lich0079
- 浏览: 1233437 次
- 性别:
- 来自: 上海
-
文章分类
最新评论
-
lankk：
lankk 写道事实上，在运行String s1=new St ...
理解String 及 String.intern() 在实际中的应用 -
lankk：
事实上，在运行String s1=new String(&qu ...
理解String 及 String.intern() 在实际中的应用 -
lankk：
同意1楼的说法http://docs.oracle.com/j ...
理解String 及 String.intern() 在实际中的应用 -
raoyutao：
...
jdk 线程池 ThreadPoolExecutor -
hongdanning：
理解了。之前困惑的一些明白了。谢谢分享。
理解String 及 String.intern() 在实际中的应用
MD5 SHA1
import java.security.MessageDigest;
MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
Base64
/**
*
*/
/**
* @author jinbinhan
*
*/
/*
* Copyright (C) 2010 The Android Open Source Project
*
* 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.
*/
import java.io.UnsupportedEncodingException;
import org.apache.commons.codec.binary.Base64OutputStream;
/**
* Utilities for encoding and decoding the Base64 representation of
* binary data. See RFCs <a
* href="http://www.ietf.org/rfc/rfc2045.txt">2045</a> and <a
* href="http://www.ietf.org/rfc/rfc3548.txt">3548</a>.
*/
public class Base64 {
/**
* Default values for encoder/decoder flags.
*/
public static final int DEFAULT = 0;
/**
* Encoder flag bit to omit the padding '=' characters at the end
* of the output (if any).
*/
public static final int NO_PADDING = 1;
/**
* Encoder flag bit to omit all line terminators (i.e., the output
* will be on one long line).
*/
public static final int NO_WRAP = 2;
/**
* Encoder flag bit to indicate lines should be terminated with a
* CRLF pair instead of just an LF. Has no effect if {@code
* NO_WRAP} is specified as well.
*/
public static final int CRLF = 4;
/**
* Encoder/decoder flag bit to indicate using the "URL and
* filename safe" variant of Base64 (see RFC 3548 section 4) where
* {@code -} and {@code _} are used in place of {@code +} and
* {@code /}.
*/
public static final int URL_SAFE = 8;
/**
* Flag to pass to {@link Base64OutputStream} to indicate that it
* should not close the output stream it is wrapping when it
* itself is closed.
*/
public static final int NO_CLOSE = 16;
// --------------------------------------------------------
// shared code
// --------------------------------------------------------
/* package */ static abstract class Coder {
public byte[] output;
public int op;
/**
* Encode/decode another block of input data. this.output is
* provided by the caller, and must be big enough to hold all
* the coded data. On exit, this.opwill be set to the length
* of the coded data.
*
* @param finish true if this is the final call to process for
* this object. Will finalize the coder state and
* include any final bytes in the output.
*
* @return true if the input so far is good; false if some
* error has been detected in the input stream..
*/
public abstract boolean process(byte[] input, int offset, int len, boolean finish);
/**
* @return the maximum number of bytes a call to process()
* could produce for the given number of input bytes. This may
* be an overestimate.
*/
public abstract int maxOutputSize(int len);
}
// --------------------------------------------------------
// decoding
// --------------------------------------------------------
/**
* Decode the Base64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but
* if any are present, there must be the correct number of them.
*
* @param str the input String to decode, which is converted to
* bytes using the default charset
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Base64.
*
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(String str, int flags) {
return decode(str.getBytes(), flags);
}
/**
* Decode the Base64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but
* if any are present, there must be the correct number of them.
*
* @param input the input array to decode
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Base64.
*
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(byte[] input, int flags) {
return decode(input, 0, input.length, flags);
}
/**
* Decode the Base64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but
* if any are present, there must be the correct number of them.
*
* @param input the data to decode
* @param offset the position within the input array at which to start
* @param len the number of bytes of input to decode
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Base64.
*
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(byte[] input, int offset, int len, int flags) {
// Allocate space for the most data the input could represent.
// (It could contain less if it contains whitespace, etc.)
