生成安全管理器

冷不防 2022-05-21 01:28 224阅读 0赞

*  生成安全管理器
    
     *  初始化安全管理器工厂
        
         *  获得ini对象
         *  设置ini对象
     *  获取安全管理器实例
        
         *  createSecurityManager
         *  createDefault
         *  buildInstances
         *  getSecurityManagerBean
         *  applyRealmsToSecurityManager
         *  initRealm
            
             *  生命周期初始化
         *  总结
     *  设置全局安全管理器对象
 *  附注
    
     *  加入新节区对象
 *  参考资料

# 生成安全管理器 #

@Before
        public void beforeInitial() {
    
            Factory<SecurityManager> factory = new IniSecurityManagerFactory("classpath:shiro.ini");
    
            SecurityManager securityManager = factory.getInstance();
    
            SecurityUtils.setSecurityManager(securityManager);
        }

这里做了三件事  
1. 初始化安全管理器工厂  
2. 获取安全管理器实例  
3. 设置全局安全管理器对象

## 初始化安全管理器工厂 ##

### 获得ini对象 ###

![IniSecurityManagerFactory 时序图][IniSecurityManagerFactory]

> new IniSecurityManagerFactory(“classpath:shiro.ini”);

IniSecurityManagerFactory

public IniSecurityManagerFactory(String iniResourcePath) {
            this(Ini.fromResourcePath(iniResourcePath));
        }

> this(Ini.fromResourcePath(iniResourcePath));

载入ini资源

Ini

public static Ini fromResourcePath(String resourcePath) throws ConfigurationException {
            if (!StringUtils.hasLength(resourcePath)) {
                throw new IllegalArgumentException("Resource Path argument cannot be null or empty.");
            }
            Ini ini = new Ini();
            ini.loadFromPath(resourcePath);
            return ini;
        }

> ini.loadFromPath(resourcePath);

public void loadFromPath(String resourcePath) throws ConfigurationException {
            InputStream is;
            try {
                is = ResourceUtils.getInputStreamForPath(resourcePath);
            } catch (IOException e) {
                throw new ConfigurationException(e);
            }
            load(is);
        }

**价值** ★★★☆

getInputStreamForPath

shiro载入配置文件的多种方式：  
1. `classpath:` 开头  
2. `url:` 开头  
3. `file:` 开头  
4. 默认从磁盘读取

读取失败就抛出异常

ResourceUtils

public static InputStream getInputStreamForPath(String resourcePath) throws IOException {
    
            InputStream is;
            if (resourcePath.startsWith(CLASSPATH_PREFIX)) {
                is = loadFromClassPath(stripPrefix(resourcePath));
    
            } else if (resourcePath.startsWith(URL_PREFIX)) {
                is = loadFromUrl(stripPrefix(resourcePath));
    
            } else if (resourcePath.startsWith(FILE_PREFIX)) {
                is = loadFromFile(stripPrefix(resourcePath));
    
            } else {
                is = loadFromFile(resourcePath);
            }
    
            if (is == null) {
                throw new IOException("Resource [" + resourcePath + "] could not be found.");
            }
    
            return is;
        }

### 设置ini对象 ###

> this(Ini.fromResourcePath(iniResourcePath));

![IniSecurityManagerFactory 类图][IniSecurityManagerFactory 1]

将 this.ini 设置为 获得的资源对象  
调用父类 AbstractFactory构造，设置 this.singleton = true;

public IniSecurityManagerFactory(Ini config) {
            setIni(config);
        }

## 获取安全管理器实例 ##

![IniSecurityManagerFactory 时序图][IniSecurityManagerFactory 2]  
从时序图上面来看,我们要跟进到 createSecurityManager 寻找下面两个问题的答案  
1. 如何创建 securityManager  
2. 如何填充里面的用户和权限信息的

public T getInstance() {
            T instance;
            // 已经设置为 true
            if (isSingleton()) {
                // 初次使用为null 
                if (this.singletonInstance == null) {
                    // createInstance 为abstract ,将由子类实例化
                    this.singletonInstance = createInstance();
                }
                instance = this.singletonInstance;
            } else {
                instance = createInstance();
            }
            if (instance == null) {
                String msg = "Factory 'createInstance' implementation returned a null object.";
                throw new IllegalStateException(msg);
            }
            return instance;
        }

IniFactorySupport 实现了createInstance

获取this.ini的值,如果存在就根据ini创建Instance,否则创建默认的Instance.

