com.alipay.api.internal.util.file.Charsets Maven / Gradle / Ivy
package com.alipay.api.internal.util.file;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.SortedMap;
import java.util.TreeMap;
public class Charsets {
//
// This class should only contain Charset instances for required encodings. This guarantees that it will load
// correctly and without delay on all Java platforms.
//
/**
* Constructs a sorted map from canonical charset names to charset objects required of every implementation of the Java platform.
*
* From the Java documentation Standard charsets:
*
*
* @return An immutable, case-insensitive map from canonical charset names to charset objects.
* @see Charset#availableCharsets()
* @since 2.5
*/
public static SortedMap requiredCharsets() {
// maybe cache?
// TODO Re-implement on Java 7 to use java.nio.charset.StandardCharsets
final TreeMap m = new TreeMap(String.CASE_INSENSITIVE_ORDER);
m.put(ISO_8859_1.name(), ISO_8859_1);
m.put(US_ASCII.name(), US_ASCII);
m.put(UTF_16.name(), UTF_16);
m.put(UTF_16BE.name(), UTF_16BE);
m.put(UTF_16LE.name(), UTF_16LE);
m.put(UTF_8.name(), UTF_8);
return Collections.unmodifiableSortedMap(m);
}
/**
* Returns the given Charset or the default Charset if the given Charset is null.
*
* @param charset A charset or null.
* @return the given Charset or the default Charset if the given Charset is null
*/
public static Charset toCharset(final Charset charset) {
return charset == null ? Charset.defaultCharset() : charset;
}
/**
* Returns a Charset for the named charset. If the name is null, return the default Charset.
*
* @param charset The name of the requested charset, may be null.
* @return a Charset for the named charset
* @throws java.nio.charset.UnsupportedCharsetException If the named charset is unavailable
*/
public static Charset toCharset(final String charset) {
return charset == null ? Charset.defaultCharset() : Charset.forName(charset);
}
/**
* CharEncodingISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
/**
*
* Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
*
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset US_ASCII = Charset.forName("US-ASCII");
/**
*
* Sixteen-bit Unicode Transformation Format, The byte order specified by a mandatory initial byte-order mark (either order accepted on
* input, big-endian used on output)
*
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset UTF_16 = Charset.forName("UTF-16");
/**
*
* Sixteen-bit Unicode Transformation Format, big-endian byte order.
*
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
/**
*
* Sixteen-bit Unicode Transformation Format, little-endian byte order.
*
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
/**
*
* Eight-bit Unicode Transformation Format.
*
*
* Every implementation of the Java platform is required to support this character encoding.
*
*
* @see Standard charsets
* @deprecated Use Java 7's {@link java.nio.charset.StandardCharsets}
*/
@Deprecated
public static final Charset UTF_8 = Charset.forName("UTF-8");
}