Decoder decoder = new Decoder(flags, new byte[len*3/4]);
if (!decoder.process(input, offset, len, true)) {
throw new IllegalArgumentException("bad base-64");
}
// Maybe we got lucky and allocated exactly enough output space.
if (decoder.op == decoder.output.length) {
return decoder.output;
}
// Need to shorten the array, so allocate a new one of the
// right size and copy.
byte[] temp = new byte[decoder.op];
System.arraycopy(decoder.output, 0, temp, 0, decoder.op);
return temp;
}
/* package */ static class Decoder extends Coder {
/**
* Lookup table for turning bytes into their position in the
* Base64 alphabet.
*/
private static final int DECODE[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
/**
* Decode lookup table for the "web safe" variant (RFC 3548
* sec. 4) where - and _ replace + and /.
*/
private static final int DECODE_WEBSAFE[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
/** Non-data values in the DECODE arrays. */
private static final int SKIP = -1;
private static final int EQUALS = -2;
/**
* States 0-3 are reading through the next input tuple.
* State 4 is having read one '=' and expecting exactly
* one more.
* State 5 is expecting no more data or padding characters
* in the input.
* State 6 is the error state; an error has been detected
* in the input and no future input can "fix" it.
*/
private int state; // state number (0 to 6)
private int value;
final private int[] alphabet;
public Decoder(int flags, byte[] output) {
this.output = output;
alphabet = ((flags & URL_SAFE) == 0) ? DECODE : DECODE_WEBSAFE;
state = 0;
value = 0;
}
/**
* @return an overestimate for the number of bytes {@code
* len} bytes could decode to.
*/
public int maxOutputSize(int len) {
return len * 3/4 + 10;
}
/**
* Decode another block of input data.
*
* @return true if the state machine is still healthy. false if
* bad base-64 data has been detected in the input stream.
*/
public boolean process(byte[] input, int offset, int len, boolean finish) {
if (this.state == 6) return false;
int p = offset;
len += offset;
// Using local variables makes the decoder about 12%
// faster than if we manipulate the member variables in
// the loop. (Even alphabet makes a measurable
// difference, which is somewhat surprising to me since
// the member variable is final.)
int state = this.state;
int value = this.value;
int op = 0;
final byte[] output = this.output;
final int[] alphabet = this.alphabet;
while (p < len) {
// Try the fast path: we're starting a new tuple and the
// next four bytes of the input stream are all data
// bytes. This corresponds to going through states
// 0-1-2-3-0. We expect to use this method for most of
// the data.
//
// If any of the next four bytes of input are non-data
// (whitespace, etc.), value will end up negative. (All
// the non-data values in decode are small negative
// numbers, so shifting any of them up and or'ing them
// together will result in a value with its top bit set.)
//
// You can remove this whole block and the output should
// be the same, just slower.
if (state == 0) {
while (p+4 <= len &&
(value = ((alphabet[input[p] & 0xff] << 18) |
(alphabet[input[p+1] & 0xff] << 12) |
(alphabet[input[p+2] & 0xff] << 6) |
(alphabet[input[p+3] & 0xff]))) >= 0) {
output[op+2] = (byte) value;
output[op+1] = (byte) (value >> 8);
output[op] = (byte) (value >> 16);
op += 3;
p += 4;
}
if (p >= len) break;
}
// The fast path isn't available -- either we've read a
// partial tuple, or the next four input bytes aren't all
// data, or whatever. Fall back to the slower state
// machine implementation.
int d = alphabet[input[p++] & 0xff];
switch (state) {
case 0:
if (d >= 0) {
value = d;
++state;
} else if (d != SKIP) {
this.state = 6;
return false;
}
break;
case 1:
if (d >= 0) {
value = (value << 6) | d;
++state;
} else if (d != SKIP) {
this.state = 6;
return false;
}
break;
case 2:
if (d >= 0) {
value = (value << 6) | d;
++state;
} else if (d == EQUALS) {
// Emit the last (partial) output tuple;
// expect exactly one more padding character.
