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* 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.wink.json4j.utils.internal;
import java.io.IOException;
import java.io.Writer;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* This class is lightweight representation of an XML tag as a JSON object.
* TODO: Look at using HashMap and collections to store the data instead of sync'ed objects.
* TODO: See if the indent/newline handling could be cleaned up. the repeated checks for compact is rather ugly.
* TODO: Look at maybe using the Java representation object as store for the XML data intsead of this customized object.
*/
public class JSONObject {
/**
* Logger.
*/
private static String className = "org.apache.commons.json.uils.xml.internal.JSONObject";
private static Logger logger = Logger.getLogger(className,null);
private static final String indent = " ";
/**
* The JSON object name. Effectively, the XML tag name.
*/
private String objectName = null;
/**
* All basic JSON object properties. Effectively same as XML tag attributes.
*/
private Properties attrs = null;
/**
* All children JSON objects referenced. Effectively the child tags of an XML tag.
*/
private Hashtable jsonObjects = null;
/**
* Any XML freeform text to associate with the JSON object,
*/
private String tagText = null;
/**
* Constructor.
* @param objectName The object (tag) name being constructed.
* @param attrs A proprerties object of all the attributes present for the tag.
*/
public JSONObject(String objectName, Properties attrs) {
this.objectName = objectName;
this.attrs = attrs;
this.jsonObjects = new Hashtable();
}
/**
* Method to add a JSON child object to this JSON object.
* @param obj The child JSON object to add to this JSON object.
*/
public void addJSONObject(JSONObject obj) {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "addJSONObject(JSONObject)");
Vector vect = (Vector) this.jsonObjects.get(obj.objectName);
if (vect != null) {
vect.add(obj);
} else {
vect = new Vector();
vect.add(obj);
this.jsonObjects.put(obj.objectName, vect);
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "addJSONObject(JSONObject)");
}
/**
* Method to set any freeform text on the object.
* @param str The freeform text to assign to the JSONObject
*/
public void setTagText(String str) {
this.tagText = str;
}
/**
* Method to get any freeform text on the object.
*/
public String getTagText() {
return this.tagText;
}
/**
* Method to write out the JSON formatted object. Same as calling writeObject(writer,indentDepth,contentOnly,false);
* @param writer The writer to use when serializing the JSON structure.
* @param indentDepth How far to indent the text for object's JSON format.
* @param contentOnly Flag to debnnote whether to assign this as an attribute name, or as a nameless object. Commonly used for serializing an array. The Array itself has the name, The contents are all nameless objects
* @throws IOException Trhown if an error occurs on write.
*/
public void writeObject(Writer writer, int indentDepth, boolean contentOnly) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeObject(Writer, int, boolean)");
writeObject(writer,indentDepth,contentOnly, false);
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeObject(Writer, int, boolean)");
}
/**
* Method to write out the JSON formatted object.
* @param writer The writer to use when serializing the JSON structure.
* @param indentDepth How far to indent the text for object's JSON format.
* @param contentOnly Flag to debnnote whether to assign this as an attribute name, or as a nameless object. Commonly used for serializing an array. The Array itself has the name, The contents are all nameless objects
* @param compact Flag to denote to write the JSON in compact form. No indentions or newlines. Setting this value to true will cause indentDepth to be ignored.
* @throws IOException Trhown if an error occurs on write.
*/
public void writeObject(Writer writer, int indentDepth, boolean contentOnly, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeObject(Writer, int, boolean, boolean)");
if (writer != null) {
try {
if (isEmptyObject()) {
writeEmptyObject(writer,indentDepth,contentOnly, compact);
} else if (isTextOnlyObject()) {
writeTextOnlyObject(writer,indentDepth,contentOnly, compact);
} else {
writeComplexObject(writer,indentDepth,contentOnly,compact);
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
} else {
throw new IOException("The writer cannot be null.");
}
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeObject(Writer, int, boolean, boolean)");
}
/**
* Internal method to write out a proper JSON attribute string.
* @param writer The writer to use while serializing
* @param name The attribute name to use.
* @param value The value to assign to the attribute.
* @param depth How far to indent the JSON text.
* @param compact Flag to denote whether or not to use pretty indention, or compact format, when writing.
* @throws IOException Trhown if an error occurs on write.
*/
private void writeAttribute(Writer writer, String name, String value, int depth, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeAttribute(Writer, String, String, int)");
if (!compact) {
writeIndention(writer, depth);
}
try {
if (!compact) {
writer.write("\"" + name + "\"" + " : " + "\"" + escapeStringSpecialCharacters(value) + "\"");
} else {
writer.write("\"" + name + "\"" + ":" + "\"" + escapeStringSpecialCharacters(value) + "\"");
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeAttribute(Writer, String, String, int)");
}
/**
* Internal method for doing a simple indention write.
* @param writer The writer to use while writing the JSON text.
* @param indentDepth How deep to indent the text.
* @throws IOException Trhown if an error occurs on write.
