【HBase】JAVA API操作HBase
文章目录
- JAVA API 操作HBase
- 1 连接到HBase的服务
- 2 抽取工具类
- 3 写一个测试的模板类
- 4 Namespace的CRUD
- 4.1 list_namespace
- 4.2 create_namespace
- 4.3 list_namespace_tables
- 4.4 修改namespace
- 4.5 删除namespace
- 5 Table的CRUD
- 5.1 建表
- 5.2 查询表中所有列簇
- 5.3 修改表
- 5.4 删除表中的列簇
- 5.5 修改列簇的属性
- 5.6 删除表
- 6 Table的DML操作
- 6.1 HBaseUtils
- 6.2 Put
- 6.3 Get
JAVA API 操作HBase
1 连接到HBase的服务
- 导入依赖
org.apache.hbase
hbase-client
1.2.1
- 配置客户端的系统中的hosts
192.168.49.100 cdh1
192.168.49.101 cdh2
192.168.49.102 cdh3
192.168.49.103 cdh4
- 测试连接HBase的服务
@Test
public void test() throws IOException {
//1. 创建配置对象，指定zookeeper集群的地址
Configuration configuration = new Configuration();
configuration.set("hbase.zookeeper.quorum", "cdh2:2181,cdh3:2181,cdh4:2181");
//2. 获取连接对象
HBaseAdmin hBaseAdmin = new HBaseAdmin(configuration);
//3. 测试
boolean b = hBaseAdmin.tableExists("t1");
System.out.println(b);
//4. 释放资源
hBaseAdmin.close();
}
2 抽取工具类
public class HBaseUtils {
private final static String KEY = "hbase.zookeeper.quorum";
private final static String VALUE = "cdh2:2181,cdh3:2181,cdh4:2181";
private static Configuration configuration;
static {
//1. 创建配置对象
configuration = HBaseConfiguration.create();
configuration.set(KEY, VALUE);
}
public static Admin getAdmin() {
try {
Connection connection = ConnectionFactory.createConnection(configuration);
Admin admin = connection.getAdmin();
return admin;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public static void close(Admin admin) {
try {
if(admin != null) admin.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
3 写一个测试的模板类
public class Demo2_Namespace {
private HBaseAdmin admin;
@Before
public void before() {
admin = (HBaseAdmin) HBaseUtils.getAdmin();
}
@Test
public void createNamespace() {
}
@After
public void after() {
HBaseUtils.close(admin);
}
}
4 Namespace的CRUD
alter_namespace,
create_namespace,
describe_namespace,
drop_namespace,
list_namespace,
list_namespace_tables
4.1 list_namespace
@Test
public void listNamespace() throws IOException {
//1. 获取到namespace的数组
NamespaceDescriptor[] namespaceDescriptors = admin.listNamespaceDescriptors();
//2. 打印namespace
for(NamespaceDescriptor namespaceDescriptor : namespaceDescriptors) {
System.out.println(namespaceDescriptor.getName());
}
}
4.2 create_namespace
@Test
public void createNamespace() throws IOException {
//1. 创建NamespaceDescriptor
NamespaceDescriptor ns1Descriptor = NamespaceDescriptor.create("ns1").build();
ns1Descriptor.setConfiguration("name", "lixi");
//2. 添加到admin
admin.createNamespace(ns1Descriptor);
}
4.3 list_namespace_tables
@Test
public void listNamespaceTables1() throws IOException {
//1. 查询指定的namespace中有多少表
TableName[] tableNames = admin.listTableNamesByNamespace("hbase");
//2. 遍历
for(TableName tableName:tableNames) {
System.out.println(tableName.getNameAsString());
}
}
@Test
public void listNamespaceTables2() throws IOException {
//1. 查询指定的namespace中有多少表
HTableDescriptor[] tableDescriptors = admin.listTableDescriptorsByNamespace("hbase");
//2. 遍历
for(HTableDescriptor tableDescriptor:tableDescriptors) {
System.out.println(tableDescriptor.getNameAsString());
}
}
4.4 修改namespace
@Test
public void alterNamespaceTables() throws IOException {
//1. 获取到namespace的数组
NamespaceDescriptor ns1Descriptor = admin.getNamespaceDescriptor("ns1");
//2. 打印namespace
ns1Descriptor.setConfiguration("name", "lee");
//3. 提交修改
admin.modifyNamespace(ns1Descriptor);
}
4.5 删除namespace
@Test
public void dropNamespace() throws IOException {
admin.deleteNamespace("ns1");
}
5 Table的CRUD
5.1 建表
@Test
public void createTable() throws IOException {
//1.创建表的表述器对象
HTableDescriptor tableDescriptor = new HTableDescriptor(TableName.valueOf("t1"));
//2. 创建列簇的描述器
HColumnDescriptor familyColumn = new HColumnDescriptor("f1");
//3.添加列簇
tableDescriptor.addFamily(familyColumn);
//4.提交表的描述器从而建表
admin.createTable(tableDescriptor);
}
5.2 查询表中所有列簇
@Test
public void listTableColumnFamilies() throws IOException {
//1. 获取到表的描述器
HTableDescriptor user_info = admin.getTableDescriptor(TableName.valueOf("user_info"));
//2. 获取到列簇信息
HColumnDescriptor[] columnFamilies = user_info.getColumnFamilies();
//3. 遍历
for(HColumnDescriptor columnFamily : columnFamilies) {
System.out.println(columnFamily.getNameAsString());
}
}
5.3 修改表
@Test
public void alterTable1() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
HTableDescriptor user_info = new HTableDescriptor(tableName);
//2. 获取到列簇信息
HColumnDescriptor familyColumn1 = new HColumnDescriptor("lixi_info");
user_info.addFamily(familyColumn1);
//3. 提交修改
admin.modifyTable(tableName, user_info);
}
tip: 以上例子，不是很好的修改案例，因为它会将表的列簇都删除，然后再添加新的列簇。因为我们是直接创建的一个新的表的描述器。
@Test
public void alterTable2() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
HTableDescriptor user_info = admin.getTableDescriptor(tableName);