output[op++] = (byte) (value >> 4);
state = 4;
} else if (d != SKIP) {
this.state = 6;
return false;
}
break;
case 3:
if (d >= 0) {
// Emit the output triple and return to state 0.
value = (value << 6) | d;
output[op+2] = (byte) value;
output[op+1] = (byte) (value >> 8);
output[op] = (byte) (value >> 16);
op += 3;
state = 0;
} else if (d == EQUALS) {
// Emit the last (partial) output tuple;
// expect no further data or padding characters.
output[op+1] = (byte) (value >> 2);
output[op] = (byte) (value >> 10);
op += 2;
state = 5;
} else if (d != SKIP) {
this.state = 6;
return false;
}
break;
case 4:
if (d == EQUALS) {
++state;
} else if (d != SKIP) {
this.state = 6;
return false;
}
break;
case 5:
if (d != SKIP) {
this.state = 6;
return false;
}
break;
}
}
if (!finish) {
// We're out of input, but a future call could provide
// more.
this.state = state;
this.value = value;
this.op = op;
return true;
}
// Done reading input. Now figure out where we are left in
// the state machine and finish up.
switch (state) {
case 0:
// Output length is a multiple of three. Fine.
break;
case 1:
// Read one extra input byte, which isn't enough to
// make another output byte. Illegal.
this.state = 6;
return false;
case 2:
// Read two extra input bytes, enough to emit 1 more
// output byte. Fine.
output[op++] = (byte) (value >> 4);
break;
case 3:
// Read three extra input bytes, enough to emit 2 more
// output bytes. Fine.
output[op++] = (byte) (value >> 10);
output[op++] = (byte) (value >> 2);
break;
case 4:
// Read one padding '=' when we expected 2. Illegal.
this.state = 6;
return false;
case 5:
// Read all the padding '='s we expected and no more.
// Fine.
break;
}
this.state = state;
this.op = op;
return true;
}
}
// --------------------------------------------------------
// encoding
// --------------------------------------------------------
/**
* Base64-encode the given data and return a newly allocated
* String with the result.
*
* @param input the data to encode
* @param flags controls certain features of the encoded output.
* Passing {@code DEFAULT} results in output that
* adheres to RFC 2045.
*/
public static String encodeToString(byte[] input, int flags) {
try {
return new String(encode(input, flags), "US-ASCII");
} catch (UnsupportedEncodingException e) {
// US-ASCII is guaranteed to be available.
throw new AssertionError(e);
}
}
/**
* Base64-encode the given data and return a newly allocated
* String with the result.
*
* @param input the data to encode
* @param offset the position within the input array at which to
* start
* @param len the number of bytes of input to encode
* @param flags controls certain features of the encoded output.
* Passing {@code DEFAULT} results in output that
* adheres to RFC 2045.
*/
public static String encodeToString(byte[] input, int offset, int len, int flags) {
try {
return new String(encode(input, offset, len, flags), "US-ASCII");
} catch (UnsupportedEncodingException e) {
// US-ASCII is guaranteed to be available.
throw new AssertionError(e);
}
}
/**
* Base64-encode the given data and return a newly allocated
* byte[] with the result.
*
* @param input the data to encode
* @param flags controls certain features of the encoded output.
* Passing {@code DEFAULT} results in output that
* adheres to RFC 2045.
*/
public static byte[] encode(byte[] input, int flags) {
return encode(input, 0, input.length, flags);
}
/**
* Base64-encode the given data and return a newly allocated
* byte[] with the result.
*
* @param input the data to encode
* @param offset the position within the input array at which to
* start
* @param len the number of bytes of input to encode
* @param flags controls certain features of the encoded output.
* Passing {@code DEFAULT} results in output that
* adheres to RFC 2045.
