simple-email/app/src/main/java/eu/faircode/email/EntityAttachment.java

package eu.faircode.email;

/*
    This file is part of Safe email.

    Safe email is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    NetGuard is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2018 by Marcel Bokhorst (M66B)
*/

import android.arch.persistence.room.Entity;
import android.arch.persistence.room.ForeignKey;
import android.arch.persistence.room.Ignore;
import android.arch.persistence.room.Index;
import android.arch.persistence.room.PrimaryKey;
import android.support.annotation.NonNull;

import javax.mail.BodyPart;

import static android.arch.persistence.room.ForeignKey.CASCADE;

@Entity(
        tableName = EntityAttachment.TABLE_NAME,
        foreignKeys = {
                @ForeignKey(childColumns = "message", entity = EntityMessage.class, parentColumns = "id", onDelete = CASCADE)
        },
        indices = {
                @Index(value = {"message"}),
                @Index(value = {"message", "sequence"}, unique = true)
        }
)
public class EntityAttachment {
    static final String TABLE_NAME = "attachment";

    @PrimaryKey(autoGenerate = true)
    public Long id;
    @NonNull
    public Long message;
    @NonNull
    public Integer sequence;
    public String name;
    @NonNull
    public String type;
    public Integer size;
    public Integer progress;
    public byte[] content;

    @Ignore
    BodyPart part;

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof EntityAttachment) {
            EntityAttachment other = (EntityAttachment) obj;
            return (this.message.equals(other.message) &&
                    this.sequence.equals(other.sequence) &&
                    (this.name == null ? other.name == null : this.name.equals(other.name)) &&
                    this.type.equals(other.type) &&
                    (this.size == null ? other.size == null : this.size.equals(other.size)) &&
                    (this.progress == null ? other.progress == null : this.progress.equals(other.progress)) &&
                    (this.content == null ? other.content == null : other.content != null));
        } else
            return false;
    }

}