hal/src/zutil/parser/json/JSONObjectOutputStream.java

253 lines
8.8 KiB
Java
Executable file

/*
* The MIT License (MIT)
*
* Copyright (c) 2015 Ziver Koc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package zutil.parser.json;
import zutil.ClassUtil;
import zutil.parser.Base64Encoder;
import zutil.parser.DataNode;
import zutil.parser.DataNode.DataType;
import javax.activation.UnsupportedDataTypeException;
import java.io.*;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static zutil.parser.json.JSONObjectInputStream.MD_CLASS;
import static zutil.parser.json.JSONObjectInputStream.MD_OBJECT_ID;
public class JSONObjectOutputStream extends OutputStream implements ObjectOutput, Closeable{
/** If the generated JSON should contain class def meta-data **/
private boolean generateMetaData = true;
/** If fields that are null should be included in the json **/
private boolean ignoreNullFields = true;
/** Cache of parsed objects **/
private HashMap<Object,Integer> objectCache;
private JSONWriter out;
private JSONObjectOutputStream() {
this.objectCache = new HashMap<Object, Integer>();
}
public JSONObjectOutputStream(OutputStream out) {
this();
this.out = new JSONWriter(out);
}
public JSONObjectOutputStream(Writer out) {
this();
this.out = new JSONWriter(out);
}
public synchronized void writeObject(Object obj) throws IOException{
try{
out.write(getDataNode(obj));
} catch (IllegalAccessException e) {
throw new IOException("Unable to serialize object", e);
} finally {
objectCache.clear();
}
}
protected DataNode getDataNode(Object obj) throws IOException, IllegalArgumentException, IllegalAccessException {
if(obj == null)
return null;
Class objClass = obj.getClass();
DataNode root;
// Check if the object is a primitive
if(ClassUtil.isPrimitive(obj.getClass()) ||
ClassUtil.isWrapper(obj.getClass())){
root = getPrimitiveDataNode(obj.getClass(), obj);
}
// Add an array
else if(objClass.isArray()){
// Special case for byte arrays
if(objClass.getComponentType() == byte.class) {
root = new DataNode(DataType.String);
root.set(Base64Encoder.encode((byte[])obj));
}
// Other arrays
else {
root = new DataNode(DataType.List);
for (int i = 0; i < Array.getLength(obj); i++) {
root.add(getDataNode(Array.get(obj, i)));
}
}
}
// List
else if(List.class.isAssignableFrom(objClass)){
root = new DataNode(DataNode.DataType.List);
List list = (List)obj;
for(Object item : list){
root.add(getDataNode(item));
}
}
// Map
else if(Map.class.isAssignableFrom(objClass)){
root = new DataNode(DataNode.DataType.Map);
Map map = (Map)obj;
for(Object key : map.keySet()){
root.set(
getDataNode(key).getString(),
getDataNode(map.get(key)));
}
}
// Object is a complex data type
else {
root = new DataNode(DataNode.DataType.Map);
// Generate meta data
if(generateMetaData){
// Cache
if(objectCache.containsKey(obj)){ // Hit
root.set(MD_OBJECT_ID, objectCache.get(obj));
return root;
}
else{ // Miss
objectCache.put(obj, objectCache.size()+1);
root.set(MD_OBJECT_ID, objectCache.size());
}
root.set(MD_CLASS, obj.getClass().getName());
}
// Add all the fields to the DataNode
for(Field field : obj.getClass().getDeclaredFields()){
if( ! Modifier.isStatic(field.getModifiers()) &&
! Modifier.isTransient(field.getModifiers())){
field.setAccessible(true);
Object fieldObj = field.get(obj);
// has object a value?
if(ignoreNullFields && fieldObj == null)
continue;
else
root.set(field.getName(), getDataNode(fieldObj));
}
}
}
return root;
}
private DataNode getPrimitiveDataNode(Class<?> type, Object value) throws UnsupportedDataTypeException, IllegalArgumentException, IllegalAccessException {
DataNode node = null;
if (type == int.class ||
type == Integer.class ||
type == long.class ||
type == Long.class ||
type == double.class ||
type == Double.class)
node = new DataNode(DataType.Number);
else if(type == boolean.class ||
type == Boolean.class)
node = new DataNode(DataType.Boolean);
else if(type == String.class ||
type == char.class ||
type == Character.class)
node = new DataNode(DataType.String);
else
throw new UnsupportedDataTypeException("Unsupported primitive data type: "+type.getName());
if(value != null)
node.set(value.toString());
return node;
}
/**
* Enable or disables the use of meta data in the JSON
* stream for class definitions and caching.
* If meta data is disabled then all parsed classes need to
* be registered in JSONObjectInputStream to be able to decode objects.
*
* All the meta-data tags will start with a '@'
*/
public void enableMetaData(boolean generate){
generateMetaData = generate;
}
/**
* Defines if null fields in objects should be included
* in the JSON output. Default value is true
*/
public void ignoreNullFields(boolean enable) {
ignoreNullFields = enable;
}
public void flush() throws IOException {
out.flush();
}
public void close() throws IOException {
if (out != null) {
out.flush();
out.close();
}
}
@Override public void writeBoolean(boolean v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeByte(int v) throws IOException {
throw new UnsupportedOperationException ();
}
@Override public void writeShort(int v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeChar(int v) throws IOException {
out.write(new DataNode((char)v));
}
@Override public void writeInt(int v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeLong(long v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeFloat(float v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeDouble(double v) throws IOException {
out.write(new DataNode(v));
}
@Override public void writeBytes(String s) throws IOException {
throw new UnsupportedOperationException ();
}
@Override public void writeChars(String s) throws IOException {
out.write(new DataNode(s));
}
@Override public void write(int b) throws IOException {
out.write(new DataNode(b));
}
@Override public void writeUTF(String s) throws IOException {
out.write(new DataNode(s));
}
}