*/
public static byte[] encode(byte[] input, int offset, int len, int flags) {
Encoder encoder = new Encoder(flags, null);
// Compute the exact length of the array we will produce.
int output_len = len / 3 * 4;
// Account for the tail of the data and the padding bytes, if any.
if (encoder.do_padding) {
if (len % 3 > 0) {
output_len += 4;
}
} else {
switch (len % 3) {
case 0: break;
case 1: output_len += 2; break;
case 2: output_len += 3; break;
}
}
// Account for the newlines, if any.
if (encoder.do_newline && len > 0) {
output_len += (((len-1) / (3 * Encoder.LINE_GROUPS)) + 1) *
(encoder.do_cr ? 2 : 1);
}
encoder.output = new byte[output_len];
encoder.process(input, offset, len, true);
assert encoder.op == output_len;
return encoder.output;
}
/* package */ static class Encoder extends Coder {
/**
* Emit a new line every this many output tuples. Corresponds to
* a 76-character line length (the maximum allowable according to
* <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>).
*/
public static final int LINE_GROUPS = 19;
/**
* Lookup table for turning Base64 alphabet positions (6 bits)
* into output bytes.
*/
private static final byte ENCODE[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/',
};
/**
* Lookup table for turning Base64 alphabet positions (6 bits)
* into output bytes.
*/
private static final byte ENCODE_WEBSAFE[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_',
};
final private byte[] tail;
/* package */ int tailLen;
private int count;
final public boolean do_padding;
final public boolean do_newline;
final public boolean do_cr;
final private byte[] alphabet;
public Encoder(int flags, byte[] output) {
this.output = output;
do_padding = (flags & NO_PADDING) == 0;
do_newline = (flags & NO_WRAP) == 0;
do_cr = (flags & CRLF) != 0;
alphabet = ((flags & URL_SAFE) == 0) ? ENCODE : ENCODE_WEBSAFE;
tail = new byte[2];
tailLen = 0;
count = do_newline ? LINE_GROUPS : -1;
}
/**
* @return an overestimate for the number of bytes {@code
* len} bytes could encode to.
*/
public int maxOutputSize(int len) {
return len * 8/5 + 10;
}
public boolean process(byte[] input, int offset, int len, boolean finish) {
// Using local variables makes the encoder about 9% faster.
final byte[] alphabet = this.alphabet;
final byte[] output = this.output;
int op = 0;
int count = this.count;
int p = offset;
len += offset;
int v = -1;
// First we need to concatenate the tail of the previous call
// with any input bytes available now and see if we can empty
// the tail.
switch (tailLen) {
case 0:
// There was no tail.
break;
case 1:
if (p+2 <= len) {
// A 1-byte tail with at least 2 bytes of
// input available now.
v = ((tail[0] & 0xff) << 16) |
((input[p++] & 0xff) << 8) |
(input[p++] & 0xff);
tailLen = 0;
};
break;
case 2:
if (p+1 <= len) {
// A 2-byte tail with at least 1 byte of input.
v = ((tail[0] & 0xff) << 16) |
((tail[1] & 0xff) << 8) |
(input[p++] & 0xff);
tailLen = 0;
}
break;
}
if (v != -1) {
output[op++] = alphabet[(v >> 18) & 0x3f];
output[op++] = alphabet[(v >> 12) & 0x3f];
output[op++] = alphabet[(v >> 6) & 0x3f];
output[op++] = alphabet[v & 0x3f];
if (--count == 0) {
if (do_cr) output[op++] = '\r';
output[op++] = '\n';
count = LINE_GROUPS;
}
}
// At this point either there is no tail, or there are fewer
// than 3 bytes of input available.
// The main loop, turning 3 input bytes into 4 output bytes on
// each iteration.
while (p+3 <= len) {
v = ((input[p] & 0xff) << 16) |
((input[p+1] & 0xff) << 8) |
(input[p+2] & 0xff);
output[op] = alphabet[(v >> 18) & 0x3f];
output[op+1] = alphabet[(v >> 12) & 0x3f];
output[op+2] = alphabet[(v >> 6) & 0x3f];
output[op+3] = alphabet[v & 0x3f];
p += 3;
op += 4;
if (--count == 0) {
if (do_cr) output[op++] = '\r';
output[op++] = '\n';
count = LINE_GROUPS;
}
}
if (finish) {
// Finish up the tail of the input. Note that we need to
// consume any bytes in tail before any bytes
// remaining in input; there should be at most two bytes
// total.