创建失败就抛出 IllegalStateException

public T createInstance() {
            Ini ini = resolveIni();
    
            T instance;
    
            if (CollectionUtils.isEmpty(ini)) {
                log.debug("No populated Ini available. Creating a default instance.");
                instance = createDefaultInstance();
                if (instance == null) {
                    String msg = getClass().getName() + " implementation did not return a default instance in " +
                            "the event of a null/empty Ini configuration. This is required to support the " +
                            "Factory interface. Please check your implementation.";
                    throw new IllegalStateException(msg);
                }
            } else {
                log.debug("Creating instance from Ini [" + ini + "]");
                instance = createInstance(ini);
                if (instance == null) {
                    String msg = getClass().getName() + " implementation did not return a constructed instance from " +
                            "the createInstance(Ini) method implementation.";
                    throw new IllegalStateException(msg);
                }
            }
    
            return instance;
        }

IniSecurityManagerFactory 本身实现 createInstance

protected SecurityManager createInstance(Ini ini) {
            if (CollectionUtils.isEmpty(ini)) {
                throw new NullPointerException("Ini argument cannot be null or empty.");
            }
            // 创建安全管理器
            SecurityManager securityManager = createSecurityManager(ini);
            if (securityManager == null) {
                String msg = SecurityManager.class + " instance cannot be null.";
                throw new ConfigurationException(msg);
            }
            return securityManager;
        }

创建安全管理器  
获取节区 \[main\] ,获取失败就获取 ” 节区

private SecurityManager createSecurityManager(Ini ini) {
    
            Ini.Section mainSection = ini.getSection(MAIN_SECTION_NAME);
            if (CollectionUtils.isEmpty(mainSection)) {
                //try the default:
                mainSection = ini.getSection(Ini.DEFAULT_SECTION_NAME);
            }
            return createSecurityManager(ini, mainSection);
        }

### createSecurityManager ###

**价值** ★★★★★

终于能看到返回 SecurityManager 的地方了 ,重中之中,配置信息都在这里加载

private SecurityManager createSecurityManager(Ini ini, Ini.Section mainSection) {
            // 创建默认的securityManager 和 iniRealm 对象
            Map<String, ?> defaults = createDefaults(ini, mainSection);
             // this.builder 初始化objects为 defaults
            // 实例化main节区的对象和填充属性 加入到builder 的objects 里面
            Map<String, ?> objects = buildInstances(mainSection, defaults);
            // 从defaults(this.builder.objects对象引用的defaults) 里面获取 SecurityManager
            SecurityManager securityMana ger = getSecurityManagerBean();
            //securityManager 是一个RealmSecurityManager，并且realms 不为空就为false
            // 查看: DefaultSecurityManager类图
            boolean autoApplyRealms = isAutoApplyRealms(securityManager);
    
            if (autoApplyRealms) {
                //realms and realm factory might have been created - pull them out first so we can
                //initialize the securityManager:
                Collection<Realm> realms = getRealms(objects);
                //set them on the SecurityManager
                if (!CollectionUtils.isEmpty(realms)) {
                    applyRealmsToSecurityManager(realms, securityManager);
                }
            }
            // securityManager 里面的realms 是否实现了org.apache.shiro.util.Initializable，实现了就调用init方法
            initRealms(securityManager);
    
            return securityManager;

DefaultSecurityManager类图

![DefaultSecurityManager类图][DefaultSecurityManager]

### createDefault ###

**级别7**

protected Map<String, ?> createDefaults(Ini ini, Ini.Section mainSection) {
            Map<String, Object> defaults = new LinkedHashMap<String, Object>();
            // 创建DefaultSecurityManager
            SecurityManager securityManager = createDefaultInstance();
            defaults.put(SECURITY_MANAGER_NAME, securityManager);
            // 验证ini是否为空,ini是否有[users]节区,[roles]节区
            if (shouldImplicitlyCreateRealm(ini)) {
                Realm realm = createRealm(ini);
                if (realm != null) {
                    defaults.put(INI_REALM_NAME, realm);
                }
            }
    
            return defaults;
        }

### buildInstances ###

这段内容很简单, , 做了下面两个步骤  
1. 创建当前的构建器 this.builder  
2. 构建目标节区对象,并返回 this.builder.objects.  
在本例中 目标节区为null,所以不会加入新的对象,

可以通过加入新节区对象获取更多信息

private Map<String, ?> buildInstances(Ini.Section section, Map<String, ?> defaults) {
            this.builder = new ReflectionBuilder(defaults);
            return this.builder.buildObjects(section);
        }

