Introduce EqualsUtil and HashCode.(Builder|Cache)

smack-core/src/main/java/org/jivesoftware/smack/packet/Message.java

@@ -24,6 +24,8 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Set;
 
+import org.jivesoftware.smack.util.EqualsUtil;
+import org.jivesoftware.smack.util.HashCode;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.TypedCloneable;
 import org.jivesoftware.smack.util.XmlStringBuilder;
@@ -561,32 +563,22 @@ public final class Message extends Stanza implements TypedCloneable<Message> {
             return subject;
         }
 
+        private final HashCode.Cache hashCodeCache = new HashCode.Cache();
 
         @Override
         public int hashCode() {
-            final int prime = 31;
-            int result = 1;
-            if (language != null) {
-                result = prime * result + this.language.hashCode();
-            }
-            result = prime * result + this.subject.hashCode();
-            return result;
+            return hashCodeCache.getHashCode(c ->
+                c.append(language)
+                 .append(subject)
+            );
         }
 
         @Override
         public boolean equals(Object obj) {
-            if (this == obj) {
-                return true;
-            }
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            Subject other = (Subject) obj;
-            // simplified comparison because language and subject are always set
-            return this.language.equals(other.language) && this.subject.equals(other.subject);
+            return EqualsUtil.equals(this, obj, (e, o) ->
+                e.append(language, o.language)
+                 .append(subject, o.subject)
+            );
         }
 
         @Override
@@ -670,31 +662,22 @@ public final class Message extends Stanza implements TypedCloneable<Message> {
             return message;
         }
 
+        private final HashCode.Cache hashCodeCache = new HashCode.Cache();
+
         @Override
         public int hashCode() {
-            final int prime = 31;
-            int result = 1;
-            if (language != null) {
-                result = prime * result + this.language.hashCode();
-            }
-            result = prime * result + this.message.hashCode();
-            return result;
+            return hashCodeCache.getHashCode(c ->
+                c.append(language)
+                .append(message)
+            );
         }
 
         @Override
         public boolean equals(Object obj) {
-            if (this == obj) {
-                return true;
-            }
-            if (obj == null) {
-                return false;
-            }
-            if (getClass() != obj.getClass()) {
-                return false;
-            }
-            Body other = (Body) obj;
-            // simplified comparison because language and message are always set
-            return Objects.equals(this.language, other.language) && this.message.equals(other.message);
+            return EqualsUtil.equals(this, obj, (e, o) ->
+                e.append(language, o.language)
+                 .append(message, o.message)
+            );
         }
 
         @Override

smack-core/src/main/java/org/jivesoftware/smack/util/EqualsUtil.java

@@ -0,0 +1,243 @@
+/**
+ *
+ * Copyright 2019 Florian Schmaus.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack.util;
+
+public final class EqualsUtil {
+
+    private EqualsUtil() {
+    }
+
+    public static <T> boolean equals(T thisObject, Object other, EqualsComperator<T> equalsComperator) {
+        if (other == null) {
+            return false;
+        }
+        if (thisObject == other) {
+            return true;
+        }
+        @SuppressWarnings("unchecked")
+        Class<T> thisObjectClass = (Class<T>) thisObject.getClass();
+        if (thisObjectClass != other.getClass()) {
+            return false;
+        }
+
+        EqualsUtil.Builder equalsBuilder = new EqualsUtil.Builder();
+
+        equalsComperator.compare(equalsBuilder, thisObjectClass.cast(other));
+
+        return equalsBuilder.isEquals;
+    }
+
+    @FunctionalInterface
+    public interface EqualsComperator<T> {
+        void compare(EqualsUtil.Builder equalsBuilder, T other);
+    }
+
+    public static final class Builder {
+        private boolean isEquals = true;
+
+        private Builder() {
+        }
+
+        private void nullSafeCompare(Object left, Object right, Runnable runnable) {
+            if (!isEquals) {
+                return;
+            }
+
+            if (left == right) {
+                return;
+            }
+
+            if (left == null || right == null) {
+                isEquals = false;
+                return;
+            }
+
+            runnable.run();
+        }
+
+        public <O> Builder append(O left, O right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            if (left == right) {
+                return this;
+            }
+
+            if (left == null || right == null) {
+                isEquals = false;
+                return this;
+            }
+
+            isEquals = left.equals(right);
+            return this;
+        }
+
+        public Builder append(boolean left, boolean right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            isEquals = left == right;
+            return this;
+        }
+
+        public Builder append(boolean[] left, boolean[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(byte left, byte right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            isEquals = left == right;
+            return this;
+        }
+
+        public Builder append(byte[] left, byte[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(char left, char right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            isEquals = left == right;
+            return this;
+        }
+
+        public Builder append(char[] left, char[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(double left, double right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            return append(Double.doubleToLongBits(left), Double.doubleToLongBits(right));
+        }
+
+        public Builder append(double[] left, double[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(float left, float right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            return append(Float.floatToIntBits(left), Float.floatToIntBits(right));
+        }
+
+        public Builder append(float[] left, float[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(int left, int right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            isEquals = left == right;
+            return this;
+        }
+
+        public Builder append(int[] left, int[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+
+        public Builder append(long left, long right) {
+            if (!isEquals) {
+                return this;
+            }
+
+            isEquals = left == right;
+            return this;
+        }
+
+        public Builder append(long[] left, long[] right) {
+            nullSafeCompare(left, right, () -> {
+                if (left.length != right.length) {
+                    isEquals = false;
+                    return;
+                }
+                for (int i = 0; i < left.length && isEquals; i++) {
+                    append(left[i], right[i]);
+                }
+            });
+            return this;
+        }
+    }
+
+}