if (p-tailLen == len-1) {
int t = 0;
v = ((tailLen > 0 ? tail[t++] : input[p++]) & 0xff) << 4;
tailLen -= t;
output[op++] = alphabet[(v >> 6) & 0x3f];
output[op++] = alphabet[v & 0x3f];
if (do_padding) {
output[op++] = '=';
output[op++] = '=';
}
if (do_newline) {
if (do_cr) output[op++] = '\r';
output[op++] = '\n';
}
} else if (p-tailLen == len-2) {
int t = 0;
v = (((tailLen > 1 ? tail[t++] : input[p++]) & 0xff) << 10) |
(((tailLen > 0 ? tail[t++] : input[p++]) & 0xff) << 2);
tailLen -= t;
output[op++] = alphabet[(v >> 12) & 0x3f];
output[op++] = alphabet[(v >> 6) & 0x3f];
output[op++] = alphabet[v & 0x3f];
if (do_padding) {
output[op++] = '=';
}
if (do_newline) {
if (do_cr) output[op++] = '\r';
output[op++] = '\n';
}
} else if (do_newline && op > 0 && count != LINE_GROUPS) {
if (do_cr) output[op++] = '\r';
output[op++] = '\n';
}
assert tailLen == 0;
assert p == len;
} else {
// Save the leftovers in tail to be consumed on the next
// call to encodeInternal.
if (p == len-1) {
tail[tailLen++] = input[p];
} else if (p == len-2) {
tail[tailLen++] = input[p];
tail[tailLen++] = input[p+1];
}
}
this.op = op;
this.count = count;
return true;
}
}
private Base64() { } // don't instantiate
}
BASE64Encoder
/**
* A utility class encodes byte array into String using Base64 encoding scheme.
*/
public class BASE64Encoder {
private static final char last2byte = (char) Integer.parseInt("00000011", 2);
private static final char last4byte = (char) Integer.parseInt("00001111", 2);
private static final char last6byte = (char) Integer.parseInt("00111111", 2);
private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
private static final char[] encodeTable = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
public BASE64Encoder() {
}
public String encode(byte[] from) {
StringBuffer to = new StringBuffer((int) (from.length * 1.34) + 3);
int num = 0;
char currentByte = 0;
for (int i = 0; i < from.length; i++) {
num = num % 8;
while (num < 8) {
switch (num) {
case 0:
currentByte = (char) (from[i] & lead6byte);
currentByte = (char) (currentByte >>> 2);
break;
case 2:
currentByte = (char) (from[i] & last6byte);
break;
case 4:
currentByte = (char) (from[i] & last4byte);
currentByte = (char) (currentByte << 2);
if ((i + 1) < from.length) {
currentByte |= (from[i + 1] & lead2byte) >>> 6;
}
break;
case 6:
currentByte = (char) (from[i] & last2byte);
currentByte = (char) (currentByte << 4);
if ((i + 1) < from.length) {
currentByte |= (from[i + 1] & lead4byte) >>> 4;
}
break;
}
to.append(encodeTable[currentByte]);
num += 6;
}
}
if (to.length() % 4 != 0) {
for (int i = 4 - to.length() % 4; i > 0; i--) {
to.append("=");
}
}
return to.toString();
}
}
HmacSHA1
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
byte[] byteHMAC = null;
try {
Mac mac = Mac.getInstance("HmacSHA1");
SecretKeySpec spec = new SecretKeySpec(key.getBytes(), "HmacSHA1");
mac.init(spec);
