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A general programming library in Java/Android. It's easy to learn and simple to use with concise and powerful APIs.
/*
* Copyright (c) 2019, Haiyang Li.
*
* 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.landawn.abacus.util;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import com.landawn.abacus.annotation.Beta;
import com.landawn.abacus.annotation.Internal;
import com.landawn.abacus.util.ExceptionalStream.ExceptionalIterator;
@Internal
public final class InternalUtil {
/**
*
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
public static final int POOL_SIZE;
static {
int multi = (int) (Runtime.getRuntime().maxMemory() / ((1024 * 1024) * 256));
POOL_SIZE = Math.max(1000, Math.min(1000 * multi, 8192));
}
// ...
static final Field listElementDataField;
static volatile boolean isListElementDataFieldGettable = true;
static {
Field tmp = null;
try {
tmp = ArrayList.class.getDeclaredField("elementData");
} catch (Throwable e) {
// ignore.
}
listElementDataField = tmp != null && tmp.getType().equals(Object[].class) ? tmp : null;
if (listElementDataField != null) {
try {
listElementDataField.setAccessible(true); //NOSONAR
isListElementDataFieldGettable = listElementDataField.canAccess(new ArrayList());
} catch (Throwable e) {
// ignore.
}
}
}
/**
*
* @param c
* @return
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
@Beta
static Object[] getInternalArray(final Collection c) {
if (c == null) {
return null;
}
if (isListElementDataFieldGettable && listElementDataField != null && c.getClass().equals(ArrayList.class)) {
try {
return (Object[]) listElementDataField.get(c);
} catch (Throwable e) {
// ignore;
isListElementDataFieldGettable = false;
}
}
return null;
}
/**
* Create an array list by initializing its elements data with the specified array a.
* The returned list may share the same elements with the specified array a.
* That's to say any change on the List/Array will affect the Array/List.
*
* @param
* @param a
* @return
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
@Beta
@SafeVarargs
static List createList(final T... a) {
if (N.isNullOrEmpty(a)) {
return new ArrayList<>();
}
return N.asList(a);
}
static volatile boolean isStringCharsGettable = true;
static volatile boolean isStringCharsCreatable = true;
static final Field strValueField;
static final Constructor sharedStringConstructor;
static {
Field tmp = null;
try {
tmp = String.class.getDeclaredField("value");
} catch (Throwable e) {
// ignore.
}
strValueField = ((tmp != null) && tmp.getName().equals("value") && tmp.getType().equals(char[].class)) ? tmp : null;
if (strValueField != null) {
ClassUtil.setAccessibleQuietly(strValueField, true);
}
Constructor tmpConstructor = null;
try {
tmpConstructor = String.class.getDeclaredConstructor(char[].class, boolean.class);
ClassUtil.setAccessibleQuietly(tmpConstructor, true);
} catch (Throwable e) {
// ignore.
}
sharedStringConstructor = tmpConstructor;
}
/**
* Gets the chars for read only.
*
* @param str
* @return
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
@Beta
public static char[] getCharsForReadOnly(final String str) {
if (isStringCharsGettable && strValueField != null && str.length() > 3) {
try {
final char[] chars = (char[]) strValueField.get(str);
if (chars.length == str.length()) {
return chars;
} else {
isStringCharsGettable = false;
}
} catch (Throwable e) {
// ignore.
isStringCharsGettable = false;
}
}
return str.toCharArray();
}
/**
*
* @param a the specified array should not be modified after it's used to
* create the new String.
* @param share the same array will be shared with the new created ArrayList
* if it's true.
* @return
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
@Beta
static String newString(final char[] a, final boolean share) {
if (isStringCharsCreatable && share && sharedStringConstructor != null) {
try {
return sharedStringConstructor.newInstance(a, true);
} catch (Throwable e) {
// ignore
isStringCharsCreatable = false;
}
}
return String.valueOf(a);
}
// /**
// * Checks if it's not null or default. {@code null} is default value for all reference types, {@code false} is default value for primitive boolean, {@code 0} is the default value for primitive number type.
// *
// *
// * @param s
// * @return true, if it's not null or default
// * @deprecated internal only
// */
// @Deprecated
// @Internal
// @Beta
// static boolean notNullOrDefault(final Object value) {
// return (value != null) && !equals(value, defaultValueOf(value.getClass()));
// }
/**
* Checks if is null or default. {@code null} is default value for all reference types, {@code false} is default value for primitive boolean, {@code 0} is the default value for primitive number type.
*
* @param s
* @return true, if is null or default
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
static boolean isNullOrDefault(final Object value) {
return (value == null) || N.equals(value, N.defaultValueOf(value.getClass()));
}
/**
* Checks if it's not null or default. {@code null} is default value for all reference types, {@code false} is default value for primitive boolean, {@code 0} is the default value for primitive number type.
*
*
* @param s
* @return true, if it's not null or default
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
static boolean notNullOrDefault(final Object value) {
return (value != null) && !N.equals(value, N.defaultValueOf(value.getClass()));
}
/**
*
* @param
* @param
* @param iter
* @return
*/
@Beta
public static ExceptionalStream newStream(final ExceptionalIterator iter) {
return ExceptionalStream.newStream(iter);
}
private InternalUtil() {
// singleton for utility class
}
}