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[JAVA] - Java Solution

Wednesday, March 13, 2019

JAVA Solution

Tips:

1. Read Response Body from Bad Request :

// Check HTTP Response Code #200 after write code below
InputStream errorstream = connection.getErrorStream();
String response = "";
String line;

BufferedReader br = new BufferedReader(new InputStreamReader(errorstream));
while ((line = br.readLine()) != null) {
    response += line;
}

Log.d("body of Bad Request HttpURLConnection", "Response: " + response);

2. Redirect page wrong with https

Description:

- If server run HTTP port = 8080, nginx proxy port = 443. When you redirect to another URL, it wrong port.

Ex:

https://ip:443/login => redirect:/home => http://ip:8080/home

Solution:

Config in server.xml of tomcat

location / {

proxy_pass http://localhost:8080;

#proxy_set_header Host $host:$proxy_port;

proxy_set_header Host $host:$server_port; => add here

proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

proxy_set_header X-Forwarded-Proto $scheme;

proxy_set_header Accept-Encoding "";

proxy_set_header Proxy "";

}

Config nginx.conf in Nginx

<Connector port="8080" protocol="HTTP/1.1"

connectionTimeout="20000"

redirectPort="8443"

scheme="https"/> => Add scheme

3. Get Real IP from Tomcat when use nginx

Problem: You get Real IP in your application and use Tomcat container and Nginx Proxy but you can not get Real IP address because Remote Address always return local address instead of Remote address.

Solution:

Config Nginx

$vi /etc/nginx/nginx.conf

proxy_set_header X-Real-IP $remote_addr;

proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

Config tomcat

$vi server.xml

<!-- Replaces the apparent client remote IP address and hostname for

the request with the IP address list presented by a proxy or a

load balancer -->

<Valve className="org.apache.catalina.valves.RemoteIpValve"

requestAttributesEnabled="true"