*/
private void writeIndention(Writer writer, int indentDepth) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeIndention(Writer, int)");
try {
for (int i = 0; i < indentDepth; i++) {
writer.write(indent);
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeIndention(Writer, int)");
}
/**
* Internal method to write out a proper JSON attribute string.
* @param writer The writer to use while serializing
* @param attrs The attributes in a properties object to write out
* @param depth How far to indent the JSON text.
* @param compact Whether or not to use pretty indention output, or compact output, format
* @throws IOException Trhown if an error occurs on write.
*/
private void writeAttributes(Writer writer, Properties attrs, int depth, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeAttributes(Writer, Properties, int, boolean)");
if (attrs != null) {
Enumeration props = attrs.propertyNames();
if (props != null && props.hasMoreElements()) {
while (props.hasMoreElements()) {
String prop = (String)props.nextElement();
writeAttribute(writer, escapeAttributeNameSpecialCharacters(prop), (String)attrs.get(prop), depth + 1, compact);
if (props.hasMoreElements()) {
try {
if (!compact) {
writer.write(",\n");
} else {
writer.write(",");
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
}
}
}
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeAttributes(Writer, Properties, int, boolean)");
}
/**
* Internal method to escape special attribute name characters, to handle things like name spaces.
* @param str The string to escape the characters in.
*/
private String escapeAttributeNameSpecialCharacters(String str) {
if (str != null) {
StringBuffer strBuf = new StringBuffer("");
for (int i = 0; i < str.length(); i++) {
char strChar = str.charAt(i);
switch (strChar) {
case ':':
{
strBuf.append("_ns-sep_");
break;
}
default:
{
strBuf.append(strChar);
break;
}
}
}
str = strBuf.toString();
}
return str;
}
/**
* Internal method to escape special attribute name characters, to handle things like name spaces.
* @param str The string to escape the characters in.
*/
private String escapeStringSpecialCharacters(String str) {
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "escapeStringSpecialCharacters(String)");
if (str != null) {
StringBuffer strBuf = new StringBuffer("");
for (int i = 0; i < str.length(); i++) {
char strChar = str.charAt(i);
switch (strChar) {
case '"':
{
strBuf.append("\\\"");
break;
}
case '\t':
{
strBuf.append("\\t");
break;
}
case '\b':
{
strBuf.append("\\b");
break;
}
case '\\':
{
strBuf.append("\\\\");
break;
}
case '\f':
{
strBuf.append("\\f");
break;
}
case '\r':
{
strBuf.append("\\r");
break;
}
case '/':
{
strBuf.append("\\/");
break;
}
default:
{
if ((strChar >= 32) && (strChar <= 126)) {
strBuf.append(strChar);
} else {
strBuf.append("\\u");
StringBuffer sb = new StringBuffer(Integer.toHexString(strChar));
while (sb.length() < 4) {
sb.insert(0,'0');
}
strBuf.append(sb.toString());
}
break;
}
}
}
str = strBuf.toString();
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "escapeStringSpecialCharacters(String)");
return str;
}
/**
* Internal method to write out all children JSON objects attached to this JSON object.
* @param writer The writer to use while writing the JSON text.
* @param depth The indention depth of the JSON text.
* @param compact Flag to denote whether or not to write in nice indent format, or compact format.
* @throws IOException Trhown if an error occurs on write.
*/
private void writeChildren(Writer writer, int depth, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeChildren(Writer, int, boolean)");
if (!jsonObjects.isEmpty()) {
Enumeration keys = jsonObjects.keys();
while (keys.hasMoreElements()) {
String objName = (String)keys.nextElement();
Vector vect = (Vector)jsonObjects.get(objName);
if (vect != null && !vect.isEmpty()) {
/**
* Non-array versus array elements.
*/
if (vect.size() == 1) {
if (logger.isLoggable(Level.FINEST)) logger.logp(Level.FINEST, className, "writeChildren(Writer, int, boolean)", "Writing child object: [" + objName + "]");
JSONObject obj = (JSONObject)vect.elementAt(0);
obj.writeObject(writer,depth + 1, false, compact);
if (keys.hasMoreElements()) {
try {
if (!compact) {
if (!obj.isTextOnlyObject() && !obj.isEmptyObject()) {
writeIndention(writer,depth + 1);
}
writer.write(",\n");
} else {
writer.write(",");
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
} else {
if (obj.isTextOnlyObject() && !compact) {
writer.write("\n");
}
}
} else {
if (logger.isLoggable(Level.FINEST)) logger.logp(Level.FINEST, className, "writeChildren(Writer, int, boolean)", "Writing array of JSON objects with attribute name: [" + objName + "]");
try {
if (!compact) {
writeIndention(writer,depth + 1);
writer.write("\"" + objName + "\"");
writer.write(" : [\n");
} else {
writer.write("\"" + objName + "\"");
writer.write(":[");
}
for (int i = 0; i < vect.size(); i++) {
JSONObject obj = (JSONObject)vect.elementAt(i);
obj.writeObject(writer,depth + 2, true, compact);
/**
* Still more we haven't handled.
*/
if (i != (vect.size() -1) ) {
if (!compact) {
if (!obj.isTextOnlyObject() && !obj.isEmptyObject()) {
writeIndention(writer,depth + 2);
}
writer.write(",\n");
} else {
writer.write(",");
}
}
}
if (!compact) {
writer.write("\n");
writeIndention(writer,depth + 1);
}
writer.write("]");
if (keys.hasMoreElements()) {
writer.write(",");
}
if (!compact) {
writer.write("\n");
}
} catch (Exception ex) {
IOException iox = new IOException("Error occurred on serialization of JSON text.");
iox.initCause(ex);
throw iox;
}
}
}
}
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeChildren(Writer, int, boolean)");
}
/**
* Method to write an 'empty' XML tag, like FOO
* @param writer The writer object to render the XML to.
* @param indentDepth How far to indent.
* @param contentOnly Whether or not to write the object name as part of the output
* @param compact Whether or not to write the ohject in compact form, or nice indent form.
* @throws IOException Trhown if an error occurs on write.
*/
private void writeTextOnlyObject(Writer writer, int indentDepth, boolean contentOnly, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeTextOnlyObject(Writer, int, boolean, boolean)");
if (!contentOnly) {
writeAttribute(writer,this.objectName,this.tagText.trim(),indentDepth, compact);
} else {
if (!compact) {
writeIndention(writer, indentDepth);
writer.write("\"" + escapeStringSpecialCharacters(this.tagText.trim()) + "\"");
} else {
writer.write("\"" + escapeStringSpecialCharacters(this.tagText.trim()) + "\"");
}
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeTextOnlyObject(Writer, int, boolean, boolean)");
}
/**
* Method to write aa standard attribute/subtag containing object
* @param writer The writer object to render the XML to.
* @param indentDepth How far to indent.
* @param contentOnly Whether or not to write the object name as part of the output
* @param compact Flag to denote whether or not to write the object in compact form.
* @throws IOException Trhown if an error occurs on write.
*/
private void writeComplexObject(Writer writer, int indentDepth, boolean contentOnly, boolean compact) throws IOException {
if (logger.isLoggable(Level.FINER)) logger.entering(className, "writeComplexObject(Writer, int, boolean, boolean)");
boolean wroteTagText = false;
if (!contentOnly) {
if (logger.isLoggable(Level.FINEST)) logger.logp(Level.FINEST, className, "writeComplexObject(Writer, int, boolean, boolean)", "Writing object: [" + this.objectName + "]");
if (!compact) {
writeIndention(writer, indentDepth);
}
writer.write( "\"" + this.objectName + "\"");
if (!compact) {
writer.write(" : {\n");
} else {
writer.write(":{");
}
} else {
if (logger.isLoggable(Level.FINEST)) logger.logp(Level.FINEST, className, "writeObject(Writer, int, boolean, boolean)", "Writing object contents as an anonymous object (usually an array entry)");
if (!compact) {
writeIndention(writer, indentDepth);
writer.write("{\n");
} else {
writer.write("{");
}
}
if (this.tagText != null && !this.tagText.equals("") && !this.tagText.trim().equals("")) {
writeAttribute(writer,"content", this.tagText.trim(), indentDepth + 1, compact);
wroteTagText = true;
}
if (this.attrs != null && !this.attrs.isEmpty() && wroteTagText) {
if (!compact) {
writer.write(",\n");
} else {
writer.write(",");
}
}
writeAttributes(writer,this.attrs,indentDepth, compact);
if (!this.jsonObjects.isEmpty()) {
if (this.attrs != null && (!this.attrs.isEmpty() || wroteTagText)) {
if (!compact) {
writer.write(",\n");
} else {
writer.write(",");
}
} else {
if (!compact) {
writer.write("\n");
}
}
writeChildren(writer, indentDepth, compact);
} else {
if (!compact) {
writer.write("\n");
}
}
if (!compact) {
writeIndention(writer, indentDepth);
writer.write("}\n");
//writer.write("\n");
} else {
writer.write("}");
}
if (logger.isLoggable(Level.FINER)) logger.exiting(className, "writeComplexObject(Writer, int, boolean, boolean)");
}
/**
* Internal Helper method for determining if this is an empty tag inan XML document, such as foo
* @return boolean denoting whether or not the object being written is a text-only XML tagset.
*/
private boolean isTextOnlyObject() {
boolean retVal = false;
/**
* Check for no attributes
*/
if (this.attrs == null || (this.attrs != null && this.attrs.isEmpty())) {
/**
* Check for no sub-children
*/
if (this.jsonObjects.isEmpty()) {
/**
* Check for tag text contents.
*/
if (this.tagText != null && !this.tagText.trim().equals("")) {
retVal = true;
}
}
}
return retVal;
}
}
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