A very simple custom vertex class in java

SampleVertexData.java

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.io.Writable;

public class  SampleVertexData implements Writable {
    /**
     * Some integer
     */
    private int a;

    /**
     * Some boolean flag
     */
    private boolean flag;

    // From what I understand the empty constructor is required by hadoop
    public SampleVertexData () {}

    public SampleVertexData(int a, boolean flag) {
        this.a = a;
        this.flag = flag;
    }

    public int getA() { return a; }

    public int getFlag() { return flag; }

    public void setA(int newA) {
        this.a = newA;
    }

    public void setFlag(int newFlag) {
        this.flag = newFlag;
    }

    @Override 
    public void readFields(DataInput input) throws IOException {
        // One of these for each of your class variables
        // See for more detail: http://docs.oracle.com/javase/7/docs/api/java/io/DataInput.html
        a = input.readInt();
        flag = input.readBoolean();
    }

    @Override
    public void write(DataOutput output) throws IOException {
        output.writeInt(a);
        output.writeBoolean(flag);
    }

    @Override
    public String toString() {
        return "(a = " + a + ", flag = " + flag + ")";
    }
}