Java简单实现session保存到redis的方法示例

本文实例讲述了java简单实现session保存到redis的方法。分享给大家供大家参考，具体如下：

在负载均衡情况下，如果用户访问不同的机器，如果没有做session同步，用户就会被提出，这样用户体验非常不好，所以我们很有必要做session同步，把session放到reids缓存服务器就能很好的解决问题。下面是代码简单的实现。

一、配置web.xml过滤器：

<filter>
    <filter-name>sessionfilter</filter-name>
    <filter-class>org.springframework.web.filter.delegatingfilterproxy</filter-class>
</filter>
<filter-mapping>
    <filter-name>sessionfilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

二、配置对应的过滤器名字：

<bean id="sessionfilter" class="com.plateno.interceptor.sessionfilter">
    <property name="redistemplate" ref="redistemplate"/>
</bean>

三、sessionfilter的实现：

public class sessionfilter extends genericfilterbean {
  private redistemplate redistemplate;
  @override
  public void dofilter(servletrequest request, servletresponse response,
      filterchain chain) throws ioexception, servletexception {
    system.out.println("filter");
    httpservletrequest re = (httpservletrequest)request;
    httpservletresponse res = (httpservletresponse)response;
    terryhttpservletrequestwrapper wrapper = new terryhttpservletrequestwrapper(re,res,redistemplate);
    chain.dofilter(wrapper, response);
  }
  public redistemplate getredistemplate() {
    return redistemplate;
  }
  public void setredistemplate(redistemplate redistemplate) {
    this.redistemplate = redistemplate;
  }
}

四、terryhttpservletrequestwrapper的实现：

public class terryhttpservletrequestwrapper extends httpservletrequestwrapper {
  private cachehttpsession session;
  private httpservletresponse response;
  private redistemplate redistemplate;
  public terryhttpservletrequestwrapper(httpservletrequest request, httpservletresponse response,redistemplate redistemplate) {
    super(request);
    this.response = response;
    this.redistemplate = redistemplate;
  }
  @override
  public httpsession getsession(boolean create) {
    if(session != null) {
      return session;
    }
    string sid = "terry" + system.currenttimemillis();
    writesidtocookie(sid);
    session = new cachehttpsession(null,sid,redistemplate);
    return session;
  }
  @override
  public httpsession getsession() {
    return getsession(false);
  }
  protected void writesidtocookie(string sid) {
    cookie mycookies = new cookie("terry", sid);
    mycookies.setmaxage(-1);
    mycookies.setdomain("locahost");
    mycookies.setpath("/");
    response.addcookie(mycookies);
  }
}

五、cachehttpsession的实现：

public class cachehttpsession extends httpsessionwrapper {
  private string sid;
  private redistemplate redistemplate;
  private stringredisserializer stringserializer = new stringredisserializer();
  public cachehttpsession(httpsession session,string sid,redistemplate redistemplate) {
    super(session);
    this.sid = sid;
    this.redistemplate = redistemplate;
  }
  @suppresswarnings("unchecked")
  @override
  public enumeration<string> getattributenames() {
    final byte[] key = stringserializer.serialize(sid);
    object result = redistemplate.execute(new rediscallback<object>() {
      @override
      public object doinredis(redisconnection connection)
          throws dataaccessexception {
        set<byte[]> set = connection.keys(key);
        return set;
      }
    });
    if(result != null) {
      set<byte[]> s = (set<byte[]>)result;
      set<string> ss = new hashset<string>();
      for(byte[] b : s) {
        ss.add(stringserializer.deserialize(b));
      }
      enumeration<string> en = new vector(ss).elements();
      return en;
    }
    return null;
  }
  @suppresswarnings("unchecked")
  @override
  public void setattribute(string name, object value) {
    final byte[] key = stringserializer.serialize(name);
    final byte[] v = stringserializer.serialize((string)value);
    redistemplate.execute(new rediscallback<object>() {
      @override
      public object doinredis(redisconnection connection)
          throws dataaccessexception {
        connection.set(key, v);
        return null;
      }
    });
  }
  @override
  public object getattribute(string name) {
    final byte[] key = stringserializer.serialize(name);
    @suppresswarnings("unchecked")
    object value = redistemplate.execute(new rediscallback<object>() {
      @override
      public object doinredis(redisconnection connection)
          throws dataaccessexception {
        return connection.get(key);
      }
    });
    return value;
  }
  @override
  public string getid() {
    return sid;
  }
}

六、httpsessionwrapper的实现：

public class httpsessionwrapper implements httpsession {
  private httpsession session;
  public httpsessionwrapper(httpsession session) {
    this.session = session;
  }
  @override
  public long getcreationtime() {
    return this.session.getcreationtime();
  }
  @override
  public string getid() {
    return this.session.getid();
  }
  @override
  public long getlastaccessedtime() {
    return this.session.getlastaccessedtime();
  }
  @override
  public servletcontext getservletcontext() {
    return this.session.getservletcontext();
  }
  @override
  public void setmaxinactiveinterval(int interval) {
    this.session.setmaxinactiveinterval(interval);
  }
  @override
  public int getmaxinactiveinterval() {
    return this.session.getmaxinactiveinterval();
  }
  @override
  public httpsessioncontext getsessioncontext() {
    return this.session.getsessioncontext();
  }
  @override
  public object getattribute(string name) {
    return this.session.getattribute(name);
  }
  @override
  public object getvalue(string name) {
    return this.session.getvalue(name);
  }
  @override
  public enumeration<string> getattributenames() {
    return this.session.getattributenames();
  }
  @override
  public string[] getvaluenames() {
    return this.session.getvaluenames();
  }
  @override
  public void setattribute(string name, object value) {
    this.session.setattribute(name,value);
  }
  @override
  public void putvalue(string name, object value) {
    this.session.putvalue(name,value);
  }
  @override
  public void removeattribute(string name) {
    this.session.removeattribute(name);
  }
  @override
  public void removevalue(string name) {
    this.session.removevalue(name);
  }
  @override
  public void invalidate() {
    this.session.invalidate();
  }
  @override
  public boolean isnew() {
    return this.session.isnew();
  }
}

以上代码就能把session保存到redis，当然这其中还有很多问题，比如sessionid的生成，session过去，对象序列化（测试为了方便统一用了string），等等很多问题。以后有时间再完善。

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