• linux 下通过过 hbase 的Java api 操作hbase


    hbase版本:0.98.5

    hadoop版本:1.2.1

    使用自带的zk

    本文的内容是在集群中创建java项目调用api来操作hbase,主要涉及对hbase的创建表格,删除表格,插入数据,删除数据,查询一条数据,查询所有数据等操作。

    具体流程如下:
    1.创建项目
    2.获取jar包到项目的lib目录下(这边试用的事hbase 0.98 lib目录下的所有jar包)
    3.编写java程序
    4.编写ant脚本

    package test2;
    import java.util.ArrayList;
    import java.util.List;
    
    import org.apache.hadoop.fs.Path;
    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.Delete;
    import org.apache.hadoop.hbase.client.Get;
    import org.apache.hadoop.hbase.client.HBaseAdmin;
    import org.apache.hadoop.hbase.client.HConnection;
    import org.apache.hadoop.hbase.client.HConnectionManager;
    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;
    
    public class TestHBase {
        
        private HBaseAdmin admin = null;
        private Configuration conf = null;
        
        public TestHBase() throws Exception
        {
            conf = HBaseConfiguration.create();
           conf.addResource(new Path("/home/work/hbase_dev/test2/lib/hbase-site.xml"));
            //conf.set("hbase.zookeeper.quorum", "10.57.90.19");
            //conf.set("hbase.zookeeper.property.clientPort", "2181");
            admin = new HBaseAdmin(conf);
        }
        
        public void createTable (String tableName , String[] columnFamily) throws Exception
        {
            if (admin.tableExists(tableName))
            {
                System.out.println(tableName + "已存在");
                return ;
                //System.exit(0);
            }
            
            HTableDescriptor tableDescriptor = new HTableDescriptor(TableName.valueOf(tableName));
            
            for (String colunm : columnFamily)
            {
                tableDescriptor.addFamily(new HColumnDescriptor(colunm));
            }
            
            admin.createTable(tableDescriptor);
            System.out.println("Create table successfully..");
        }
        
        public boolean deleteTable (String tableName)
        {
            try {
                if(admin.tableExists(tableName))
                {
                    admin.disableTable(tableName);
                    admin.deleteTable(tableName);
                    System.out.println("drop table " + tableName);
                }
                return true;
            } catch (Exception e) {
                System.out.println("删除" + tableName + "失败");
                return false;
            }
        }
        
        public List getAllTables()
        {
            List<String> tables = null;
            if (admin != null)
            {
                try{
                    HTableDescriptor[] allTables = admin.listTables();
                    if(allTables.length > 0)
                    {
                        tables = new ArrayList<String>();
                    }
                    
                    for (HTableDescriptor tableDesc : allTables)
                    {
                        tables.add(tableDesc.getNameAsString());
                        System.out.println(tableDesc.getNameAsString());
                    }
                }catch(Exception ex)
                {
                    ex.printStackTrace();
                }
            }
            
            return tables;
        }
        
        public boolean addOneRecord (String tableName , String key , String family , String column 
                , byte[] dataIn) throws Exception
        {
            HConnection connection = HConnectionManager.createConnection(conf);
            //HTable table = new HTable(hbaseConf, tableName);
            HTable table = (HTable)connection.getTable(tableName);
            Put put = new Put(key.getBytes());
            put.add(family.getBytes(), column.getBytes(), dataIn);
            try {
                table.put(put);
                System.out.println("插入数据条 " + key + "成功");
                return true;
            } catch (Exception e) {
                // TODO: handle exception
                System.out.println("插入数据条 " + key + "失败");
                return false;
            }
        }
        
        public void getValueFromKey (String tableName , String key)
        {
            try{
                HConnection conn = HConnectionManager.createConnection(conf);
                HTable table = (HTable) conn.getTable(tableName);
                Get get = new Get(key.getBytes());
                Result rs = table.get(get);
                if (rs.rawCells().length == 0)
                {
                    System.out.println("不存在关键字为" + key + "的行...");
                }
                else
                {
                    for (Cell cell : rs.rawCells())
                    {
                        System.out.println(new String(CellUtil.cloneFamily(cell)) + 
                                "  " + new String(CellUtil.cloneQualifier(cell)) + "  " + new String(CellUtil.cloneValue(cell)));
                    }
                }
            }
            catch(Exception ex)
            {
                System.out.println("查询失败");
                ex.printStackTrace();
            }
        }
        
