com.nytimes.android.external.cache3.MoreObjects Maven / Gradle / Ivy
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/*
* Copyright (C) 2014 The Guava Authors
*
* 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 com.nytimes.android.external.cache3;
import java.util.Arrays;
import javax.annotation.Nonnull;
public final class MoreObjects {
public static T firstNonNull(T first, T second) {
return first != null ? first : Preconditions.checkNotNull(second);
}
/**
* Creates an instance of {@link ToStringHelper}.
*
* This is helpful for implementing {@link Object#toString()}.
* Specification by example:
{@code
* // Returns "ClassName{}"
* MoreObjects.toStringHelper(this)
* .toString();
*
* // Returns "ClassName{x=1}"
* MoreObjects.toStringHelper(this)
* .add("x", 1)
* .toString();
*
* // Returns "MyObject{x=1}"
* MoreObjects.toStringHelper("MyObject")
* .add("x", 1)
* .toString();
*
* // Returns "ClassName{x=1, y=foo}"
* MoreObjects.toStringHelper(this)
* .add("x", 1)
* .add("y", "foo")
* .toString();
*
* // Returns "ClassName{x=1}"
* MoreObjects.toStringHelper(this)
* .omitNullValues()
* .add("x", 1)
* .add("y", null)
* .toString();
* }}
*
* Note that in GWT, class names are often obfuscated.
*
* @param self the object to generate the string for (typically {@code this}), used only for its
* class name
* @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
*/
@Nonnull
public static ToStringHelper toStringHelper(@Nonnull Object self) {
return new ToStringHelper(self.getClass().getSimpleName());
}
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Creates an instance of {@link ToStringHelper} in the same manner as {@link
// * #toStringHelper(Object)}, but using the simple name of {@code clazz} instead of using an
// * instance's {@link Object#getClass()}.
// *
// *
Note that in GWT, class names are often obfuscated.
// *
// * @param clazz the {@link Class} of the instance
// * @since 18.0 (since 7.0 as {@code Objects.toStringHelper()}).
// */
// public static ToStringHelper toStringHelper(Class clazz) {
// return new ToStringHelper(clazz.getSimpleName());
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Creates an instance of {@link ToStringHelper} in the same manner as {@link
// * #toStringHelper(Object)}, but using {@code className} instead of using an instance's {@link
// * Object#getClass()}.
// *
// * @param className the name of the instance type
// * @since 18.0 (since 7.0 as {@code Objects.toStringHelper()}).
// */
// public static ToStringHelper toStringHelper(String className) {
// return new ToStringHelper(className);
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
/**
* Support class for {@link MoreObjects#toStringHelper}.
*
* @author Jason Lee
* @since 18.0 (since 2.0 as {@code Objects.ToStringHelper}).
*/
public static final class ToStringHelper {
private final String className;
@Nonnull
private ValueHolder holderHead = new ValueHolder();
@Nonnull
private ValueHolder holderTail = holderHead;
private boolean omitNullValues = false;
/**
* Use {@link MoreObjects#toStringHelper(Object)} to create an instance.
*/
private ToStringHelper(@Nonnull String className) {
this.className = Preconditions.checkNotNull(className);
}
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Configures the {@link ToStringHelper} so {@link #toString()} will ignore
// * properties with null value. The order of calling this method, relative
// * to the {@code add()}/{@code addValue()} methods, is not significant.
// *
// * @since 18.0 (since 12.0 as {@code Objects.ToStringHelper.omitNullValues()}).
// */
// public ToStringHelper omitNullValues() {
// omitNullValues = true;
// return this;
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format. If {@code value} is {@code null}, the string {@code "null"}
* is used, unless {@link #omitNullValues()} is called, in which case this
* name/value pair will not be added.
*/
@Nonnull
public ToStringHelper add(@Nonnull String name, Object value) {
return addHolder(name, value);
}
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds a name/value pair to the formatted output in {@code name=value}
// * format.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
// */
// public ToStringHelper add(String name, boolean value) {
// return addHolder(name, String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds a name/value pair to the formatted output in {@code name=value}
// * format.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
// */
// public ToStringHelper add(String name, char value) {
// return addHolder(name, String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds a name/value pair to the formatted output in {@code name=value}
// * format.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
// */
// public ToStringHelper add(String name, double value) {
// return addHolder(name, String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds a name/value pair to the formatted output in {@code name=value}
// * format.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
// */
// public ToStringHelper add(String name, float value) {
// return addHolder(name, String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
*/
@Nonnull
public ToStringHelper add(@Nonnull String name, int value) {
return addHolder(name, String.valueOf(value));
}
/**
* Adds a name/value pair to the formatted output in {@code name=value}
* format.
*
* @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.add()}).
*/
@Nonnull
public ToStringHelper add(@Nonnull String name, long value) {
return addHolder(name, String.valueOf(value));
}
/**
* Adds an unnamed value to the formatted output.
*
*
It is strongly encouraged to use {@link #add(String, Object)} instead
* and give value a readable name.
*/
@Nonnull
public ToStringHelper addValue(Object value) {
return addHolder(value);
}
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, boolean)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(boolean value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, char)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(char value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, double)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(double value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, float)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(float value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, int)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(int value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
// --Commented out by Inspection START (11/29/16, 5:04 PM):
// /**
// * Adds an unnamed value to the formatted output.
// *
// *
It is strongly encouraged to use {@link #add(String, long)} instead
// * and give value a readable name.
// *
// * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue()}).
// */
// public ToStringHelper addValue(long value) {
// return addHolder(String.valueOf(value));
// }
// --Commented out by Inspection STOP (11/29/16, 5:04 PM)
/**
* Returns a string in the format specified by
* {@link MoreObjects#toStringHelper(Object)}.
*
*
After calling this method, you can keep adding more properties to later
* call toString() again and get a more complete representation of the
* same object; but properties cannot be removed, so this only allows
* limited reuse of the helper instance. The helper allows duplication of
* properties (multiple name/value pairs with the same name can be added).
*/
@Override
public String toString() {
// create a copy to keep it consistent in case value changes
boolean omitNullValuesSnapshot = omitNullValues;
String nextSeparator = "";
StringBuilder builder = new StringBuilder(32).append(className).append('{');
for (ValueHolder valueHolder = holderHead.next;
valueHolder != null;
valueHolder = valueHolder.next) {
Object value = valueHolder.value;
if (!omitNullValuesSnapshot || value != null) {
builder.append(nextSeparator);
nextSeparator = ", ";
if (valueHolder.name != null) {
builder.append(valueHolder.name).append('=');
}
if (value != null && value.getClass().isArray()) {
Object[] objectArray = {value};
String arrayString = Arrays.deepToString(objectArray);
builder.append(arrayString.substring(1, arrayString.length() - 1));
} else {
builder.append(value);
}
}
}
return builder.append('}').toString();
}
@Nonnull
private ValueHolder addHolder() {
ValueHolder valueHolder = new ValueHolder();
holderTail = holderTail.next = valueHolder;
return valueHolder;
}
@Nonnull
private ToStringHelper addHolder(Object value) {
ValueHolder valueHolder = addHolder();
valueHolder.value = value;
return this;
}
@Nonnull
private ToStringHelper addHolder(@Nonnull String name, Object value) {
ValueHolder valueHolder = addHolder();
valueHolder.value = value;
valueHolder.name = Preconditions.checkNotNull(name);
return this;
}
private static final class ValueHolder {
String name;
Object value;
ValueHolder next;
}
}
private MoreObjects() {}
}