Spring Boot确保Web应用安全（登陆认证）

Spring Boot官方提供了一个登陆认证的清晰易懂的 例子 ，
我们在次以此例展开演示Spring Boot是如何实现登陆认证的。

首先我们去 https://start.spring.io/ 下载一个样例工程 spring-test。

我们这个例子中包含三个页面，放在src/main/resources/templates/目录下：

• 登陆页面：login.html
• 主页：home.html
• 欢迎页面：hello.html

包含三个类：

• 主类：SpringTestApplication.java
• MVC映射关系类：MvcConfig.java
• 安全控制类：WebSecurityConfig.java

相关的maven依赖：

pom.xml

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- tag::security[] -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <!-- end::security[] -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

MvcConfig.java

package com.zifeiy.springtest.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class MvcConfig implements WebMvcConfigurer {

    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/home").setViewName("home");
        registry.addViewController("/").setViewName("home");
        registry.addViewController("/hello").setViewName("hello");
        registry.addViewController("/login").setViewName("login");
    }

}

这个类主要用于配置url和view的对应关系。

WebSecurityConfig.java

package com.zifeiy.springtest.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
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.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/", "/home").permitAll()
                .anyRequest().authenticated()
                .and()
            .formLogin()
                .loginPage("/login")
                .permitAll()
                .and()
            .logout()
                .permitAll();
    }

    @Bean
    @Override
    public UserDetailsService userDetailsService() {
        UserDetails user =
             User.withDefaultPasswordEncoder()
                .username("user")
                .password("password")
                .roles("USER")
                .build();

        return new InMemoryUserDetailsManager(user);
    }
}

其中：

        http
            .authorizeRequests()
                .antMatchers("/", "/home").permitAll()
                .anyRequest().authenticated()
                .and()
            .formLogin()
                .loginPage("/login")
                .permitAll()
                .and()
            .logout()
                .permitAll();

表示的意思是：
允许所有用户可以访问"/"和"/home"；
通过form上传表单的形式登陆，form对应的url为"/login"；
允许所有用户登出（logout）。
但是除此之外的所有的url都不能直接访问，除非登陆了，比如这里的"/hello"链接，就不能直接登陆。

这里的 UserDetails 用于设置登陆的用户名为user，密码为password的时候才能正确登陆。

login.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
    <head>
        <title>Spring Security Example </title>
    </head>
    <body>
        <div th:if="${param.error}">
            Invalid username and password.
        </div>
        <div th:if="${param.logout}">
            You have been logged out.
        </div>
        <form th:action="@{/login}" method="post">
            <div><label> User Name : <input type="text" name="username"/> </label></div>
            <div><label> Password: <input type="password" name="password"/> </label></div>
            <div><input type="submit" value="Sign In"/></div>
        </form>
    </body>
</html>

home.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org" xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
    <head>
        <title>Spring Security Example</title>
    </head>
    <body>
        <h1>Welcome!</h1>
        
        <p>Click <a th:href="@{/hello}">here</a> to see a greeting.</p>
    </body>
</html>

hello.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
    <head>
        <title>Hello World!</title>
    </head>
    <body>
        <h1 th:inline="text">Hello [[${#httpServletRequest.remoteUser}]]!</h1>
        <form th:action="@{/logout}" method="post">
            <input type="submit" value="Sign Out"/>
        </form>
    </body>
</html>