org.apache.hadoop.mrunit.testutil

Class TemporaryPath

java.lang.Object

org.junit.rules.ExternalResource

org.apache.hadoop.mrunit.testutil.TemporaryPath

All Implemented Interfaces:

org.junit.rules.TestRule

public final class TemporaryPath
extends org.junit.rules.ExternalResource

A JUnit Rule that creates a managed temporary directory for a test case and destroys it afterwards. This works much like JUnit's TemporaryFolder but is geared towards Hadoop applications. The temporary directory is deleted after each test case, no matter if the test case succeeded or failed.

This is how it works:

 public class TestExample {
   @Rule
   public TemporaryPath tmpDir = new TemporaryPath();

   @Test
   public void testSomething() {
     Path input = tmpDir.copyResourcePath("my-test-data");
     Path output = tmpDir.getPath("output");

     // create and run a Hadoop job reading from input and writing to output
   }
 }
 

In some cases, the frameworks you use in your tests use temporary directories internally. If those directories are configurable via Hadoop properties, you can let overridePathProperties(Configuration) override them so that they point to your managed temporary directory. You have to specify the properties to override via the constructor.

Constructor Summary

Constructors

Constructor and Description
TemporaryPath(String... confKeys) Construct TemporaryPath.

Method Summary

Methods

Modifier and Type	Method and Description
org.junit.runners.model.Statement	apply(org.junit.runners.model.Statement base, org.junit.runner.Description description) Used by JUnit internally.
File	copyResourceFile(String resourceName) Copy a classpath resource to File.
String	copyResourceFileName(String resourceName) Copy a classpath resource returning its absolute file name.
org.apache.hadoop.fs.Path	copyResourcePath(String resourceName) Copy a classpath resource to a Path.
org.apache.hadoop.conf.Configuration	getDefaultConfiguration() Get a new Configuration instance.
File	getFile(String fileName) Get a File below the temporary directory.
String	getFileName(String fileName) Get an absolute file name below the temporary directory.
org.apache.hadoop.fs.Path	getPath(String fileName) Get a Path below the temporary directory.
File	getRootFile() Get the root directory which will be deleted automatically.
String	getRootFileName() Get the root directory as an absolute file name.
org.apache.hadoop.fs.Path	getRootPath() Get the root directory as a Path.
org.apache.hadoop.conf.Configuration	overridePathProperties(org.apache.hadoop.conf.Configuration conf) Set all keys specified in the constructor to temporary directories.

Methods inherited from class org.junit.rules.ExternalResource

after, before

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TemporaryPath

public TemporaryPath(String... confKeys)

Construct TemporaryPath.

Parameters:

confKeys - Configuration keys containing directories to override

Method Detail

apply

public org.junit.runners.model.Statement apply(org.junit.runners.model.Statement base,
                                      org.junit.runner.Description description)

Used by JUnit internally.

Specified by:

apply in interface org.junit.rules.TestRule

Overrides:

apply in class org.junit.rules.ExternalResource

getRootFile

public File getRootFile()

Get the root directory which will be deleted automatically.

getRootPath

public org.apache.hadoop.fs.Path getRootPath()

Get the root directory as a Path.

getRootFileName

public String getRootFileName()

Get the root directory as an absolute file name.

getFile

public File getFile(String fileName)

Get a File below the temporary directory.

getPath

public org.apache.hadoop.fs.Path getPath(String fileName)

Get a Path below the temporary directory.

getFileName

public String getFileName(String fileName)

Get an absolute file name below the temporary directory.

copyResourceFile

public File copyResourceFile(String resourceName)
                      throws IOException

Copy a classpath resource to File.

Throws:

IOException

copyResourcePath

public org.apache.hadoop.fs.Path copyResourcePath(String resourceName)
                                           throws IOException

Copy a classpath resource to a Path.

Throws:

IOException

getDefaultConfiguration

public org.apache.hadoop.conf.Configuration getDefaultConfiguration()

Get a new Configuration instance.

overridePathProperties

public org.apache.hadoop.conf.Configuration overridePathProperties(org.apache.hadoop.conf.Configuration conf)

Set all keys specified in the constructor to temporary directories.

copyResourceFileName

public String copyResourceFileName(String resourceName)
                            throws IOException

Copy a classpath resource returning its absolute file name.

Throws:

IOException