压缩 ~~~ function Compress(strNormalString) { alert("压缩前长度：" + strNormalString.length); var strCompressedString = ""; var ht = new Array(); for(i = 0; i < 128; i++) { ht[i] = i; } var used = 128; var intLeftOver = 0; var intOutputCode = 0; var pcode = 0; var ccode = 0; var k = 0; for(var i=0; i<strNormalString.length; i++) { ccode = strNormalString.charCodeAt(i); k = (pcode << 8) | ccode; if(ht[k] != null) { pcode = ht[k]; } else { intLeftOver += 12; intOutputCode <<= 12; intOutputCode |= pcode; pcode = ccode; if(intLeftOver >= 16) { strCompressedString += String.fromCharCode( intOutputCode >> ( intLeftOver - 16 ) ); intOutputCode &= (Math.pow(2, (intLeftOver - 16)) - 1); intLeftOver -= 16; } if(used < 4096) { used ++; ht[k] = used - 1; } } } if(pcode != 0) { intLeftOver += 12; intOutputCode <<= 12; intOutputCode |= pcode; } if(intLeftOver >= 16) { strCompressedString += String.fromCharCode( intOutputCode >> ( intLeftOver - 16 ) ); intOutputCode &= (Math.pow(2,(intLeftOver - 16)) - 1); intLeftOver -= 16; } if( intLeftOver > 0) { intOutputCode <<= (16 - intLeftOver); strCompressedString += String.fromCharCode( intOutputCode ); } alert("压缩后长度：" + strCompressedString.length); return strCompressedString; } ~~~ 解压缩 ~~~ function Decompress(strCompressedString) { var strNormalString = ""; var ht = new Array(); for(i = 0; i < 128; i++) { ht[i] = String.fromCharCode(i); } var used = 128; var intLeftOver = 0; var intOutputCode = 0; var ccode = 0; var pcode = 0; var key = 0; for(var i=0; i<strCompressedString.length; i++) { intLeftOver += 16; intOutputCode <<= 16; intOutputCode |= strCompressedString.charCodeAt(i); while(1) { if(intLeftOver >= 12) { ccode = intOutputCode >> (intLeftOver - 12); if( typeof( key = ht[ccode] ) != "undefined" ) { strNormalString += key; if(used > 128) { ht[ht.length] = ht[pcode] + key.substr(0, 1); } pcode = ccode; } else { key = ht[pcode] + ht[pcode].substr(0, 1); strNormalString += key; ht[ht.length] = ht[pcode] + key.substr(0, 1); pcode = ht.length - 1; } used ++; intLeftOver -= 12; intOutputCode &= (Math.pow(2,intLeftOver) - 1); } else { break; } } } return strNormalString; } ~~~ 使用 ~~~ Compress(str) //压缩 Decompress(str) //解压 ~~~