/**
* 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.io;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import org.apache.avro.AvroTypeException;
import org.apache.avro.Schema;
import org.apache.avro.io.parsing.JsonGrammarGenerator;
import org.apache.avro.io.parsing.Parser;
import org.apache.avro.io.parsing.Symbol;
import org.apache.avro.util.Utf8;
import org.codehaus.jackson.Base64Variant;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonLocation;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonStreamContext;
import org.codehaus.jackson.JsonToken;
import org.codehaus.jackson.ObjectCodec;
/** A {@link Decoder} for Avro's JSON data encoding.
* </p>
* Construct using {@link DecoderFactory}.
* </p>
* JsonDecoder is not thread-safe.
* */
public class JsonDecoder extends ParsingDecoder
implements Parser.ActionHandler {
private JsonParser in;
private static JsonFactory jsonFactory = new JsonFactory();
Stack<ReorderBuffer> reorderBuffers = new Stack<ReorderBuffer>();
ReorderBuffer currentReorderBuffer;
private static class ReorderBuffer {
public Map<String, List<JsonElement>> savedFields = new HashMap<String, List<JsonElement>>();
public JsonParser origParser = null;
}
static final String CHARSET = "ISO-8859-1";
private JsonDecoder(Symbol root, InputStream in) throws IOException {
super(root);
configure(in);
}
private JsonDecoder(Symbol root, String in) throws IOException {
super(root);
configure(in);
}
JsonDecoder(Schema schema, InputStream in) throws IOException {
this(getSymbol(schema), in);
}
JsonDecoder(Schema schema, String in) throws IOException {
this(getSymbol(schema), in);
}
private static Symbol getSymbol(Schema schema) {
if (null == schema) {
throw new NullPointerException("Schema cannot be null!");
}
return new JsonGrammarGenerator().generate(schema);
}
/**
* Reconfigures this JsonDecoder to use the InputStream provided.
* <p/>
* If the InputStream provided is null, a NullPointerException is thrown.
* <p/>
* Otherwise, this JsonDecoder will reset its state and then
* reconfigure its input.
* @param in
* The IntputStream to read from. Cannot be null.
* @throws IOException
* @return this JsonDecoder
*/
public JsonDecoder configure(InputStream in) throws IOException {
if (null == in) {
throw new NullPointerException("InputStream to read from cannot be null!");
}
parser.reset();
this.in = jsonFactory.createJsonParser(in);
this.in.nextToken();
return this;
}
/**
* Reconfigures this JsonDecoder to use the String provided for input.
* <p/>
* If the String provided is null, a NullPointerException is thrown.
* <p/>
* Otherwise, this JsonDecoder will reset its state and then
* reconfigure its input.
* @param in
* The String to read from. Cannot be null.
* @throws IOException
* @return this JsonDecoder
*/
public JsonDecoder configure(String in) throws IOException {
if (null == in) {
throw new NullPointerException("String to read from cannot be null!");
}
parser.reset();
this.in = new JsonFactory().createJsonParser(in);
this.in.nextToken();
return this;
}
private void advance(Symbol symbol) throws IOException {
this.parser.processTrailingImplicitActions();
if (in.getCurrentToken() == null && this.parser.depth() == 1)
throw new EOFException();
parser.advance(symbol);
}
@Override
public void readNull() throws IOException {
advance(Symbol.NULL);
if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
in.nextToken();
} else {
throw error("null");
}
}
@Override
public boolean readBoolean() throws IOException {
advance(Symbol.BOOLEAN);
JsonToken t = in.getCurrentToken();
if (t == JsonToken.VALUE_TRUE || t == JsonToken.VALUE_FALSE) {
in.nextToken();
return t == JsonToken.VALUE_TRUE;
} else {
throw error("boolean");
}
}
@Override
public int readInt() throws IOException {
advance(Symbol.INT);
if (in.getCurrentToken().isNumeric()) {
