HBase Learning (12) Java API and HBase Interactive instance

HBase provides access to the Java API, which is as important as JDBC when using RDBMS with Java applications

Import Java.io.ioexception;import Org.apache.hadoop.conf.configuration;import Org.apache.hadoop.hbase.hbaseconfiguration;import Org.apache.hadoop.hbase.hcolumndescriptor;import Org.apache.hadoop.hbase.htabledescriptor;import Org.apache.hadoop.hbase.keyvalue;import Org.apache.hadoop.hbase.client.delete;import Org.apache.hadoop.hbase.client.get;import Org.apache.hadoop.hbase.client.hbaseadmin;import Org.apache.hadoop.hbase.client.htable;import Org.apache.hadoop.hbase.client.htablepool;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.util.bytes;public class HBase {//declares statically configured static    Configuration conf = null;        static {conf = Hbaseconfiguration.create ();    Conf.set ("Hbase.zookeeper.quorum", "localhost"); }/* * CREATE TABLE * * @tableName table name * * @family column Family list */public static void CREAttable (String tableName, string[] family) throws Exception {hbaseadmin admin = new hbaseadmin (conf);        Htabledescriptor desc = new Htabledescriptor (tableName);        for (int i = 0; i < family.length; i++) {desc.addfamily (new Hcolumndescriptor (Family[i]));            } if (Admin.tableexists (TableName)) {System.out.println ("table exists!");        System.exit (0);            } else {admin.createtable (desc);        SYSTEM.OUT.PRINTLN ("CREATE Table success!"); }/* * Add data to the table (for fixed tables that know how many column families are) * * @rowKey rowKey * * @tableName table name * * @column1 first column Family List * * @value1 the list of values for the first column * * @column2 second column family list * * @value2 a list of values for the second column */public static VO ID addData (String rowKey, String tableName, string[] column1, string[] value1, string[] column2, string[] Value 2) throws IOException {put put = new put (Bytes.tobytes (RowKey));//Set RowKey        htable table = new htable (conf, bytes.tobytes (tableName));//Htabel responsible for record-related operations such as additions and deletions, etc. Get table hcolumndescriptor[] columnfamilies = Table.gettabledescriptor ()//Get        All the column families. Getcolumnfamilies (); for (int i = 0; i < columnfamilies.length; i++) {String familyname = columnfamilies[i].getnameasstring (); /Gets the column family name if (familyname.equals ("article")) {//Article column family put data for (int j = 0; J < Column1.len Gth J + +) {Put.add (Bytes.tobytes (familyname), Bytes.tobytes (Column1[j]), BYTES.T                Obytes (Value1[j])); }} if (Familyname.equals ("author")) {//Author column family put data for (int j = 0; J < column 2.length; J + +) {Put.add (Bytes.tobytes (familyname), Bytes.tobytes (Column2[j]), BYTES.T                Obytes (Value2[j]));          }  }} table.put (Put);    SYSTEM.OUT.PRINTLN ("Add Data success!"); }/* * Based on rwokey query * * @rowKey rowKey * * @tableName table name */public static Result GetResult (S        Tring TableName, String RowKey) throws IOException {Get get = new Get (Bytes.tobytes (RowKey));        htable table = new htable (conf, bytes.tobytes (tableName));//Get table result = Table.get (get);            For (KeyValue kv:result.list ()) {System.out.println ("family:" + bytes.tostring (kv.getfamily ()));            System.out. println ("qualifier:" + bytes.tostring (Kv.getqualifier ()));            System.out.println ("Value:" + bytes.tostring (Kv.getvalue ()));            System.out.println ("Timestamp:" + kv.gettimestamp ());        System.out.println ("-------------------------------------------");    } return result; }/* * Traversal query hbase table * * @tableName table name */public static void Getresultscann (StRing TableName) throws IOException {Scan scan = new scan ();        Resultscanner rs = null;        htable table = new htable (conf, bytes.tobytes (tableName));            try {rs = Table.getscanner (scan); for (Result r:rs) {KeyValue kv:r.list ()) {System.out.println ("row:" + bytes.t                    Ostring (Kv.getrow ()));                    System.out.println ("Family:" + bytes.tostring (kv.getfamily ()));                    System.out.println ("qualifier:" + bytes.tostring (Kv.getqualifier ()));                    System.out. println ("value:" + bytes.tostring (Kv.getvalue ()));                    System.out.println ("timestamp:" + kv.gettimestamp ());                System.out. println ("-------------------------------------------");        }}} finally {Rs.close (); }}/* * Traverse query HBase table * * @tableName table name */public static void Getresultscann (String tableName, String Start_rowkey,        String Stop_rowkey) throws IOException {Scan scan = new scan ();        Scan.setstartrow (Bytes.tobytes (Start_rowkey));        Scan.setstoprow (Bytes.tobytes (Stop_rowkey));        Resultscanner rs = null;        htable table = new htable (conf, bytes.tobytes (tableName));            try {rs = Table.getscanner (scan); for (Result r:rs) {KeyValue kv:r.list ()) {System.out.println ("row:" + bytes.t                    Ostring (Kv.getrow ()));                    System.out.println ("Family:" + bytes.tostring (kv.getfamily ()));                    System.out.println ("qualifier:" + bytes.tostring (Kv.getqualifier ()));                    System.out. println ("value:" + bytes.tostring (Kv.getvalue ())); System.out.println ("Timestamp:" +Kv.gettimestamp ());                System.out. println ("-------------------------------------------");        }}} finally {Rs.close (); }/* * Query a column in the table * * @tableName table name * * @rowKey RowKey */public static void GETRESULTB Ycolumn (String tableName, String RowKey, String familyname, String columnName) throws IOException {Htab        Le table = new htable (conf, bytes.tobytes (tableName));        Get get = new Get (Bytes.tobytes (RowKey)); Get.addcolumn (Bytes.tobytes (familyname), Bytes.tobytes (ColumnName));        Gets the column that corresponds to the specified column family and column modifier, result = Table.get (get);            For (KeyValue kv:result.list ()) {System.out.println ("family:" + bytes.tostring (kv.getfamily ()));            System.out. println ("qualifier:" + bytes.tostring (Kv.getqualifier ()));            System.out.println ("Value:" + bytes.tostring (Kv.getvalue ())); SyStem.out.println ("Timestamp:" + kv.gettimestamp ());        System.out.println ("-------------------------------------------");      }/* * Update a column in the table * * @tableName table name * * @rowKey rowKey * * @familyName column Family name *            * @columnName Column Name * * @value Updated value */public static void UpdateTable (String tableName, String RowKey, String familyname, String columnName, String value) throws IOException {htable table = new HTABL        E (Conf, bytes.tobytes (tableName));        Put put = new put (Bytes.tobytes (RowKey));        Put.add (Bytes.tobytes (familyname), Bytes.tobytes (ColumnName), bytes.tobytes (value));        Table.put (Put);    SYSTEM.OUT.PRINTLN ("Update table success!");  * * * Query Multiple versions of a column of data * * @tableName table name * * @rowKey rowKey * * @familyName Column Family name * *          @columnName Column name */public static void Getresultbyversion (String tableName, String RowKey,  String familyname, String columnName) throws IOException {htable table = new htable (conf, bytes.tobytes (Tablenam        e));        Get get = new Get (Bytes.tobytes (RowKey));        Get.addcolumn (Bytes.tobytes (familyname), Bytes.tobytes (ColumnName));        Get.setmaxversions (5);        Result result = Table.get (get);            For (KeyValue kv:result.list ()) {System.out.println ("family:" + bytes.tostring (kv.getfamily ()));            System.out. println ("qualifier:" + bytes.tostring (Kv.getqualifier ()));            System.out.println ("Value:" + bytes.tostring (Kv.getvalue ()));            System.out.println ("Timestamp:" + kv.gettimestamp ());        System.out.println ("-------------------------------------------"); }/* * list<?> results = table.get (GET). List (); iterator<?> it = * Results.iterator ();         while (It.hasnext ()) {* SYSTEM.OUT.PRINTLN (It.next (). toString ());}    */}/* Delete the specified column * * @tableName Table name * * @rowKey rowKey * * @familyName Column Family name * * @columnName Column name * * Pub Lic static void DeleteColumn (String tableName, String RowKey, String falilyname, String columnName) throws Ioex        ception {htable table = new htable (conf, bytes.tobytes (tableName));        Delete DeleteColumn = new Delete (Bytes.tobytes (RowKey));        Deletecolumn.deletecolumns (Bytes.tobytes (Falilyname), Bytes.tobytes (ColumnName));        Table.delete (DeleteColumn);    System.out.println (Falilyname + ":" + ColumnName + "is deleted!");}  /* * Delete the specified column * * @tableName table name * * @rowKey RowKey */public static void Deleteallcolumn (String TableName, String RowKey) throws IOException {htable table = new htable (conf, bytes.tobytes (TABLENAME)        );        Delete DeleteAll = new Delete (Bytes.tobytes (RowKey));        Table.delete (DELETEALL); System.out.println ("All columns is deleted!");   }/* * Delete table * * @tableName table name */public static void Deletetable (String tableName) throws Ioexcept        Ion {hbaseadmin admin = new hbaseadmin (conf);        Admin.disabletable (TableName);        Admin.deletetable (TableName);    System.out.println (TableName + "is deleted!");        } public static void Main (string[] args) throws Exception {//create TABLE String tableName = "BLOG2";        String[] Family = {"article", "Author"};        Creattable (TableName, family);        Add data to the table string[] Column1 = {"title", "Content", "tag"}; String[] value1 = {"Head first HBase", "HBase is the Hadoop database."        Use it if you need random, realtime Read/write access to your Big Data. "," Hadoop,hbase,nosql "};        String[] Column2 = {"Name", "nickname"};        String[] value2 = {"Nicholas", "Lee"};        AddData ("Rowkey1", "blog2", Column1, Value1, Column2, value2); AddData ("Rowkey2", "Blog2", Column1, Value1, Column2, value2);        AddData ("Rowkey3", "blog2", Column1, Value1, Column2, value2);        Traverse Query Getresultscann ("Blog2", "Rowkey4", "Rowkey5");        Traverse Query Getresultscann ("Blog2", "Rowkey4", "Rowkey5") according to the row key range;        Query GetResult ("Blog2", "rowkey1");        Query the value of a column getresultbycolumn ("Blog2", "Rowkey1", "author", "Name");        Update column updateTable ("Blog2", "Rowkey1", "author", "Name", "Bin");        Query the value of a column getresultbycolumn ("Blog2", "Rowkey1", "author", "Name");        Querying multiple versions of a column getresultbyversion ("Blog2", "Rowkey1", "author", "Name");        Delete a column of DeleteColumn ("Blog2", "Rowkey1", "Author", "nickname");        Delete all Columns Deleteallcolumn ("Blog2", "rowkey1");    Delete Table deletetable ("blog2"); }}

HBase Learning (12) Java API and HBase Interactive instance