        
        
        public void getAllData(String tableName) throws Exception
        {
            HConnection conn = HConnectionManager.createConnection(conf);
            HTable table = (HTable) conn.getTable(tableName);
            Scan scan = new Scan();
            ResultScanner rs = table.getScanner(scan);
            for (Result result : rs)
            {
                for (Cell cell : result.rawCells())
                {
                    System.out.println("RowName: " + new String(CellUtil.cloneRow(cell)) + " ");
                    System.out.println("Timetamp: " + cell.getTimestamp() + " ");
                    System.out.println("Column family: " + new String(CellUtil.cloneFamily(cell)) + " ");
                    System.out.println("row name: " + new String(CellUtil.cloneQualifier(cell)) + " ");
                    System.out.println("value: " + new String(CellUtil.cloneValue(cell)) + " ");
                }
            }
        }
        
        public void deleteRecord(String tableName , String key)
        {
            try
            {
                HConnection conn = HConnectionManager.createConnection(conf);
                HTable table = (HTable)conn.getTable(tableName);
                Delete delete = new Delete(key.getBytes());
                
                table.delete(delete);
                System.out.println("删除" + key +"成功...");
            }
            catch(Exception ex)
            {
                System.out.println("删除数据失败...");
                ex.printStackTrace();
            }
        }
        
    
        public static void main(String[] args) throws Exception{
            // TODO Auto-generated method stub
            String[] column = {"family1" , "family2"};
            try {
                TestHBase hbase = new TestHBase();
                hbase.deleteTable("students");
                hbase.createTable("students", column);
                //hbase.getAllData("scores");
                hbase.addOneRecord("students", "id1", "family1", "name", "Jack".getBytes());
                hbase.addOneRecord("students", "id1", "family1", "grade", "gaosan".getBytes());
                //hbase.getAllTables();
                //hbase.getAllData("students");
                hbase.getValueFromKey("students", "id1");
                hbase.deleteRecord("students", "id1");
                hbase.addOneRecord("students", "id2", "family1", "name", "Holen".getBytes());
                hbase.getValueFromKey("students", "id2");
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
            }
            
            
            
        }
    
    }

    ant脚本

    <?xml version="1.0"?>  
    <project name="HBaseProject" default="run" basedir=".">  
        <property name="src.dir" value="src" />  
        <property name="report.dir" value="report" />  
        <property name="classes.dir" value="classes" />  
        <property name="lib.dir" value="lib" />  
        <property name="dist.dir" value="dist" />  
        <property name="doc.dir" value="doc"/>  
        <path id="master-classpath">  
            <fileset file="${lib.dir}/*.jar" />  
            <pathelement path="${classes.dir}"/>  
        </path>  
    
        <path id="run.path">  
            <path path="${classes.dir}"/>
            <path refid="master-classpath" />
        </path> 
        <target name="init" depends="clean">
            <mkdir dir="${classes.dir}"/>
            <mkdir dir="${dist.dir}"/>
        </target>  
        <target name="compile" depends="init" description="compile the source files">  
    
            <javac srcdir="${src.dir}" destdir="${classes.dir}" target="1.6" includeantruntime="false">  
                <classpath refid="master-classpath"/>  
            </javac>  
        </target>  
    
        <target name="run" depends="compile">
            <java classname="test2.TestHBase" classpathref="run.path" fork="true" >
            </java>
        </target>
    
        <target name="pack" depends="compile" description="make .jar file">  
            <mkdir dir="${dist.dir}" />  
            <jar destfile="${dist.dir}/hbaseproject.jar" basedir="${classes.dir}">  
                <exclude name="**/*Test.*" />  
                <exclude name="**/Test*.*" />  
            </jar>  
        </target> 
    
    
        <target name="clean" description="clean the project">
            <delete dir="${classes.dir}"></delete>
            <delete dir="${dist.dir}"></delete>
        </target>
    </project>

    最后把项目放在集群中,进入项目的根目录,执行命令:ant run

    即可运行!

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  • 原文地址:https://www.cnblogs.com/zlingh/p/3936284.html
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