本篇博客,小菌为大家带来HBase的进阶使用,关于基础入门操作大家可以去阅览小菌之前的博客《HBase的JavaAPI使用–基础篇》。
在展示代码之前先为大家介绍一下过滤器,同时它也是我们这篇博客介绍的主角。
过滤器的类型很多，但是可以分为两大类——比较过滤器，专用过滤器 过滤器的作用是在服务端判断数据是否满足条件，然后只将满足条件的数据返回给客户端；
hbase过滤器的比较运算符：
LESS < LESS_OR_EQUAL <= EQUAL = NOT_EQUAL <> GREATER_OR_EQUAL >= GREATER > NO_OP 排除所有
Hbase过滤器的专用过滤器（指定比较机制）：
BinaryComparator 按字节索引顺序比较指定字节数组，采用Bytes.compareTo(byte[]) BinaryPrefixComparator 跟前面相同，只是比较左端的数据是否相同 NullComparator 判断给定的是否为空 BitComparator 按位比较 RegexStringComparator 提供一个正则的比较器，仅支持 EQUAL 和非EQUAL SubstringComparator 判断提供的子串是否出现在value中。
接下来正式上我们的代码!
一、比较过滤器
1、rowKey过滤器RowFilter
通过RowFilter过滤比rowKey 0003小的所有值出来
代码语言：javascript复制/**
* hbase 行键过滤器 RowFilter
* [通过RowFilter过滤 比rowKey 0003小的所有值出来]
* @throws Exception
*/
@Test
public void rowKeyFilter() throws Exception{
// 连接 数据库
Configuration conf = new Configuration();
conf.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(conf);
//读取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
Scan scan = new Scan();
//创建一个过滤器,并将其添加至scan对象 <=
RowFilter rowFilter = new RowFilter(LESS, new BinaryComparator(Bytes.toBytes("0003")));
scan.setFilter(rowFilter);
// scanner 为 行数据result的集合
ResultScanner scanner = mytest1.getScanner(scan);
for (Result result : scanner) {
// 获取 rowkey
System.out.println("rowkey:" Bytes.toString(result.getRow()));
// 指定列族以及列 打印 列 当中的数据出来
System.out.println("id:" Bytes.toInt(result.getValue("f1".getBytes(),"id".getBytes())));
System.out.println("age:" Bytes.toInt(result.getValue("f1".getBytes(),"age".getBytes())));
System.out.println("name:" Bytes.toString(result.getValue("f1".getBytes(),"name".getBytes())));
}
mytest1.close();
connection.close();
}2、列族过滤器FamilyFilter
查询比f2列族小的所有的列族内的数据
代码语言：javascript复制 /**
* 列族过滤器 FamilyFilter
* [查询比f2列族小的所有的列族内的数据]
* @throws Exception
*/
@Test
public void familyFilter() throws Exception{
// 获取连接
Configuration conf = new Configuration();
conf.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(conf);
// 获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
Scan scan = new Scan();
// 创建一个过滤器并添置给scan对象
FamilyFilter familyFilter = new FamilyFilter(LESS, new BinaryComparator("f2".getBytes()));
scan.setFilter(familyFilter);
ResultScanner resultScanner = mytest1.getScanner(scan);
for (Result result : resultScanner) {
// 获取rowkey
System.out.println(Bytes.toString(result.getRow()));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(),"name".getBytes())));
}
mytest1.close();
connection.close();
}3、列过滤器QualifierFilter
只查询name列的值</font
代码语言：javascript复制 /**
* hbase 列过滤器
* [只查询name列]
* @throws Exception
*/
@Test
public void qualifier() throws Exception{
// 获取连接
Configuration conf = new Configuration();
conf.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(conf);
// 获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//全表扫描
Scan scan = new Scan();
QualifierFilter qualifierFilter = new QualifierFilter(EQUAL, new SubstringComparator("name"));
scan.setFilter(qualifierFilter);
ResultScanner scanner = mytest1.getScanner(scan);
//result 是一行数据
for (Result result : scanner) {
// 获取 rowkey
System.out.println(Bytes.toString(result.getRow()));
// 指定列族 以及列打印当中的数据
System.out.println(Bytes.toString(result.getValue("f1".getBytes(),"id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(),"name".getBytes())));
}
// 关闭资源
mytest1.close();
connection.close();
}4、列值过滤器ValueFilter
查询所有列当中包含8的数据
代码语言：javascript复制 /**
* 列值过滤器ValueFilter
* [查询所有列当中包含8的数据]
* @throws Exception
*/
@Test
