magro/SpringSecurityUserRegistration.java

## SpringSecurityUserRegistration.java
package de.javakaffee.web.msm.serializer.kryo;

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.userdetails.User;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.serialize.IntSerializer;
import com.esotericsoftware.kryo.serialize.SimpleSerializer;
import com.esotericsoftware.kryo.serialize.StringSerializer;

/**
 * Provides a custom kryo serializer for the Spring Security User class.
 * <p>
 * This is needed because the User class internally contains a collection
 * of {@link GrantedAuthority}, which is actually a TreeSet with a
 * Comparator. During deserialization kryo creates a TreeSet *without*
 * any comparator and therefore expects that the contained items are
 * Comparable, which is not the case for SimpleGrantedAuthority - ClassCastException.
 * </p>
 * <p>
 * Motivated by <a href="http://code.google.com/p/memcached-session-manager/issues/detail?id=145">
 * issue #145: Deserialization fails on ConcurrentHashMap in Spring User object
 * </a>.
 * </p>
 * @author Martin Grotzke
 */
public class SpringSecurityUserRegistration implements KryoCustomization {

  @Override
  public void customize(final Kryo kryo) {
    kryo.register( User.class, new SpringSecurityUserSerializer( kryo ) );
  }

  static class SpringSecurityUserSerializer extends SimpleSerializer<User> {

    private final Kryo _kryo;

    public SpringSecurityUserSerializer(final Kryo kryo) {
      _kryo = kryo;
    }

    @Override
    public User read(final ByteBuffer buffer) {
      final String password = StringSerializer.get(buffer);
      final String username = StringSerializer.get(buffer);

      final int size = IntSerializer.get(buffer, true);
      final List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>(size);
      for (int i = 0; i < size; i++) {
        authorities.add((GrantedAuthority)_kryo.readClassAndObject(buffer));
      }

      final boolean accountNonExpired = buffer.get() == 1;
      final boolean accountNonLocked = buffer.get() == 1;
      final boolean credentialsNonExpired = buffer.get() == 1;
      final boolean enabled = buffer.get() == 1;

      return new User(username, password, enabled, accountNonExpired, credentialsNonExpired,
        accountNonLocked, authorities);
    }

    @Override
    public void write(final ByteBuffer buffer, final User user) {
      StringSerializer.put(buffer, user.getPassword());
      StringSerializer.put(buffer, user.getUsername());

      final Collection<GrantedAuthority> authorities = user.getAuthorities();
      IntSerializer.put(buffer, authorities.size(), true);
      for (final GrantedAuthority item : authorities) {
        _kryo.writeClassAndObject(buffer, item);
      }

      put(buffer, user.isAccountNonExpired());
      put(buffer, user.isAccountNonLocked());
      put(buffer, user.isCredentialsNonExpired());
      put(buffer, user.isEnabled());
    }

    private void put(final ByteBuffer buffer, final boolean value) {
      buffer.put(value ? (byte)1 : (byte)0);
    }

  }

}
	package de.javakaffee.web.msm.serializer.kryo;

	import java.nio.ByteBuffer;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.List;

	import org.springframework.security.core.GrantedAuthority;
	import org.springframework.security.core.userdetails.User;

	import com.esotericsoftware.kryo.Kryo;
	import com.esotericsoftware.kryo.serialize.IntSerializer;
	import com.esotericsoftware.kryo.serialize.SimpleSerializer;
	import com.esotericsoftware.kryo.serialize.StringSerializer;

	/**
	* Provides a custom kryo serializer for the Spring Security User class.
	* <p>
	* This is needed because the User class internally contains a collection
	* of {@link GrantedAuthority}, which is actually a TreeSet with a
	* Comparator. During deserialization kryo creates a TreeSet without
	* any comparator and therefore expects that the contained items are
	* Comparable, which is not the case for SimpleGrantedAuthority - ClassCastException.
	* </p>
	* <p>
	* Motivated by <a href="http://code.google.com/p/memcached-session-manager/issues/detail?id=145">
	* issue #145: Deserialization fails on ConcurrentHashMap in Spring User object
	* </a>.
	* </p>
	* @author Martin Grotzke
	*/
	public class SpringSecurityUserRegistration implements KryoCustomization {

	@Override
	public void customize(final Kryo kryo) {
	kryo.register( User.class, new SpringSecurityUserSerializer( kryo ) );
	}

	static class SpringSecurityUserSerializer extends SimpleSerializer<User> {

	private final Kryo _kryo;

	public SpringSecurityUserSerializer(final Kryo kryo) {
	_kryo = kryo;
	}

	@Override
	public User read(final ByteBuffer buffer) {
	final String password = StringSerializer.get(buffer);
	final String username = StringSerializer.get(buffer);

	final int size = IntSerializer.get(buffer, true);
	final List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>(size);
	for (int i = 0; i < size; i++) {
	authorities.add((GrantedAuthority)_kryo.readClassAndObject(buffer));
	}

	final boolean accountNonExpired = buffer.get() == 1;
	final boolean accountNonLocked = buffer.get() == 1;
	final boolean credentialsNonExpired = buffer.get() == 1;
	final boolean enabled = buffer.get() == 1;

	return new User(username, password, enabled, accountNonExpired, credentialsNonExpired,
	accountNonLocked, authorities);
	}

	@Override
	public void write(final ByteBuffer buffer, final User user) {
	StringSerializer.put(buffer, user.getPassword());
	StringSerializer.put(buffer, user.getUsername());

	final Collection<GrantedAuthority> authorities = user.getAuthorities();
	IntSerializer.put(buffer, authorities.size(), true);
	for (final GrantedAuthority item : authorities) {
	_kryo.writeClassAndObject(buffer, item);
	}

	put(buffer, user.isAccountNonExpired());
	put(buffer, user.isAccountNonLocked());
	put(buffer, user.isCredentialsNonExpired());
	put(buffer, user.isEnabled());
	}

	private void put(final ByteBuffer buffer, final boolean value) {
	buffer.put(value ? (byte)1 : (byte)0);
	}

	}

	}