byteHMAC = mac.doFinal(data.getBytes());
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException ignore) {
}
String oauth = new BASE64Encoder().encode(byteHMAC);
System.out.println("oauth= "+oauth);
参考：
http://www.iteye.com/topic/855357
http://www.iteye.com/topic/604440
http://www.oschina.net/code/snippet_87799_740
0
顶
顶
0
踩
踩
分享到：
发表评论
-
连接池exception GetConnectionTimeoutException get/close not same thread
2015-09-24 14:44 7124环境 hibernate 4.2.0.Final sp ... -
tomcat 7 应用不能访问 及 配置管理界面
2015-09-16 15:26 2751tomcat 7 应用不能访问 及 配置管理界面 ... -
iteye blog 备份
2015-06-01 11:03 1198以前javaeye有博客导出成pdf的功能， 现在这个功能 ... -
jaxb xml 解析出 list对象
2015-03-26 16:29 10631jaxb想直接解析出list对象， 不用在list对象上再去 ... -
jvm notes
2014-12-16 15:19 1722运行时数据区 program counter re ... -
string split 空字符串问题
2014-09-02 15:02 1944String str="123,123,,1 ... -
IntelliJ IDEA keys
2014-05-29 15:35 1192open type Ctrl+N open ... -
POI excel 触发 公式 计算 删除空白行
2013-04-15 12:44 5093用POI api修改excel 表格数据后， 想触发计算公式 ... -
javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated 异常处理
2013-01-05 14:13 3230引用: http://javaskeleton.blogs ... -
struts2 jsp 禁止 直接 访问
2011-10-13 14:16 3152想要禁止 struts2 应用中 部分jsp 的 直接访问 ... -
jboss-log4j.xml
2011-09-22 17:42 3175使用 jboss_home/server/default/co ... -
jboss 映射 url 虚拟目录 设置system property
2011-08-31 12:56 2198jboss 4.2.3 在[jboss home ... -
jboss 连接池 scheduler
2011-08-04 19:13 1572将oracle-ds.xml 放到 jboss_home\s ... -
jboss Caused by: LifecycleException: Error initializaing : javax.management.R
2011-08-04 14:55 2317Caused by: LifecycleException: ... -
axis2 spring pojo 集成
2011-04-28 15:28 2496之前写的 http://renxiangzyq.iteye.c ... -
wsdl axis2 spring
2011-04-28 11:12 3317WSDL 文档是利用这些主要的元素来描述某个 web s ... -
apache jboss ssl 配置
2011-03-10 19:37 1601httpd.conf Include "co ... -
cron 表达式
2010-12-13 17:47 1135http://sosuny.iteye.com/blog/46 ... -
资源文件转码
2010-10-27 14:54 1198GBK to utf-8 native2ascii ... -
maven test jar
2010-09-18 11:32 2385多模块的时候 模块之间的test代码也是互相依赖 但默认打包 ...
相关推荐
在这个压缩包中，包含的资源可以帮助我们理解并实现SHA1、SHA、MD5、AES加密与解密，以及BASE64编码和解码。下面我们将详细探讨这些加密算法和它们在Java中的实现。 1. **SHA（Secure Hash Algorithm）**: SHA是一...
Vue-常用加密（MD5, DES, SHA256, BASE64, SHA1, RSA） Vue 中常见的加密算法可以分成三类：对称加密算法、非对称加密算法和 Hash 算法。下面将详细介绍每种加密算法的特点、优点和缺点，以及它们的应用场景。 一...
SHA.exe、HMAC.exe、BASE64.exe、URL.exe、MD5.exe这些文件可能是使用Delphi编写的独立可执行程序，分别对应实现了SHA加密、HMAC-SHA签名、Base64编码与解码、URL编码与解码以及MD5加密的功能。
前端JS实现密码加密（base64.js， md5.js， sha1.js，jsencrypt.js），使用方式请看我这篇文章：https://blog.csdn.net/guxingsheng/article/details/84451573
文字在线加密解密、散列/哈希、BASE64、SHA1、SHA224、SHA256、SHA384、SHA512、MD5、HmacSHA1、HmacSHA224、HmacSHA256、HmacSHA384、HmacSHA512、HmacMD5、urlencode、urldecode
使用方法 sha256_digest("weyckart年胜多负少123111...."); md5("weyckart年胜多负少123111...."); Base64.toBase64("weyckart年胜多负少123111....");
实现HmacMD5,HmacSHA1,HmacSHA256,HmacSHA384,HmacSHA512对于文字的加密。 实现了对称加密算法DES和AES. 实现了非对称加密算法RSA. - 不懂运行，下载完可以私聊问，可远程教学 1、该资源内项目代码都经过测试运行...
