【发布时间】：2014-11-09 19:52:25
【问题描述】：
我的页面中有大数据，需要发布到服务器。
所以我使用https://github.com/dankogai/js-deflate 来压缩大数据。
似乎工作正常。
helloworld -> w4tIw43DicOJL8OPL8OKSQEA
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Demo</title>
</head>
<body>
<h1>Demo</h1>
<p>$Id: demo.html,v 0.4 2013/04/09 14:25:38 dankogai Exp dankogai $</p>
<dl>
<dt>Inflated + Base64-Decoded (Original):</dt>
<dd><textarea id="inflated" cols="64" rows="16" onkeyup="(function(that, dst){
setTimeout(function(){
dst.value = Base64.toBase64(RawDeflate.deflate(Base64.utob(that.value)));
},0)
})(this,$('deflated'))"></textarea></dd>
<dt>Deflated + Base64-Encoded (Compressed):</dt>
<dd><textarea id="deflated" cols="64" rows="16" onkeyup="(function(that, dst){
setTimeout(function(){
dst.value = Base64.btou(RawDeflate.inflate(Base64.fromBase64(that.value)));
},0);
})(this, $('inflated'))"></textarea></dd>
</dl>
<script src="./base64.js"></script>
<script src="../rawinflate.js"></script>
<script src="../rawdeflate.js"></script>
<script>
$ = function(id){ return document.getElementById(id) };
</script>
</body>
</html>
所以我想通过将 deflate 的结果放入 java 代码来获得问候 我得到了错误：
java.util.zip.DataFormatException: incorrect header check
以下是我的代码：
public static void main(String[] args) throws IOException {
try {
// Encode a String into bytes
String output1 = "w4tIw43DicOJL8OPL8OKSQEA";
byte[] output2 = Base64Util.decode(output1);
// Decompress the bytes
Inflater decompresser = new Inflater();
decompresser.setInput(output2);
System.out.println("a:" + new String(output2));
byte[] result = new byte[100];
int resultLength = decompresser.inflate(result);
decompresser.end();
// Decode the bytes into a String
String outputString = new String(result, 0, resultLength, "UTF-8");
System.out.println("b:" + outputString);
} catch (java.io.UnsupportedEncodingException ex) {
ex.printStackTrace();
// handle
} catch (java.util.zip.DataFormatException ex) {
ex.printStackTrace();
// handle
}
}
那么问题出在哪里？
这是我的 Base64Util 类，我已经测试过了。没关系：
public class Base64Util {
private final static char[] ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
private static int[] toInt = new int[128];
static {
for(int i=0; i< ALPHABET.length; i++){
toInt[ALPHABET[i]]= i;
}
}
/**
* Translates the specified byte array into Base64 string.
*
* @param buf the byte array (not null)
* @return the translated Base64 string (not null)
*/
public static String encode(byte[] buf){
int size = buf.length;
char[] ar = new char[((size + 2) / 3) * 4];
int a = 0;
int i=0;
while(i < size){
byte b0 = buf[i++];
byte b1 = (i < size) ? buf[i++] : 0;
byte b2 = (i < size) ? buf[i++] : 0;
int mask = 0x3F;
ar[a++] = ALPHABET[(b0 >> 2) & mask];
ar[a++] = ALPHABET[((b0 << 4) | ((b1 & 0xFF) >> 4)) & mask];
ar[a++] = ALPHABET[((b1 << 2) | ((b2 & 0xFF) >> 6)) & mask];
ar[a++] = ALPHABET[b2 & mask];
}
switch(size % 3){
case 1: ar[--a] = '=';
case 2: ar[--a] = '=';
}
return new String(ar);
}
/**
* Translates the specified Base64 string into a byte array.
*
* @param s the Base64 string (not null)
* @return the byte array (not null)
*/
public static byte[] decode(String s){
int delta = s.endsWith( "==" ) ? 2 : s.endsWith( "=" ) ? 1 : 0;
byte[] buffer = new byte[s.length()*3/4 - delta];
int mask = 0xFF;
int index = 0;
for(int i=0; i< s.length(); i+=4){
int c0 = toInt[s.charAt( i )];
int c1 = toInt[s.charAt( i + 1)];
buffer[index++]= (byte)(((c0 << 2) | (c1 >> 4)) & mask);
if(index >= buffer.length){
return buffer;
}
int c2 = toInt[s.charAt( i + 2)];
buffer[index++]= (byte)(((c1 << 4) | (c2 >> 2)) & mask);
if(index >= buffer.length){
return buffer;
}
int c3 = toInt[s.charAt( i + 3 )];
buffer[index++]= (byte)(((c2 << 6) | c3) & mask);
}
return buffer;
}
}
【问题讨论】：
-
什么是
utob和btou？
标签： java javascript base64 deflate inflate