//2. 获取到列簇信息
HColumnDescriptor familyColumn1 = new HColumnDescriptor("base_info");
user_info.addFamily(familyColumn1);
//3. 提交修改
admin.modifyTable(tableName, user_info);
}
tip: 正确的修改业务逻辑，应该先将原表的信息查询出来，然后再原表的基础之上进行数据的修改。
5.4 删除表中的列簇
@Test
public void deleteColumnFamily1() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
HTableDescriptor user_info = admin.getTableDescriptor(tableName);
//2. 删除列簇
user_info.removeFamily(Bytes.toBytes("lixi_info"));
//3. 提交修改
admin.modifyTable(tableName, user_info);
}
@Test
public void deleteColumnFamily2() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
//2. 提交删除
admin.deleteColumn(tableName, Bytes.toBytes("rock_info"));
}
5.5 修改列簇的属性
@Test
public void modifyColumnFamily() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
//2. 列簇
HColumnDescriptor familyColumn1 = new HColumnDescriptor("base_info");
//2. 提交删除
admin.modifyColumn(tableName, familyColumn1);
}
5.6 删除表
@Test
public void deleteTable() throws IOException {
//1. 获取到表的描述器
TableName tableName = TableName.valueOf("user_info");
//2. 处理表是否失效
if(!admin.isTableDisabled(tableName)) {
admin.disableTable(tableName);
}
//3. 删除表
admin.deleteTable(tableName);
}
6 Table的DML操作
6.1 HBaseUtils
public class HBaseUtils {
private final static String KEY = "hbase.zookeeper.quorum";
private final static String VALUE = "cdh2:2181,cdh3:2181,cdh4:2181";
private static Configuration configuration;
static {
//1. 创建配置对象
configuration = HBaseConfiguration.create();
configuration.set(KEY, VALUE);
}
public static Admin getAdmin() {
try {
Connection connection = ConnectionFactory.createConnection(configuration);
Admin admin = connection.getAdmin();
return admin;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public static Table getTable() {
return getTable("user_info");
}
public static Table getTable(String tablename) {
try {
Connection connection = ConnectionFactory.createConnection(configuration);
return connection.getTable(TableName.valueOf(tablename));
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public static void close(Admin admin) {
try {
if(admin != null) admin.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void close(Table table) {
try {
if(table != null) table.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void close(Admin admin, Table table) {
close(admin);
close(table);
}
}
6.2 Put
/**
* put 'ns1:t1', 'r1', 'c1', 'value'
*/
@Test
public void put1() throws IOException {
//1. 创建Put对象
Put put = new Put(Bytes.toBytes("001"));
//2. 添加列数据
put.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("name"), Bytes.toBytes("lixi"));
//3. 插入一条记录
table.put(put);
}
@Test
public void put2() throws IOException {
//1. 创建Put对象
Put put1 = new Put(Bytes.toBytes("002"));
Put put2 = new Put(Bytes.toBytes("003"));
//2. 添加列数据
put1.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("name"), Bytes.toBytes("lixi"));
put2.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("name"), Bytes.toBytes("lixi"));
List plist = new ArrayList<>();
plist.add(put1);
plist.add(put2);
//3. 插入一条记录
table.put(plist);
}
6.3 Get
- 通过行键查询指定的列簇的信息
@Test
public void get1() throws IOException {
//1. 创建get对象
Get get = new Get(Bytes.toBytes("001"));
//2. 查询数据，返回结果对象
Result result = table.get(get);
//3. 查询指定列簇
NavigableMap navigableMap = result.getFamilyMap(Bytes.toBytes("base_info"));
//4. 遍历
Set> entries = navigableMap.entrySet();
for(Map.Entry entry : entries) {
System.out.println(new String(entry.getKey()) +"--->" + new String(entry.getValue()) );
}
}
- get查询二
@Test
public void get2() throws IOException {
//1. 创建get对象
Get get = new Get(Bytes.toBytes("001"));
//2. 查询数据，返回结果对象
Result result = table.get(get);
//3. 获取cell的扫描器
CellScanner cellScanner = result.cellScanner();
//4. 遍历扫描器
while(cellScanner.advance()) {
//5. 获取单词扫描的Cell
Cell cell = cellScanner.current();
System.out.println(new String(cell.getFamilyArray(),cell.getFamilyOffset(), cell.getFamilyLength())); // 列簇
System.out.println(new String(cell.getQualifierArray(), cell.getQualifierOffset(), cell.getQualifierLength())); // 列名
System.out.println(new String(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength())); // 列值
}
- get查询三
@Test
public void get3() throws IOException {
//1. 创建get对象
Get get = new Get(Bytes.toBytes("001"));
//2. 查询数据，返回结果对象
Result result = table.get(get);
//3. 获取cell的扫描器
CellScanner cellScanner = result.cellScanner();
//4. 遍历扫描器
while(cellScanner.advance()) {
//5. 获取单词扫描的Cell
Cell cell = cellScanner.current();
System.out.println(new String(CellUtil.cloneRow(cell)));
System.out.println(new String(CellUtil.cloneFamily(cell))); // 列簇
System.out.println(new String(CellUtil.cloneQualifier(cell))); // 列名
System.out.println(new String(CellUtil.cloneValue(cell))); // 列值
}
}
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