Java
Oracle •
Since 1996
Quick Actions
Official Docs
What is Java?
The Java user agent appears when Java applications make HTTP requests using the platform's built-in HTTP client without specifying a custom user agent. Common in enterprise environments, this user agent often represents backend services, integration systems, and enterprise applications. Java's widespread use in corporate environments means this user agent frequently appears in logs from business-to-business communications, API integrations, and automated systems. The version number typically indicates the Java runtime version being used.
User Agent String
Java/17.0.8
How to Control Java
Block Completely
To prevent Java from accessing your entire website, add this to your robots.txt file:
# Block Java
User-agent: Java
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: Java
Disallow: /admin/
Disallow: /private/
Disallow: /wp-admin/
Allow: /public/
Set Crawl Delay
To slow down the crawl rate (note: not all bots respect this directive):
User-agent: Java
Crawl-delay: 10
How to Verify Java
Verification Method:
Java version in user agent string
Java version in user agent string
Learn more in the official documentation.
Detection Patterns
Multiple ways to detect Java in your application:
Basic Pattern
/Java/i
Strict Pattern
/^Java/17\.0\.8$/
Flexible Pattern
/Java[\s\/]?[\d\.]*?/i
Vendor Match
/.*Oracle.*Java/i
Implementation Examples
// PHP Detection for Java
function detect_java() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/Java/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('Java detected from IP: ' . $_SERVER['REMOTE_ADDR']);
// Set cache headers
header('Cache-Control: public, max-age=3600');
header('X-Robots-Tag: noarchive');
// Optional: Serve cached version
if (file_exists('cache/' . md5($_SERVER['REQUEST_URI']) . '.html')) {
readfile('cache/' . md5($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for Java
import re
from flask import request, make_response
def detect_java():
user_agent = request.headers.get('User-Agent', '')
pattern = r'Java'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
# Django Middleware
class JavaMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for Java
const express = require('express');
const app = express();
// Middleware to detect Java
function detectJava(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /Java/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('Java detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'Java';
}
next();
}
app.use(detectJava);
# Apache .htaccess rules for Java
# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Java [NC]
RewriteRule .* - [F,L]
# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} Java [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "Java" is_bot=1
# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /Java/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for Java
# Map user agent to variable
map $http_user_agent $is_java {
default 0;
~*Java 1;
}
server {
# Block the bot completely
if ($is_java) {
return 403;
}
# Or serve cached content
location / {
if ($is_java) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
# Add headers for bot requests
location @backend {
if ($is_java) {
add_header Cache-Control "public, max-age=3600";
add_header X-Robots-Tag "noarchive";
}
proxy_pass http://backend;
}
}
Should You Block This Bot?
Recommendations based on your website type:
| Site Type | Recommendation | Reasoning |
|---|---|---|
| E-commerce | Optional | Evaluate based on bandwidth usage vs. benefits |
| Blog/News | Allow | Increases content reach and discoverability |
| SaaS Application | Block | No benefit for application interfaces; preserve resources |
| Documentation | Selective | Allow for public docs, block for internal docs |
| Corporate Site | Limit | Allow for public pages, block sensitive areas like intranets |
Advanced robots.txt Configurations
E-commerce Site Configuration
User-agent: Java
Crawl-delay: 5
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Disallow: /api/
Disallow: /*?sort=
Disallow: /*?filter=
Disallow: /*&page=
Allow: /products/
Allow: /categories/
Sitemap: https://example.com/sitemap.xml
Publishing/Blog Configuration
User-agent: Java
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
User-agent: Java
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
Java
Robots.txt Name
Java
Category
other
Respects robots.txt
May not respect
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