I am a not very experienced when it comes to Java Spring but what I was hoping to achieve was to launch a JPanel after a specific controller method is invoked after a user submits a form. Unfortunately, I am getting an error when I try to launch my JPanel in the Spring application. I've tried to find examples of people using JPanel in combination with Spring and I could not find anything, so I am inclined to believe that the use of JPanel in combination with Spring is not possible.
The expected behavior is that when the form is submitted, some relevant information relating to the submitted form pops up in a newly Created JPanel.
Also, note that I tried to run the GUI generating code in a separate class and it worked perfectly fine. It was only when I tried running the code inside of the Spring application when problems arrived.
My Spring controller Class (Relevant method is createForm())
package com.datavisulizer.datavisulizer;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import javax.swing.*;
import java.awt.BorderLayout;
import java.util.*;
import java.io.*;
import java.lang.*;
import org.objectweb.asm.*;
@Controller
public class indexController {
@GetMapping("/create")
public String createPage(Model model) {
model.addAttribute("codeForm", new codeForm());
return "create";
}
@PostMapping("/create")
public String createForm(codeForm cf) throws Exception{
System.out.println(cf.getCodeText());
ArrayList<String[]> CL = codeParser(cf.getCodeText());
String name = classFinder(CL);
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("java");
//GUI Code START
JFrame frame = new JFrame();
frame.add( new JLabel(" Outout" ), BorderLayout.NORTH );
JTextArea ta = new JTextArea();
TextAreaOutputStream taos = new TextAreaOutputStream( ta, 60 );
PrintStream ps = new PrintStream( taos );
System.setOut( ps );
System.setErr( ps );
frame.add( new JScrollPane( ta ) );
frame.pack();
frame.setVisible( true );
frame.setSize(800,600);
//GUI CODE END
if (engine == null) {
System.err.println("Engine error (unknown engine)!");
} else {
try{
engine.put(ScriptEngine.FILENAME, name);
engine.eval(cf.getCodeText());
cf.setCodeTextOutput("Java code Succefully compiled...");
}
catch(Exception ex){
cf.setCodeTextOutput("Java code has an error");
}
}
return "create";
}
private String classFinder(ArrayList<String[]> CL){
String name = "_No_Name";
if(CL.size()<1 || CL.get(0).length<2) return name;
return CL.get(0)[CL.get(0).length-1] ".java";
}
private ArrayList codeParser(String code){
ArrayList<String> lineList = new ArrayList<String>();
String line = "";
for(int c = 0; c<code.length()-1; c ){
if(code.substring(c, c 1).compareTo("{")==0 || code.substring(c, c 1).compareTo("}")==0){
lineList.add(line);
line = "";
}
else{
line =code.substring(c, c 1);
}
}
ArrayList<String[]> codeList = new ArrayList<String[]>();
for(String s : lineList){codeList.add(s.split(" "));}
System.out.println("Testing code array list");
for(String[] s : codeList){for(String c : s){System.out.println(c);}}
return codeList;
}
}
Console Logs
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.awt.HeadlessException] with root cause
java.awt.HeadlessException: null
at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:166) ~[na:na]
at java.desktop/java.awt.Window.<init>(Window.java:553) ~[na:na]
at java.desktop/java.awt.Frame.<init>(Frame.java:428) ~[na:na]
at java.desktop/java.awt.Frame.<init>(Frame.java:393) ~[na:na]
at java.desktop/javax.swing.JFrame.<init>(JFrame.java:180) ~[na:na]
at com.datavisulizer.datavisulizer.indexController.createForm(indexController.java:34) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.23.jar:5.3.23]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1071) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:964) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.23.jar:5.3.23]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.23.jar:5.3.23]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:696) ~[tomcat-embed-core-9.0.68.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.23.jar:5.3.23]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:779) ~[tomcat-embed-core-9.0.68.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.23.jar:5.3.23]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.23.jar:5.3.23]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.23.jar:5.3.23]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
CodePudding user response：
As per documentation from Oracle you can only do this
Create lightweight components such as Canvas, Panel, and Swing components, except the top levels
you can enable headless mode using
System.setProperty("java.awt.headless", "true");
or
java -Djava.awt.headless=true