int result = in.getIntValue();
in.nextToken();
return result;
} else {
throw error("int");
}
}
@Override
public long readLong() throws IOException {
advance(Symbol.LONG);
if (in.getCurrentToken().isNumeric()) {
long result = in.getLongValue();
in.nextToken();
return result;
} else {
throw error("long");
}
}
@Override
public float readFloat() throws IOException {
advance(Symbol.FLOAT);
if (in.getCurrentToken().isNumeric()) {
float result = in.getFloatValue();
in.nextToken();
return result;
} else {
throw error("float");
}
}
@Override
public double readDouble() throws IOException {
advance(Symbol.DOUBLE);
if (in.getCurrentToken().isNumeric()) {
double result = in.getDoubleValue();
in.nextToken();
return result;
} else {
throw error("double");
}
}
@Override
public Utf8 readString(Utf8 old) throws IOException {
return new Utf8(readString());
}
@Override
public String readString() throws IOException {
advance(Symbol.STRING);
if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
parser.advance(Symbol.MAP_KEY_MARKER);
if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
throw error("map-key");
}
} else {
if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
throw error("string");
}
}
String result = in.getText();
in.nextToken();
return result;
}
@Override
public void skipString() throws IOException {
advance(Symbol.STRING);
if (parser.topSymbol() == Symbol.MAP_KEY_MARKER) {
parser.advance(Symbol.MAP_KEY_MARKER);
if (in.getCurrentToken() != JsonToken.FIELD_NAME) {
throw error("map-key");
}
} else {
if (in.getCurrentToken() != JsonToken.VALUE_STRING) {
throw error("string");
}
}
in.nextToken();
}
@Override
public ByteBuffer readBytes(ByteBuffer old) throws IOException {
advance(Symbol.BYTES);
if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
byte[] result = readByteArray();
in.nextToken();
return ByteBuffer.wrap(result);
} else {
throw error("bytes");
}
}
private byte[] readByteArray() throws IOException {
byte[] result = in.getText().getBytes(CHARSET);
return result;
}
@Override
public void skipBytes() throws IOException {
advance(Symbol.BYTES);
if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
in.nextToken();
} else {
throw error("bytes");
}
}
private void checkFixed(int size) throws IOException {
advance(Symbol.FIXED);
Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
if (size != top.size) {
throw new AvroTypeException(
"Incorrect length for fixed binary: expected " +
top.size + " but received " + size + " bytes.");
}
}
@Override
public void readFixed(byte[] bytes, int start, int len) throws IOException {
checkFixed(len);
if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
byte[] result = readByteArray();
in.nextToken();
if (result.length != len) {
throw new AvroTypeException("Expected fixed length " + len
+ ", but got" + result.length);
}
System.arraycopy(result, 0, bytes, start, len);
} else {
throw error("fixed");
}
}
@Override
public void skipFixed(int length) throws IOException {
checkFixed(length);
doSkipFixed(length);
}
private void doSkipFixed(int length) throws IOException {
if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
byte[] result = readByteArray();
in.nextToken();
if (result.length != length) {
throw new AvroTypeException("Expected fixed length " + length
+ ", but got" + result.length);
}
} else {
throw error("fixed");
}
}
@Override
protected void skipFixed() throws IOException {
advance(Symbol.FIXED);
Symbol.IntCheckAction top = (Symbol.IntCheckAction) parser.popSymbol();
doSkipFixed(top.size);
}
@Override
public int readEnum() throws IOException {
advance(Symbol.ENUM);
Symbol.EnumLabelsAction top = (Symbol.EnumLabelsAction) parser.popSymbol();
if (in.getCurrentToken() == JsonToken.VALUE_STRING) {
in.getText();
int n = top.findLabel(in.getText());
if (n >= 0) {
