Spark pagerank

算法的流程：

Spark pagerank。初始化：我们用pages（pairRDD）来记录每个页面和其相关联的页面之间的关系，用ranks（pairRDD）来记录每个页面初始化的rank，初始值为1.0 在每次迭代的过程中，对页面p，我们向其每个相邻的页面，发送一个至为rank(p)/numNeighbors(p)的贡献值 将每个页面收到的contributions相加得到contributionsReceived 将每个页面的排序值设置为0.15 +0.85 * contributionsReceived 算法的实现：

    public static JavaPairRDD> run_page(){
        JavaPairRDD> res = sc.textFile(
                "/home/liang/workspace/learnSpark/pagerank.txt"
        ).mapToPair(new PairFunction>() {
            @Override
            public Tuple2> call(String s) throws Exception {
                String key = s.split(" ")[0];
                String values = s.split(" ")[1];
                ArrayList values_integer = new ArrayList();
                for(String str : values.split(",")){
                    values_integer.add(Integer.parseInt(str));
                }
                return new Tuple2>(Integer.parseInt(key), values_integer);
            }
        });
        return res;
    }
    public static JavaPairRDD run_rank(){
        JavaPairRDD res = sc.textFile(
                "/home/liang/workspace/learnSpark/pagerank.txt"
        ).mapToPair(
                line->new Tuple2(Integer.parseInt(line.split("")[0]),1.0)
                );
        return res;
    }

    public static JavaPairRDD> run_page(){
        JavaPairRDD> res = sc.textFile(
                "/home/liang/workspace/learnSpark/pagerank.txt"
        ).mapToPair(new PairFunction>() {
            @Override
            public Tuple2> call(String s) throws Exception {
                String key = s.split(" ")[0];
                String values = s.split(" ")[1];
                ArrayList values_integer = new ArrayList();
                for(String str : values.split(",")){
                    values_integer.add(Integer.parseInt(str));
                }
                return new Tuple2>(Integer.parseInt(key), values_integer);
            }
        });
        return res;
    }
    public static JavaPairRDD run_rank(){
        JavaPairRDD res = sc.textFile(
                "/home/liang/workspace/learnSpark/pagerank.txt"
        ).mapToPair(
                line->new Tuple2(Integer.parseInt(line.split("")[0]),1.0)
                );
        return res;
    }