[HTTPCLIENT-1959] Proxy support not working in 5.0 (IllegalArgumentException: Inet address must not be null)

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.0 Beta3
• Fix Version/s: 5.0 Beta4
• Component/s: HttpClient (classic)
• Assignee: Unassigned
• Reporter: Matthias Fritschi
• Created: 09/Jan/19 13:47
• Updated: 10/Jan/19 10:01
• Resolved: 10/Jan/19 10:01

Description

When a proxy host and port are specified via the JVM properties https.proxyHost / https.proxyPort, an IllegalArgumentException is thrown on any HTTP request (see stacktrace below)

Steps to reproduce

1) Specify a proxy via https.proxyHost/https.proxyPort JVM properties
2) Execute for example a HTTP GET via httpClient.execute(...)
3) java.lang.IllegalArgumentException: Inet address must not be null is thrown (see stacktrace below)

Analysis

The sun.net.spi.DefaultProxySelector deliberately does not resolve the proxy's address, see http://hg.openjdk.java.net/jdk10/jdk10/jdk/file/9b8c96f96a0f/src/share/classes/sun/net/spi/DefaultProxySelector.java#l294.

SystemDefaultRoutePlanner in httpclient5 assumes the address has been resolved, see https://github.com/apache/httpcomponents-client/blob/5.0-beta3/httpclient5/src/main/java/org/apache/hc/client5/http/impl/routing/SystemDefaultRoutePlanner.java#L100

See the attached reproducer test or the code snippet below.

Versions used

org.apache.httpcomponents.client5:httpclient5:5.0-beta3
Oracle JDK 10.0.2 on OSX and Windows

java.lang.IllegalArgumentException: Inet address must not be null
	at org.apache.hc.core5.util.Args.illegalArgumentExceptionNotNull(Args.java:101)
	at org.apache.hc.core5.util.Args.notNull(Args.java:150)
	at org.apache.hc.core5.http.HttpHost.<init>(HttpHost.java:286)
	at org.apache.hc.client5.http.impl.routing.SystemDefaultRoutePlanner.determineProxy(SystemDefaultRoutePlanner.java:100)
	at org.apache.hc.client5.http.impl.routing.DefaultRoutePlanner.determineRoute(DefaultRoutePlanner.java:71)
	at org.apache.hc.client5.http.impl.classic.InternalHttpClient.determineRoute(InternalHttpClient.java:122)
	at org.apache.hc.client5.http.impl.classic.InternalHttpClient.doExecute(InternalHttpClient.java:166)
	at org.apache.hc.client5.http.impl.classic.CloseableHttpClient.execute(CloseableHttpClient.java:77)
	at org.apache.hc.client5.http.impl.classic.CloseableHttpClient.execute(CloseableHttpClient.java:102)

System.setProperty("https.proxyHost", "<TODO: Your Proxy Host Here>");
System.setProperty("https.proxyPort", "8080");
CloseableHttpClient httpClient = HttpClients.createSystem();
HttpGet httpGet = new HttpGet("https://www.google.com/");
CloseableHttpResponse response = httpClient.execute(httpGet);
System.out.println(response.getCode());