in.nextToken();
return n;
}
throw new AvroTypeException("Unknown symbol in enum " + in.getText());
} else {
throw error("fixed");
}
}
@Override
public long readArrayStart() throws IOException {
advance(Symbol.ARRAY_START);
if (in.getCurrentToken() == JsonToken.START_ARRAY) {
in.nextToken();
return doArrayNext();
} else {
throw error("array-start");
}
}
@Override
public long arrayNext() throws IOException {
advance(Symbol.ITEM_END);
return doArrayNext();
}
private long doArrayNext() throws IOException {
if (in.getCurrentToken() == JsonToken.END_ARRAY) {
parser.advance(Symbol.ARRAY_END);
in.nextToken();
return 0;
} else {
return 1;
}
}
@Override
public long skipArray() throws IOException {
advance(Symbol.ARRAY_START);
if (in.getCurrentToken() == JsonToken.START_ARRAY) {
in.skipChildren();
in.nextToken();
advance(Symbol.ARRAY_END);
} else {
throw error("array-start");
}
return 0;
}
@Override
public long readMapStart() throws IOException {
advance(Symbol.MAP_START);
if (in.getCurrentToken() == JsonToken.START_OBJECT) {
in.nextToken();
return doMapNext();
} else {
throw error("map-start");
}
}
@Override
public long mapNext() throws IOException {
advance(Symbol.ITEM_END);
return doMapNext();
}
private long doMapNext() throws IOException {
if (in.getCurrentToken() == JsonToken.END_OBJECT) {
in.nextToken();
advance(Symbol.MAP_END);
return 0;
} else {
return 1;
}
}
@Override
public long skipMap() throws IOException {
advance(Symbol.MAP_START);
if (in.getCurrentToken() == JsonToken.START_OBJECT) {
in.skipChildren();
in.nextToken();
advance(Symbol.MAP_END);
} else {
throw error("map-start");
}
return 0;
}
@Override
public int readIndex() throws IOException {
advance(Symbol.UNION);
Symbol.Alternative a = (Symbol.Alternative) parser.popSymbol();
String label;
if (in.getCurrentToken() == JsonToken.VALUE_NULL) {
label = "null";
} else if (in.getCurrentToken() == JsonToken.START_OBJECT &&
in.nextToken() == JsonToken.FIELD_NAME) {
label = in.getText();
in.nextToken();
parser.pushSymbol(Symbol.UNION_END);
} else {
throw error("start-union");
}
int n = a.findLabel(label);
if (n < 0)
throw new AvroTypeException("Unknown union branch " + label);
parser.pushSymbol(a.getSymbol(n));
return n;
}
@Override
public Symbol doAction(Symbol input, Symbol top) throws IOException {
if (top instanceof Symbol.FieldAdjustAction) {
Symbol.FieldAdjustAction fa = (Symbol.FieldAdjustAction) top;
String name = fa.fname;
if (currentReorderBuffer != null) {
List<JsonElement> node = currentReorderBuffer.savedFields.get(name);
if (node != null) {
currentReorderBuffer.savedFields.remove(name);
currentReorderBuffer.origParser = in;
in = makeParser(node);
return null;
}
}
if (in.getCurrentToken() == JsonToken.FIELD_NAME) {
do {
String fn = in.getText();
in.nextToken();
if (name.equals(fn)) {
return null;
} else {
if (currentReorderBuffer == null) {
currentReorderBuffer = new ReorderBuffer();
}
currentReorderBuffer.savedFields.put(fn, getVaueAsTree(in));
}
} while (in.getCurrentToken() == JsonToken.FIELD_NAME);
throw new AvroTypeException("Expected field name not found: " + fa.fname);
}
} else if (top == Symbol.FIELD_END) {
if (currentReorderBuffer != null && currentReorderBuffer.origParser != null) {
in = currentReorderBuffer.origParser;
currentReorderBuffer.origParser = null;
}
} else if (top == Symbol.RECORD_START) {
if (in.getCurrentToken() == JsonToken.START_OBJECT) {
in.nextToken();
reorderBuffers.push(currentReorderBuffer);
currentReorderBuffer = null;
} else {
throw error("record-start");
}
} else if (top == Symbol.RECORD_END || top == Symbol.UNION_END) {
if (in.getCurrentToken() == JsonToken.END_OBJECT) {
in.nextToken();
if (top == Symbol.RECORD_END) {
if (currentReorderBuffer != null && !currentReorderBuffer.savedFields.isEmpty()) {
