~~~ package org.apache.ibatis.cache.decorators; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.ObjectStreamClass; import java.io.Serializable; import org.apache.ibatis.cache.Cache; import org.apache.ibatis.cache.CacheException; import org.apache.ibatis.io.Resources; /** * @author Clinton Begin */ public class SerializedCache implements Cache { private final Cache delegate; public SerializedCache(Cache delegate) { this.delegate = delegate; } @Override public String getId() { return delegate.getId(); } @Override public int getSize() { return delegate.getSize(); } @Override public void putObject(Object key, Object object) { if (object == null || object instanceof Serializable) { delegate.putObject(key, serialize((Serializable) object)); } else { throw new CacheException("SharedCache failed to make a copy of a non-serializable object: " + object); } } @Override public Object getObject(Object key) { Object object = delegate.getObject(key); return object == null ? null : deserialize((byte[]) object); } @Override public Object removeObject(Object key) { return delegate.removeObject(key); } @Override public void clear() { delegate.clear(); } @Override public int hashCode() { return delegate.hashCode(); } @Override public boolean equals(Object obj) { return delegate.equals(obj); } //内部实现了序列化 private byte[] serialize(Serializable value) { try (ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos)) { oos.writeObject(value); oos.flush(); return bos.toByteArray(); } catch (Exception e) { throw new CacheException("Error serializing object. Cause: " + e, e); } } //内部实现了反序列化 private Serializable deserialize(byte[] value) { Serializable result; try (ByteArrayInputStream bis = new ByteArrayInputStream(value); ObjectInputStream ois = new CustomObjectInputStream(bis)) { result = (Serializable) ois.readObject(); } catch (Exception e) { throw new CacheException("Error deserializing object. Cause: " + e, e); } return result; } public static class CustomObjectInputStream extends ObjectInputStream { public CustomObjectInputStream(InputStream in) throws IOException { super(in); } @Override protected Class<?> resolveClass(ObjectStreamClass desc) throws ClassNotFoundException { return Resources.classForName(desc.getName()); } } } ~~~