How to download a .jar file from a URL

Question

I have to download a .jar file from a remote kie maven repository which requires authentication using my java code. The code is as follows.

String url = "http://localhost:18080/kiewb/maven2/group/artifact/version/file.jar";
        UrlResource urlResource = (UrlResource) resources.newUrlResource(url);
        urlResource.setUsername("username"); 
        urlResource.setPassword("password");

        urlResource.setBasicAuthentication("enabled");

    InputStream is = urlResource.getInputStream();

But, its throwing

Exception in thread "main" java.io.IOException: Server returned HTTP response code: 500 for URL:http://localhost:18080/kiewb/maven2/group/artifact/version/file.jar
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1839)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440)
    at url.main(url.java:47)

And in the server in which the maven repo is, I am getting the following error. My server is Wildfly10.

ERROR [io.undertow.request] (default task-58) UT005023: Exception handling request to /kiewb/maven2/group/artifact/version/file.jar: java.lang.ArrayIndexOutOfBoundsException: 1
        at org.uberfire.ext.security.server.BasicAuthSecurityFilter.authenticate(BasicAuthSecurityFilter.java:112)
        at org.uberfire.ext.security.server.BasicAuthSecurityFilter.doFilter(BasicAuthSecurityFilter.java:69)
        at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
        at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
        at org.uberfire.ext.security.server.SecureHeadersFilter.doFilter(SecureHeadersFilter.java:69)
        at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
        at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
        at org.uberfire.ext.security.server.SecurityIntegrationFilter.doFilter(SecurityIntegrationFilter.java:57)
        at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
        at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
        at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
        at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
        at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
        at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
        at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
        at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
        at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:53)
        at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
        at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
        at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:59)
        at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
        at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
        at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
        at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
        at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
        at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
        at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)
        at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
        at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
        at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
        at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
        at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
        at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
        at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
        at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
        at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
        at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:805)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)

And the same jar I am able to download it by directly hitting the URL in the browser.

Answer 1

Try another way to download. Note that it should be Java 8

public void downloadFile(String fromUrl, String localFileName) throws IOException {
    File localFile = new File(localFileName);
    if (localFile.exists()) {
        localFile.delete();
    }
    localFile.createNewFile();
    URL url = new URL(fromUrl);
    OutputStream out = new BufferedOutputStream(new FileOutputStream(localFileName));
    URLConnection conn = url.openConnection();
    String encoded = Base64.getEncoder().encodeToString(("username"+":"+"password").getBytes(StandardCharsets.UTF_8));  //Java 8
    conn.setRequestProperty("Authorization", "Basic "+ encoded);
    InputStream in = conn.getInputStream();
    byte[] buffer = new byte[1024];

    int numRead;
    while ((numRead = in.read(buffer)) != -1) {
        out.write(buffer, 0, numRead);
    }
    if (in != null) {
        in.close();
    }
    if (out != null) {
        out.close();
    }
}

Answer 2

Simply rename the newest file to file name that is in your application and then download it. The example above is very good for launchers, because it delete the old file.