4.HBase_基礎應用Java API
阿新 • • 發佈：2018-11-06
使用Java呼叫HBase的常用操作。首先，新建一個Maven專案，匯入HBase依賴，編寫Java操作HBase的工具包。
1.新建Maven專案，匯入HBase相關依賴
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.lv</groupId> <artifactId>hbase-study</artifactId> <version>0.0.1-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.apache.hadoop</groupId> <artifactId>hadoop-hdfs</artifactId> <version>2.7.4</version> </dependency> <dependency> <groupId>org.apache.hbase</groupId> <artifactId>hbase-client</artifactId> <version>1.1.2</version> </dependency> <dependency> <groupId>jdk.tools</groupId> <artifactId>jdk.tools</artifactId> <version>1.7</version> <scope>system</scope> <systemPath>${JAVA_HOME}/lib/tools.jar</systemPath> </dependency> </dependencies> <build> <finalName>hbase-study</finalName> <plugins> <plugin> <artifactId>maven-assembly-plugin</artifactId> <configuration> <descriptorRefs> <descriptorRef>jar-with-dependencies</descriptorRef> </descriptorRefs> </configuration> <executions> <execution> <id>make-assembly</id> <phase>package</phase> <goals> <goal>assembly</goal> </goals> </execution> </executions> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.2</version> <configuration> <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> </plugins> </build> </project>
2.編寫程式碼
package cn.lv; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.Cell; import org.apache.hadoop.hbase.CellUtil; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.HColumnDescriptor; import org.apache.hadoop.hbase.HTableDescriptor; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.client.Admin; import org.apache.hadoop.hbase.client.Connection; import org.apache.hadoop.hbase.client.ConnectionFactory; import org.apache.hadoop.hbase.client.Delete; import org.apache.hadoop.hbase.client.Get; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.client.Put; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.client.Table; import org.apache.hadoop.hbase.util.Bytes; import org.apache.log4j.Logger; @SuppressWarnings("all") public class HBaseOperationUtil { /** * 1.配置檔案 2.會話連線 3.管理物件 */ private static Logger logger = Logger.getLogger(HBaseOperationUtil.class); private static Configuration conf = null; private static Connection conn = null; private static Admin admin = null; /** * 初始化 */ static { try { conf = HBaseConfiguration.create(); conn = ConnectionFactory.createConnection(conf); admin = conn.getAdmin(); logger.info("init complete successfully!"); } catch (IOException e) { logger.error("init error" + e.getMessage()); } } /** * 建立表 * * @param tb * @param cf * @throws IOException */ public static void createHTable(String tb, String cf) throws IOException { TableName tableName = TableName.valueOf(tb); if (!admin.tableExists(tableName)) { HTableDescriptor desc = new HTableDescriptor(tableName); HColumnDescriptor family = new HColumnDescriptor(cf); desc.addFamily(family); admin.createTable(desc); logger.info(tb + " create success!"); } else { logger.warn(tb + " is already exists!"); } } /** * 刪除表 * * @param tb * @throws IOException */ public static void deleteTable(String tb) throws IOException { TableName tableName = TableName.valueOf(tb); admin.deleteTable(tableName); logger.info(tb + " delete success!"); } /** * 插入資料 * * @param tb * @param rowKey * @param family * @param column * @param value * @throws IOException */ public static void put(String tb, String rowKey, String family, String column, String value) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Put put = new Put(Bytes.toBytes(rowKey)); put.add(Bytes.toBytes(family), Bytes.toBytes(column), Bytes.toBytes(value)); table.put(put); table.close(); logger.info("put table " + tb + " data success!"); } /** * 查詢資料 * * @param tb * @param rowKey * @param family * @param qualifier * @return * @throws IOException */ public static String get(String tb, String rowKey, String family, String qualifier) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Get get = new Get(Bytes.toBytes(rowKey)); get.addFamily(Bytes.toBytes(family)); get.addColumn(Bytes.toBytes(family), Bytes.toBytes(qualifier)); Result result = table.get(get); return Bytes.toString(result.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier))); } /** * 範圍掃描 * * @param tb * @param startRow * @param endRow * @param family * @param qualifier * @return * @throws IOException */ public static List<String> scan(String tb, String startRow, String endRow, String family, String qualifier) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Scan scan = new Scan(); scan.setStartRow(Bytes.toBytes(startRow)); scan.setStopRow(Bytes.toBytes(endRow)); scan.addFamily(Bytes.toBytes(family)); scan.addColumn(Bytes.toBytes(family), Bytes.toBytes(qualifier)); ResultScanner result = table.getScanner(scan); List<String> list = new ArrayList<String>(); for (Result r : result) { list.add(Bytes.toString(r.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier)))); } return list; } /** * 條件查詢 * * @param tb * @param family * @param qualifier * @return * @throws IOException */ public static List<String> scan(String tb, String family, String qualifier) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Scan scan = new Scan(); scan.addFamily(Bytes.toBytes(family)); scan.addColumn(Bytes.toBytes(family), Bytes.toBytes(qualifier)); ResultScanner result = table.getScanner(scan); List<String> list = new ArrayList<String>(); for (Result r : result) { list.add(Bytes.toString(r.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier)))); } return list; } /** * 全表掃描 * * @param tb * @return * @throws IOException */ public static List<String> scan(String tb) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Scan scan = new Scan(); ResultScanner result = table.getScanner(scan); List<String> list = new ArrayList<String>(); for (Result r : result) { List<Cell> cells = r.listCells(); for (Cell cell : cells) { StringBuilder sb = new StringBuilder(); sb.append("rowKey:").append(Bytes.toString(CellUtil.cloneRow(cell))).append("\t"); sb.append("family:").append(Bytes.toString(CellUtil.cloneFamily(cell))).append(","); sb.append("qualifier:").append(Bytes.toString(CellUtil.cloneQualifier(cell))).append("="); sb.append("value:").append(Bytes.toString(CellUtil.cloneValue(cell))); list.add(sb.toString()); } } return list; } /** * 刪除資料 * * @param tb * @param rowKey * @param family * @param qualifier * @throws IOException */ public static void delete(String tb, String rowKey, String family, String qualifier) throws IOException { Table table = conn.getTable(TableName.valueOf(tb)); Delete delete = new Delete(Bytes.toBytes(rowKey)); delete.addColumn(family.getBytes(), qualifier.getBytes()); table.delete(delete); } /** * 關閉 * * @throws IOException */ public static void close() throws IOException { admin.close(); conn.close(); } public static void main(String[] args) throws IOException { // 插入資料 put("lv:emp", "10002", "info", "name", "lisi"); put("lv:emp", "10002", "info", "age", "22"); // 查詢資料,只取name List<String> list = scan("lv:emp", "info", "name"); // 刪除資料,刪除10001的age列 delete("lv:emp", "10001", "info", "age"); } }