Revert JENKINS-20679 (jenkins-infra#591)

# Conflicts:
#	src/main/java/io/jenkins/update_center/Main.java
#	src/main/java/io/jenkins/update_center/PluginUpdateCenterEntry.java

README.adoc

@@ -242,11 +242,3 @@ Once update site JSON files are generated, configure Jenkins to download them in
 Either set up a local HTTP server so the URL would be something like `+http://localhost:8000/update-center.json+`, or specify a `file://` URL like `+file:///Users/yourname/git/update-center2/www2/update-center.json+`
 
 NOTE: For historical reason, the configured URL points to `update-center.json`, but the file actually downloaded by Jenkins (at least up to 2.235 as of this writing) is `update-center.json.html`.
-
-=== Filtering Java versions
-
-The `--java-version <version>` CLI argument can be used to filter plugins based on their minimum Java version requirement.
-By default such filtering happens based on the `Minimum-Java-Version` manifest entry provided in Plugin HPIs starting from https://github.com/jenkinsci/maven-hpi-plugin#30-2018-12-05[Maven HPI Plugin 3.0] and https://github.com/jenkinsci/plugin-pom/blob/master/CHANGELOG.md#329[Plugin POM 3.29].
-
-Plugin HPIs without `Minimum-Java-Version` will be accepted by default.
-If you want to create an update center for old Java, use the `--limit-plugin-core-dependency` option to set the filter for core dependencies in plugins.

src/main/java/io/jenkins/update_center/HPI.java

@@ -26,7 +26,6 @@
 import com.alibaba.fastjson.annotation.JSONField;
 import com.google.common.annotations.VisibleForTesting;
 import hudson.util.VersionNumber;
-import io.jenkins.update_center.util.JavaSpecificationVersion;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
 import org.dom4j.Document;
@@ -44,7 +43,6 @@
 import org.owasp.html.Sanitizers;
 import org.xml.sax.SAXException;
 
-import javax.annotation.CheckForNull;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -112,22 +110,6 @@ public String getCompatibleSinceVersion() throws IOException {
         return getManifestAttributes().getValue("Compatible-Since-Version");
     }
 
-    /**
-     * Gets Minimum Java Version required by the plugin.
-     * This uses the value of the {@code Minimum-Java-Version} manifest entry
-     * @return Minimum Java Version or {@code null} if it is unknown
-     * @throws IOException Manifest read error
-     */
-    @CheckForNull
-    public JavaSpecificationVersion getMinimumJavaVersion() throws IOException {
-        String manifestEntry = getManifestAttributes().getValue("Minimum-Java-Version");
-        if (StringUtils.isNotBlank(manifestEntry)) {
-            return new JavaSpecificationVersion(manifestEntry);
-        }
-
-        return null;
-    }
-
     public List<Dependency> getDependencies() throws IOException {
         String deps = getManifestAttributes().getValue("Plugin-Dependencies");
         if(deps==null)  return Collections.emptyList();

src/main/java/io/jenkins/update_center/Main.java

@@ -38,12 +38,9 @@
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 
-import io.jenkins.update_center.filters.JavaVersionPluginFilter;
 import io.jenkins.update_center.json.PluginVersionsRoot;
 import io.jenkins.update_center.json.ReleaseHistoryRoot;
 import io.jenkins.update_center.json.UpdateCenterRoot;
-import io.jenkins.update_center.util.JavaSpecificationVersion;
-import io.jenkins.update_center.wrappers.FilteringRepository;
 import io.jenkins.update_center.wrappers.TruncatedMavenRepository;
 import io.jenkins.update_center.wrappers.AllowedArtifactsListMavenRepository;
 import org.kohsuke.args4j.ClassParser;
@@ -100,9 +97,6 @@ public class Main {
     @Option(name = "--with-experimental", usage = "Include experimental alpha/beta releases")
     public boolean includeExperimental;
 
-    @Option(name = "--java-version", usage = "Target Java version for the update center. Plugins will be excluded if their minimum Java version does not match. If not set, required Java version will be ignored")
-    @CheckForNull public String javaVersion;
-
     @Option(name = "--max-plugins", usage = "For testing purposes: Limit the number of plugins included to the specified number.")
     @CheckForNull public Integer maxPlugins;
 
@@ -369,9 +363,6 @@ private MavenRepository createRepository() throws Exception {
             VersionNumber vc = capCore == null ? null : new VersionNumber(capCore);
             repo = new VersionCappedMavenRepository(vp, vc).withBaseRepository(repo);
         }
-        if (javaVersion != null) {
-            repo = new FilteringRepository().withPluginFilter(new JavaVersionPluginFilter(new JavaSpecificationVersion(this.javaVersion))).withBaseRepository(repo);
-        }
         return repo;
     }
 

src/main/java/io/jenkins/update_center/PluginUpdateCenterEntry.java

@@ -3,7 +3,6 @@
 import com.alibaba.fastjson.annotation.JSONField;
 import hudson.util.VersionNumber;
 import io.jenkins.update_center.util.Environment;
-import io.jenkins.update_center.util.JavaSpecificationVersion;
 
 import javax.annotation.CheckForNull;
 import java.io.IOException;
@@ -132,11 +131,6 @@ public String getCompatibleSinceVersion() throws IOException {
         return latestOffered.getCompatibleSinceVersion();
     }
 
-    public String getMinimumJavaVersion() throws IOException {
-        final JavaSpecificationVersion minimumJavaVersion = latestOffered.getMinimumJavaVersion();
-        return minimumJavaVersion == null ? null : minimumJavaVersion.toString();
-    }
-
     public String getBuildDate() throws IOException {
         return latestOffered.getTimestampAsString();
     }