> this.builder = new ReflectionBuilder(defaults);

构造ReflectionBuilder时,设置成员变量 this.objects的值

ReflectionBuilder

public ReflectionBuilder(Map<String, ?> defaults) {
            this.objects = CollectionUtils.isEmpty(defaults) ? new LinkedHashMap<String, Object>() : defaults;
        }

### getSecurityManagerBean ###

通过builder 获取 securityManager 对象

public static final String SECURITY_MANAGER_NAME = "securityManager";
        private SecurityManager getSecurityManagerBean() {
            return builder.getBean(SECURITY_MANAGER_NAME, SecurityManager.class);
        }

> return builder.getBean(SECURITY\_MANAGER\_NAME, SecurityManager.class);

可以看出来,实际上就是当前ReflectionBuilder的objects中获取一个key为securityManager的对象,在强转为目标对象

ReflectionBuilder

public Object getBean(String id) {
            return objects.get(id);
        }
        public <T> T getBean(String id, Class<T> requiredType) {
            if (requiredType == null) {
                throw new NullPointerException("requiredType argument cannot be null.");
            }
            Object bean = getBean(id);
            if (bean == null) {
                return null;
            }
            if (!requiredType.isAssignableFrom(bean.getClass())) {
                throw new IllegalStateException("Bean with id [" + id + "] is not of the required type [" +
                        requiredType.getName() + "].");
            }
            return (T) bean;
        }

**级别8**  
根据创建Realm

protected Realm createRealm(Ini ini) {
             IniRealm realm = new IniRealm(ini);
             realm.setName(INI_REALM_NAME);
             return realm;
         }

IniRealm 类图:  
![IniRealm类图][IniRealm]

**级别9**

public IniRealm(Ini ini) {
            this();
            processDefinitions(ini);
        }

**级别10**  
1. 填充SimpleAccountRealm 的 Map

private void processDefinitions(Ini ini) {
            if (CollectionUtils.isEmpty(ini)) {
                log.warn("{} defined, but the ini instance is null or empty.", getClass().getSimpleName());
                return;
            }
    
            Ini.Section rolesSection = ini.getSection(ROLES_SECTION_NAME);
            if (!CollectionUtils.isEmpty(rolesSection)) {
                log.debug("Discovered the [{}] section. Processing...", ROLES_SECTION_NAME);
                processRoleDefinitions(rolesSection);
            }
    
            Ini.Section usersSection = ini.getSection(USERS_SECTION_NAME);
            if (!CollectionUtils.isEmpty(usersSection)) {
                log.debug("Discovered the [{}] section. Processing...", USERS_SECTION_NAME);
                processUserDefinitions(usersSection);
            } else {
                log.info("{} defined, but there is no [{}] section defined. This realm will not be populated with any " +
                        "users and it is assumed that they will be populated programatically. Users must be defined " +
                        "for this Realm instance to be useful.", getClass().getSimpleName(), USERS_SECTION_NAME);
            }
        }

### applyRealmsToSecurityManager ###

获取安全数据源集合

private Collection<Realm> getRealms(Map<String, ?> instances) {
    
            //realms and realm factory might have been created - pull them out first so we can
            //initialize the securityManager:
            List<Realm> realms = new ArrayList<Realm>();
    
            //iterate over the map entries to pull out the realm factory(s):
            for (Map.Entry<String, ?> entry : instances.entrySet()) {
    
                String name = entry.getKey();
                Object value = entry.getValue();
                // 加入用户创建的realm
                if (value instanceof RealmFactory) {
                    addToRealms(realms, (RealmFactory) value);
                } else if (value instanceof Realm) {
                // 加入iniRealm
                    Realm realm = (Realm) value;
                    //set the name if null:
                    String existingName = realm.getName();
                    if (existingName == null || existingName.startsWith(realm.getClass().getName())) {
                        if (realm instanceof Nameable) {
                            ((Nameable) realm).setName(name);
                            log.debug("Applied name '{}' to Nameable realm instance {}", name, realm);
                        } else {
                            log.info("Realm does not implement the {} interface. Configured name will not be applied.",
                                    Nameable.class.getName());
                        }
                    }
                    realms.add(realm);
                }
            }
    
            return realms;
        }

设置 securityManager 的 realms

protected void applyRealmsToSecurityManager(Collection<Realm> realms, SecurityManager securityManager) {
       // 验证 securityManager!=null 并且 securityManager 必须是一个 RealmSecurityManager
            assertRealmSecurityManager(securityManager);
            ((RealmSecurityManager) securityManager).setRealms(realms);
        }