public void valueFilter()throws Exception {
// 获取连接
Configuration conf = new Configuration();
conf.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(conf);
// 获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//全表扫描
Scan scan = new Scan();
ValueFilter valueFilter = new ValueFilter(EQUAL, new SubstringComparator("30"));
scan.setFilter(valueFilter);
ResultScanner scanner = mytest1.getScanner(scan);
for (Result result : scanner) {
// 获取 rowkey
System.out.println(Bytes.toString(result.getRow()));
//指定列族 以及 列打印当中的数据出来
//System.out.println(Bytes.toInt(result.getValue("f1".getBytes(),"id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f2".getBytes(),"phone".getBytes())));
}
// 关闭资源
mytest1.close();
connection.close();
}二、专用过滤器
1、单列值过滤器 SingleColumnValueFilter
SingleColumnValueFilter会返回满足条件的整列值的所有字段
代码语言：javascript复制/**
* 单列值过滤器，返回满足条件的整行数据
*/
@Test
public void singleColumnFilter() throws IOException {
//获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
Table myuser = connection.getTable(TableName.valueOf("myuser"));
Scan scan = new Scan();
SingleColumnValueFilter singleColumnValueFilter = new SingleColumnValueFilter("f1".getBytes(), "name".getBytes(), CompareFilter.CompareOp.EQUAL, "刘备".getBytes());
scan.setFilter(singleColumnValueFilter);
ResultScanner resultScanner = myuser.getScanner(scan);
for (Result result : resultScanner) {
//获取rowkey
System.out.println(Bytes.toString(result.getRow()));
//指定列族以及列打印列当中的数据出来
System.out.println(Bytes.toInt(result.getValue("f1".getBytes(), "id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(), "name".getBytes())));
System.out.println(Bytes.toString(result.getValue("f2".getBytes(), "phone".getBytes())));
}
myuser.close();
}2、列值排除过滤器SingleColumnValueExcludeFilter
与SingleColumnValueFilter相反，会排除掉指定的列，其他的列全部返回。
3.rowkey前缀过滤器PrefixFilter
查询以00开头的所有前缀的rowkey
代码语言：javascript复制 /**
* rowkey前缀过滤器PrefixFilter
* [查询以00开头的所有前缀的rowkey]
*
* @throws IOException
*/
@Test
public void preFilter() throws IOException{
//获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
//获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//扫描全表
Scan scan = new Scan();
PrefixFilter prefixFilter = new PrefixFilter("00".getBytes());
scan.setFilter(prefixFilter);
ResultScanner resultScanner = mytest1.getScanner(scan);
// result 代表一行数据
for (Result result : resultScanner) {
// 获取rowkey
System.out.println(Bytes.toString(result.getRow()));
//指定列族以及列打印列当中的数据出来
System.out.println(Bytes.toInt(result.getValue("f1".getBytes(),"id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(),"name".getBytes())));
System.out.println(Bytes.toString(result.getValue("f2".getBytes(),"phone".getBytes())));
}
mytest1.close();
connection.close();
}4、分页过滤器PageFilter
通过pageFilter实现分页过滤器
代码语言：javascript复制/**
* 分页过滤器PageFilter
* [通过pageFilter实现分页过滤器]
* @throws IOException
*/
@Test
public void pageFilter2() throws IOException {
// 获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum", "node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
// 获取表
Table myuser = connection.getTable(TableName.valueOf("mytest1"));
int pageNum = 3;
int pageSize = 2;
Scan scan = new Scan();
if (pageNum == 1) {
PageFilter filter = new PageFilter(pageSize);
scan.setStartRow(Bytes.toBytes(""));
scan.setFilter(filter);
scan.setMaxResultSize(pageSize);
ResultScanner scanner = myuser.getScanner(scan);
for (Result result : scanner) {
//获取rowkey
System.out.println(Bytes.toString(result.getRow()));