throw error("Unknown fields: " + currentReorderBuffer.savedFields.keySet());
}
currentReorderBuffer = reorderBuffers.pop();
}
} else {
throw error(top == Symbol.RECORD_END ? "record-end" : "union-end");
}
} else {
throw new AvroTypeException("Unknown action symbol " + top);
}
return null;
}
private static class JsonElement {
public final JsonToken token;
public final String value;
public JsonElement(JsonToken t, String value) {
this.token = t;
this.value = value;
}
public JsonElement(JsonToken t) {
this(t, null);
}
}
private static List<JsonElement> getVaueAsTree(JsonParser in) throws IOException {
int level = 0;
List<JsonElement> result = new ArrayList<JsonElement>();
do {
JsonToken t = in.getCurrentToken();
switch (t) {
case START_OBJECT:
case START_ARRAY:
level++;
result.add(new JsonElement(t));
break;
case END_OBJECT:
case END_ARRAY:
level--;
result.add(new JsonElement(t));
break;
case FIELD_NAME:
case VALUE_STRING:
case VALUE_NUMBER_INT:
case VALUE_NUMBER_FLOAT:
case VALUE_TRUE:
case VALUE_FALSE:
case VALUE_NULL:
result.add(new JsonElement(t, in.getText()));
break;
}
in.nextToken();
} while (level != 0);
result.add(new JsonElement(null));
return result;
}
private JsonParser makeParser(final List<JsonElement> elements) throws IOException {
return new JsonParser() {
int pos = 0;
@Override
public ObjectCodec getCodec() {
throw new UnsupportedOperationException();
}
@Override
public void setCodec(ObjectCodec c) {
throw new UnsupportedOperationException();
}
@Override
public void close() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public JsonToken nextToken() throws IOException {
pos++;
return elements.get(pos).token;
}
@Override
public JsonParser skipChildren() throws IOException {
int level = 0;
do {
switch(elements.get(pos++).token) {
case START_ARRAY:
case START_OBJECT:
level++;
break;
case END_ARRAY:
case END_OBJECT:
level--;
break;
}
} while (level > 0);
return this;
}
@Override
public boolean isClosed() {
throw new UnsupportedOperationException();
}
@Override
public String getCurrentName() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public JsonStreamContext getParsingContext() {
throw new UnsupportedOperationException();
}
@Override
public JsonLocation getTokenLocation() {
throw new UnsupportedOperationException();
}
@Override
public JsonLocation getCurrentLocation() {
throw new UnsupportedOperationException();
}
@Override
public String getText() throws IOException {
return elements.get(pos).value;
}
@Override
public char[] getTextCharacters() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public int getTextLength() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public int getTextOffset() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public Number getNumberValue() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public NumberType getNumberType() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public int getIntValue() throws IOException {
return Integer.parseInt(getText());
}
@Override
public long getLongValue() throws IOException {
return Long.parseLong(getText());
}
@Override
public BigInteger getBigIntegerValue() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public float getFloatValue() throws IOException {
return Float.parseFloat(getText());
}
@Override
public double getDoubleValue() throws IOException {
return Double.parseDouble(getText());
}
@Override
public BigDecimal getDecimalValue() throws IOException {
throw new UnsupportedOperationException();
}
@Override
public byte[] getBinaryValue(Base64Variant b64variant)
throws IOException {
throw new UnsupportedOperationException();
}
@Override
public JsonToken getCurrentToken() {
return elements.get(pos).token;
}
};
}
private AvroTypeException error(String type) {
return new AvroTypeException("Expected " + type +
". Got " + in.getCurrentToken());
}
}