JDBC读取SciDB数据

SciDB一个典型的Array Database，官网地址：​​http://www.paradigm4.com/​​，提供了C++，Java，Python和R的接口。

下面说说如何使用Java的接口（JDBC）读取SciDB数据：
我使用的SciDB版本是14.12，JDK版本为1.7。
依赖的JDBC的jar包可从​​​https://downloads.paradigm4.com/client/14.12/jdbc/​​​下载，主要用到的jar包括scidb4j.jar和iquery.jar。
此外，还需要Google的protolib库，版本为2.4.1。

代码如下：

package cn.tzy.scidb;

import org.scidb.jdbc.IResultSetWrapper;

import java.sql.*;

public class Main {

    public static void main(String[] args) {
        try {
            Class.forName("org.scidb.jdbc.Driver");
        } catch (ClassNotFoundException ex) {
            System.out.println("Driver is not in the CLASSPATH -> " + ex);
        }

        String iqueryHost = "127.0.0.1";
        String iqueryPort = "1239";
        String arrayName = "landsat_wuhan";

        try {
            String url = "jdbc:scidb://" + iqueryHost + ":" + iqueryPort + "/";
            Connection conn = DriverManager.getConnection(url);
            ResultSet res;
            try (Statement st = conn.createStatement()) {
                res = st.executeQuery("select * from " + arrayName);
            }
            ResultSetMetaData meta = res.getMetaData();
            System.out.println("Source array name: " + meta.getTableName(0));
            System.out.println(meta.getColumnCount() + " columns:");
            IResultSetWrapper resWrapper = res.unwrap(IResultSetWrapper.class);

            // 输出Array的元数据
            for(int i = 1; i <= meta.getColumnCount(); ++i) {
                System.out.println(meta.getColumnName(i) + " - " + meta.getColumnTypeName(i) + " - is attribute:" + resWrapper.isColumnAttribute(i));
            }

            int count = 0;
            // 输出Array的前10行数据
            while(!res.isAfterLast() && count < 10) {
                System.out.println(res.getLong(1) + " " + res.getLong(2) + " " + res.getShort(3));
                res.next();
                count++;
            }
        } catch (SQLException ex) {
            System.out.println(ex);

输出结果如下：

Source array name: landsat_wuhan@1
3 columns:
y - int64 - is attribute:false
x - int64 - is attribute:false
band1 - uint8 - is attribute:true
0 0 0
0 1 0
0 2 0
0 3 0
0 4 0
0 5 0
0 6 0
0 7 0
0 8 0
0 9 0