(DataSourceUtils.getDataSource());
        String sql = "insert into user values(?,?,?,?,?,?,?,?,?,?)";
        try {
            runner.update(sql, user.getUid(), user.getUsername(), user.getPassword(), user.getName(), user.getEmail(),
                    null, user.getBirthday(), user.getSex(), null, null);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

抽取的连接池工具类：

package register;

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;

public class DataSourceUtils {

    private static DataSource dataSource = new ComboPooledDataSource();

    private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();

    // 直接可以获取一个连接池
    public static DataSource getDataSource() {
        return dataSource;
    }

    // 获取连接对象
    public static Connection getConnection() throws SQLException {

        Connection con = tl.get();
        if (con == null) {
            con = dataSource.getConnection();
            tl.set(con);
        }
        return con;
    }

    // 开启事务
    public static void startTransaction() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.setAutoCommit(false);
        }
    }

    // 事务回滚
    public static void rollback() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.rollback();
        }
    }

    // 提交并且 关闭资源及从ThreadLocall中释放
    public static void commitAndRelease() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.commit(); // 事务提交
            con.close();// 关闭资源
            tl.remove();// 从线程绑定中移除
        }
    }

    // 关闭资源方法
    public static void closeConnection() throws SQLException {
        Connection con = getConnection();
        if (con != null) {
            con.close();
        }
    }

    public static void closeStatement(Statement st) throws SQLException {
        if (st != null) {
            st.close();
        }
    }

    public static void closeResultSet(ResultSet rs) throws SQLException {
        if (rs != null) {
            rs.close();
        }
    }

}

c3p0-config.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
    <default-config>
        <property name="user">root</property>
        <property name="password">xuyiqing</property>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="jdbcUrl">jdbc:mysql:///web</property>
    </default-config>
</c3p0-config> 

注意导入相关jar包

web.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>WEB5</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>RegisterServlet</display-name>
    <servlet-name>RegisterServlet</servlet-name>
    <servlet-class>register.RegisterServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>RegisterServlet</servlet-name>
    <url-pattern>/register</url-pattern>
  </servlet-mapping>
</web-app>

原文地址：https://www.cnblogs.com/xuyiqing/p/8412782.html