在Java中将图像（jpg）转换为Base64格式时出现问题

Question

I need to read an image file from the local hard drive and convert the same to base64 format. 我需要从本地硬盘驱动器读取图像文件，并将其转换为base64格式。 After conversion i need to pass the base64 string to a webservice and get the result from a webservice. 转换后，我需要将base64字符串传递给Web服务，并从Web服务获取结果。

I have a code for the same: 我有一个相同的代码：

<html>

<script>
// create the object

//test = new Base64();

x = new XMLHttpRequest();

// set the function that should be called when
// the ready state changes (the callback)
x.onreadystatechange = handleDoc;
// establish the method and URL
//x.open('GET', "Latest Eticket.jpg", true);
x.overrideMimeType("text/plain; charset=x-user-defined");
x.open('GET', 'file:///C:\\vishwa\\Node_JS\\Jquery_ajax\\JS_with_Ajax\\base64_encode\\Latest Eticket.jpg', true);
//x.open('GET', 'C:\vishwa\Node_JS\Jquery_ajax\JS_with_Ajax\base64_encode\Latest Eticket.jpg', true);
//x.open('GET', 'http://www.google.co.in/imgres?imgurl=http://1.bp.blogspot.com/_PveGYAt2T10/TDRH1kJsXAI/AAAAAAAAAgI/a45pNA5hxrA/s1600/hi-pig.jpg&imgrefurl=http://weiwei95.blogspot.com/2010_07_01_archive.html&usg=__k761BPCJk7FGxAgy8UHUiCCO1dA=&h=474&w=600&sz=51&hl=en&start=1&sig2=K2Z27chXr6EPO-lHJVY43g&zoom=1&tbnid=NSx-UedGEdm84M:&tbnh=107&tbnw=135&ei=uezUTbaDFMSBgAet_7iVDA&prev=/search%3Fq%3Dhi%26hl%3Den%26biw%3D1024%26bih%3D548%26gbv%3D2%26tbm%3Disch&itbs=1', true);
//x.open('GET', 'http://localhost:80//Latest Eticket.jpg', true);
// initiate the HTTP transaction
x.send(null);


//
function handleDoc() {
//window.alert("READY STATE IS " +
//x.readyState);
if(x.readyState == 1)
{
    window.alert("Handling x 1 State: The response is started");
}
if(x.readyState == 4)
{
    var encodeImagescanned_image = '';
    alert("Am i coming here 4-2"+x.responseText);
                    //var base64 = new Base64();
                    encodeImagescanned_image = encode(x.responseText);
                    alert("Am i coming here 4-3"+encodeImagescanned_image);
    window.alert("Handling x 4 State: The response is ended");

    alert("Constructing Soap body");
    var xmlp = "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:dsf=\"http://DSFService/\">" +
                    "<soapenv:Header/>" +
                    "<soapenv:Body>" +
                    "<dsf:FieldExtraction>" +
                    "<dsf:inImage>" +
                    this.encodeImagescanned_image +
                    "</dsf:inImage>" +
                    "</dsf:FieldExtraction>" +
                    "</soapenv:Body>" +
                    "</soapenv:Envelope>";
                    var xmlps = "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:dsf=\"http://DSFService/\">" +
                    "<soapenv:Header/>" +
                    "<soapenv:Body>" +
                    "<dsf:FieldExtraction>" +
                    "<dsf:inImage>" +
                    "</dsf:inImage>" +
                    "</dsf:FieldExtraction>" +
                    "</soapenv:Body>" +
                    "</soapenv:Envelope>";

                    var dsfUrl = "http://hpldsf-tst.asiapacific.cpqcorp.net:8090/DSFServiceSite/DSFService.svc/basic";
                    request = new XMLHttpRequest();
                        // We're going to be POSTing to this URL and want a synchronous response
                    request.open("POST", dsfUrl, true);
                    request.setRequestHeader("Content-Type", "text/xml;charset=UTF-8");
                    request.setRequestHeader("Content-length", xmlp.length);
                    request.setRequestHeader("Accept-Encoding", "gzip,deflate");
                    request.timeout = 300000;
                    // This header is a required part of the SOAP protocol
                    request.setRequestHeader("SOAPAction", '\"http://DSFService/DSFService/FieldExtraction\"');
                    // Now send an XML-formatted SOAP request to the server
                    request.send(xmlp);
                    request.onreadystatechange = handlesoap;


