Question

我想将画布转换为图像并将该图像发送到我的服务器。所以我想要的是使用javascript从html页面收集画布，然后将该数据发送到我的servlet，我可以在服务器上执行上传图像。

谢谢......

Note: further occurrences of HTTP header parsing errors will be logged at DEBUG level.
 java.lang.IllegalArgumentException: Request header is too large
    at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:701)
    at org.apache.coyote.http11.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:455)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:667)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

＆＃13;

 function saveImg() {
    var canvasData = document.getElementById("myCanvas").toDataURL("image/png");
    alert(canvasData);    
    var xmlhttp = new XMLHttpRequest();
    var url = "Signature?image=" + canvasData;
    xmlhttp.onreadystatechange = function(){
    if(xmlhttp.readyState === 4 && xmlhttp.status === 200){
    var response = xmlhttp.responseText;
    response = response.replace(/\r?\n|\r/g, " ");
    response = response.trim();
    if(response === "Bill Receipt sent successfully"){
    alert("Bill Mailed Successfully");
    }
    else{
    alert("Something's not good please contact the admin");
    }
    }

    };
    try{
    xmlhttp.open("GET",url,true);
    xmlhttp.send();
    }catch(e){alert("unable to connect to server");
   }

＆＃13;

public class Signature extends Canvas {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String image = request.getParameter("image");

        System.out.println(image);

    }
}

发送数据：image / png; base64从javascript到servlet并从servlet接收

0 个答案: