/**
* 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.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.List;
import org.apache.trevni.Input;
import org.apache.trevni.ColumnFileReader;
import org.apache.trevni.ColumnMetaData;
import org.apache.trevni.ColumnValues;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.util.MinimalPrettyPrinter;
/** Tool to read Trevni files and print them as JSON.
* This can read any Trevni file. Nested structure is reconstructed from the
* columns rather than any schema information.
*/
public class TrevniToJsonTool implements Tool {
static final JsonFactory FACTORY = new JsonFactory();
private JsonGenerator generator;
private ColumnFileReader reader;
private ColumnValues[] values;
private String[] shortNames;
@Override
public String getName() {
return "trevni_tojson";
}
@Override
public String getShortDescription() {
return "Dumps a Trevni file as JSON.";
}
@Override
public int run(InputStream stdin, PrintStream out, PrintStream err,
List<String> args) throws Exception {
String filename;
boolean pretty = false;
if (args.size() == 2 && "-pretty".equals(args.get(0))) {
pretty = true;
filename = args.get(1);
} else if (args.size() == 1) {
filename = args.get(0);
} else {
err.println("Usage: [-pretty] input");
return 1;
}
toJson(TrevniUtil.input(filename), out, pretty);
return 0;
}
/** Read a Trevni file and print each row as a JSON object. */
public void toJson(Input input, PrintStream out, boolean pretty)
throws IOException {
this.generator = FACTORY.createJsonGenerator(out, JsonEncoding.UTF8);
if (pretty) {
generator.useDefaultPrettyPrinter();
} else { // ensure newline separation
MinimalPrettyPrinter pp = new MinimalPrettyPrinter();
pp.setRootValueSeparator(System.getProperty("line.separator"));
generator.setPrettyPrinter(pp);
}
this.reader = new ColumnFileReader(input);
int columnCount = (int)reader.getColumnCount();
this.values = new ColumnValues[columnCount];
this.shortNames = new String[columnCount];
for (int i = 0; i < columnCount; i++) {
values[i] = reader.getValues(i);
shortNames[i] = shortName(reader.getColumnMetaData(i));
}
List<ColumnMetaData> roots = reader.getRoots();
for (long row = 0; row < reader.getRowCount(); row++) {
for (ColumnValues v : values)
v.startRow();
generator.writeStartObject();
for (ColumnMetaData root : roots)
valueToJson(root);
generator.writeEndObject();
}
generator.flush();
out.println();
reader.close();
}
private void valueToJson(ColumnMetaData column) throws IOException {
generator.writeFieldName(shortNames[column.getNumber()]);
ColumnValues in = values[column.getNumber()];
if (!column.isArray()) {
primitiveToJson(column, in.nextValue());
} else {
generator.writeStartArray();
int length = in.nextLength();
for (int i = 0; i < length; i++) {
Object value = in.nextValue();
List<ColumnMetaData> children = column.getChildren();
if (children.size() == 0) {
primitiveToJson(column, value);
} else {
generator.writeStartObject();
if (value != null) {
generator.writeFieldName("value$");
primitiveToJson(column, value);
}
for (ColumnMetaData child : children)
valueToJson(child);
generator.writeEndObject();
}
}
generator.writeEndArray();
}
}
private void primitiveToJson(ColumnMetaData column, Object value)
throws IOException {
switch (column.getType()) {
case NULL:
generator.writeNull(); break;
case INT:
generator.writeNumber((Integer)value); break;
case LONG:
generator.writeNumber((Long)value); break;
case FIXED32:
generator.writeNumber((Integer)value); break;
case FIXED64:
generator.writeNumber((Long)value); break;
case FLOAT:
generator.writeNumber((Float)value); break;
case DOUBLE:
generator.writeNumber((Double)value); break;
case STRING:
generator.writeString((String)value); break;
case BYTES:
generator.writeBinary((byte[])value);
break;
default:
throw new RuntimeException("Unknown value type: "+column.getType());
}
}
// trim off portion of name shared with parent
private String shortName(ColumnMetaData column) {
String name = column.getName();
ColumnMetaData parent = column.getParent();
if (parent != null && name.startsWith(parent.getName()))
name = name.substring(parent.getName().length());
if (!Character.isLetterOrDigit(name.charAt(0)))
name = name.substring(1);
return name;
}
}