/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.avro.tool;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericDatumReader;
import org.apache.avro.io.JsonDecoder;
import org.apache.avro.file.DataFileReader;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
/** Static utility methods for tools. */
class Util {
/**
* Returns stdin if filename is "-", else opens the local or HDFS file
* and returns an InputStream for it.
* @throws IOException
*/
static BufferedInputStream fileOrStdin(String filename, InputStream stdin)
throws IOException {
if (filename.equals("-")) {
return new BufferedInputStream(stdin);
}
else {
String[] parts = filename.split(":");
if (parts.length == 1) {
return new BufferedInputStream(new FileInputStream(new File(filename)));
}
else if (parts[0].equals("hdfs")) {
FileSystem fs = FileSystem.get(
URI.create(filename), new Configuration());
return new BufferedInputStream(fs.open(new Path(filename)));
}
else {
throw new FileNotFoundException();
}
}
}
/**
* Returns stdout if filename is "-", else opens the local or HDFS file
* and returns an OutputStream for it.
* @throws IOException
*/
static BufferedOutputStream fileOrStdout(String filename, OutputStream stdout)
throws IOException {
if (filename.equals("-")) {
return new BufferedOutputStream(stdout);
}
else {
String[] parts = filename.split(":");
if (parts.length == 1) {
return new BufferedOutputStream(
new FileOutputStream(new File(filename)));
}
else if (parts[0].equals("hdfs")) {
FileSystem fs = FileSystem.get(
URI.create(filename), new Configuration());
return new BufferedOutputStream(fs.create(new Path(filename)));
}
else {
throw new FileNotFoundException();
}
}
}
/**
* Converts a String JSON object into a generic datum.
*
* This is inefficient (creates extra objects), so should be used
* sparingly.
*/
static Object jsonToGenericDatum(Schema schema, String jsonData) throws IOException {
GenericDatumReader<Object> reader =
new GenericDatumReader<Object>(schema);
Object datum = reader.read(null, new JsonDecoder(schema, jsonData));
return datum;
}
/** Reads and returns the first datum in a data file. */
static Object datumFromFile(Schema schema, String file) throws IOException {
DataFileReader<Object> in =
new DataFileReader<Object>(new File(file),
new GenericDatumReader<Object>(schema));
try {
return in.next();
} finally {
in.close();
}
}
}