MD5和SHA1是两种广泛使用的哈希函数，在信息技术领域，特别是网络安全和数据完整性验证方面发挥着重要作用。Java作为一种多平台支持的编程语言，提供了对这些算法的内置支持，使得开发者能够轻松地在Java程序中实现...
C# 常用的加密算法md5、des、rsa、aes、base、HMAC-SHA256、sha1
Vive.Crypto（Vive.Crypto对各种常用的加密算法进行封装，有 Base64、对称加密（DES、3DES、AES、SM4）、非对称加密（RSA、SM2）、Hash(MD4、MD5、HMAC、HMAC-MD5、HMAC-SHA1、HMAC-SHA256、HMAC-SHA384、HMAC-SHA...
基于Base64,MD5,SHA,Hmac,DES,AES,RSA信息加密的设计与实现。 实现Base64对于文字的加密和解密。 实现MD5对于文字的校验。 实现SHA1,SHA256,SHA384,SHA512对于文字的加密。 实现HmacMD5,HmacSHA1,HmacSHA256,...
HMAC支持多种哈希算法，例如HMAC-MD5、HMAC-SHA1、HMAC-SHA256等。 在Java中实现这些算法，我们可以使用`java.security.MessageDigest`类来处理MD5和SHA，如下： ```java MessageDigest md = MessageDigest....
6.字符串哈希算法：MD5、SHA1、RIPEMD160、SHA256、Tiger、SHA512、Whirlpool、CRC32、HmacSha1、HmacSha256 7.URI编码解码 8.Base64编码解码，文件Base64编码 9.硬盘序列号、网卡物理地址 10.http、https的POST...
6.字符串哈希算法：MD5、SHA1、RIPEMD160、SHA256、Tiger、SHA512、Whirlpool、CRC32、HmacSha1、HmacSha256 7.URI编码解码 8.Base64编码解码，文件Base64编码 9.硬盘序列号、网卡物理地址 10.http、https的POST...
对称加解密 AES 3DES SM4 DES RC4 ChaCha20 非对称加解密 RSA 支持指定长度密钥对生成 ...HmacMD5 HmacSHA1 HmacSHA256 HmacSHA384 HmacSHA512 SM3 SM4CMAC 编码转换 String Base64 Hex Url Unicode Byte 一键互转
6.字符串哈希算法：MD5、SHA1、RIPEMD160、SHA256、Tiger、SHA512、Whirlpool、CRC32、HmacSha1、HmacSha256 7.URI编码解码 8.Base64编码解码，文件Base64编码 9.硬盘序列号、网卡物理地址 10.http、https的POST和...
6.字符串哈希算法：MD5、SHA1、RIPEMD160、SHA256、Tiger、SHA512、Whirlpool、CRC32、HmacSha1、HmacSha256、HmacMd5 7.URI编码解码 8.Base64编码解码，文件Base64编码 9.硬盘序列号、网卡物理地址 10.http、...
这里包含了几种常见的加密算法：AES、HMACSHA256、MD5和Base64的C语言实现代码以及展示如何应用这些算法来保护数据. AES:是一种广泛使用的对称加密算法，以其强大的安全性和高效的计算性能而闻名。它支持128、192和...
本文主要探讨了Java中实现的一些基础加密方法，如BASE64、MD5、SHA和HMAC。 1. BASE64编码：BASE64并不是一种加密算法，而是一种编码方式，用于将任意字节序列转换成不易被人直接识别的形式。它常用于电子邮件和...
在实际应用中，这些加密算法常常结合使用，例如先使用MD5或SHA生成哈希值，然后用BASE64进行编码，以生成更便于传输和存储的字符串。同时，为了提高安全性，HMAC经常用于验证数据完整性，防止中间人攻击。 在Web...