我尝试在hadoop系统上运行java程序,将图像存储在序列文件中,然后尝试读取序列文件。我的序列已创建,但图像数据未附加到序列文件中。
我试图通过运行这个命令来运行下面的代码
sudo-u hdfs hadoop jar/usr/java_jar/imagestorage.jar图像存储12e2baa2aee0e455ac40015942b682c4b.jpg
请帮帮我。
import java.io.*;
import java.util.*;
import java.net.*;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.SequenceFile.Writer.Option;
import org.apache.hadoop.io.Writable;
public class ImageStorage {
private static void openOutputFile(String args1) throws Exception {
String uri = "hdfs://localhost:8020/";
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(URI.create(uri), conf);
Path path = new Path("hdfs://localhost:8020/user/img_data/SequenceFileCodecTest.seq");
String string1 = "hdfs://localhost:8020/user/img_data/";
string1 = string1 + args1;
Path inPath = new Path(string1);
FSDataInputStream in = null;
Text key = new Text();
BytesWritable value = new BytesWritable();
SequenceFile.Writer writer = null;
try{
in = fs.open(inPath);
byte buffer[] = new byte[in.available()];
in.read(buffer);
System.out.println(buffer);
in.close();
Option optPath = SequenceFile.Writer.file(path);
Option optKey = SequenceFile.Writer.keyClass(key.getClass());
Option optVal = SequenceFile.Writer.valueClass(value.getClass());
Option optCom = SequenceFile.Writer.compression(SequenceFile.CompressionType.BLOCK);
FSDataOutputStream fileOutputStream = fs.append(path);
BufferedWriter br = new BufferedWriter(new OutputStreamWriter(fileOutputStream));
writer.append(new Text(inPath.getName()), new BytesWritable(buffer));
br.close();
fileOutputStream.close();
}catch (Exception e) {
System.out.println("Exception MESSAGES = "+e.getMessage());
}
finally {
IOUtils.closeStream(writer);
System.out.println("last line of the code....!!!!!!!!!!");
}
}
private static void openReadFile() throws Exception {
String uri = "hdfs://localhost:8020/";
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(URI.create(uri), conf);
Path path = new Path("hdfs://localhost:8020/user/img_data/SequenceFileCodecTest.seq");
/* Reading Operations */
org.apache.hadoop.io.SequenceFile.Reader.Option filePath = SequenceFile.Reader.file(path);
SequenceFile.Reader sequenceFileReader = new SequenceFile.Reader(conf,filePath);
Writable key1 = (Writable) ReflectionUtils.newInstance(
sequenceFileReader.getKeyClass(), conf);
Writable value1 = (Writable) ReflectionUtils.newInstance(
sequenceFileReader.getValueClass(), conf);
try {
while (sequenceFileReader.next(key1, value1)) {
System.out.printf("[%s] %s %s \n", sequenceFileReader.getPosition(), key1,value1.getClass());
}
} finally {
IOUtils.closeStream(sequenceFileReader);
}
/* Reading operations */
}
public static void main(String[] args) throws Exception {
openOutputFile(args[1]);
openReadFile();
}
}
暂无答案!
目前还没有任何答案,快来回答吧!