}
}

function handlesoap()
{
    alert("Inside handlesoap function");
    if(request.readyState == 4)
    {
        var xmls = request.responseText;
        var xmlDoc = (new DOMParser()).parseFromString(xmls, "text/xml");
        var doc = xmlDoc.documentElement;
        var nvalue = xmlDoc.getElementsByTagName('FieldExtractionResponse')[0];
        alert("nvalu ="+nvalue);
        if ((nvalue !== null) && (nvalue !== undefined)) 
        {

            ////var docidval = nodes.getAttribute("id");
            ///Mojo.Log.info("docidval:" + docidval);
            dsfxml = xmls; //nodes.nodeValue;
            var pattern = /\cM/;

                                // Break the string into pieces separated by the pattern above and
                                // and store the pieces in an array called nameList
                                var nameList = [];
                                nameList = dsfxml.split(pattern);
                                var clean = '';
                                for (i = 0; i < nameList.length; i++) {

                                    clean = clean + nameList[i].replace(pattern, "").trim();
                                }
        }
        else
        {
            alert("nvalue is eitheer null or undefined");
        }
    }
}



    function encode(input) {
    alert("I am in encode function");
    var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var output = "";
    var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
    var i = 0;

    while (i < input.length) {
        chr1 = input.charCodeAt(i++) & 0xff; //alert('chr1 : ' + chr1.toString(16));
        chr2 = input.charCodeAt(i++) & 0xff; //alert('chr2 : ' + chr2.toString(16));
        chr3 = input.charCodeAt(i++) & 0xff; //alert('chr3 : ' + chr3.toString(16));

        enc1 = chr1 >> 2;
        enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
        enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
        enc4 = chr3 & 63;

        if (isNaN(chr2)) {
        enc3 = enc4 = 64;
        } else if (isNaN(chr3)) {
        enc4 = 64;
        }

        output = output +
        _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
        _keyStr.charAt(enc3) + _keyStr.charAt(enc4);

    }

    return output;
}

</script>
</html>

The problem is its not converting the image properly to base64 format. 问题是它没有将图像正确转换为base64格式。 Can you please help me know where I am going wrong.... 您能帮我知道我要去哪里了吗...

Answer 1

It this browser-based? 它基于浏览器吗？ If so, you're going about this wrong. 如果是这样，您将要解决这个错误。 If you need to copy from the local hard drive, the page containing your javascript will not be able to access anything on your hard drive at a byte level. 如果您需要从本地硬盘驱动器进行复制，则包含javascript的页面将无法以字节级别访问硬盘驱动器上的任何内容。 At best, you can provide an upload link, and post your form to the server using something like a 'multipart/form-data' encoding type. 充其量，您可以提供一个上传链接，然后使用“ multipart / form-data”编码类型将表单发布到服务器。

Here's the catch... If your Web service can't understand a form post as is, you may consider creating a proxy to accept the standard form submission, then pass it along through your (urk) SOAP request. 这很重要……如果您的Web服务不能原样理解表单发布，则可以考虑创建一个代理来接受标准表单提交，然后将其传递给您的（urk）SOAP请求。 Note that this would be a server API, not a client-side one. 请注意，这将是服务器API，而不是客户端API。

Flow (if needing a proxy): 流（如果需要代理）：

1). 1）。 User navigates to Web page. 用户导航到网页。

2). 2）。 User adds image. 用户添加图像。

3). 3）。 User clicks Submit 用户点击提交

4). 4）。 File is transferred to proxy 文件已传输到代理

5). 5）。 Proxy initiates soap request. 代理发起肥皂请求。

6). 6）。 Proxy returns results of SOAP request to client. 代理将SOAP请求的结果返回给客户端。

在Java中将图像（jpg）转换为Base64格式时出现问题

问题描述

1 个解决方案

解决方案1
1 2011-05-20 02:12:15

在Java中将图像（jpg）转换为Base64格式时出现问题

问题描述

1 个解决方案

解决方案1 1 2011-05-20 02:12:15

解决方案1
1 2011-05-20 02:12:15