React deployed in Nginx, AJAX Axios don't work - ajax

Question

I want to combinate frontend with backend on the cloud virtual machine like DigitalOcean or AWS or Microsoft Azure.
Frontend: React
Backend: Spring Spring MVC Mybatis + Tomcat (NOT Spring Boot)
So I have searched for some methods using Nginx on the Internet. Firstly, I am going to combinate the frontend with backend on the local (macOS). Secondly, if the method succeeded, I will deploy the project on the cloud host. But, it occurs an error in the first step.
When I typed the localhost:8081 site, the browser can show the normal website. But no any backend data. I have supposed that the Nginx configuration may be inappropriate for access to the backend.
Maybe add proxy_pass http://localhost:8080/example_war_exploded/; in nginx.conf, but I got the JSP content without any CSS or JavaScript. I only want to access data by AJAX Axios.
Related files
nginx.conf
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
server {
listen 8081;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root html/build;
index index.html index.htm;
}
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;
# location / {
# root html;
# index index.html index.htm;
# }
#}
# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;
# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;
# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;
# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;
# location / {
# root html;
# index index.html index.htm;
# }
#}
include servers/*;
}
Backend, Tomcat URL: http://localhost:8080/example_war_exploded/
Spring MVC Controller
#Controller
#RequestMapping(value = "/comment")
public class CommentController {
#GetMapping(value = "/comments")
}
Frontend Axios
axios.get(`/comment/comments`).then((response) => {
this.setState({
comments: response.data,
});
});
What should I do... Thanks.

Answer 1

Usually, if you want to get JSON from the backend, we need to access http://localhost:8080/example_war_exploded/comment/comments.
So, we should add the code snippet in nginx.conf.
location ^~ /comment {
proxy_pass http://localhost:8080/example_war_exploded/comment;
}
Completed code in nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile off;
keepalive_timeout 65;
server {
listen 8081;
server_name localhost;
location / {
root html/build;
index index.html index.htm;
}
# New
location ^~ /comment {
proxy_pass http://localhost:8080/example_war_exploded/comment;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
include servers/*;
}