前面已经给大家讲解过如何使用Hbase建表,以及基本的操作和一些常用shell命令,今天就给大家介绍下如何使用java对Hbase进行各种操作。
没印象的话可以再去浏览下:
Hbase入门教程,shell命令大全讲解
Java操作Hbase主要方法:
1.Configuration
在使用Java API时,Client端需要知道HBase的配置环境,如存储地址,zookeeper等信息。
这些信息通过Configuration对象来封装,可通过如下代码构建该对象:
Configuration config = HBaseConfiguration.create();
在调用HBaseConfiguration.create()方法时,HBase首先会在classpath下查找hbase-site.xml文件,将里面的信息解析出来封装到Configuration对象中,如果hbase-site.xml文件不存在,则使用默认的hbase-core.xml文件。
2.HBaseAdmin
HBaseAdmin用于创建数据库表格,并管理表格的元数据信息,通过如下方法构建:
HBaseAdmin admin=new HBaseAdmin(config);
3.HTableDescriptor
在HTableDescriptor中,建立了一个表结构,HTableDescriptor封装表格对象,对表格的增删改查操作主要通过它来完成,构造方法如下:
HTableDescriptor table = new HTableDescriptor(TableName.valueOf(“表名”));
4.addFamily
addFamily用于建立表下的列簇,并存放到表结构,方法如下:
HColumnDescriptor base = new HColumnDescriptor(“列簇名”);
table.addFamily(base);
代码如下:
首先建一个maven工程,导入依赖包导pom.xml
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<dependency> <groupId>org.apache.hbase</groupId> <artifactId>hbase-client</artifactId> <version> 1.2 . 0 </version> </dependency> <dependency> <groupId>org.apache.hbase</groupId> <artifactId>hbase-common</artifactId> <version> 1.2 . 0 </version> </dependency> <dependency> <groupId>org.apache.hbase</groupId> <artifactId>hbase-server</artifactId> <version> 1.2 . 0 </version> </dependency |
1、创建表操作
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public class HBaseClient { public void createTable() throws IOException { // 1. 创建配置 Configuration conf = HBaseConfiguration.create(); conf.set( "hbase.zookeeper.quorum" , "ip1" ); //hbase主默认端口是60000 conf.set( "hbase.master" , "ip1:60000" ); //zookeeper客户端的端口号2181 conf.set( "hbase.zookeeper.property.clientPort" , "2181" ); // 2. 创建连接 Connection conn = ConnectionFactory.createConnection(conf); //3.获得一个建表、删表的对象hbaseAdmin()是继承admin() Admin admin = conn.getAdmin(); // 4. 创建表的描述信息 HTableDescriptor student = new HTableDescriptor(TableName.valueOf( "表名" )); // 5. 添加列簇 student.addFamily( new HColumnDescriptor( "列簇名1" )); student.addFamily( new HColumnDescriptor( "列簇名2" )); // 6. 调用API进行建表操作 admin.createTable(student); } } |
2、判断表是否存在
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public void isTableExists() throws IOException { // 1. 创建配置 Configuration conf = HBaseConfiguration.create(); conf.set( "hbase.zookeeper.quorum" , "ip1" ); conf.set( "hbase.zookeeper.property.clientPort" , "2181" ); // 2. 创建连接 Connection conn = ConnectionFactory.createConnection(conf); // 3. 创建admin Admin admin = conn.getAdmin(); // 4. 调用API进行判断表是否存在 System.out.println(admin.tableExists(TableName.valueOf( "表名" ))); } |
3、向表中插入数据
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public void putData2Table() throws IOException { // 1. 创建配置 Configuration conf = HBaseConfiguration.create(); conf.set( "hbase.zookeeper.quorum" , "ip1" ); conf.set( "hbase.zookeeper.property.clientPort" , "2181" ); // 2. 创建连接 Connection conn = ConnectionFactory.createConnection(conf); // 3. 创建Table类 Table student = conn.getTable(TableName.valueOf( "表名" )); // 4. 创建Put类 Put put = new Put(Bytes.toBytes( "1001" )); // 5. 向Put中添加 列簇,列名,值 注意:需要转化成字节数组 put.addColumn(Bytes.toBytes( "列簇1" ),Bytes.toBytes( "列1" ),Bytes.toBytes( "zhangsan" )); put.addColumn(Bytes.toBytes( "列簇1" ),Bytes.toBytes( "列2" ),Bytes.toBytes( "female" )); put.addColumn(Bytes.toBytes( "列簇2" ),Bytes.toBytes( "列3" ),Bytes.toBytes( "math" )); put.addColumn(Bytes.toBytes( "列簇2" ),Bytes.toBytes( "列4" ),Bytes.toBytes( "89" )); // 6.调用API进行插入数据 student.put(put); } |
4、查看一条数据
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public void getDataFromTable() throws IOException { // 1. 创建配置 Configuration conf = HBaseConfiguration.create(); conf.set( "hbase.zookeeper.quorum" , "ip1" ); conf.set( "hbase.zookeeper.property.clientPort" , "2181" ); // 2. 创建连接 Connection conn = ConnectionFactory.createConnection(conf); // 3. 创建Table类 Table student = conn.getTable(TableName.valueOf( "表名" )); // 4. 创建 Get 类 Get get = new Get(Bytes.toBytes( "1001" )); // 5.调用API进行获取数据 Result result = student.get(get); // 6. 将返回的结果进行遍历输出 Cell[] cells = result.rawCells(); for (Cell cell : cells) { System.out.println( "rowkey :" +Bytes.toString(CellUtil.cloneRow(cell))); System.out.println( "列簇 :" +Bytes.toString(CellUtil.cloneFamily(cell))); System.out.println( "列名 :" +Bytes.toString(CellUtil.cloneQualifier(cell))); System.out.println( "值 :" +Bytes.toString(CellUtil.cloneValue(cell))); System.out.println( "----------------" ); } } |
