Shiro的会话管理SessionDao

SessionDao

Shiro提供SessionDAO用于会话的CRUD，源码如下：

package org.apache.shiro.session.mgt.eis;

import org.apache.shiro.session.Session;
import org.apache.shiro.session.UnknownSessionException;

import java.io.Serializable;
import java.util.Collection;

public interface SessionDAO

    // 创建session
    Serializable create(Session session);

    // 获取session
    Session readSession(Serializable sessionId) throws UnknownSessionException;

    // 更新session
    void update(Session session) throws UnknownSessionException;

    // 删除session
    void delete(Session session);

    // 获取当前所有的session

AbstractSessionDAO

AbstractSessionDAO提供了SessionDAO的基础实现，如生成会话ID等，源码如下：

package org.apache.shiro.session.mgt.eis;

import org.apache.shiro.session.Session;
import org.apache.shiro.session.UnknownSessionException;
import org.apache.shiro.session.mgt.SimpleSession;

import java.io.Serializable;

public abstract class AbstractSessionDAO implements SessionDAO

    private SessionIdGenerator sessionIdGenerator;

    public AbstractSessionDAO() {
        this.sessionIdGenerator = new JavaUuidSessionIdGenerator();
    }

    public SessionIdGenerator getSessionIdGenerator() {
        return sessionIdGenerator;
    }

    public void setSessionIdGenerator(SessionIdGenerator sessionIdGenerator) {
        this.sessionIdGenerator = sessionIdGenerator;
    }

    protected Serializable generateSessionId(Session session) {
        if (this.sessionIdGenerator == null) {
            String msg = "sessionIdGenerator attribute has not been configured.";
            throw new IllegalStateException(msg);
        }
        return this.sessionIdGenerator.generateId(session);
    }

    public Serializable create(Session session) {
        Serializable sessionId = doCreate(session);
        verifySessionId(sessionId);
        return sessionId;
    }

    private void verifySessionId(Serializable sessionId) {
        if (sessionId == null) {
            String msg = "sessionId returned from doCreate implementation is null.  Please verify the implementation.";
            throw new IllegalStateException(msg);
        }
    }

    protected void assignSessionId(Session session, Serializable sessionId) {
        ((SimpleSession) session).setId(sessionId);
    }

    protected abstract Serializable doCreate(Session session);

    public Session readSession(Serializable sessionId) throws UnknownSessionException {
        Session s = doReadSession(sessionId);
        if (s == null) {
            throw new UnknownSessionException("There is no session with id [" + sessionId + "]");
        }
        return s;
    }

    protected abstract Session doReadSession(Serializable sessionId);

}