使用Java和Spring Boot实现用户身份验证

使用Java和Spring Boot实现用户身份验证

大家好，我是微赚淘客系统3.0的小编，是个冬天不穿秋裤，天冷也要风度的程序猿！

在现代Web应用中，用户身份验证是确保应用安全的核心部分。通过身份验证，我们可以识别用户的身份，并为他们提供相应的访问权限。本文将介绍如何使用Java和Spring Boot实现用户身份验证，包括配置Spring Security、创建用户实体、设置安全过滤器等。

1. 引入Spring Security依赖

在Spring Boot项目中引入Spring Security依赖是第一步。我们需要在pom.xml中添加以下依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

2. 配置Spring Security

为了配置Spring Security，我们需要创建一个配置类SecurityConfig，并在其中定义身份验证的逻辑。

package cn.juwatech.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/login").permitAll()
                .anyRequest().authenticated()
            .and()
            .formLogin()
                .loginPage("/login")
                .defaultSuccessURL("/home", true)
                .permitAll()
            .and()
            .logout()
                .permitAll();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
            .withUser("user")
            .password(passwordEncoder().encode("password"))
            .roles("USER");
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

3. 创建用户实体类

我们需要创建一个用户实体类来表示用户信息，并与数据库表进行映射。

package cn.juwatech.model;

import javax.persistence.*;

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, unique = true)
    private String username;

    @Column(nullable = false)
    private String password;

    // getters and setters
}

4. 创建Repository接口

创建一个Repository接口来访问用户数据。

package cn.juwatech.repository;

import cn.juwatech.model.User;
import org.springframework.data.jpa.repository.JpaRepository;

public interface UserRepository extends JpaRepository<User, Long> {
    User findByUsername(String username);
}

5. 自定义UserDetailsService

我们需要实现一个自定义的UserDetailsService来从数据库中加载用户信息。

package cn.juwatech.service;

import cn.juwatech.model.User;
import cn.juwatech.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.stereotype.Service;

import java.util.HashSet;
import java.util.Set;

@Service
public class CustomUserDetailsService implements UserDetailsService {

    @Autowired
    private UserRepository userRepository;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userRepository.findByUsername(username);
        if (user == null) {
            throw new UsernameNotFoundException("User not found");
        }

        Set<GrantedAuthority> grantedAuthorities = new HashSet<>();
        grantedAuthorities.add(new SimpleGrantedAuthority("ROLE_USER"));

        return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(), grantedAuthorities);
    }
}

6. 修改SecurityConfig以使用自定义UserDetailsService

我们需要在SecurityConfig中配置自定义的UserDetailsService。

package cn.juwatech.config;

import cn.juwatech.service.CustomUserDetailsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private CustomUserDetailsService customUserDetailsService;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/login").permitAll()
                .anyRequest().authenticated()
            .and()
            .formLogin()
                .loginPage("/login")
                .defaultSuccessURL("/home", true)
                .permitAll()
            .and()
            .logout()
                .permitAll();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(customUserDetailsService).passwordEncoder(passwordEncoder());
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

7. 创建登录页面和控制器

创建一个简单的登录页面和控制器来处理登录请求。

login.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Login</title>
</head>
<body>
    <h1>Login</h1>
    <form th:action="@{/login}" method="post">
        <div>
            <label>Username:</label>
            <input type="text" name="username"/>
        </div>
        <div>
            <label>Password:</label>
            <input type="password" name="password"/>
        </div>
        <div>
            <button type="submit">Login</button>
        </div>
    </form>
</body>
</html>

LoginController.java

package cn.juwatech.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class LoginController {

    @GetMapping("/login")
    public String login() {
        return "login";
    }
}

8. 创建主页控制器

创建一个简单的主页控制器来处理登录成功后的请求。

HomeController.java

package cn.juwatech.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class HomeController {

    @GetMapping("/home")
    public String home() {
        return "home";
    }
}

home.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Home</title>
</head>
<body>
    <h1>Welcome Home!</h1>
    <a th:href="@{/logout}">Logout</a>
</body>
</html>

9. 运行项目

启动Spring Boot应用并访问http://localhost:8080/login，使用用户名user和密码password登录，成功登录后将重定向到主页。

总结

通过本文，我们学习了如何使用Java和Spring Boot实现用户身份验证。从配置Spring Security到创建自定义UserDetailsService，我们逐步实现了一个简单而完整的用户身份验证系统。

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