| /** |
| * 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.data; |
| |
| import java.io.IOException; |
| import java.io.StringReader; |
| import java.util.Iterator; |
| |
| import org.apache.avro.util.internal.JacksonUtils; |
| import org.codehaus.jackson.JsonFactory; |
| import org.codehaus.jackson.JsonNode; |
| import org.codehaus.jackson.JsonParseException; |
| import org.codehaus.jackson.map.ObjectMapper; |
| import org.codehaus.jackson.node.JsonNodeFactory; |
| import org.codehaus.jackson.node.LongNode; |
| import org.codehaus.jackson.node.DoubleNode; |
| import org.codehaus.jackson.node.TextNode; |
| import org.codehaus.jackson.node.BooleanNode; |
| import org.codehaus.jackson.node.NullNode; |
| import org.codehaus.jackson.node.ArrayNode; |
| import org.codehaus.jackson.node.ObjectNode; |
| |
| import org.apache.avro.Schema; |
| import org.apache.avro.AvroRuntimeException; |
| import org.apache.avro.io.DatumReader; |
| import org.apache.avro.io.DatumWriter; |
| import org.apache.avro.io.Encoder; |
| import org.apache.avro.io.Decoder; |
| import org.apache.avro.io.DecoderFactory; |
| import org.apache.avro.io.ResolvingDecoder; |
| |
| /** Utilities for reading and writing arbitrary Json data in Avro format. */ |
| public class Json { |
| private Json() {} // singleton: no public ctor |
| |
| static final JsonFactory FACTORY = new JsonFactory(); |
| static final ObjectMapper MAPPER = new ObjectMapper(FACTORY); |
| |
| /** The schema for Json data. */ |
| public static final Schema SCHEMA; |
| static { |
| try { |
| SCHEMA = Schema.parse |
| (Json.class.getResourceAsStream("/org/apache/avro/data/Json.avsc")); |
| } catch (IOException e) { |
| throw new AvroRuntimeException(e); |
| } |
| } |
| |
| /** |
| * {@link DatumWriter} for arbitrary Json data. |
| * @deprecated use {@link ObjectWriter} |
| */ |
| @Deprecated |
| public static class Writer implements DatumWriter<JsonNode> { |
| |
| @Override public void setSchema(Schema schema) { |
| if (!SCHEMA.equals(schema)) |
| throw new RuntimeException("Not the Json schema: "+schema); |
| } |
| |
| @Override |
| public void write(JsonNode datum, Encoder out) throws IOException { |
| Json.write(datum, out); |
| } |
| } |
| |
| /** |
| * {@link DatumReader} for arbitrary Json data. |
| * @deprecated use {@link ObjectReader} |
| */ |
| @Deprecated |
| public static class Reader implements DatumReader<JsonNode> { |
| private Schema written; |
| private ResolvingDecoder resolver; |
| |
| @Override public void setSchema(Schema schema) { |
| this.written = SCHEMA.equals(written) ? null : schema; |
| } |
| |
| @Override |
| public JsonNode read(JsonNode reuse, Decoder in) throws IOException { |
| if (written == null) // same schema |
| return Json.read(in); |
| |
| // use a resolver to adapt alternate version of Json schema |
| if (resolver == null) |
| resolver = DecoderFactory.get().resolvingDecoder(written, SCHEMA, null); |
| resolver.configure(in); |
| JsonNode result = Json.read(resolver); |
| resolver.drain(); |
| return result; |
| } |
| } |
| |
| /** {@link DatumWriter} for arbitrary Json data using the object model described |
| * in {@link org.apache.avro.JsonProperties}. */ |
| public static class ObjectWriter implements DatumWriter<Object> { |
| |
| @Override public void setSchema(Schema schema) { |
| if (!SCHEMA.equals(schema)) |
| throw new RuntimeException("Not the Json schema: "+schema); |
| } |
| |
| @Override |
| public void write(Object datum, Encoder out) throws IOException { |
| Json.writeObject(datum, out); |
| } |
| } |
| |
| /** {@link DatumReader} for arbitrary Json data using the object model described |
| * in {@link org.apache.avro.JsonProperties}. */ |
| public static class ObjectReader implements DatumReader<Object> { |
| private Schema written; |
| private ResolvingDecoder resolver; |
| |
| @Override public void setSchema(Schema schema) { |
| this.written = SCHEMA.equals(written) ? null : schema; |
| } |
| |
| @Override |
| public Object read(Object reuse, Decoder in) throws IOException { |
| if (written == null) // same schema |
| return Json.readObject(in); |
| |
