search

kaleksandrov / steganography

This is a web application written in java that implements LSB steganography algorithm. It uses jQuery to manage AJAX requests. The application processes PNG images.
6 stars 2 forks source link

Image : false #1

Open ziziiy opened 6 years ago

ziziiy commented 6 years ago

for some reason when I upload a photo , the console produces image:false POST http://localhost:8081/Steganography/encode 500 (Internal Server Error) please help.

kaleksandrov commented 6 years ago

So in order for the application to work, a temporary folder should be created where the images are stored. This folder is /tmp/steganography. Make sure the folder exists and is writable.

ziziiy commented 6 years ago

I created a tmp folder and placed the images. but when I open anyway an error on console. jquery-1.7.2.min.js:4 POST http://localhost:8081/Steganography/encode 500 (Internal Server Error) send @ jquery-1.7.2.min.js:4 ajax @ jquery-1.7.2.min.js:4 fileUploadXhr @ jquery.form.js:262 $.fn.ajaxSubmit @ jquery.form.js:199 doAjaxSubmit @ jquery.form.js:718 dispatch @ jquery-1.7.2.min.js:3 i @ jquery-1.7.2.min.js:3 and already Image:false

kaleksandrov commented 6 years ago

Have you checked the tomcat logs? Is there any exception there?

ziziiy commented 6 years ago

Image : false мар 29, 2018 2:55:51 PM org.apache.catalina.core.StandardWrapperValve invoke SEVERE: Servlet.service() for servlet [org.university.steganography.servlet.EncodeImageServlet] in context with path [/Steganography] threw exception java.lang.NullPointerException at org.university.steganography.servlet.EncodeImageServlet.doPost(EncodeImageServlet.java:81) at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1539) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1495) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)

kaleksandrov commented 6 years ago

Can please explain in details how do you build and run the application. Have you followed the steps explained in the README file?

kaleksandrov commented 6 years ago

According to the log it seems the image is null. Let me update the code a little as the current exception handling is awful :)