Shiro源码学习之一

一.最基本的使用

1.Maven依赖

        <dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-core</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>  
            <groupId>org.slf4j</groupId>  
            <artifactId>slf4j-api</artifactId>  
            <version>1.7.13</version>  
        </dependency>  
        <dependency>  
            <groupId>org.slf4j</groupId>  
            <artifactId>slf4j-log4j12</artifactId>  
            <version>1.7.13</version>  
        </dependency>

2.配置文件

[users]
user1 = http://blog.youkuaiyun.com/unix21
admin1 = 11111

3.调用代码

import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.UsernamePasswordToken;
import org.apache.shiro.config.IniSecurityManagerFactory;
import org.apache.shiro.mgt.SecurityManager;
import org.apache.shiro.subject.Subject;
import org.apache.shiro.util.Factory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HelloShiro {
    private static final Logger logger =  LoggerFactory.getLogger(HelloShiro.class);
    
    public static void main(String[] args) {
        // 初始化 SecurityManager
        Factory<SecurityManager> factory = new IniSecurityManagerFactory("classpath:shiro.ini");
        SecurityManager securityManager = factory.getInstance();
        SecurityUtils.setSecurityManager(securityManager);
 
        // 获取当前用户
        Subject subject = SecurityUtils.getSubject();
 
        // 登录
        UsernamePasswordToken token = new UsernamePasswordToken("user1", "http://blog.youkuaiyun.com/unix21");
        try {
            subject.login(token);
        } catch (AuthenticationException ae) {
            logger.info("登录失败！");
            return;
        }
        logger.info("登录成功！Hello " + subject.getPrincipal());
 
        // 注销
        subject.logout();
    }
}

参考:Shiro 那点事儿

跟我学Shiro目录贴

二.源码学习

1.SecurityManager

SecurityManager securityManager = factory.getInstance();

进入public T getInstance()

进入public T createInstance()

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;
    }

进入protected Ini resolveIni()

protected Ini resolveIni() {
        Ini ini = getIni();
        if (CollectionUtils.isEmpty(ini)) {
            log.debug("Null or empty Ini instance.  Falling back to the default {} file.", DEFAULT_INI_RESOURCE_PATH);
            ini = loadDefaultClassPathIni();
        }
        return ini;
    }

public Ini getIni()

ini是一个自定义的Class

public class Ini implements Map<String, Ini.Section> {

    private static transient final Logger log = LoggerFactory.getLogger(Ini.class);

    public static final String DEFAULT_SECTION_NAME = ""; //empty string means the first unnamed section
    public static final String DEFAULT_CHARSET_NAME = "UTF-8";

    public static final String COMMENT_POUND = "#";
    public static final String COMMENT_SEMICOLON = ";";
    public static final String SECTION_PREFIX = "[";
    public static final String SECTION_SUFFIX = "]";

    protected static final char ESCAPE_TOKEN = '\\';

    private final Map<String, Section> sections;

    /**
     * Creates a new empty {@code Ini} instance.
     */
    public Ini() {
        this.sections = new LinkedHashMap<String, Section>();
    }

跳出protected Ini resolveIni()

回到public T createInstance()

进入protected SecurityManager createInstance(Ini ini)

进入public Section getSection(String sectionName)

进入private static String cleanName(String sectionName)

private static String cleanName(String sectionName) {
        String name = StringUtils.clean(sectionName);
        if (name == null) {
            log.trace("Specified name was null or empty.  Defaulting to the default section (name = \"\")");
            name = DEFAULT_SECTION_NAME;
        }
        return name;
    }

org.apache.shiro.util的StringUtils

EMPTY_STRING是StringUtils定义的静态常量

public class StringUtils {
    public static final String EMPTY_STRING = "";
    public static final char DEFAULT_DELIMITER_CHAR = ',';
    public static final char DEFAULT_QUOTE_CHAR = '"';

out返回"main"

private static String cleanName(String sectionName)返回"main"

回到public Section getSection(String sectionName)

ini.getSection返回null回到private SecurityManager createSecurityManager(Ini ini)

又到public Section getSection(String sectionName)返回null

public Section getSection(String sectionName) {
        String name = cleanName(sectionName);
        return sections.get(name);
    }

