使用Phoenix5 Java api操作HBase

r囧r小猫 2021-11-29 19:06 357阅读 0赞

### 文章目录 ###

*  引入依赖
 *  配置文件
 *  编写测试类
 *   *  建表
     *  插入记录
     *  查询

# 引入依赖 #

<dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-client</artifactId>
        <version>2.1.5</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.phoenix</groupId>
        <artifactId>phoenix-core</artifactId>
        <version>5.0.0-HBase-2.0</version>
    </dependency>

# 配置文件 #

类似于[使用最新的 hbase-client 2.1 操作 hbase][hbase-client 2.1 _ hbase]，这里也需要将配置文件`hbase-site.xml core-site.xml hdfs-site.xml`添加到工程目录下：  
![在这里插入图片描述][20190722165628619.png]

> 网上的资料都是需要将这几个配置文件拷贝过来，我实际测试过程中（我用的Phoenix5），即使将不拷贝这几个配置文件也是可以的。

# 编写测试类 #

public class PhoenixTest { 
    
        static Connection conn = null;
        static ResultSet rs = null;
     /** 这里可以不用主动加载PhoenixDriver static { try { Class.forName("org.apache.phoenix.jdbc.PhoenixDriver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } } */
        /** * 创建一个新的链接不是一个昂贵的操作，所以这里就不使用连接池了。 * @return */
        @Before
        public void getConnection() { 
            try { 
                // jdbc 的 url 类似为 jdbc:phoenix [ :<zookeeper quorum> [ :<port number> ] [ :<root node> ] ]，
                conn = DriverManager.getConnection("jdbc:phoenix:node1,node2,node3:2181");
            } catch (SQLException e) { 
                e.printStackTrace();
            }
        }
    
        @After
        public void close(){ 
            System.out.println("close........");
            if (rs != null) { 
                try { 
                    rs.close();
                } catch (SQLException e) { 
                    e.printStackTrace();
                }
            }
            if (conn != null) { 
                try { 
                    conn.close();
                } catch (SQLException e) { 
                    e.printStackTrace();
                }
            }
        }
    }

上面代码包含了getConnection和关闭的代码，便于后续测试。

## 建表 ##

@Test
    public void create() { 
        try { 
            String createSql = "CREATE TABLE user (id varchar PRIMARY KEY,name varchar ,passwd varchar)";
            PreparedStatement ps = conn.prepareStatement(createSql);
            ps.execute();
            ps.close();
        } catch (SQLException e) { 
            e.printStackTrace();
        }
    }

执行成功后可以在Phoenix 的 shell 中使用`!table`命令查看表。

## 插入记录 ##

@Test
    public void  upsert() { 
        try { 
            String upsertSql = "upsert into user(id, name, passwd) values(?, ?, ?)";
    // String[] param = {"1", "张三", "123456"};
            String[] param = { "2", "李四", "111111"};
            PreparedStatement ps = conn.prepareStatement(upsertSql);
            for (int i = 1; i <= param.length; i++) { 
                ps.setString(i, param[i - 1]);
            }
            ps.executeUpdate();
            conn.commit(); // you must commit
            ps.close();
        } catch (SQLException e) { 
            e.printStackTrace();
        }
    }

插入成功后查询：

0: jdbc:phoenix:node1,node2,node3:2181> select * from user;
    +-----+-------+---------+
    | ID  | NAME  | PASSWD  |
    +-----+-------+---------+
    | 1   | 张三    | 123456  |
    | 2   | 李四    | 111111  |
    +-----+-------+---------+
    2 rows selected (0.122 seconds)

## 查询 ##

@Test
    public void query() { 
        try { 
            String sql = "select * from user";
            String[] param = null;
    
            PreparedStatement ps = conn.prepareStatement(sql);
            if (param != null) { 
                for (int i = 1; i <= param.length; i++) { 
                    ps.setString(i, param[i - 1]);
                }
            }
    
            rs = ps.executeQuery();
            ResultSetMetaData meta = rs.getMetaData();
            int colLength = meta.getColumnCount();
            List<String> colName = new ArrayList<>();
            for (int i = 1; i <= colLength; i++) { 
                colName.add(meta.getColumnName(i));
            }
    
            List<String[]> result = new ArrayList<>();
            String[] colArr;
            while (rs.next()) { 
                colArr = new String[colLength];
                for (int i = 0; i < colLength; i++) { 
                    colArr[i] = rs.getString(colName.get(i));
                }
                result.add(colArr);
            }
            ps.close();
            System.out.println(JSON.toJSONString(result));
        } catch (Throwable e) { 
            e.printStackTrace();
        }
    }

输出

System mutex table already appears to exist, not creating it
    Re-resolved stale table USER with seqNum 0 at timestamp 1563785295742 with 3 columns: [ID, 0.NAME, 0.PASSWD]
    Scan ready for iteration: {"loadColumnFamiliesOnDemand":true,"startRow":"","stopRow":"","batch":-1,"cacheBlocks":true,"totalColumns":1,"maxResultSize":-1,"families":{"0":["ALL"]},"caching":2147483647,"maxVersions":1,"timeRange":[0,9223372036854775807]}
    Iterator ready: org.apache.phoenix.iterate.RoundRobinResultIterator@66de00f2
    Explain plan: CLIENT 1-CHUNK PARALLEL 1-WAY ROUND ROBIN FULL SCAN OVER USER
    Getting iterators for ResultIterators [name=PARALLEL,id=dfeee496-823e-995a-d22a-4395ead54589,scans=[[{"loadColumnFamiliesOnDemand":true,"startRow":"","stopRow":"","batch":-1,"cacheBlocks":true,"totalColumns":3,"maxResultSize":-1,"families":{"0":["\\x00\\x00\\x00\\x00","\\x80\\x0B","\\x80\\x0C"]},"caching":2147483647,"maxVersions":1,"timeRange":[0,9223372036854775807]}]]]
    Id: dfeee496-823e-995a-d22a-4395ead54589, Time: 1ms, Scan: {"loadColumnFamiliesOnDemand":true,"startRow":"","stopRow":"","batch":-1,"cacheBlocks":true,"totalColumns":3,"maxResultSize":-1,"families":{"0":["\\x00\\x00\\x00\\x00","\\x80\\x0B","\\x80\\x0C"]},"caching":2147483647,"maxVersions":1,"timeRange":[0,9223372036854775807]}
    [["1","张三","123456"],["2","李四","111111"],["211","李四","111111"]]
    close........

上面日志中不仅输出了最终结果，还输出了一些中间信息，比如：`3 columns: [ID, 0.NAME, 0.PASSWD]`标识这个表总共有三列，而且列族我们没有设置，默认是`0`。

我们把查询的SQL改为`String sql = "select * from \"test\"";` test表中的数据是不规整的，hbase中存储的数据大多是这样的，Phoenix会将没有数据的列使用null代替。

输出结果：

[["row1","value1",null,null,"12"],
    ["row2","value2a","value2",null,"13"],
    ["row3",null,null,"value3",null]]

[hbase-client 2.1 _ hbase]: https://blog.csdn.net/liubenlong007/article/details/96453098
[20190722165628619.png]: /images/20211129/17db82cb0f53409abeea1fabcb42c47f.png