memcache 怎么存储的对象

memchache 将对象序列化后保存

memcahce将值序列化成字节数组，然后存储到缓存中。

如下例，我们将user对象序列化到文件a.txt中，同时将user保存到缓存中，通过比较文件和缓存中的值
发现，两者是一样的。

public class User implements Serializable{

    private String name;
    private String address;



    public User(String name, String address) {
        super();
        this.name = name;
        this.address = address;
    }
}

public static void main(String[] args) throws InterruptedException, ExecutionException, FileNotFoundException, IOException {
         MemcachedClient mcc =  null;
          try{
             // 本地连接 Memcached 服务
              mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
             System.out.println("Connection to server sucessful.");



          }catch(Exception ex){
             System.out.println( ex.getMessage() );
          }

          User u = new User("junwang","qingdao city");

          ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File("a.txt")) );
          oos.writeObject(u);


          Future fo =  mcc.set("myuser", 5*60*1000, u);
          // 查看存储状态
          System.out.println("set status:" + fo.get());

          // 输出值
          System.out.println("myuser value in cache - " + mcc.get("myuser"));

          // 关闭连接
           mcc.shutdown();
       }

查看源代码

查看源代码，可以发现正是将对象序列化，然后保存。证明了我们上述的猜想。

BaseSerializingTranscoder.java

protected byte[] serialize(Object o) {
    if (o == null) {
      throw new NullPointerException("Can‘t serialize null");
    }
    byte[] rv=null;
    ByteArrayOutputStream bos = null;
    ObjectOutputStream os = null;
    try {
      bos = new ByteArrayOutputStream();
      os = new ObjectOutputStream(bos);
      os.writeObject(o);
      os.close();
      bos.close();
      rv = bos.toByteArray();
    } catch (IOException e) {
      throw new IllegalArgumentException("Non-serializable object", e);
    } finally {
      CloseUtil.close(os);
      CloseUtil.close(bos);
    }
    return rv;
  }

结论

值的存储，都是序列化成字节数组，然后保存