Eclipse fails to update Maven index while behind c

问题:

Eclipse Mars m2e plugin fails to download repository index updates on startup. I run Eclipse behind a company firewall but the proxy settings work fine for "check for updates", "eclipse marketplace", and eclipse's built-in browser.

I have tried the following:

1. Deleting the cache directory \eclipse\p2\org.eclipse.equinox.p2.repository\cache and then refreshing the repositories. Preferences -> Install Update -> Available Software Sites => select the entry and click "Reload"

2. Adding -Djava.net.preferIPv4Stack=true to -vmargs in eclipse.ini

Edit: Proxy configurations are correctly set in $HOME/.m2/settings.xml
Edit: Seems like a bug. So I raised a bug request with eclipse.org. You can view it here

Due to this issue, eclipse fails to search and add dependency from maven repositories.

Here is the error in .metadata/.log

eclipse.buildId=4.5.0.I20150603-2000
java.version=1.8.0_60
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_IN
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product

!ENTRY org.eclipse.m2e.logback.appender 4 0 2015-09-30 14:39:59.820
!MESSAGE Unable to update index for central|https://repo.maven.apache.org/maven2
!STACK 0
java.net.ConnectException: Connection timed out: connect
        at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at com.squareup.okhttp.internal.Platform.connectSocket(Platform.java:107)
        at com.squareup.okhttp.Connection.connect(Connection.java:156)
        at com.squareup.okhttp.Connection.connectAndSetOwner(Connection.java:175)
        at com.squareup.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:120)
        at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:330)
        at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
        at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
        at com.squareup.okhttp.Call.getResponse(Call.java:271)
        at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
        at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
        at com.squareup.okhttp.Call.execute(Call.java:79)
        at io.takari.aether.okhttp.OkHttpAetherClient.execute(OkHttpAetherClient.java:154)
        at io.takari.aether.okhttp.OkHttpAetherClient.get(OkHttpAetherClient.java:100)
        at org.eclipse.m2e.core.internal.index.nexus.AetherClientResourceFetcher.retrieve(AetherClientResourceFetcher.java:79)
        at org.apache.maven.index.updater.AbstractResourceFetcher.retrieve(AbstractResourceFetcher.java:35)
        at org.apache.maven.index.updater.DefaultIndexUpdater.downloadIndexProperties(DefaultIndexUpdater.java:452)
        at org.apache.maven.index.updater.DefaultIndexUpdater.access$100(DefaultIndexUpdater.java:75)
        at org.apache.maven.index.updater.DefaultIndexUpdater$IndexAdaptor.setProperties(DefaultIndexUpdater.java:607)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:788)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:135)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateRemoteIndex(NexusIndexManager.java:1127)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateIndex(NexusIndexManager.java:1084)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager$1.run(NexusIndexManager.java:656)
        at org.eclipse.m2e.core.internal.index.nexus.IndexUpdaterJob.run(IndexUpdaterJob.java:72)
        at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

回答1:

I've found solution. It's quite simple. After some code investigation I've found following thing: https://github.com/eclipse/m2e-core/blob/releases/1.6/1.6.2.20150902-0002/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/embedder/MavenImpl.java#L1226

So m2e scans proxy list and trying to find correct by protocol. If you look at central url: https://repo.maven.apache.org/maven2. It's starts from "https".

Your proxy settings should looks like that (one proxy for http and second for https):

<proxies>
  <proxy>
    <active>true</active>
    <protocol>http</protocol>
    <host>myproxy.company.com</host>
    <port>8080</port>
  </proxy>
    <proxy>
      <active>true</active>
      <protocol>https</protocol>
      <host>myproxy.company.com</host>
      <port>8080</port>
    </proxy>
</proxies>

回答2:

Although you have configured proxy in eclispe, you have to do the same config for maven, into settinggs.xml file. Here you have my proxy configuration section:

<proxies>
  <proxy>
    <active>true</active>
    <protocol>http</protocol>
    <host>myproxy.company.com</host>
    <port>8080</port>
  </proxy>
</proxies>

Then you have to ensure in eclipse that you are using the configured settings.xml file, in window->preferences-maven->user settings.

Hope it helps.

回答3:

Maven uses its own proxy settings, defined in .m2/settings.xml. You can find the settings used my m2e plugin in Eclipse's menu: Windows / Preferences / Maven / User Settings. Remember to hit the Update Settings -button after editing:

<!-- proxies
 | This is a list of proxies which can be used on this machine to connect to the network.
 | Unless otherwise specified (by system property or command-line switch), the first proxy
 | specification in this list marked as active will be used.
 |-->
<proxies>
  <!-- proxy
   | Specification for one proxy, to be used in connecting to the network.
   |
  <proxy>
    <id>optional</id>
    <active>true</active>
    <protocol>http</protocol>
    <username>proxyuser</username>
    <password>proxypass</password>
    <host>proxy.host.net</host>
    <port>80</port>
    <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
  </proxy>
  -->
</proxies>