Apache
/
hbase
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fixed example code 

Signed-off-by: stack <stack@apache.org>
This commit is contained in:
Lars Francke 2015-04-30 09:37:49 +02:00 committed by stack
parent 1f02fffd04
commit 0dfb364723
1 changed files with 53 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

109
src/main/asciidoc/_chapters/hbase_apis.adoc
View File

@ -36,102 +36,99 @@ See <<external_apis>> for more information.
== Examples
.Create a Table Using Java
.Create, modify and delete a Table Using Java
====
[source,java]
----
package com.example.hbase.admin;
package util;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HConstants;
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.io.compress.Compression.Algorithm;
import org.apache.hadoop.conf.Configuration;
import static com.example.hbase.Constants.*;
public class Example {
public class CreateSchema {
private static final String TABLE_NAME = "MY_TABLE_NAME_TOO";
private static final String CF_DEFAULT = "DEFAULT_COLUMN_FAMILY";
public static void createOrOverwrite(Admin admin, HTableDescriptor table) throws IOException {
if (admin.tableExists(table.getName())) {
admin.disableTable(table.getName());
admin.deleteTable(table.getName());
if (admin.tableExists(table.getTableName())) {
admin.disableTable(table.getTableName());
admin.deleteTable(table.getTableName());
}
admin.createTable(table);
}
public static void createSchemaTables (Configuration config) {
try {
final Admin admin = new Admin(config);
public static void createSchemaTables(Configuration config) throws IOException {
try (Connection connection = ConnectionFactory.createConnection(config);
Admin admin = connection.getAdmin()) {
HTableDescriptor table = new HTableDescriptor(TableName.valueOf(TABLE_NAME));
table.addFamily(new HColumnDescriptor(CF_DEFAULT).setCompressionType(Algorithm.SNAPPY));
System.out.print("Creating table. ");
createOrOverwrite(admin, table);
System.out.println(" Done.");
admin.close();
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}
}
}
----
====
public static void modifySchema (Configuration config) throws IOException {
try (Connection connection = ConnectionFactory.createConnection(config);
Admin admin = connection.getAdmin()) {
.Add, Modify, and Delete a Table
====
TableName tableName = TableName.valueOf(TABLE_NAME);
if (admin.tableExists(tableName)) {
System.out.println("Table does not exist.");
System.exit(-1);
}
[source,java]
----
public static void upgradeFrom0 (Configuration config) {
HTableDescriptor table = new HTableDescriptor(tableName);
try {
final Admin admin = new Admin(config);
TableName tableName = TableName.valueOf(TABLE_ASSETMETA);
HTableDescriptor table_assetmeta = new HTableDescriptor(tableName);
table_assetmeta.addFamily(new HColumnDescriptor(CF_DEFAULT).setCompressionType(Algorithm.SNAPPY));
// Update existing table
HColumnDescriptor newColumn = new HColumnDescriptor("NEWCF");
newColumn.setCompactionCompressionType(Algorithm.GZ);
newColumn.setMaxVersions(HConstants.ALL_VERSIONS);
admin.addColumn(tableName, newColumn);
// Create a new table.
// Update existing column family
HColumnDescriptor existingColumn = new HColumnDescriptor(CF_DEFAULT);
existingColumn.setCompactionCompressionType(Algorithm.GZ);
existingColumn.setMaxVersions(HConstants.ALL_VERSIONS);
table.modifyFamily(existingColumn);
admin.modifyTable(tableName, table);
System.out.print("Creating table_assetmeta. ");
admin.createTable(table_assetmeta);
System.out.println(" Done.");
// Disable an existing table
admin.disableTable(tableName);
// Update existing table
HColumnDescriptor newColumn = new HColumnDescriptor("NEWCF");
newColumn.setCompactionCompressionType(Algorithm.GZ);
newColumn.setMaxVersions(HConstants.ALL_VERSIONS);
admin.addColumn(tableName, newColumn);
// Delete an existing column family
admin.deleteColumn(tableName, CF_DEFAULT.getBytes("UTF-8"));
// Update existing column family
HColumnDescriptor existingColumn = new HColumnDescriptor(CF_DEFAULT);
existingColumn.setCompactionCompressionType(Algorithm.GZ);
existingColumn.setMaxVersions(HConstants.ALL_VERSIONS);
table_assetmeta.modifyFamily(existingColumn)
admin.modifyTable(tableName, table_assetmeta);
// Delete a table (Need to be disabled first)
admin.deleteTable(tableName);
}
}
// Disable an existing table
admin.disableTable(tableName);
public static void main(String... args) throws IOException {
Configuration config = HBaseConfiguration.create();
// Delete an existing column family
admin.deleteColumn(tableName, CF_DEFAULT);
// Delete a table (Need to be disabled first)
admin.deleteTable(tableName);
admin.close();
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
//Add any necessary configuration files (hbase-site.xml, core-site.xml)
config.addResource(new Path(System.getenv("HBASE_CONF_DIR"), "hbase-site.xml"));
config.addResource(new Path(System.getenv("HADOOP_CONF_DIR"), "core-site.xml"));
createSchemaTables(config);
modifySchema(config);
}
}
----