smack-core/src/main/java/org/jivesoftware/smack/util/HashCode.java

@@ -0,0 +1,211 @@
+/**
+ *
+ * Copyright 2019 Florian Schmaus.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack.util;
+
+public class HashCode {
+
+    private static final int MULTIPLIER_VALUE = 37;
+
+    public static class Cache {
+        private boolean calculated;
+        private int hashcode;
+
+        public int getHashCode(Calculator hashCodeCalculator) {
+            if (calculated) {
+                return hashcode;
+            }
+
+            HashCode.Builder hashCodeBuilder = new HashCode.Builder();
+            hashCodeCalculator.calculateHash(hashCodeBuilder);
+
+            calculated = true;
+            hashcode = hashCodeBuilder.hashcode;
+
+            return hashcode;
+        }
+
+    }
+
+    @FunctionalInterface
+    public interface Calculator {
+        void calculateHash(HashCode.Builder hashCodeBuilder);
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+        private int hashcode = 17;
+
+        private void applyHash() {
+            applyHash(0);
+        }
+
+        private void applyHash(int hash) {
+            hashcode = MULTIPLIER_VALUE * hashcode + hash;
+        }
+
+        public Builder append(Object object) {
+            if (object == null) {
+                applyHash();
+                return this;
+            }
+
+            if (object.getClass().isArray()) {
+                if (object instanceof int[]) {
+                    append((int[]) object);
+                } else if (object instanceof long[]) {
+                    append((long[]) object);
+                } else if (object instanceof boolean[]) {
+                    append((boolean[]) object);
+                } else if (object instanceof double[]) {
+                    append((double[]) object);
+                } else if (object instanceof float[]) {
+                    append((float[]) object);
+                } else if (object instanceof short[]) {
+                    append((short[]) object);
+                } else if (object instanceof char[]) {
+                    append((char[]) object);
+                } else if (object instanceof byte[]) {
+                    append((byte[]) object);
+                } else {
+                    append((Object[]) object);
+                }
+            }
+            applyHash(object.hashCode());
+            return this;
+        }
+
+        public Builder append(boolean value) {
+            applyHash(value ? 0 : 1);
+            return this;
+        }
+
+        public Builder append(boolean[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (boolean bool : array) {
+                append(bool);
+            }
+            return this;
+        }
+
+        public Builder append(byte value) {
+            applyHash(value);
+            return this;
+        }
+
+        public Builder append(byte[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (byte b : array) {
+                append(b);
+            }
+            return this;
+        }
+
+        public Builder append(char value) {
+            applyHash(value);
+            return this;
+        }
+
+        public Builder append(char[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (char c : array) {
+                append(c);
+            }
+            return this;
+        }
+
+        public Builder append(double value) {
+            return append(Double.doubleToLongBits(value));
+        }
+
+        public Builder append(double[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (double d : array) {
+                append(d);
+            }
+            return this;
+        }
+
+        public Builder append(float value) {
+            return append(Float.floatToIntBits(value));
+        }
+
+        public Builder append(float[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (float f : array) {
+                append(f);
+            }
+            return this;
+        }
+
+        public Builder append(long value) {
+            applyHash((int) (value ^ (value >>> 32)));
+            return this;
+        }
+
+        public Builder append(long[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (long l : array) {
+                append(l);
+            }
+            return this;
+        }
+
+        public Builder append(Object[] array) {
+            if (array == null) {
+                applyHash();
+                return this;
+            }
+
+            for (Object element : array) {
+                append(element);
+            }
+            return this;
+        }
+
+        public int build() {
+            return hashcode;
+        }
+    }
+
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/disco/packet/DiscoverInfo.java

