需求：完成用户登录页面校验
第一步：创建一个用户登录的html页面
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/WEB13/login" method="post">
用户名：<input type="text" name="username" /><br/>
密码：<input type="password" name="password" /><br/>
<input type="submit" value="登录"/><br/>
</form>
</body>
</html>
第二步：导入所需要的jar包
导入jar之后记得add to bulid path.
第三步：创建c3p0连接池的配置文件，文件名为c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config> <default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql:///web13</property>
<property name="user">root</property>
<property name="password">root</property>
<property name="initialPoolSize">5</property>
<property name="maxPoolSize">20</property>
</default-config> <named-config name="myconfig">
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql:///web13</property>
<property name="user">root</property>
<property name="password">root</property>
</named-config> </c3p0-config>
文件放到src目录下
第四步：创建c3p0工具类
package p1.utils; import java.sql.Connection;
import java.sql.SQLException; import javax.sql.DataSource; import com.mchange.v2.c3p0.ComboPooledDataSource; public class C3P0Utils {
private static ComboPooledDataSource dataSource = new ComboPooledDataSource(); public static DataSource getDataSource() {
return dataSource;
} public static Connection getConnection() {
try {
return dataSource.getConnection();
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
第五步：创建User类
package p3.domain;
public class User {
private int uid;
private String username;
private String upassword;
private String email;
public User(){}
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUpassword() {
return upassword;
}
public void setUpassword(String upassword) {
this.upassword = upassword;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public String toString() {
return "User [uid=" + uid + ", username=" + username + ", upassword=" + upassword + ", email=" + email + "]";
}
}第六步：编写LoginServlet类
package p2.login_servlet; import java.io.IOException;
import java.sql.SQLException; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler; import p1.utils.C3P0Utils;
import p3.domain.User; public class LoginServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 2查询数据库中是否有相应的用户名和密码
QueryRunner qr = new QueryRunner(C3P0Utils.getDataSource());
String sql = "select * from user where username=? and upassword=?";
Object[] params = {username,password};
User user = null;
try {
user = qr.query(sql, new BeanHandler<User>(User.class), params);
} catch (SQLException e) { e.printStackTrace();
}
// 3 根据返回结果给用户不同的显示信息
if(user!=null){
response.getWriter().write(user.toString());
response.getWriter().write(user.getUsername()+":登录成功");
}else{
response.getWriter().write("sorry the username or password is wrong");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
} }
第七部：发布的时候如果出现找不到网页404的情况，有时候重新启动tomcat就可以了。