什么是SpringSecurity ? Spring Security是一个能够为基于Spring的企业应用系统提供声明式的安全访问控制解决方案的安全框架。它提供了一组可以在Spring应用上下文中配置的Bean,充分利用了Spring IoC,DI(控制反转Inversion of Control ,DI:Dependency Injection 依赖注入)和AOP(面向切面编程)功能,为应用系统提供声明式的安全访问控制功能,减少了为企业系统安全控制编写大量重复代码的工作。以上来介绍来自wiki,比较官方。 用自己的话 简单介绍一下,Spring Security 基于 Servlet 过滤器链的形式,为我们的web项目提供认证与授权服务。它来自于Spring,那么它与SpringBoot整合开发有着天然的优势,目前与SpringSecurity对应的开源框架还有shiro。接下来我将通过一个简单的例子带大家来认识SpringSecurity,然后通过分析它的源码带大家来认识一下SpringSecurity是如何工作,从一个简单例子入门,大家由浅入深的了解学习SpringSecurity。通常大家在做一个后台管理的系统的时候,应该采用session判断用户是否登录。我记得我在没有接触学习SpringSecurity与shiro之前。对于用户登录功能实现通常是如下:public String login(User user, HttpSession session){ //1、根据用户名或者id从数据库读取数据库中用户 //2、判断密码是否一致 //3、如果密码一致 session.setAttribute(“user”,user); //4、否则返回登录页面 }对于之后那些需要登录之后才能访问的url,通过SpringMvc的拦截器中的#preHandle来判断session中是否有user对象如果没有 则返回登录页面如果有, 则允许访问这个页面。但是在SpringSecurity中,这一些逻辑已经被封装起来,我们只需要简单的配置一下就能使用。接下来我通过一个简单例子大家认识一下SpringSecurity本文基于SpringBoot,如果大家对SpringBoot不熟悉的话可以看看我之前写的SpringBoot入门系列我使用的是:SpringBoot 2.1.4.RELEASESpringSecurity 5<?xml version=“1.0” encoding=“UTF-8”?><project xmlns=“http://maven.apache.org/POM/4.0.0" xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=“http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.4.RELEASE</version> <relativePath/> <!– lookup parent from repository –> </parent> <groupId>com.yukong</groupId> <artifactId>springboot-springsecurity</artifactId> <version>0.0.1-SNAPSHOT</version> <name>springboot-springsecurity</name> <description>springboot-springsecurity study</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-security</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <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> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>配置一下数据库 以及MyBatisspring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://127.0.0.1:3306/db_test?useUnicode=true&characterEncoding=utf8 password: abc123mybatis: mapper-locations: classpath:mapper/*.xml这里我用的MySQL8.0 大家注意一下 MySQL8.0的数据库驱动的类的包改名了在前面我有讲过SpringBoot中如何整合Mybatis,在这里我就不累述,有需要的话看这篇文章user.sqlCREATE TABLE user ( id bigint(20) NOT NULL AUTO_INCREMENT COMMENT ‘主键’, username varchar(32) NOT NULL COMMENT ‘用户名’, svc_num varchar(32) DEFAULT NULL COMMENT ‘用户号码’, password varchar(100) DEFAULT NULL COMMENT ‘密码’, cust_id bigint(20) DEFAULT NULL COMMENT ‘客户id 1对1’, PRIMARY KEY (id)) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;对应的UserMapper.javapackage com.yukong.mapper;import com.yukong.entity.User;/** * * @author yukong * @date 2019-04-11 16:50 /public interface UserMapper { int insertSelective(User record); User selectByUsername(String username);}UserMapper.xml<?xml version=“1.0” encoding=“UTF-8”?><!DOCTYPE mapper PUBLIC “-//mybatis.org//DTD Mapper 3.0//EN” “http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace=“com.yukong.mapper.UserMapper”> <resultMap id=“BaseResultMap” type=“com.yukong.entity.User”> <id column=“id” jdbcType=“BIGINT” property=“id” /> <result column=“username” jdbcType=“VARCHAR” property=“username” /> <result column=“svc_num” jdbcType=“VARCHAR” property=“svcNum” /> <result column=“password” jdbcType=“VARCHAR” property=“password” /> <result column=“cust_id” jdbcType=“BIGINT” property=“custId” /> </resultMap> <sql id=“Base_Column_List”> id, username, svc_num, password, cust_id </sql> <select id=“selectByUsername” parameterType=“java.lang.String” resultMap=“BaseResultMap”> select <include refid=“Base_Column_List” /> from user where username = #{username,jdbcType=VARCHAR} </select> <insert id=“insertSelective” keyColumn=“id” keyProperty=“id” parameterType=“com.yukong.entity.User” useGeneratedKeys=“true”> insert into user <trim prefix=”(” suffix=”)” suffixOverrides=","> <if test=“username != null”> username, </if> <if test=“svcNum != null”> svc_num, </if> <if test=“password != null”> password, </if> <if test=“custId != null”> cust_id, </if> </trim> <trim prefix=“values (” suffix=")" suffixOverrides=","> <if test=“username != null”> #{username,jdbcType=VARCHAR}, </if> <if test=“svcNum != null”> #{svcNum,jdbcType=VARCHAR}, </if> <if test=“password != null”> #{password,jdbcType=VARCHAR}, </if> <if test=“custId != null”> #{custId,jdbcType=BIGINT}, </if> </trim> </insert></mapper>在这里我们定义了两个方法。国际惯例ctrl+shift+t创建mapper的测试方法,并且插入一条记录package com.yukong.mapper;import com.yukong.SpringbootSpringsecurityApplicationTests;import com.yukong.entity.User;import org.junit.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.security.crypto.password.PasswordEncoder;import static org.junit.Assert.;/** * @author yukong * @date 2019-04-11 16:53 /public class UserMapperTest extends SpringbootSpringsecurityApplicationTests { @Autowired private UserMapper userMapper; @Test public void insert() { User user = new User(); user.setUsername(“yukong”); user.setPassword(“abc123”); userMapper.insertSelective(user); }}运行测试方法,并且成功插入一条记录。