已在本地idea上连接上虚拟机的Hadoop,用idea编写一个Driver类,配置MapReduce作业的输入路径、输出路径、Mapper类、Reducer类等参数,并将作业自动提交到Hadoop并运行
时间: 2024-03-19 17:44:25 浏览: 14
好的,我可以为您提供一份Java代码示例,帮助您完成这个任务。请按照以下步骤操作:
1. 首先,您需要在本地安装Hadoop,并连接到虚拟机上的Hadoop集群。您可以使用以下代码片段来连接到Hadoop:
```java
Configuration conf = new Configuration();
conf.set("fs.defaultFS", "hdfs://[your-hdfs-hostname]:[your-hdfs-port]");
conf.set("mapreduce.framework.name", "yarn");
conf.set("yarn.resourcemanager.address", "[your-rm-hostname]:[your-rm-port]");
conf.set("yarn.resourcemanager.scheduler.address", "[your-rm-hostname]:[your-rm-scheduler-port]");
conf.set("mapreduce.jobhistory.address", "[your-historyserver-hostname]:[your-historyserver-port]");
conf.set("mapreduce.jobhistory.webapp.address", "[your-historyserver-hostname]:[your-historyserver-webapp-port]");
```
2. 接下来,您需要创建一个Driver类,并配置MapReduce作业的输入路径、输出路径、Mapper类、Reducer类等参数。以下是一个简单的示例代码:
```java
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
public class MyDriver {
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
Job job = Job.getInstance(conf, "myjob");
job.setJarByClass(MyDriver.class);
job.setMapperClass(MyMapper.class);
job.setReducerClass(MyReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path("/input"));
FileOutputFormat.setOutputPath(job, new Path("/output"));
job.waitForCompletion(true);
}
}
```
3. 在上面的代码中,我们使用了MyMapper和MyReducer作为Mapper和Reducer类。您需要根据您的需求创建这两个类,并实现map和reduce方法。
4. 最后,您需要自动提交作业并运行它。以下是一个简单的示例代码:
```java
job.submit();
while (!job.isComplete()) {
Thread.sleep(1000);
}
System.exit(job.isSuccessful() ? 0 : 1);
```
这将自动提交作业并等待它完成。如果作业成功完成,则退出程序并返回0。否则,返回1。
希望这可以帮助您完成此任务!