Permission Denied Error when Creating file in Java/Springboot - Tomcat

I am trying to create a File in Java/SpringBoot and writing to it using FileWriter Method.
Below is my Code.

                String filename = file.csv;
				LOGGER.info("Creating File CSV");
				File file = new File(filename);
				Boolean Isexists =file.exists();
				boolean isexistsabs = file.getAbsoluteFile().exists();
				LOGGER.info("CSV File Exists? : "+Isexists);
				LOGGER.info("CSV File ABSExists? : "+isexistsabs);
				boolean setwritable = file.setWritable(true);
				LOGGER.info("SetWritable CSV Output : "+Boolean.toString(setwritable));
				boolean setExecutable = file.setExecutable(true);
				LOGGER.info("SetExecutable CSV Output : "+Boolean.toString(setExecutable));
				LOGGER.info("before file Writer CSV");
				FileWriter filewriter = new FileWriter(filename);
				LOGGER.info("after file Writer CSV");
				LOGGER.info("Writing File CSV");
				String content ="Some CSV Content";
				filewriter.write(content);
				LOGGER.info("Written to File CSV");
				filewriter.close();
				LOGGER.info("Closing File CSV");

When I execute the code in my local system it is working and below is the log of the code

2020-07-28 00:56:17.204  INFO 15956 --- Controller       : Creating File CSV
2020-07-28 00:56:17.205  INFO 15956 --- Controller       : CSV File Exists? : true
2020-07-28 00:56:17.206  INFO 15956 --- Controller       : CSV File ABSExists? : true
2020-07-28 00:56:17.206  INFO 15956 --- Controller       : SetWritable CSV Output : true
2020-07-28 00:56:17.207  INFO 15956 --- Controller       : SetExecutable CSV Output : true
2020-07-28 00:56:17.207  INFO 15956 --- Controller       : before file Writer CSV
2020-07-28 00:56:17.208  INFO 15956 --- Controller       : after file Writer CSV
2020-07-28 00:56:17.209  INFO 15956 --- Controller       : Writing File CSV
2020-07-28 00:56:17.209  INFO 15956 --- Controller       : Written to File CSV
2020-07-28 00:56:17.210  INFO 15956 --- Controller       : Closing File CSV

But when I execute the same after deploying to a tomcat server below is the log/error I am recieveing

2020-07-27 14:34:15.465  INFO 17902 --- Controller       : Creating File CSV
2020-07-27 14:34:15.465  INFO 17902 --- Controller       : CSV File Exists? : false
2020-07-27 14:34:15.465  INFO 17902 --- Controller       : CSV File ABSExists? : false
2020-07-27 14:34:15.466  INFO 17902 --- Controller       : SetWritable CSV Output : false
2020-07-27 14:34:15.466  INFO 17902 --- Controller       : SetExecutable CSV Output : false
2020-07-27 14:34:15.466  INFO 17902 --- Controller       : before file Writer CSV
2020-07-27 14:34:15.488 ERROR 17902 --- [http-nio-8080-exec-31] o.s.b.w.servlet.support.ErrorPageFilter  : Forwarding to error page from request [/api/getFlighPlanCSV] due to exception [file.csv (Permission denied)]

java.io.FileNotFoundException: file.csv (Permission denied)
	at java.base/java.io.FileOutputStream.open0(Native Method) ~[na:na]
	at java.base/java.io.FileOutputStream.open(FileOutputStream.java:291) ~[na:na]
	at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:234) ~[na:na]
	at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:123) ~[na:na]
	at java.base/java.io.FileWriter.<init>(FileWriter.java:66) ~[na:na]
	at com.aiknights.com.rapidviewmain.controller.SiteInspectionController.DownloadFlightPlan(SiteInspectionController.java:175) ~[classes/:0.0.1-SNAPSHOT]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[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:564) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]

It seems to be erroring out when writing into the file saying File not found, seems like the application/.war is not able to create a file in the PWD because of the permission issue.

My application name - applicationmain.war
resides at - /opt/tomcat/webapps/applicationmain.war
there is also a folder created whenever I deploy the war file - /opt/tomcat/webapps/applicationmain
I tried assiging all permissions to both the war file itself and the folder that is created when deploying the war file with no luck

I will answer to any comments asking for more details about the setup and code.

Any kind of help would be really appreciated as I already spent too many hours on dealing with this.

Ensure that you have read and execute access to all parent directories as well.

Example:

chmod o+x /opt