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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.
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/*
* 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
*
* https://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.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;
@Internal
public final class InternalUtil {
public static final String ERROR_MSG_FOR_NO_SUCH_EX = "Target object/value does not exist or is not found";
public static final String ERROR_MSG_FOR_NULL_ELEMENT_EX = "Target object/value does not exist or is not found, or its value is null";
// To avoid SpotBugs: CD_CIRCULAR_DEPENDENCY, IC_INIT_CIRCULARITY
static final int CPU_CORES = Runtime.getRuntime().availableProcessors();
/**
*
* @deprecated DO NOT call the methods defined in this class. it's for internal use only.
*/
@Deprecated
public static final int POOL_SIZE;
static {
final 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 (final 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 (final 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; // NOSONAR
}
if (isListElementDataFieldGettable && listElementDataField != null && c.getClass().equals(ArrayList.class)) {
try {
return (Object[]) listElementDataField.get(c);
} catch (final Throwable e) {
// ignore;
isListElementDataFieldGettable = false;
}
}
return null; // NOSONAR
}
/**
* Create an array list by initializing its elements with the specified array {@code a}.
* The returned list may share the same elements with the specified array {@code 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.isEmpty(a)) {
return new ArrayList<>();
}
return N.asList(a);
}
// static volatile boolean isStringCharsGettable = JavaVersion.of(System.getProperty("java.version")).atMost(JavaVersion.JAVA_1_8);
// static volatile boolean isStringCharsCreatable = JavaVersion.of(System.getProperty("java.version")).atMost(JavaVersion.JAVA_1_8);
//
// 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;
// }
// }
if (N.isEmpty(str)) {
return N.EMPTY_CHAR_ARRAY;
}
return str.toCharArray();
}
// /**
// *
// * @param a the 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, @SuppressWarnings("unused") 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 a primitive number type.
// *
// * @param s
// * @return true, if it 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 a 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()));
// }
private InternalUtil() {
// singleton for utility class
}
}
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