public class HbaseDemo {
private Configuration conf = null;
@Before
public void init(){
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "lp5,lp6,lp7");
}
/*
* 新建表
*/
@Test
public void create() throws Exception{
//Provides an interface to manage HBase database table metadata + general administrative functions. Use HBaseAdmin to create, drop, list, enable and disable tables. Use it also to add and drop table column families.
//See HTable to add, update, and delete data from an individual table.
//Currently HBaseAdmin instances are not expected to be long-lived. For example, an HBaseAdmin instance will not ride over a Master restart.
//操纵hbase的客户端
HBaseAdmin client = new HBaseAdmin(conf);
//表名
TableName tableName = TableName.valueOf("production");
//表描述
HTableDescriptor htd = new HTableDescriptor(tableName);
//列族描述
HColumnDescriptor base_info = new HColumnDescriptor("base_info");
base_info.setMaxVersions(5);
HColumnDescriptor external_info = new HColumnDescriptor("external_info");
external_info.setMaxVersions(5);
//添加列族
htd.addFamily(base_info);
htd.addFamily(external_info);
//建表
client.createTable(htd);
client.close();
}
/*
* 删除表结构
*/
@Test
public void drop() throws Exception{
HBaseAdmin client = new HBaseAdmin(conf);
client.disableTable("production");
client.deleteTable("production");
client.close();
}
/*
* 向表中添加数据
*/
@Test
public void insert() throws Exception{
//1.这种方法线程不安全
//得到表
HTable table = new HTable(conf, "production");
//指定一行
Put put = new Put(Bytes.toBytes("p_computer_0001"));
//插入值
put.add("base_info".getBytes(),"name".getBytes(),"Hongji".getBytes());
put.add("base_info".getBytes(),"price".getBytes(),"3890".getBytes());
put.add("external_info".getBytes(),"image".getBytes(),"nothing".getBytes());
table.put(put);
table.close();
/*HConnection conn = HConnectionManager.getConnection(conf);
HTableInterface table = conn.getTable("production");
Put put = new Put(Bytes.toBytes("p_computer_0001"));
put.add("base_info".getBytes(),"name".getBytes(),"Apple".getBytes());
table.put(put);
table.close();*/
}
/*
* 删除表中数据
* 但是删除新版本的数据后,旧版本的就顶上来了,咋个办???、、、指定版本即可
*/
@Test
public void delete() throws Exception{
HTable table = new HTable(conf,"production");
//单行删除
Delete del = new Delete(Bytes.toBytes("p_computer_0001"));
del.deleteColumn(Bytes.toBytes("base_info"), Bytes.toBytes("name"));
table.delete(del);
table.close();
}
/*
* 查找数据
*/
@Test
public void get() throws IOException{
HTable table = new HTable(conf,"production");
Get get = new Get(Bytes.toBytes("p_computer_0001"));
get.setMaxVersions(1);//设定要查几个版本的数据
Result result = table.get(get);
List<Cell> cells = result.listCells();
for(KeyValue kv : result.list()){
String family = new String(kv.getFamily());//获取列族
System.out.println(family);
String qualifier = new String(kv.getQualifier());
System.out.println(qualifier);
System.out.println(new String(kv.getValue()));
}
table.close();
}
/*
* 过滤查找数据
*/
@Test
public void scan() throws IOException{
HTable table = new HTable(conf,"production");
Scan scan = new Scan(Bytes.toBytes("p_computer_0001"), Bytes.toBytes("p_computer_0003"));
//前缀过滤器----针对行键
Filter filter = new PrefixFilter(Bytes.toBytes("p"));
//行过滤器
ByteArrayComparable rowComparator = new BinaryComparator(Bytes.toBytes("p_computer_0001"));
RowFilter rf = new RowFilter(CompareOp.LESS_OR_EQUAL, rowComparator);
/**
* 假设rowkey格式为:创建日期_发布日期_ID_TITLE
* 目标:查找 发布日期 为 2014-12-21 的数据
*/
rf = new RowFilter(CompareOp.EQUAL , new SubstringComparator("_2014-12-21_"));
//单值过滤器 1 完整匹配字节数组
new SingleColumnValueFilter("base_info".getBytes(), "name".getBytes(), CompareOp.EQUAL, "zhangsan".getBytes());
//单值过滤器2 匹配正则表达式
ByteArrayComparable comparator = new RegexStringComparator("zhang.");
new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);
//单值过滤器2 匹配是否包含子串,大小写不敏感
comparator = new SubstringComparator("wu");
new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);
//键值对元数据过滤-----family过滤----字节数组完整匹配
FamilyFilter ff = new FamilyFilter(
CompareOp.EQUAL ,
new BinaryComparator(Bytes.toBytes("base_info")) //表中不存在inf列族,过滤结果为空
);
//键值对元数据过滤-----family过滤----字节数组前缀匹配
ff = new FamilyFilter(
CompareOp.EQUAL ,
new BinaryPrefixComparator(Bytes.toBytes("inf")) //表中存在以inf打头的列族info,过滤结果为该列族所有行
);
//键值对元数据过滤-----qualifier过滤----字节数组完整匹配
filter = new QualifierFilter(
CompareOp.EQUAL ,
new BinaryComparator(Bytes.toBytes("na")) //表中不存在na列,过滤结果为空
);
filter = new QualifierFilter(
CompareOp.EQUAL ,
new BinaryPrefixComparator(Bytes.toBytes("na")) //表中存在以na打头的列name,过滤结果为所有行的该列数据
);
//基于列名(即Qualifier)前缀过滤数据的ColumnPrefixFilter
filter = new ColumnPrefixFilter("na".getBytes());
//基于列名(即Qualifier)多个前缀过滤数据的MultipleColumnPrefixFilter
byte[][] prefixes = new byte[][] {Bytes.toBytes("na"), Bytes.toBytes("me")};
filter = new MultipleColumnPrefixFilter(prefixes);
//为查询设置过滤条件
scan.setFilter(filter);
scan.addFamily(Bytes.toBytes("base_info"));
ResultScanner scanner = table.getScanner(scan);
for(Result r : scanner){
/**
for(KeyValue kv : r.list()){
String family = new String(kv.getFamily());
System.out.println(family);
String qualifier = new String(kv.getQualifier());
System.out.println(qualifier);
System.out.println(new String(kv.getValue()));
}
*/
//直接从result中取到某个特定的value
byte[] value = r.getValue(Bytes.toBytes("base_info"), Bytes.toBytes("name"));
System.out.println(new String(value));
}
table.close();
}
}
hbase API操作范例
最新推荐文章于 2025-02-21 14:39:32 发布