| // use a resolver to adapt alternate version of Json schema |
| if (resolver == null) |
| resolver = DecoderFactory.get().resolvingDecoder(written, SCHEMA, null); |
| resolver.configure(in); |
| Object result = Json.readObject(resolver); |
| resolver.drain(); |
| return result; |
| } |
| } |
| |
| /** |
| * Parses a JSON string and converts it to the object model described in |
| * {@link org.apache.avro.JsonProperties}. |
| */ |
| public static Object parseJson(String s) { |
| try { |
| return JacksonUtils.toObject(MAPPER.readTree(FACTORY.createJsonParser( |
| new StringReader(s)))); |
| } catch (JsonParseException e) { |
| throw new RuntimeException(e); |
| } catch (IOException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * Converts an instance of the object model described in |
| * {@link org.apache.avro.JsonProperties} to a JSON string. |
| */ |
| public static String toString(Object datum) { |
| return JacksonUtils.toJsonNode(datum).toString(); |
| } |
| |
| /** Note: this enum must be kept aligned with the union in Json.avsc. */ |
| private enum JsonType { LONG, DOUBLE, STRING, BOOLEAN, NULL, ARRAY, OBJECT } |
| |
| /** |
| * Write Json data as Avro data. |
| * @deprecated internal method |
| */ |
| @Deprecated |
| public static void write(JsonNode node, Encoder out) throws IOException { |
| switch(node.asToken()) { |
| case VALUE_NUMBER_INT: |
| out.writeIndex(JsonType.LONG.ordinal()); |
| out.writeLong(node.getLongValue()); |
| break; |
| case VALUE_NUMBER_FLOAT: |
| out.writeIndex(JsonType.DOUBLE.ordinal()); |
| out.writeDouble(node.getDoubleValue()); |
| break; |
| case VALUE_STRING: |
| out.writeIndex(JsonType.STRING.ordinal()); |
| out.writeString(node.getTextValue()); |
| break; |
| case VALUE_TRUE: |
| out.writeIndex(JsonType.BOOLEAN.ordinal()); |
| out.writeBoolean(true); |
| break; |
| case VALUE_FALSE: |
| out.writeIndex(JsonType.BOOLEAN.ordinal()); |
| out.writeBoolean(false); |
| break; |
| case VALUE_NULL: |
| out.writeIndex(JsonType.NULL.ordinal()); |
| out.writeNull(); |
| break; |
| case START_ARRAY: |
| out.writeIndex(JsonType.ARRAY.ordinal()); |
| out.writeArrayStart(); |
| out.setItemCount(node.size()); |
| for (JsonNode element : node) { |
| out.startItem(); |
| write(element, out); |
| } |
| out.writeArrayEnd(); |
| break; |
| case START_OBJECT: |
| out.writeIndex(JsonType.OBJECT.ordinal()); |
| out.writeMapStart(); |
| out.setItemCount(node.size()); |
| Iterator<String> i = node.getFieldNames(); |
| while (i.hasNext()) { |
| out.startItem(); |
| String name = i.next(); |
| out.writeString(name); |
| write(node.get(name), out); |
| } |
| out.writeMapEnd(); |
| break; |
| default: |
| throw new AvroRuntimeException(node.asToken()+" unexpected: "+node); |
| } |
| } |
| |
| /** |
| * Read Json data from Avro data. |
| * @deprecated internal method |
| */ |
| @Deprecated |
| public static JsonNode read(Decoder in) throws IOException { |
| switch (JsonType.values()[in.readIndex()]) { |
| case LONG: |
| return new LongNode(in.readLong()); |
| case DOUBLE: |
| return new DoubleNode(in.readDouble()); |
| case STRING: |
| return new TextNode(in.readString()); |
| case BOOLEAN: |
| return in.readBoolean() ? BooleanNode.TRUE : BooleanNode.FALSE; |
| case NULL: |
| in.readNull(); |
| return NullNode.getInstance(); |
| case ARRAY: |
| ArrayNode array = JsonNodeFactory.instance.arrayNode(); |
| for (long l = in.readArrayStart(); l > 0; l = in.arrayNext()) |
| for (long i = 0; i < l; i++) |
| array.add(read(in)); |
| return array; |
| case OBJECT: |
| ObjectNode object = JsonNodeFactory.instance.objectNode(); |
| for (long l = in.readMapStart(); l > 0; l = in.mapNext()) |
| for (long i = 0; i < l; i++) |
| object.put(in.readString(), read(in)); |
| return object; |
| default: |
| throw new AvroRuntimeException("Unexpected Json node type"); |
| } |
| } |
| |
| private static void writeObject(Object datum, Encoder out) throws IOException { |
| write(JacksonUtils.toJsonNode(datum), out); |
| } |
| |
| private static Object readObject(Decoder in) throws IOException { |
| return JacksonUtils.toObject(read(in)); |
| } |
| |
| } |