Example usage for org.apache.hadoop.fs FileContext resolvePath

Introduction

In this page you can find the example usage for org.apache.hadoop.fs FileContext resolvePath.

Prototype

public Path resolvePath(final Path f)
        throws FileNotFoundException, UnresolvedLinkException, AccessControlException, IOException 

Source Link

Document

Resolve the path following any symlinks or mount points

Usage

From source file:co.cask.cdap.internal.app.runtime.batch.distributed.MapReduceContainerHelper.java

License:Apache License

/**
 * Gets the MapReduce framework URI based on the {@code mapreduce.application.framework.path} setting.
 *
 * @param hConf the job configuration//from   w w w.  j a v a 2  s .  c o m
 * @return the framework URI or {@code null} if not present or if the URI in the config is invalid.
 */
@Nullable
public static URI getFrameworkURI(Configuration hConf) {
    String framework = hConf.get(MRJobConfig.MAPREDUCE_APPLICATION_FRAMEWORK_PATH);
    if (framework == null) {
        return null;
    }

    try {
        // Parse the path. It can contains '#' to represent the localized file name
        URI uri = new URI(framework);
        String linkName = uri.getFragment();

        // The following resolution logic is copied from JobSubmitter in MR.
        FileSystem fs = FileSystem.get(hConf);
        Path frameworkPath = fs.makeQualified(new Path(uri.getScheme(), uri.getAuthority(), uri.getPath()));
        FileContext fc = FileContext.getFileContext(frameworkPath.toUri(), hConf);
        frameworkPath = fc.resolvePath(frameworkPath);
        uri = frameworkPath.toUri();

        // If doesn't have localized name (in the URI fragment), then use the last part of the URI path as name
        if (linkName == null) {
            linkName = uri.getPath();
            int idx = linkName.lastIndexOf('/');
            if (idx >= 0) {
                linkName = linkName.substring(idx + 1);
            }
        }
        return new URI(uri.getScheme(), uri.getAuthority(), uri.getPath(), null, linkName);
    } catch (URISyntaxException e) {
        LOG.warn("Failed to parse {} as a URI. MapReduce framework path is not used. Check the setting for {}.",
                framework, MRJobConfig.MAPREDUCE_APPLICATION_FRAMEWORK_PATH, e);
    } catch (IOException e) {
        LOG.warn("Failed to resolve {} URI. MapReduce framework path is not used. Check the setting for {}.",
                framework, MRJobConfig.MAPREDUCE_APPLICATION_FRAMEWORK_PATH, e);
    }
    return null;
}

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