HBaseAPI操作看这一章就够了

前言:

API介绍

HBase Java类	HBase数据模型
HBaseAdmin	数据库(DataBase)
HBaseConfiguration
HTable	Table
HTableDescriptor	列族
Put	列标识符
Get

介绍相关的类:

类	描述
HBaseConfiguration	完成对HBase的配置，主要设置一些相关属性
HBaseAdmin	用于管理Hbase数据库的表信息，用于操作DDL
HTableDescriptor	用于描述表的相关信息，例如可以获取表的名字，添加列族
HTable	可以用于直接操作表，但是对于更新操作是非线程安全的。
Put	执行插入数据操作的
Get	用于获取行的相关信息。

一、环境准备

这里基于IDEA去实行开发，所以我们只需要导入依赖

<dependencies>
    <dependency>
        
        <groupId>org.apache.hbasegroupId>
        <artifactId>hbase-serverartifactId>
        <version>1.3.1version>
    dependency>

    
    <dependency>
        <groupId>org.apache.hbasegroupId>
        <artifactId>hbase-clientartifactId>
        <version>1.3.1version>
    dependency>
dependencies>

二、HbaseAPI基本操作

抽取对象 避免多次创建对象 影响程序的效率

//获取Configuration对象
 private static Configuration conf;
 private static Connection connection;
 private static Admin admin; //该对象用于操作和管理以及访问表

 static{
     //创建Configuration对象
     conf = HBaseConfiguration.create();
     conf.set("hbase.zookeeper.quorum", "master,slave1,slave2");
     try {
         connection = ConnectionFactory.createConnection(conf);
         admin = connection.getAdmin();
     } catch (IOException e) {
         e.printStackTrace();
     }
 }

①判断表是否存在

 public static boolean isTableExist(String tableName) throws IOException {
        //2.执行对应的操作
        boolean flag = admin.tableExists(TableName.valueOf(tableName));

        return flag;
    }

②创建表

/**
 * 创建表
 * @param tableName 表名
 * @param columnFamily 列族名 可以有若干个这里使用可变形参
 */
public static void createTable(String tableName,String... columnFamily){
    try {
        //1.判断表是否存在
        if (isTableExist(tableName)){
            System.out.println("表已经存在了");
            return;
        }
        //2.不存在该表 去创建表
        HTableDescriptor descriptor = new HTableDescriptor(TableName.valueOf(tableName));

        //创建多个列族
        for (String cf : columnFamily){
            descriptor.addFamily(new HColumnDescriptor(cf));
        }

        //3.创建表
        admin.createTable(descriptor);
        System.out.println("表:" + tableName + "创建成功");
    } catch (IOException e) {
        e.printStackTrace();
    }

}

③删除表

/**
 * 删除表
 * @param tableName
 * @throws IOException
 */
public static void dropTable(String  tableName) throws IOException {
    //1.表不存在情况下
    if (!isTableExist(tableName)){
        System.out.println(tableName + "表不存在!!");
        return;
    }
    //2.删除表操作 在shell交互式命令下 删除操作的步骤:
    //a.先禁用表 b.再删除
    //2.1禁用表
    admin.disableTable(TableName.valueOf(tableName));
    //2.2删除表
    admin.deleteTable(TableName.valueOf(tableName));
    System.out.println(tableName + "表删除成功!!!");
}

④创建命名空间

   public static void createNameSpace(String nameSpace){
        try{
            //1.创建命名空间描述器
            NamespaceDescriptor build = NamespaceDescriptor.create(nameSpace).build();
            admin.createNamespace(build);
            System.out.println(nameSpace + "命名空间创建成功!!");
        }catch (NamespaceExistException e){ //创建同一个命名空间 抛出的异常 在这捕捉
            System.out.println("命名空间已存在!!!");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

⑤插入数据

/**
 * 添加数据
 * @param tableName
 * @param rowKey
 * @param columnFamily
 * @param column
 * @param value
 */
public static void putData(String tableName,String rowKey,String columnFamily,String column,String value){
    try {
        //1.创建HTable对象
        HTable table = new HTable(conf,tableName);

