Configuring java HTTP proxy cached before restarting JVM

Question

I am trying to change proxy settings for JVM in my user interface (Eclipse application running on Java 1.6.0.23)

if (isUseProxy()) { System.setProperty("java.net.useSystemProxies", "true"); System.setProperty("http.proxyHost", getProxyHost()); System.setProperty("http.proxyPort", getProxyPort()); System.setProperty("https.proxyHost", getProxyHost()); System.setProperty("https.proxyPort", getProxyPort()); .......... } else { System.clearProperty("http.proxyHost"); System.clearProperty("http.proxyPort"); System.clearProperty("https.proxyHost"); System.clearProperty("https.proxyPort"); } 

the problem is that the NEW proxy server value is not used until the JVM is restarted, it is cached somewhere in Java.

Java version:

 java.runtime.version=1.6.0_26-b03 java.specification.name=Java Platform API Specification java.specification.vendor=Sun Microsystems Inc. 

UPDATE: the magic continues ... I tried to isolate the problem to find out how Java magically works with system.properties. It seems that Java is ignoring the wrong proxy setting in some random cases. This test fails:

 import org.junit.Test; import java.io.IOException; import java.net.*; import static org.junit.Assert.fail; public class ProxySetTest { @Test public void verifyProxyIsNotCachedInJVM() throws IOException { tryConnectionToGoogleCom(); System.setProperty("http.proxyHost", getInvalidProxyHost()); System.setProperty("http.proxyPort", getInvalidProxyPort()+""); System.setProperty("https.proxyHost", getInvalidProxyHost()); System.setProperty("https.proxyPort", getInvalidProxyPort()+""); // Next connection will be through the invalid proxy. must fail? try { tryConnectionToGoogleCom(); fail("must have failed with an exception because of invalid proxy setting"); } catch (Exception e) { System.out.println("received exception: " + e); } // clear the proxy setting and try connecting again - must succeed System.clearProperty("http.proxyHost"); System.clearProperty("http.proxyPort"); System.clearProperty("https.proxyHost"); System.clearProperty("https.proxyPort"); // and without proxy again tryConnectionToGoogleCom(); } private void tryConnectionToGoogleCom() throws IOException { URL url = new URL("http://google.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.connect(); } private int getInvalidProxyPort() { return 1234; } private String getInvalidProxyHost() { return "asd"; } } 

Answer 1

 package com.alskor; import org.junit.Test; import java.io.IOException; import java.net.*; import static org.junit.Assert.fail; public class ProxySetTest { @Test public void verifyProxyIsNotCachedInJVM() throws IOException { tryConnectionToGoogleCom(); ProxySelector savedSelector = ProxySelector.getDefault(); java.net.ProxySelector.setDefault(new FixedProxySelector(getInvalidProxyHost(), getInvalidProxyPort())); // Next connection will be through the invalid proxy. must fail? try { tryConnectionToGoogleCom(); fail("must have failed with an exception because of invalid proxy setting"); } catch (Exception e) { System.out.println("received exception: " + e); } // clear the proxy setting and try connecting again - must succeed java.net.ProxySelector.setDefault(savedSelector); // and without proxy again tryConnectionToGoogleCom(); } private void tryConnectionToGoogleCom() throws IOException { URL url = new URL("http://google.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.connect(); } private int getInvalidProxyPort() { return 1234; } private String getInvalidProxyHost() { return "asd"; } } 

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 package com.alskor; import sun.misc.RegexpPool; import java.io.IOException; import java.net.*; import java.util.ArrayList; import java.util.List; public class FixedProxySelector extends ProxySelector { private final String host; private final int port; public FixedProxySelector(String host, int port) { this.host = host; this.port = port; } @Override public java.util.List<Proxy> select(URI uri) { if (uri == null) { throw new IllegalArgumentException("URI can't be null."); } List<Proxy> proxies = new ArrayList<Proxy>(); SocketAddress addr = new InetSocketAddress(host, port); proxies.add(new Proxy(Proxy.Type.SOCKS, addr)); proxies.add(new Proxy(Proxy.Type.HTTP, addr)); return proxies; } @Override public void connectFailed(URI uri, SocketAddress sa, IOException ioe) { if (uri == null || sa == null || ioe == null) { throw new IllegalArgumentException("Arguments can't be null."); } throw new RuntimeException(ioe.toString(), ioe); } } 

Answer 2

So I have the same problem and we tracked it down to the axis caching the information.

In org.apache.axis.components.net.TransportClientPropertiesFactory

This method:

 public static TransportClientProperties create(String protocol) { TransportClientProperties tcp = (TransportClientProperties)cache.get(protocol); if (tcp == null) { tcp = (TransportClientProperties) AxisProperties.newInstance(TransportClientProperties.class, (Class)defaults.get(protocol)); if (tcp != null) { cache.put(protocol, tcp); } } return tcp; } 

At the first call, a tcp object is created with all the current JVM settings for the proxy. On subsequent calls, it pulls out the cached version, so even if you change the proxy settings in the JVM, it does not matter. See if I can find a way to clear the cache.

Answer 3

pass the java.net.Proxy object to the URL.openConnection (Proxy) method. You can use Proxy.NO_PROXY for direct connection. Or create a new proxy, for example:

 new Proxy(Proxy.Type.HTTP, new InetSocketAddress("localhost", 8080)) 

Here is the complete sample:

 public class TestConnectOverProxy { static class Connector { private Proxy proxy = Proxy.NO_PROXY; public void setProxy(Proxy proxy) { this.proxy = proxy; } /** * This method works with java.net.Proxy field of the Connector class * as described * <a href="http://www.rgagnon.com/javadetails/java-0085.html">here</a> */ public String getContent(URL url) throws IOException { HttpURLConnection conn = (HttpURLConnection) url.openConnection(proxy); conn.connect(); System.out.println(conn.getRequestMethod()); System.out.println(conn.getResponseCode()); return IOUtils.toString(conn.getInputStream()); } } @Test public void test() throws IOException { URL url = new URL("http://www.google.com"); Connector connector = new Connector(); //connect directly connector.setProxy(Proxy.NO_PROXY); System.out.println(connector.getContent(url)); //connect over proxy connector.setProxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress("localhost", 8080))); System.out.println(connector.getContent(url)); } }