導出SQL運行結果的方法總結

private static final String accessId = "userAccessId";
private static final String accessKey = "userAccessKey";
private static final String endPoint = "http://service.odps.aliyun.com/api";
private static final String project = "userProject";
private static final String sql = "userSQL";
private static final String table = "Tmp_" + UUID.randomUUID().toString().replace("-", "_");//其實也就是隨便找了個隨機字符串作爲臨時表的名字
private static final Odps odps = getOdps();

public static void main(String[] args) {
    System.out.println(table);
    runSql();
    tunnel();
}

/*
 * 把SQLTask的結果下載過來
 * */
private static void tunnel() {
    TableTunnel tunnel = new TableTunnel(odps);
    try {
        DownloadSession downloadSession = tunnel.createDownloadSession(
                project, table);
        System.out.println("Session Status is : "
                + downloadSession.getStatus().toString());
        long count = downloadSession.getRecordCount();
        System.out.println("RecordCount is: " + count);
        RecordReader recordReader = downloadSession.openRecordReader(0,
                count);
        Record record;
        while ((record = recordReader.read()) != null) {
            consumeRecord(record, downloadSession.getSchema());
        }
        recordReader.close();
    } catch (TunnelException e) {
        e.printStackTrace();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
}

/*
 * 保存這條數據
 * 數據量少的話直接打印後拷貝走也是一種取巧的方法。實際場景可以用Java.io寫到本地文件，或者寫到遠端數據等各種目標保存起來。
 * */
private static void consumeRecord(Record record, TableSchema schema) {
    System.out.println(record.getString("username")+","+record.getBigint("cnt"));
}

/*
 * 運行SQL，把查詢結果保存成臨時表，方便後面用Tunnel下載
 * 這裏保存數據的lifecycle爲1天，所以哪怕刪除步驟出了問題，也不會太浪費存儲空間
 * */
private static void runSql() {
    Instance i;
    StringBuilder sb = new StringBuilder("Create Table ").append(table)
            .append(" lifecycle 1 as ").append(sql);
    try {
        System.out.println(sb.toString());
        i = SQLTask.run(getOdps(), sb.toString());
        i.waitForSuccess();

    } catch (OdpsException e) {
        e.printStackTrace();
    }
}

/*
 * 初始化MaxCompute(原ODPS)的連接信息
 * */
private static Odps getOdps() {
    Account account = new AliyunAccount(accessId, accessKey);
    Odps odps = new Odps(account);
    odps.setEndpoint(endPoint);
    odps.setDefaultProject(project);
    return odps;
}