程序包 java.util

类 Base64.Encoder

java.lang.Object

java.util.Base64.Encoder

封闭类:

Base64

public static class Base64.Encoder
extends Object

This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.

Instances of Encoder class are safe for use by multiple concurrent threads.

Unless otherwise noted, passing a null argument to a method of this class will cause a NullPointerException to be thrown.

从以下版本开始:

1.8

另请参阅:

Base64.Decoder

方法概要

限定符和类型	方法	说明
byte[]	encode(byte[] src)	Encodes all bytes from the specified byte array into a newly-allocated byte array using the Base64 encoding scheme.
int	encode(byte[] src, byte[] dst)	Encodes all bytes from the specified byte array using the Base64 encoding scheme, writing the resulting bytes to the given output byte array, starting at offset 0.
ByteBuffer	encode(ByteBuffer buffer)	Encodes all remaining bytes from the specified byte buffer into a newly-allocated ByteBuffer using the Base64 encoding scheme.
String	encodeToString(byte[] src)	Encodes the specified byte array into a String using the Base64 encoding scheme.
Base64.Encoder	withoutPadding()	Returns an encoder instance that encodes equivalently to this one, but without adding any padding character at the end of the encoded byte data.
OutputStream	wrap(OutputStream os)	Wraps an output stream for encoding byte data using the Base64 encoding scheme.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

方法详细资料

encode

public byte[] encode(byte[] src)

Encodes all bytes from the specified byte array into a newly-allocated byte array using the Base64 encoding scheme. The returned byte array is of the length of the resulting bytes.

参数:

src - the byte array to encode

返回:

A newly-allocated byte array containing the resulting encoded bytes.

encode

public int encode(byte[] src,
                  byte[] dst)

Encodes all bytes from the specified byte array using the Base64 encoding scheme, writing the resulting bytes to the given output byte array, starting at offset 0.

It is the responsibility of the invoker of this method to make sure the output byte array dst has enough space for encoding all bytes from the input byte array. No bytes will be written to the output byte array if the output byte array is not big enough.

参数:

src - the byte array to encode

dst - the output byte array

返回:

The number of bytes written to the output byte array

抛出:

IllegalArgumentException - if dst does not have enough space for encoding all input bytes.

encodeToString

public String encodeToString(byte[] src)

Encodes the specified byte array into a String using the Base64 encoding scheme.

This method first encodes all input bytes into a base64 encoded byte array and then constructs a new String by using the encoded byte array and the ISO-8859-1 charset.

In other words, an invocation of this method has exactly the same effect as invoking new String(encode(src), StandardCharsets.ISO_8859_1).

参数:

src - the byte array to encode

返回:

A String containing the resulting Base64 encoded characters

encode

public ByteBuffer encode(ByteBuffer buffer)

Encodes all remaining bytes from the specified byte buffer into a newly-allocated ByteBuffer using the Base64 encoding scheme. Upon return, the source buffer's position will be updated to its limit; its limit will not have been changed. The returned output buffer's position will be zero and its limit will be the number of resulting encoded bytes.

参数:

buffer - the source ByteBuffer to encode

返回:

A newly-allocated byte buffer containing the encoded bytes.

wrap

public OutputStream wrap(OutputStream os)

Wraps an output stream for encoding byte data using the Base64 encoding scheme.

It is recommended to promptly close the returned output stream after use, during which it will flush all possible leftover bytes to the underlying output stream. Closing the returned output stream will close the underlying output stream.

参数:

os - the output stream.

返回:

the output stream for encoding the byte data into the specified Base64 encoded format

withoutPadding

public Base64.Encoder withoutPadding()

Returns an encoder instance that encodes equivalently to this one, but without adding any padding character at the end of the encoded byte data.

The encoding scheme of this encoder instance is unaffected by this invocation. The returned encoder instance should be used for non-padding encoding operation.

返回:

an equivalent encoder that encodes without adding any padding character at the end