@@ -25,6 +25,8 @@ import java.util.List;
 import java.util.Set;
 
 import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.util.EqualsUtil;
+import org.jivesoftware.smack.util.HashCode;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.TypedCloneable;
 import org.jivesoftware.smack.util.XmlStringBuilder;
@@ -397,37 +399,22 @@ public class DiscoverInfo extends IQ implements TypedCloneable<DiscoverInfo> {
          */
         @Override
         public boolean equals(Object obj) {
-            if (obj == null)
-                return false;
-            if (obj == this)
-                return true;
-            if (obj.getClass() != getClass())
-                return false;
-
-            DiscoverInfo.Identity other = (DiscoverInfo.Identity) obj;
-            if (!this.key.equals(other.key))
-                return false;
-
-            String otherLang = other.lang == null ? "" : other.lang;
-            String thisLang = lang == null ? "" : lang;
-            if (!otherLang.equals(thisLang))
-                return false;
-
-            String otherName = other.name == null ? "" : other.name;
-            String thisName = name == null ? "" : other.name;
-            if (!thisName.equals(otherName))
-                return false;
-
-            return true;
+            return EqualsUtil.equals(this, obj, (e, o) -> {
+                e.append(key, o.key)
+                 .append(lang, o.lang)
+                 .append(name, o.name);
+            });
         }
 
+        private final HashCode.Cache hashCodeCache = new HashCode.Cache();
+
         @Override
         public int hashCode() {
-            int result = 1;
-            result = 37 * result + key.hashCode();
-            result = 37 * result + (lang == null ? 0 : lang.hashCode());
-            result = 37 * result + (name == null ? 0 : name.hashCode());
-            return result;
+            return hashCodeCache.getHashCode(c ->
+                c.append(key)
+                 .append(lang)
+                 .append(name)
+            );
         }
 
         /**
@@ -522,15 +509,9 @@ public class DiscoverInfo extends IQ implements TypedCloneable<DiscoverInfo> {
 
         @Override
         public boolean equals(Object obj) {
-            if (obj == null)
-                return false;
-            if (obj == this)
-                return true;
-            if (obj.getClass() != getClass())
-                return false;
-
-            DiscoverInfo.Feature other = (DiscoverInfo.Feature) obj;
-            return variable.equals(other.variable);
+            return EqualsUtil.equals(this, obj, (e, o) -> {
+                e.append(variable, o.variable);
+            });
         }
 
         @Override

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/JingleSession.java

@@ -23,6 +23,8 @@ import java.util.concurrent.Future;
 
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.util.EqualsUtil;
+import org.jivesoftware.smack.util.HashCode;
 
 import org.jivesoftware.smackx.jingle.element.Jingle;
 import org.jivesoftware.smackx.jingle.element.JingleContent;
@@ -112,22 +114,20 @@ public abstract class JingleSession implements JingleSessionHandler {
 
     @Override
     public int hashCode() {
-        int hashCode = 31 + getInitiator().hashCode();
-        hashCode = 31 * hashCode + getResponder().hashCode();
-        hashCode = 31 * hashCode + getSessionId().hashCode();
-        return hashCode;
+        return HashCode.builder()
+                       .append(getInitiator())
+                       .append(getResponder())
+                       .append(getSessionId())
+                       .build();
     }
 
     @Override
     public boolean equals(Object other) {
-        if (!(other instanceof JingleSession)) {
-            return false;
-        }
-
-        JingleSession otherJingleSession = (JingleSession) other;
-        return getInitiator().equals(otherJingleSession.getInitiator())
-                && getResponder().equals(otherJingleSession.getResponder())
-                && sid.equals(otherJingleSession.sid);
+        return EqualsUtil.equals(this, other, (e, o) ->
+            e.append(getInitiator(), o.getInitiator())
+              .append(getResponder(), o.getResponder())
+              .append(sid, o.sid)
+        );
     }
 
     @Override

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/FormField.java

@@ -30,6 +30,8 @@ import javax.xml.namespace.QName;
 import org.jivesoftware.smack.packet.FullyQualifiedElement;
 import org.jivesoftware.smack.packet.XmlEnvironment;
 import org.jivesoftware.smack.util.CollectionUtil;
+import org.jivesoftware.smack.util.EqualsUtil;
+import org.jivesoftware.smack.util.HashCode;
 import org.jivesoftware.smack.util.MultiMap;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 
@@ -770,33 +772,20 @@ public final class FormField implements FullyQualifiedElement {
 
         @Override
         public boolean equals(Object obj) {
-            if (obj == null)
-                return false;
-            if (obj == this)
-                return true;
-            if (obj.getClass() != getClass())
-                return false;
-
-            Option other = (Option) obj;
-
-            if (!value.equals(other.value))
-                return false;
-
-            String thisLabel = label == null ? "" : label;
-            String otherLabel = other.label == null ? "" : other.label;
-
-            if (!thisLabel.equals(otherLabel))
-                return false;
-
-            return true;
+            return EqualsUtil.equals(this, obj, (e, o) -> {
+                e.append(value, o.value)
+                 .append(label, o.label);
+            });
         }
 
