External-Memory Sorting in Java: useful to sort very large files using multiple cores and an external-memory algorithm.
The versions 0.1 of the library are compatible with Java 6 and above. Versions 0.2 and above require at least Java 8.
This code is used in Apache Jackrabbit Oak.
import com.google.code.externalsorting.ExternalSort;
//... inputfile: input file name
//... outputfile: output file name
// next command sorts the lines from inputfile to outputfile
ExternalSort.mergeSortedFiles(ExternalSort.sortInBatch(new File(inputfile)), new File(outputfile));
// you can also provide a custom string comparator, see APIhttp://www.javadoc.io/doc/com.google.code.externalsortinginjava/externalsortinginjava/
You can download the jar files from the Maven central repository: http://repo1.maven.org/maven2/com/google/code/externalsortinginjava/externalsortinginjava/
You can also specify the dependency in the Maven "pom.xml" file:
<dependencies>
<dependency>
<groupId>com.google.code.externalsortinginjava</groupId>
<artifactId>externalsortinginjava</artifactId>
<version>[0.1.9,)</version>
</dependency>
</dependencies>- get the java jdk
- Install Maven 2
- mvn install - builds jar (requires signing)
- mvn test - runs tests