回到private SecurityManager createSecurityManager(Ini ini)

进入createSecurityManager

@SuppressWarnings({"unchecked"})
    private SecurityManager createSecurityManager(Ini ini, Ini.Section mainSection) {

        Map<String, ?> defaults = createDefaults(ini, mainSection);
        Map<String, ?> objects = buildInstances(mainSection, defaults);

        SecurityManager securityManager = getSecurityManagerBean();

        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);
            }
        }

        return securityManager;
    }

进入createDefaults

    protected Map<String, ?> createDefaults(Ini ini, Ini.Section mainSection) {
        Map<String, Object> defaults = new LinkedHashMap<String, Object>();

        SecurityManager securityManager = createDefaultInstance();
        defaults.put(SECURITY_MANAGER_NAME, securityManager);

        if (shouldImplicitlyCreateRealm(ini)) {
            Realm realm = createRealm(ini);
            if (realm != null) {
                defaults.put(INI_REALM_NAME, realm);
            }
        }

        return defaults;
    }

protected SecurityManager createDefaultInstance() {
        return new DefaultSecurityManager();
    }

public DefaultSecurityManager() {
        super();
        this.subjectFactory = new DefaultSubjectFactory();
        this.subjectDAO = new DefaultSubjectDAO();
    }

public SessionsSecurityManager() {
        super();
        this.sessionManager = new DefaultSessionManager();
        applyCacheManagerToSessionManager();
    }

public AuthorizingSecurityManager() {
        super();
        this.authorizer = new ModularRealmAuthorizer();
    }

public AuthenticatingSecurityManager() {
        super();
        this.authenticator = new ModularRealmAuthenticator();
    }

public RealmSecurityManager() {
        super();
    }

最终是个空方法

public abstract class CachingSecurityManager implements SecurityManager, Destroyable, CacheManagerAware {
    private CacheManager cacheManager;
    public CachingSecurityManager() {
    }

...之后
回到createDefaults

protected boolean shouldImplicitlyCreateRealm(Ini ini)

protected boolean shouldImplicitlyCreateRealm(Ini ini) {
        return !CollectionUtils.isEmpty(ini) &&
                (!CollectionUtils.isEmpty(ini.getSection(IniRealm.ROLES_SECTION_NAME)) ||
                        !CollectionUtils.isEmpty(ini.getSection(IniRealm.USERS_SECTION_NAME)));
    }

回到createDefaults进入createRealm

IniRealm声明

public class IniRealm extends TextConfigurationRealm {

    public static final String USERS_SECTION_NAME = "users";
    public static final String ROLES_SECTION_NAME = "roles";

    private static transient final Logger log = LoggerFactory.getLogger(IniRealm.class);

    private String resourcePath;
    private Ini ini; //reference added in 1.2 for SHIRO-322

    public IniRealm() {
        super();
    }

调用super()的super()

实例化LinkedHashMap和读写锁ReadWriteLock

回到createRealm

回到createDefaults

回到createSecurityManager

进入buildInstances

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

进入ReflectionBuilder

这行代码很简洁，defaults不为空，所以this.objects指向defaults的引用

this.objects = CollectionUtils.isEmpty(defaults) ? new LinkedHashMap<String, Object>() : defaults;

进入buildObjects 因为kvPairs为null所以直接跳到LifecycleUtils.init(objects.values());

再跳到public static void init(Object o)，判断对象不能Initializable

第二次又进入这次对象是可以Initializable

进入

public final void init() {
        //trigger obtaining the authorization cache if possible
        getAvailableAuthenticationCache();
        onInit();
    }

进入getAvailableAuthenticationCache

private Cache<Object, AuthenticationInfo> getAvailableAuthenticationCache() {
        Cache<Object, AuthenticationInfo> cache = getAuthenticationCache();
        boolean authcCachingEnabled = isAuthenticationCachingEnabled();
        if (cache == null && authcCachingEnabled) {
            cache = getAuthenticationCacheLazy();
        }
        return cache;
    }

返回是null

回到

public final void init() {
        //trigger obtaining the authorization cache if possible
        getAvailableAuthenticationCache();
        onInit();
    }

进入onInit()

@Override
    protected void onInit() {
        super.onInit();

        // This is an in-memory realm only - no need for an additional cache when we're already
        // as memory-efficient as we can be.
        
