在Java中将图像（jpg）转换为Base64格式时出现问题
[英]Problem in Converting an image (jpg) to Base64 format in Javascript
问题描述
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。 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。
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>
问题是它没有将图像正确转换为base64格式。 您能帮我知道我要去哪里了吗...
1 个解决方案
解决方案1
1 2011-05-20 02:12:15
它基于浏览器吗？ 如果是这样，您将要解决这个错误。 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。 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。
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。 请注意，这将是服务器API，而不是客户端API。
流（如果需要代理）：
1）。 用户导航到网页。
2）。 用户添加图像。
3）。 用户点击提交
4）。 文件已传输到代理
5）。 代理发起肥皂请求。
6）。 代理将SOAP请求的结果返回给客户端。
将base64转换为图像文件（jpeg，jpg）
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.