        //2 向表中插入数据
        Put put = new Put(Bytes.toBytes(rowKey));
        //2.1
        put.addColumn(Bytes.toBytes(columnFamily),Bytes.toBytes(column),Bytes.toBytes(value));

        //3.完成插入操作
        table.put(put);
        System.out.println("数据插入成功!!!");



    } catch (IOException e) {
        e.printStackTrace();
    }
}

⑥批量插入数据

//1.批量插入数据
    public static void putMoreData(String tableName,String[] rowKey,String[] columnFamily,String[] columnQualifier,String[] value) throws IOException {
        //1.先判断表是否存在
        if (!admin.tableExists(TableName.valueOf(tableName))){
            System.out.println(tableName + "表不存在");
            return;
        }
        //2.获取表对象
        Table table = connection.getTable(TableName.valueOf(tableName));
        int length = rowKey.length;
        //3.创建List集合存放Put对象
        List<Put> putList = new ArrayList<Put>();
        for (int i = 0; i < length; i++){
            Put put = new Put(Bytes.toBytes(rowKey[i]));
            put.addColumn(Bytes.toBytes(columnFamily[i]),Bytes.toBytes(columnQualifier[i]),
                    Bytes.toBytes(value[i]));
            putList.add(put);

        }
        //4.批量插入数据
        table.put(putList);
        table.close();

        System.out.println("插入数据成功");
    }
    public static void main(String[] args) throws IOException {
        putMoreData("stu3",new String[]{"1001","1002"},
                new String[]{"info","info"},new String[]{"name","age"},
                new String[]{"zhangsan","18"});
    }
}

⑦删除数据

 /**
     * 删除数据 根据传入 行键 列族 列标识符 来删除数据
     * shell : delete 'tableName' 'rowKey' '列族'
     * @param tableName
     */
    public static void delete(String tableName,String rowKey,String columnFamily,String qualifier) throws IOException {
        if (!admin.tableExists(TableName.valueOf(tableName))){
            System.out.println(tableName + "不存在");
            return;
        }

        //1.创建表的操作对象 Table HTable
        HTable table = new HTable(configuration,TableName.valueOf(tableName));

        //2.创建Delete对象 (构建对象)
        Delete delete = new Delete(Bytes.toBytes(rowKey));
        delete.addColumn(Bytes.toBytes(columnFamily),Bytes.toBytes(qualifier));

        //3.删除
        table.delete(delete);
        System.out.println("删除成功...");
    }

⑧批量删除

 public static void deleteMultiRow(String tableName,String... rowKey) throws IOException {
        //1.获取表操作对象
        HTable table = new HTable(configuration, TableName.valueOf(tableName));

        //2.创建List集合 存储Delete待删除的元素
        List<Delete> deleteList = new ArrayList<Delete>();

        //表不存在不执行删除操作
        if (!admin.tableExists(TableName.valueOf(tableName))){
            System.out.println(tableName + "该表不存在");
            return;
        }

        //3.构建Delete对象
        for (String row : rowKey){
            Delete delete = new Delete(Bytes.toBytes(row));
            deleteList.add(delete);
        }
        //4.执行删除
        table.delete(deleteList);
        table.close();
        System.out.println("删除成功");
    }

⑨释放资源

   public static void close(){
        if (admin != null){
            try {
                admin.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        if (connection != null){
            try {
                connection.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

三、测试上述方法

public static void main(String[] args) throws IOException {
      //1.测试表是否存在
        boolean flag = isTableExists("stu");
        System.out.println(flag);

        //2.创建表
        //createTable("test:stu3","info1","info2");

        //3.删除表测试
        //deleteTable("stu3");

        //4.创建命名空间
        //createNameSpace("test");

        //5.插入数据
       // putData("test:stu3","0001","info1","name","lisi");

        //6.获取数据
       // getData("test:stu3","0001","info1","name");

        //7.scan扫描全表
       // scanTable("test:stu3");

        //8.插入数据
        //putData("stu3","1001","info","name","lisi");

        //9.删除多行数据
        //deleteMultiRow("test:stu3","1003","1002");
        //关闭资源

        //10删除数据
        delete("stu3","1001","info","sex");
        close();
}