Map Reduce RXJava

MapReduce.java

package fr.mga.mashup.mapreduce;

import rx.Observable;

import java.util.List;

public class MapReduce {

    private List<Integer> list;

    public MapReduce(List<Integer> list) {
        this.list = list;
    }

    public Integer sum() {
        return Observable.from(list).map(new Square()).filter(new WhenSuperiorAtHundredFilter()).take(3).reduce(new Sum())
                .toBlocking().first();
    }
}

MapReduceTest.java

package fr.mga.mashup;

import fr.mga.mashup.mapreduce.MapReduce;
import org.fest.assertions.api.Assertions;
import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

public class MapReduceTest {
    @Test
    public void should_map_reduce_to_numbers() {
        List<Integer> maList = new ArrayList<>();
        for (int i = 1; i <= 1000; i++) {
            maList.add(i);
        }

        MapReduce mapReduce = new MapReduce(maList);

        Integer sum = mapReduce.sum();
        Assertions.assertThat(sum).isEqualTo(434);
    }
}

pom.xml

<?xml version="1.0"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>fr.mga.mashup</groupId>
    <artifactId>mashup</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <junit.version>4.11</junit.version>
        <festassert.version>2.0M10</festassert.version>
        <rxjava.version>1.0.0-rc.3</rxjava.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven-compiler-plugin.version>3.1</maven-compiler-plugin.version>
        <source.level>1.7</source.level>
        <target.level>1.7</target.level>
    </properties>
    <dependencies>
        <dependency>
            <groupId>io.reactivex</groupId>
            <artifactId>rxjava</artifactId>
            <version>${rxjava.version}</version>
        </dependency>

        <!-- Unit test -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.easytesting</groupId>
            <artifactId>fest-assert-core</artifactId>
            <version>${festassert.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>
                <configuration>
                    <source>${source.level}</source>
                    <target>${target.level}</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Square.java

package fr.mga.mashup.mapreduce;

import rx.functions.Func1;

public class Square implements Func1<Integer,Integer> {

    @Override public Integer call(Integer integer) {
        return integer * integer;
    }
}

Sum.java

package fr.mga.mashup.mapreduce;

import rx.functions.Func2;

public class Sum implements Func2<Integer,Integer,Integer> {

    @Override public Integer call(Integer integer, Integer integer2) {
        return integer + integer2;
    }
}

WhenSuperiorAtHundredFilter.java

package fr.mga.mashup.mapreduce;

import rx.functions.Func1;

public class WhenSuperiorAtHundredFilter implements Func1<Integer,Boolean> {
    @Override public Boolean call(Integer integer) {
        return integer > 100;
    }
}