+        private final HashCode.Cache hashCodeCache = new HashCode.Cache();
+
         @Override
         public int hashCode() {
-            int result = 1;
-            result = 37 * result + value.hashCode();
-            result = 37 * result + (label == null ? 0 : label.hashCode());
-            return result;
+            return hashCodeCache.getHashCode(c ->
+                c.append(value)
+                 .append(label)
+            );
         }
 
     }
@@ -917,5 +906,15 @@ public final class FormField implements FullyQualifiedElement {
             xml.escape(value);
             return xml.closeElement(this);
         }
+
+        @Override
+        public boolean equals(Object other) {
+            return EqualsUtil.equals(this, other, (e, o) -> e.append(this.value, o.value));
+        }
+
+        @Override
+        public int hashCode() {
+            return value.hashCode();
+        }
     }
 }

smack-im/src/main/java/org/jivesoftware/smack/roster/RosterEntry.java

@@ -31,6 +31,7 @@ import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.Presence;
 import org.jivesoftware.smack.packet.Presence.Type;
 import org.jivesoftware.smack.roster.packet.RosterPacket;
+import org.jivesoftware.smack.util.EqualsUtil;
 
 import org.jxmpp.jid.BareJid;
 
@@ -251,15 +252,9 @@ public final class RosterEntry extends Manager {
 
     @Override
     public boolean equals(Object object) {
-        if (this == object) {
-            return true;
-        }
-        if (object != null && object instanceof RosterEntry) {
-            return getJid().equals(((RosterEntry) object).getJid());
-        }
-        else {
-            return false;
-        }
+        return EqualsUtil.equals(this, object, (e, o) ->
+            e.append(getJid(), o.getJid())
+        );
     }
 
     /**
@@ -272,14 +267,9 @@ public final class RosterEntry extends Manager {
      *         otherwise.
      */
     public boolean equalsDeep(Object obj) {
-        if (this == obj)
-            return true;
-        if (obj == null)
-            return false;
-        if (getClass() != obj.getClass())
-            return false;
-        RosterEntry other = (RosterEntry) obj;
-        return other.item.equals(this.item);
+        return EqualsUtil.equals(this, obj, (e, o) ->
+            e.append(item, o.item)
+        );
     }
 
     /**

smack-im/src/main/java/org/jivesoftware/smack/roster/packet/RosterPacket.java

@@ -27,6 +27,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
 import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.NamedElement;
 import org.jivesoftware.smack.packet.Stanza;
+import org.jivesoftware.smack.util.EqualsUtil;
+import org.jivesoftware.smack.util.HashCode;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.XmlStringBuilder;
@@ -292,51 +294,26 @@ public final class RosterPacket extends IQ {
 
         @Override
         public int hashCode() {
-            final int prime = 31;
-            int result = 1;
-            result = prime * result + ((groupNames == null) ? 0 : groupNames.hashCode());
-            result = prime * result + (subscriptionPending ? 0 : 1);
-            result = prime * result + ((itemType == null) ? 0 : itemType.hashCode());
-            result = prime * result + ((name == null) ? 0 : name.hashCode());
-            result = prime * result + ((jid == null) ? 0 : jid.hashCode());
-            result = prime * result + ((approved == false) ? 0 : 1);
-            return result;
+            return HashCode.builder()
+                .append(groupNames)
+                .append(subscriptionPending)
+                .append(itemType)
+                .append(name)
+                .append(jid)
+                .append(approved)
+                .build();
         }
 
         @Override
         public boolean equals(Object obj) {
-            if (this == obj)
-                return true;
-            if (obj == null)
-                return false;
-            if (getClass() != obj.getClass())
-                return false;
-            Item other = (Item) obj;
-            if (groupNames == null) {
-                if (other.groupNames != null)
-                    return false;
-            }
-            else if (!groupNames.equals(other.groupNames))
-                return false;
-            if (subscriptionPending != other.subscriptionPending)
-                return false;
-            if (itemType != other.itemType)
-                return false;
-            if (name == null) {
-                if (other.name != null)
-                    return false;
-            }
-            else if (!name.equals(other.name))
-                return false;
-            if (jid == null) {
-                if (other.jid != null)
-                    return false;
-            }
-            else if (!jid.equals(other.jid))
-                return false;
-            if (approved != other.approved)
-                return false;
-            return true;
+            return EqualsUtil.equals(this, obj, (e, o) ->
+                e.append(groupNames, o.groupNames)
+                 .append(subscriptionPending, o.subscriptionPending)
+                 .append(itemType, o.itemType)
+                 .append(name, o.name)
+                 .append(jid, o.jid)
+                 .append(approved, o.approved)
+            );
         }
 
     }