创建UserController.javapackage com.yukong.controller;import com.yukong.entity.User;import com.yukong.mapper.UserMapper;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;/* * @author yukong * @date 2019-04-11 15:22 /@RestControllerpublic class UserController { @Autowired private UserMapper userMapper; @RequestMapping("/user/{username}") public User hello(@PathVariable String username) { return userMapper.selectByUsername(username); }}这个方法就是根据用户名去数据库查找用户详细信息。启动。因为我们之前插入过一条username=yukong的记录,所以我们查询一下,访问127.0.0.1:8080/user/yukong[图片上传失败…(image-ea02ac-1554981869345)]我们可以看到 我们被重定向到了一个登录界面,这也是我们之前引入的spring-boot-security-starter起作用了。大家可能想问了,用户名跟密码是什么,用户名默认是user,密码在启动的时候已经通过日志打印在控制台了。现在我们输入用户跟密码并且登录。就可以成功访问我们想要访问的接口。从这里我们可以知道,我只需要引入了Spring-Security的依赖,它就开始生效,并且保护我们的接口了,但是现在有一个问题就是,它的用户名只能是user并且密码是通过日志打印在控制台,但是我们希望它能通过数据来访问我们的用户并且判断登录。其实想实现这个功能也很简单。这里我们需要了解两个接口。UserDetailsUserDetailsService所以,我们需要将我们的User.java实现这个接口package com.yukong.entity;import org.springframework.security.core.GrantedAuthority;import org.springframework.security.core.authority.AuthorityUtils;import org.springframework.security.core.userdetails.UserDetails;import java.util.Collection;/* * * @author yukong * @date 2019-04-11 16:50 /public class User implements UserDetails { /* * 主键 / private Long id; /* * 用户名 / private String username; /* * 用户号码 / private String svcNum; /* * 密码 / private String password; /* * 客户id 1对1 / private Long custId; public Long getId() { return id; } public void setId(Long id) { this.id = id; } @Override public String getUsername() { return username; } @Override public boolean isAccountNonExpired() { return false; } @Override public boolean isAccountNonLocked() { return false; } @Override public boolean isCredentialsNonExpired() { return false; } @Override public boolean isEnabled() { return false; } public void setUsername(String username) { this.username = username; } public String getSvcNum() { return svcNum; } public void setSvcNum(String svcNum) { this.svcNum = svcNum; } @Override public Collection<? extends GrantedAuthority> getAuthorities() { // 这里我们没有用到权限,所以返回一个默认的admin权限 return AuthorityUtils.commaSeparatedStringToAuthorityList(“admin”); } @Override public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public Long getCustId() { return custId; } public void setCustId(Long custId) { this.custId = custId; }}接下来我们再看看UserDetailsService它只有一个方法的声明,就是通过用户名去查找用户信息,从这里我们应该知道了,SpringSecurity回调UserDetails#loadUserByUsername去获取用户,但是它不知道用户信息存在哪里,所以定义成接口,让使用者去实现。在我们这个项目用 我们的用户是存在了数据库中,所以我们需要调用UserMapper的方法去访问数据库查询用户信息。这里我们新建一个类叫MyUserDetailsServiceImplpackage com.yukong.config;import com.yukong.mapper.UserMapper;import org.springframework.beans.factory.annotation.Autowired;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;/* * @author yukong * @date 2019-04-11 17:35 /@Servicepublic class MyUserDetailServiceImpl implements UserDetailsService { @Autowired private UserMapper userMapper; @Override public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException { return userMapper.selectByUsername(username); }}然后新建一个类去把我们的UserDetailsService配置进去这里我们新建一个SecurityConfigpackage com.yukong.config;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.WebSecurityConfigurerAdapter;import org.springframework.security.core.userdetails.UserDetailsService;import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;import org.springframework.security.crypto.password.PasswordEncoder;/* * @author yukong * @date 2019-04-11 15:08 /@Configurationpublic class SecurityConfig extends WebSecurityConfigurerAdapter { @Autowired private UserDetailsService userDetailsService; @Bean public PasswordEncoder passwordEncoder(){ return new BCryptPasswordEncoder(); } @Autowired public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception { // 配置UserDetailsService 跟 PasswordEncoder 加密器 auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder()); auth.eraseCredentials(false); }}在这里我们还配置了一个PasswordEncoder加密我们的密码,大家都知道密码明文存数据库是很不安全的。接下里我们插入一条记录,需要注意的是 密码需要加密。package com.yukong.mapper;import com.yukong.SpringbootSpringsecurityApplicationTests;import com.yukong.entity.User;import org.junit.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.security.crypto.password.PasswordEncoder;import static org.junit.Assert.;/** * @author yukong * @date 2019-04-11 16:53 */public class UserMapperTest extends SpringbootSpringsecurityApplicationTests { @Autowired private PasswordEncoder passwordEncoder; @Autowired private UserMapper userMapper; @Test public void insert() { User user = new User(); user.setUsername(“yukong”); user.setPassword(passwordEncoder.encode(“abc123”)); userMapper.insertSelective(user); }}接下来启动程序,并且登录,这次只需要输入插入到数据中的那条记录的用户名跟密码即可。在这里一节中,我们了解到如何使用springsecurity 完成一个登录功能,接下我们将通过分析源码来了解为什么需要这个配置,以及SpringSecurity的工作原理是什么。