        Ini ini = getIni();
        String resourcePath = getResourcePath();
                
        if (!CollectionUtils.isEmpty(this.users) || !CollectionUtils.isEmpty(this.roles)) {
            if (!CollectionUtils.isEmpty(ini)) {
                log.warn("Users or Roles are already populated.  Configured Ini instance will be ignored.");
            }
            if (StringUtils.hasText(resourcePath)) {
                log.warn("Users or Roles are already populated.  resourcePath '{}' will be ignored.", resourcePath);
            }
            
            log.debug("Instance is already populated with users or roles.  No additional user/role population " +
                    "will be performed.");
            return;
        }
        
        if (CollectionUtils.isEmpty(ini)) {
            log.debug("No INI instance configuration present.  Checking resourcePath...");
            
            if (StringUtils.hasText(resourcePath)) {
                log.debug("Resource path {} defined.  Creating INI instance.", resourcePath);
                ini = Ini.fromResourcePath(resourcePath);
                if (!CollectionUtils.isEmpty(ini)) {
                    setIni(ini);
                }
            }
        }
        
        if (CollectionUtils.isEmpty(ini)) {
            String msg = "Ini instance and/or resourcePath resulted in null or empty Ini configuration.  Cannot " +
                    "load account data.";
            throw new IllegalStateException(msg);
        }

        processDefinitions(ini);
    }

super.onInit()也就是protected void onInit()

@Override
    protected void onInit() {
        super.onInit();
        processDefinitions();
    }

processDefinitions调用processRoleDefinitions()，roleDefinitions为null直接返回到processDefinitions

processUserDefinitions中userDefinitions也是null直接return回processDefinitions了

回到onInit()

返回

返回

回到buildObjects返回objects

回到buildInstances

回到createSecurityManager

private SecurityManager getSecurityManagerBean() {
        return builder.getBean(SECURITY_MANAGER_NAME, SecurityManager.class);
    }

进入org.apache.shiro.config的public class ReflectionBuilder

instanceof运算符 只被用于对象引用变量，检查左边的被测试对象 是不是 右边类或接口的 实例化。如果被测对象是null值，则测试结果总是false。 
Class类的isInstance(Object obj)方法，obj是被测试的对象，如果obj是调用这个方法的class或接口 的实例，则返回true。这个方法是instanceof运算符的动态等价。 
Class类的isAssignableFrom(Class cls)方法，如果调用这个方法的class或接口 与 参数cls表示的类或接口相同，或者是参数cls表示的类或接口的父类，则返回true。 

instanceof, isinstance,isAssignableFrom的区别

回到createSecurityManager

进入isAutoApplyRealms

realms为null，返回autoApply为true

回到createSecurityManager

进入applyRealmsToSecurityManager

再调用setRealms

回到protected void afterRealmsSet()

回到setRealms

回到

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回到最外层调用函数

至此，SecurityManager securityManager = factory.getInstance();才完成。

2.Subject

// 获取当前用户
        Subject subject = SecurityUtils.getSubject();

public static Subject getSubject() {
        Subject subject = ThreadContext.getSubject();
        if (subject == null) {
            subject = (new Subject.Builder()).buildSubject();
            ThreadContext.bind(subject);
        }
        return subject;
    }

进入org.apache.shiro.util的public abstract class ThreadContext 

getValue

回到public static Subject getSubject()

回到最外层

3.UsernamePasswordToken

UsernamePasswordToken token = new UsernamePasswordToken("user1", "http://blog.youkuaiyun.com/unix21");

调用构造函数

private声明

public class UsernamePasswordToken implements HostAuthenticationToken, RememberMeAuthenticationToken {
private String username;
private char[] password;
private boolean rememberMe = false;
private String host;
...

HostAuthenticationToken接口定义

public interface HostAuthenticationToken extends AuthenticationToken {
String getHost();
}

public interface AuthenticationToken extends Serializable {
Object getPrincipal();
Object getCredentials();
}

Shiro源码学习之二