使用JQuery读取二进制文件的浏

时间:2012-08-13 10:38:32

标签: javascript jquery character-encoding readfile

我正在尝试读取与MyFile.html位于同一域的二进制文件MyFile.xxx。使用JQuery我只是尝试在MyFile.xxx中显示一个包含字符数的警报,并打印每个字符的数字表示。但是,根据浏览器的不同,我会得到不同的结果:

谷歌浏览器:我正确显示33,并显示正确的整数 Firefox:警报显示“未定义”,不会打印整数。 IE9:警告显示“1”,不会打印整数。

有什么想法吗?感谢

MyFile.html

<html>                                                                  
 <head>                                                                  
 <script type="text/javascript" src="jquery.js"></script>          
 <script type="text/javascript">                                         
    $.get('/MyFile.xxx', function(a){
    var l=a.length,x=[l];
    alert(l);
    for(i=0;i<l;i++){
      x[i]=a[i].charCodeAt(0);
      document.write(x[i]);
      document.write("<br>");
    }    
});                              
 </script>                                                               
 </head>                                                                 
 <body>                                                                  
 </body>                                                                 
 </html>

1 个答案:

答案 0 :(得分:1)

试试这个:

$.ajax( "/MyFile.xxx", {
    dataType: "text",
    beforeSend: function( xhr ) {
        xhr.overrideMimeType( "text/plain; charset=x-user-defined");
    },

    success: function( data ) {
        var len = data.length,
            str = "";

        for( var i = 0; i < len; ++i ) {
            var byte = data.charCodeAt(i) & 0xFF;
            str += byte + " ";

        }
        document.body.innerHTML = str;
    }
});

演示:http://jsfiddle.net/SXgfu/(显示åöä的UTF-8字节)

请注意,IE9不支持此功能。它不支持获取响应的原始字节的任何其他方式。

如果您使用的是PHP,则可以使用此解决方法进行IE:

$.get("/base64encoder.php?file=MyFile.xxx", function(data) {
    data = decode64(data);
    var len = data.length,
        str = "";
    for (var i = 0; i < len; ++i) {
        var byte = data.charCodeAt(i) & 0xFF;
        str += byte + " ";
    }
    document.body.innerHTML = str;
}, "text");

base64encoder.php类似于:

<?php
echo base64_encode(file_get_contents( $_GET['file'] ));

记得来清理以上内容,否则这是一个巨大的安全漏洞

decode64(src http://ntt.cc/2008/01/19/base64-encoder-decoder-with-javascript.html):

var keyStr = "ABCDEFGHIJKLMNOP" +
           "QRSTUVWXYZabcdef" +
           "ghijklmnopqrstuv" +
           "wxyz0123456789+/" +
           "=";

function decode64(input) {
    var output = "";
    var chr1, chr2, chr3 = "";
    var enc1, enc2, enc3, enc4 = "";
    var i = 0;
    // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
    var base64test = /[^A-Za-z0-9\+\/\=]/g;
    if (base64test.exec(input)) {
        alert("There were invalid base64 characters in the input text.\n" + "Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='\n" + "Expect errors in decoding.");
    }
    input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
    do {
        enc1 = keyStr.indexOf(input.charAt(i++));
        enc2 = keyStr.indexOf(input.charAt(i++));
        enc3 = keyStr.indexOf(input.charAt(i++));
        enc4 = keyStr.indexOf(input.charAt(i++));
        chr1 = (enc1 << 2) | (enc2 >> 4);
        chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
        chr3 = ((enc3 & 3) << 6) | enc4;
        output = output + String.fromCharCode(chr1);
        if (enc3 != 64) {
            output = output + String.fromCharCode(chr2);
        }
        if (enc4 != 64) {
            output = output + String.fromCharCode(chr3);
        }
        chr1 = chr2 = chr3 = "";
        enc1 = enc2 = enc3 = enc4 = "";
    } while (i < input.length);
    return output;
}