5、删除表操作
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public void dropTable() throws IOException { // 1. 创建配置 Configuration conf = HBaseConfiguration.create(); conf.set( "hbase.zookeeper.quorum" , "ip1" ); conf.set( "hbase.zookeeper.property.clientPort" , "2181" ); // 2. 创建连接 Connection conn = ConnectionFactory.createConnection(conf); // 3. 创建admin Admin admin = conn.getAdmin(); // 4. 调用API禁用表 admin.disableTable(TableName.valueOf( "表名" )); // 5. 调用API删除表 admin.deleteTable(TableName.valueOf( "表名" )); } } |
6、删除hbase中的table里面的rowkey
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public static void deleteRow(String tableName,String rowKey) throws Exception{ HTable hTable = new HTable(configuration,tableName); Delete delete = new Delete(rowKey.getBytes()); List<Delete> list = new ArrayList<Delete>(); list.add(delete); hTable.delete(list); } |
7、查询row = rowKey的数据
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public static void getRow(String tableName,String rowKey) throws Exception{ HTable hTable = new HTable(configuration, tableName); Get get = new Get(rowKey.getBytes()); Result result = hTable.get(get); for (KeyValue value:result.raw()){ System.out.println( "cf:" + new String(value.getFamily())+ new String(value.getQualifier())+ "=" + new String(value.getValue())); } } |
8、查询rowkey在startRow和endRow之间的数据,及rowkey的范围查询
Put、Delete与Get对象都是Row的子类,从该继承关系中我们就可以了解到Get、Delete与Pu对象本身就只能进行单行的操作,
HBase客户端还提供了一套能够进行全表扫描的API,方便用户能够快速对整张表进行扫描,以获取想要的结果—scan:
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public static void getBetweenRow(String tableName,String startRow,String stopRow) throws Exception{ HTable table = new HTable(configuration, tableName); Scan scan = new Scan(); scan.addColumn( "cf1" .getBytes(), "colum1" .getBytes()); scan.addColumn( "cf1" .getBytes(), "colum2" .getBytes()); scan.addColumn( "cf1" .getBytes(), "colum3" .getBytes()); scan.setStartRow(startRow.getBytes()); scan.setStopRow(stopRow.getBytes()); ResultScanner scanner = table.getScanner(scan); for (Result result:scanner){ for (KeyValue value:result.raw()){ System.out.println( "cf:" + new String(value.getFamily())+ new String(value.getQualifier())+ "=" + new String(value.getValue())); } } } |
9、批量写入
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public <T> void puts(String tableName, Map<String, Object> items) { if (items == null || items.isEmpty()) { LOG.error( "[HBase] Adding null/empty item map!" ); return ; } int maxSize = 10000 ; Table table = null ; try { table = con.getTable(TableName.valueOf(tableName)); int eachSize = Math.min(maxSize, items.size()); List<Put> puts = new ArrayList<Put>(eachSize); int handled = 0 ; for (Entry<String, Object> entry : items.entrySet()) { String ultimateRowKey = getHashedID(entry.getKey()); Object value = entry.getValue(); if (ultimateRowKey == null || ultimateRowKey.isEmpty()) { LOG.error( "[HBase] Adding null/empty hashed key! Original key is " + entry.getKey()); handled++; continue ; } Put put = new Put(Bytes.toBytes(ultimateRowKey)); put.addColumn(Bytes.toBytes(familyName1), Bytes.toBytes( "ab" ), Bytes.toBytes(value .getAb())); put.addColumn(Bytes.toBytes(familyName1), Bytes.toBytes( "dt" ), Bytes.toBytes(value .getDt())); put.addColumn(Bytes.toBytes(familyName1), Bytes.toBytes( "hb" ), Bytes.toBytes(value .getHb())); Gson gson = new Gson(); String valuestr = gson.toJson(value); put.addColumn(Bytes.toBytes(familyName2), Bytes.toBytes( "js" ), Bytes.toBytes(valuestr)); puts.add(put); handled++; // 每隔10000,写一次 if (handled == eachSize) { LOG.info( "[HBase] Adding " + eachSize + "rows!" ); table.put(puts); puts = new ArrayList<Put>(eachSize); } } if (puts.size() > 0 ) table.put(puts); } catch (IOException e) { LOG.error( "[HBase] Error while putting data " + e.getMessage()); } finally { try { if (table != null ) table.close(); } catch (IOException e) { LOG.error( "[HBase] Error while closing table " + e.getMessage()); } } } |
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原文链接:https://blog.csdn.net/zp17834994071/article/details/107501922