> ((RealmSecurityManager) securityManager).setRealms(realms);

public void setRealms(Collection<Realm> realms) {
            if (realms == null) {
                throw new IllegalArgumentException("Realms collection argument cannot be null.");
            }
            if (realms.isEmpty()) {
                throw new IllegalArgumentException("Realms collection argument cannot be empty.");
            }
            this.realms = realms;
            // 依次调用父类的afterReamlSet
            afterRealmsSet();
        }

> afterRealmsSet();

AuthorizingSecurityManager 的 afterRealmsSet  
第三个设置 this.authorizer 的realms

protected void afterRealmsSet() {
            super.afterRealmsSet();
            if (this.authorizer instanceof ModularRealmAuthorizer) {
                ((ModularRealmAuthorizer) this.authorizer).setRealms(getRealms());
            }
        }

AuthenticatingSecurityManager 的 afterRealmsSet  
第二个设置 this.authenticator 的realms

protected void afterRealmsSet() {
            super.afterRealmsSet();
            if (this.authenticator instanceof ModularRealmAuthenticator) {
                ((ModularRealmAuthenticator) this.authenticator).setRealms(getRealms());
            }
        }

RealmSecurityManager 的 afterRealmsSet  
第一个设置 realms里面每个Realm 的缓存管理器

protected void afterRealmsSet() {
            applyCacheManagerToRealms();
        }

protected void applyCacheManagerToRealms() {
            CacheManager cacheManager = getCacheManager();
            Collection<Realm> realms = getRealms();
            if (cacheManager != null && realms != null && !realms.isEmpty()) {
                for (Realm realm : realms) {
                    if (realm instanceof CacheManagerAware) {
                        ((CacheManagerAware) realm).setCacheManager(cacheManager);
                    }
                }
            }
        }

### initRealm ###

初始化realm 做了什么呢?  
1. 验证安全管理器 不为空 并且 必须是 RealmSecurityManager 或者子类对象  
2. 获取 securityManager 的所有安全数据源  
3. 调用生命周期工具的初始化

private Collection<Realm> getRealms(SecurityManager securityManager) {
            assertRealmSecurityManager(securityManager);
            return ((RealmSecurityManager) securityManager).getRealms();
        }
    
        private void initRealms(SecurityManager securityManager) {
            Collection<Realm> realms = getRealms(securityManager);
            if (!CollectionUtils.isEmpty(realms)) {
                LifecycleUtils.init(realms);
            }
        }

#### 生命周期初始化 ####

> LifecycleUtils.init(realms);

从下面的代码可以看出来,实际上就是遍历集合,判断集合的每个元素是否实现了接口 Initializable.

如果实现了,就调用接口的init方法

// init((Initializable) o);
    public static void init(Initializable initializable) throws ShiroException {
            initializable.init();
        }
         // init(o);
    public static void init(Object o) throws ShiroException {
            if (o instanceof Initializable) {
                init((Initializable) o);
            }
        }
        // LifecycleUtils.init(realms);
    public static void init(Collection c) throws ShiroException {
            if (c == null || c.isEmpty()) {
                return;
            }
            for (Object o : c) {
                init(o);
            }
        }

### 总结 ###

到这里为止,SecurityManager 就已经创建完成，里面的数据也依次填充完成了

## 设置全局安全管理器对象 ##

设置 SecurityUtils 的静态变量securityManager

SecurityUtils

public static void setSecurityManager(SecurityManager securityManager) {
            SecurityUtils.securityManager = securityManager;
        }

# 附注 #

## 加入新节区对象 ##

# 参考资料 #

[官网教程][Link 1]

[IniSecurityManagerFactory]: https://gitee.com/ls9527/src-analysis/raw/master/shiro/uml/seq/IniSecurityManagerFactory.png
[IniSecurityManagerFactory 1]: https://gitee.com/ls9527/src-analysis/raw/master/shiro/uml/class/IniSecurityManagerFactory.png
[IniSecurityManagerFactory 2]: https://gitee.com/ls9527/src-analysis/raw/master/shiro/uml/seq/IniSecurityManagerFactory.getInstance.png
[DefaultSecurityManager]: https://gitee.com/ls9527/src-analysis/raw/master/shiro/uml/class/DefaultSecurityManager.png
[IniRealm]: https://gitee.com/ls9527/src-analysis/raw/master/shiro/uml/class/IniRealm.png
[Link 1]: https://shiro.apache.org/tutorial.html