使用HBase java api创建名为“patients”的HBase表,并导入数据集patients1.csv,导入前先创建列族 “demographics”、“anthropometry”和“medical_history”及列限定符,详见下表
时间: 2024-10-13 19:17:58 浏览: 54
在HBase中使用Java API创建表并导入CSV数据,首先你需要做的是设置好项目依赖,确保已经添加了HBase的Java客户端库。以下是创建名为“patients”的表以及指定列族的步骤:
1. **创建表**:
```java
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.TableDescriptor;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
// 创建连接
Connection connection = ConnectionFactory.createConnection();
TableDescriptor descriptor = new TableDescriptor(TableName.valueOf("patients"));
// 定义列族
HColumnDescriptor demographicsCF = new HColumnDescriptor("demographics");
HColumnDescriptor anthropometryCF = new HColumnDescriptor("anthropometry");
HColumnDescriptor medicalHistoryCF = new HColumnDescriptor("medical_history");
// 设置列族属性(如列限定符)
// 这里假设列限定符没有特殊配置,通常不需要显式设置
demographicsCF.setScope(HRegion Scope.CATALOG);
anthropometryCF.setScope(HRegion.Scope.CATALOG);
medicalHistoryCF.setScope(HRegion.Scope.CATALOG);
// 添加列族到表描述符
descriptor.addFamily(demographicsCF);
descriptor.addFamily(anthropometryCF);
descriptor.addFamily(medicalHistoryCF);
// 创建表
connection.createTable(descriptor);
```
2. **导入CSV数据**:
```java
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.MapWritable;
import org.apache.hadoop.hbase.mapreduce.LoadIncrementalHFiles;
import org.apache.hadoop.mapreduce.Job;
Configuration config = connection.getConfiguration();
config.set("hbase.rootdir", "your_hbase_directory"); // 设置HBase根目录
Path inputPath = new Path("path/to/patients1.csv");
Job loadJob = Job.getInstance(config, "ImportPatientsData");
loadJob.setJarByClass(LoadIncrementalHFiles.class);
loadJob.setInputFormatClass(TextDelimitedInputFormat.class);
TextDelimitedInputFormat.configureInputFormat(loadJob, inputPath, "\t"); // 如果CSV文件是以逗号分隔的
loadJob.setOutputKeyClass(MapWritable.class); // 默认输出键值对
loadJob.setOutputValueClass(byte[].class);
LoadIncrementalHFiles.setInputTableName(loadJob, "patients"); // 表名
// 执行导入任务
try {
boolean success = loadJob.waitForCompletion(true);
if (!success) {
System.err.println("Failed to import data.");
} else {
System.out.println("Data imported successfully.");
}
} catch (Exception e) {
e.printStackTrace();
}
```
记得将`your_hbase_directory`替换为实际的HBase根目录,`path/to/patients1.csv`替换为CSV文件的实际路径。
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