net.imadz.util.json.io.JsonWriter Maven / Gradle / Ivy
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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2013-2020 Madz. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://raw.github.com/zhongdj/Lifecycle/master/License.txt
* . See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package net.imadz.util.json.io;
import java.io.PrintWriter;
import java.math.BigDecimal;
import net.imadz.util.StringPrintWriter;
/**
* Writes JSON formatted names and values to a Writer.
*/
public class JsonWriter {
private Formatter formatter;
private final PrintWriter out;
/**
* Create a new JsonWriter that writes to a StringPrintWriter.
*
*
* The String contents can be obtained by calling toString on this
* object.
*
*/
public JsonWriter() {
this(new StringPrintWriter(), JsonTextType.object, false);
}
/**
* Create a new JsonWriter wrapped around a PrintWriter
*/
public JsonWriter(PrintWriter out) {
this(out, JsonTextType.object, false);
}
/**
* Create a new JsonWriter wrapped around a PrintWriter
*/
public JsonWriter(PrintWriter out, JsonTextType jsonText, boolean anonymous) {
assert null != out;
this.out = out;
this.formatter = new Formatter(null, out, "", true, null).startSection(null, jsonText, anonymous);
}
private static class Formatter {
private final Formatter parent;
private final PrintWriter out;
private final String prefix;
private boolean firstElement = true;
private boolean skipLabels;
private final JsonTextType jsonText;
public Formatter(Formatter parent, PrintWriter out, String prefix, boolean skipLabels, JsonTextType jsonText) {
this.parent = parent;
this.out = out;
this.prefix = prefix;
this.skipLabels = skipLabels;
this.jsonText = jsonText;
}
public Formatter startSection(String label, final JsonTextType jsonText, boolean anonymous) {
startElement(label);
print(jsonText.getBeginString());
return new Formatter(this, out, this.prefix + "\t", anonymous, jsonText);
}
private Formatter doEndSection(String endString) {
if ( !firstElement ) {
out.println();
out.print(this.prefix);
}
print(endString);
return this;
}
public Formatter endSection() {
return parent.doEndSection(jsonText.getEndString());
}
public void startElement(String name) {
if ( !firstElement ) {
out.print(",");
}
firstElement = false;
if ( null != this.parent ) {
out.println();
}
out.print(this.prefix);
if ( null != name && !skipLabels ) {
printString(name);
out.print(": ");
}
}
public void print(String str) {
out.print(str);
}
public void printString(String str) {
if ( null == str ) {
out.print("null");
} else {
out.print("\"");
for ( char ch : str.toCharArray() ) {
switch (ch) {
case '"':
out.print("\\\"");
break;
case '\b':
out.print("\\b");
break;
case '\f':
out.print("\\f");
break;
case '\n':
out.print("\\n");
break;
case '\r':
out.print("\\r");
break;
case '\t':
out.print("\\t");
break;
case '\\':
out.print("\\\\");
break;
default:
if ( Character.isISOControl(ch) || ch > 127 ) {
out.print(String.format("\\u+%04x", ( (int) ch ) & 0x0ffff));
} else {
out.print(ch);
}
}
}
out.print("\"");
}
}
}
/**
* Start a JSON Object element.
*
*
* The
*
*/
public void startObject(String label) {
this.formatter = this.formatter.startSection(label, JsonTextType.object, false);
}
public void startAnonymousObject(String label) {
this.formatter = this.formatter.startSection(label, JsonTextType.object, true);
}
public void endObject() {
formatter = this.formatter.endSection();
}
public void startArray(String label) {
this.formatter = this.formatter.startSection(label, JsonTextType.array, false);
}
public void startAnonymousArray(String label) {
this.formatter = this.formatter.startSection(label, JsonTextType.array, true);
}
public void endArray() {
formatter = this.formatter.endSection();
}
/**
* Write a named number in JSON format.
*
* argument name
* Name written as a JSON String.
* argument value
* Value (may be null) as a simple JSON decimal.
*/
public void printNumber(String name, BigDecimal value) {
formatter.startElement(name);
if ( null == value ) {
formatter.print("null");
} else {
formatter.print(value.toPlainString());
}
}
/**
* Write a named number in JSON format.
*
* argument name
* Name written as a JSON String.
* argument value
* Value (may be null) as a simple JSON decimal.
*/
public void printNumber(String name, Number value) {
formatter.startElement(name);
if ( null == value ) {
formatter.print("null");
} else {
formatter.print(value.toString());
}
}
/**
* Write a named boolean in JSON format.
*
* argument name
* Name written as a JSON String.
* argument value
* Value (may be null) as a JSON boolean.
*/
public void printBoolean(String name, Boolean value) {
formatter.startElement(name);
if ( null == value ) {
formatter.print("null");
} else {
formatter.print(value.toString());
}
}
/**
* Write a named decimal in JSON format.
*
* argument name
* Name written as a JSON String.
* argument value
* Value (may be null) as a JSON decimal.
*/
public void printEngineeringNumber(String name, BigDecimal value) {
formatter.startElement(name);
if ( null == value ) {
formatter.print("null");
} else {
formatter.print(value.toEngineeringString());
}
}
/**
* Write a named string in JSON format.
*
* argument name
* Name written as a JSON String.
* argument value
* Value (may be null) as a JSON String.
*/
public void printString(String name, String str) {
formatter.startElement(name);
formatter.printString(str);
}
public void finish() {
while ( this.formatter.parent != null ) {
this.formatter = this.formatter.endSection();
}
}
public void close() {
finish();
out.close();
}
@Override
public String toString() {
return out.toString();
}
public static void main(String[] parms) {
JsonWriter writer = new JsonWriter(new PrintWriter(System.out));
writer.startObject("Bob");
writer.printString("name", "Larry Has a \"Quote\"");
writer.printString("type", "Object");
writer.printString("iso", "This has a tab(\t), a backslash (\\), a newline(\n), a null (\0), as well as some \u2341 stuff");
writer.printNumber("value", 1243);
writer.startArray("numberArray");
try {
for ( int idx = 1; idx < 10; idx++ ) {
writer.printNumber(null, idx);
}
} finally {
writer.endArray();
}
writer.endObject();
writer.close();
}
}