使用hive客户端java api读写hive集群上的信息

上文介绍了hdfs集群信息的读取方式，本文说hive

1、先解决依赖

<properties>
        <hive.version>1.2.1</hive.version>
    </properties>
<dependency>
            <groupId>org.apache.hive</groupId>
            <artifactId>hive-exec</artifactId>
            <version>${hive.version}</version>
            <scope>provided</scope>
        </dependency>

2、配置文件

这里我们给出一种简单的配置方法，就是直接将hive-site.xml通过添加文件的方式加载到配置

例如，hive-site.xml中的配置如下

<configuration>
    <property>
        <name>hive.metastore.uris</name>
        <value>thrift://10.91.64.23:9083,thrift://10.91.64.23:9083,thrift://10.91.64.23:9083</value>
    </property>
</configuration>

3、hive client api

说明：

1、hiveConf.addResource("hive-site.xml") 可以直接把配置文件加载到配置

2、hive的api很丰富，下面只介绍了其中一部分，如果用到其他再进行封装即可

package com.xiaoju.dqa.prometheus.client.hive;

import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.IMetaStoreClient;
import org.apache.hadoop.hive.metastore.RetryingMetaStoreClient;
import org.apache.hadoop.hive.metastore.api.Database;
import org.apache.hadoop.hive.metastore.api.FieldSchema;
import org.apache.hadoop.hive.metastore.api.MetaException;
import org.apache.thrift.TException;
import org.slf4j.Logger;

import java.util.List;

public class HiveClient {
    protected final Logger logger = org.slf4j.LoggerFactory.getLogger(this.getClass());
    IMetaStoreClient client;

    public HiveClient() {
        try {
            HiveConf hiveConf = new HiveConf();
            hiveConf.addResource("hive-site.xml");
            client = RetryingMetaStoreClient.getProxy(hiveConf);
        } catch (MetaException ex) {
            logger.error(ex.getMessage());
        }
    }

    public List<String> getAllDatabases() {
        List<String> databases = null;
        try {
            databases = client.getAllDatabases();
        } catch (TException ex) {
            logger.error(ex.getMessage());
        }
        return databases;
    }

    public Database getDatabase(String db) {
        Database database = null;
        try {
            database = client.getDatabase(db);
        } catch (TException ex) {
            logger.error(ex.getMessage());
        }
        return database;
    }

    public List<FieldSchema> getSchema(String db, String table) {
        List<FieldSchema> schema = null;
        try {
            schema = client.getSchema(db, table);
        } catch (TException ex) {
            logger.error(ex.getMessage());
        }
        return schema;
    }

    public List<String> getAllTables(String db) {
        List<String> tables = null;
        try {
            tables = client.getAllTables(db);
        } catch (TException ex) {
            logger.error(ex.getMessage());
        }
        return tables;
    }

    public String getLocation(String db, String table) {
        String location = null;
        try {
            location = client.getTable(db, table).getSd().getLocation();
        }catch (TException ex) {
            logger.error(ex.getMessage());
        }
        return location;
    }

}