//指定列族以及列打印列当中的数据出来
// System.out.println(Bytes.toInt(result.getValue("f1".getBytes(), "id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(), "name".getBytes())));
//System.out.println(Bytes.toString(result.getValue("f2".getBytes(), "phone".getBytes())));
}
}else{
String startRowKey ="";
PageFilter filter = new PageFilter((pageNum - 1) * pageSize 1 );
scan.setStartRow(startRowKey.getBytes());
scan.setMaxResultSize((pageNum - 1) * pageSize 1);
scan.setFilter(filter);
ResultScanner scanner = myuser.getScanner(scan);
for (Result result : scanner) {
byte[] row = result.getRow();
startRowKey = new String(row);
}
Scan scan2 = new Scan();
scan2.setStartRow(startRowKey.getBytes());
scan2.setMaxResultSize(Long.valueOf(pageSize));
PageFilter filter2 = new PageFilter(pageSize);
scan2.setFilter(filter2);
ResultScanner scanner1 = myuser.getScanner(scan2);
for (Result result : scanner1) {
byte[] row = result.getRow();
System.out.println(new String(row));
}
}
myuser.close();
connection.close();
}三、多过滤器综合查询FilterList
需求：使用SingleColumnValueFilter查询f1列族，name为刘备的数据，并且同时满足rowkey的前缀以00开头的数据（PrefixFilter）
代码语言：javascript复制/**
* 多过滤器综合查询FilterList
* 需求：使用SingleColumnValueFilter查询f1列族，name为刘备的数据，并且同时满足rowkey的前缀以00开头的数据（PrefixFilter）
* @throws Exception
*/
@Test
public void manyFilter() throws Exception{
//获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
//获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//扫描全表
Scan scan = new Scan();
FilterList filterList = new FilterList();
// 单列过滤
SingleColumnValueFilter singleColumnValueFilter = new SingleColumnValueFilter("f1".getBytes(), "name".getBytes(), EQUAL, "刘备".getBytes());
// rowkey 前缀过滤
PrefixFilter prefixFilter = new PrefixFilter("00".getBytes());
filterList.addFilter(singleColumnValueFilter);
filterList.addFilter(prefixFilter);
// 设置过滤
scan.setFilter(filterList);
ResultScanner scanner = mytest1.getScanner(scan);
for (Result result : scanner) {
//获取rowkey
System.out.println(Bytes.toString(result.getRow()));
//指定列族以及列 打印当中的数据出来
System.out.println(Bytes.toInt(result.getValue("f1".getBytes(),"id".getBytes())));
System.out.println(Bytes.toString(result.getValue("f1".getBytes(),"name".getBytes())));
System.out.println(Bytes.toString(result.getValue("f2".getBytes(),"phone".getBytes())));
}
mytest1.close();
connection.close();
}好了到这里,关于过滤器的使用就到这里了,接下来要为大家展示如何调用API删除表数据和表!
四.删除数据
根据rowkey删除数据
代码语言：javascript复制/**
* 根据rowkey删除数据
* @throws Exception
*/
@Test
public void deleteByRowKey() throws Exception{
//获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
//获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//根据RowKey 确定需要删除掉的行
Delete delete = new Delete("0001".getBytes());
mytest1.delete(delete);
//关闭连接
mytest1.close();
connection.close();
}五.删除表
删除指定的数据表
代码语言：javascript复制 @Test
public void deleteTable() throws Exception{
//获取连接
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","node01:2181,node02:2181,node03:2181");
Connection connection = ConnectionFactory.createConnection(configuration);
//获取表
Table mytest1 = connection.getTable(TableName.valueOf("mytest1"));
//创建一个管理员对象
Admin admin = connection.getAdmin();
admin.disableTable(TableName.valueOf("myuser"));
admin.deleteTable(TableName.valueOf("myuser"));
// 关闭资源
admin.close();
mytest1.close();
connection.close();
}这里需要注意一下,在删除数据表之前一定要先禁用数据表
好了,看到这里也很不容易,给热爱学习的你们点个赞!
话说回来,上面的所有代码小菌都亲测过没问题的！有疑惑的小伙伴们可以私信我哟(＾Ｕ＾)ノ~ＹＯ
本次的分享就到这里了,受益的小伙伴们,不要忘了点赞关注小菌٩(๑❛ᴗ❛๑)۶
