oracle.kv.impl.util.JsonUtils Maven / Gradle / Ivy
/*-
* Copyright (C) 2011, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle NoSQL
* Database made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/nosqldb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle NoSQL Database for a copy of the license and
* additional information.
*/
package oracle.kv.impl.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ObjectWriter;
import org.codehaus.jackson.node.ArrayNode;
import org.codehaus.jackson.node.ObjectNode;
/**
* Provides utilities to aid in interaction with Jackson JSON processing
* libraries as well as helpful JSON operations.
*/
public class JsonUtils {
protected static final ObjectMapper mapper = new ObjectMapper();
/*
* Symbols used to converting hex string
*/
private static final String HEX = "0123456789ABCDEF";
/**
* Returns a JSON parser that parses input from a reader.
*
* @param in the reader
* @return the parser
* @throws IOException if there is a problem parsing the input
*/
public static JsonParser createJsonParser(Reader in)
throws IOException {
return enableFeatures(mapper.getJsonFactory().createJsonParser(in));
}
/**
* Returns a JSON parser that parses input from an input stream.
*
* @param in the input stream
* @return the parser
* @throws IOException if there is a problem parsing the input
*/
public static JsonParser createJsonParser(InputStream in)
throws IOException {
return enableFeatures(mapper.getJsonFactory().createJsonParser(in));
}
/**
* Enables some non-default features:
* - allow leading 0 in numerics
* - allow non-numeric values such as INF, -INF, NaN for float and double
*/
private static JsonParser enableFeatures(JsonParser parser) {
parser.enable(JsonParser.Feature.ALLOW_NUMERIC_LEADING_ZEROS);
return parser.enable(JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS);
}
/**
* Returns an object node.
*
* @return the object node
*/
public static ObjectNode createObjectNode() {
return mapper.createObjectNode();
}
/**
* Returns an array node.
*
* @return the array node
*/
public static ArrayNode createArrayNode() {
return mapper.createArrayNode();
}
/**
* Returns the default object writer.
*
* @param pretty whether the writer should do prettyprinting
* @return the object writer
*/
@SuppressWarnings("deprecation")
public static ObjectWriter createWriter(boolean pretty) {
/*
* NOTE: currently using jackson 1.9, which deprecates the method
* defaultPrettyPrintingWriter() and replaces it with the new method
* writerWithDefaultPrettyPrinter(). Unfortunately, the latest
* versions of CDH are distributed with version 1.8 of jackson;
* which specifies only defaultPrettyPrintingWriter(). Thus,
* although it is preferable to use writerWithDefaultPrettyPrinter(),
* any Table API based MapReduce jobs that are run will fail because
* the Hadoop infrastructure has no knowledge of that method.
*
* As a result, until CDH upgrades to jackson 1.9 or greater,
* this method must continue to employ defaultPrettyPrintingWriter()
* below; after which it may be changed to use
* writerWithDefaultPrettyPrinter() instead.
*/
return (pretty ? mapper.defaultPrettyPrintingWriter() :
mapper.writer());
}
/**
* Returns the value of a field in text format if the node is an object
* node with the specified value field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value as text or null
*/
public static String getAsText(JsonNode node, String field) {
return getAsText(node, field, null);
}
/**
* Returns the value of a field in text format if the node is an object
* node with the specified value field, otherwise returns the default
* value.
*
* @param node the node
* @param field the field name
* @param defaultValue the default value
* @return the field value as text or the default
*/
public static String getAsText(JsonNode node, String field,
String defaultValue) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isValueNode()) {
return defaultValue;
}
return fieldNode.asText();
}
/**
* Returns the Long value of a field if the node is an object node with the
* specified long field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value or null
*/
public static Long getLong(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isLong()) {
return null;
}
return fieldNode.getLongValue();
}
/**
* Returns the Integer value of a field if the node is an object node with
* the specified int field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value or null
*/
public static Integer getInt(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isInt()) {
return null;
}
return fieldNode.getIntValue();
}
/**
* Returns the Double value of a field if the node is an object node with
* the specified double field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value or null
*/
public static Double getDouble(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isDouble()) {
return null;
}
return fieldNode.getDoubleValue();
}
/**
* Returns the Boolean value of a field if the node is an object node with
* the specified boolean field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value or null
*/
public static Boolean getBoolean(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isBoolean()) {
return null;
}
return fieldNode.getBooleanValue();
}
/**
* Returns the boolean value of a field if the node is an object node with
* the specified boolean field, otherwise returns the default value.
*
* @param node the node
* @param field the field name
* @param defaultValue the default
* @return the field value or the default
*/
public static boolean getBoolean(JsonNode node, String field,
boolean defaultValue) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isBoolean()) {
return defaultValue;
}
return fieldNode.getBooleanValue();
}
/**
* Returns the object node for a field if the node is an object node with
* the specified object field, otherwise null.
*
* @param node the node
* @param field the field name
* @return the field value or null
*/
public static ObjectNode getObject(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isObject()) {
return null;
}
return (ObjectNode) fieldNode;
}
/**
* Returns an iterable object over the elements of an array for a field if
* the node is an object node with the specified array field, otherwise
* an empty iterable.
*
* @param node the node
* @param field the field name
* @return an iterable over the array elements or an empty iterable
*/
public static Iterable getArray(JsonNode node, String field) {
final JsonNode fieldNode = node.get(field);
if ((fieldNode == null) || !fieldNode.isArray()) {
return Collections.emptyList();
}
return fieldNode;
}
/**
* Compare the contents of two JSON strings without regard
* to the order in which fields appear in the string.
*
* @param a , b Two JSON strings to compare
* @return true if the two strings represent equivalent JSON documents
*/
public static boolean jsonStringsEqual(String a, String b) {
Map mapa = getMapFromJsonStr(a);
Map mapb = getMapFromJsonStr(b);
if (mapa == null) {
return false;
}
return mapa.equals(mapb);
}
/**
* Turn a JSON string into a Map.
*
* @param s the JSON string
* @return A Map representing the JSON document.
*/
@SuppressWarnings("unchecked")
public static Map getMapFromJsonStr(String s) {
try {
return mapper.readValue(s, HashMap.class);
} catch (IOException e) {
return null;
}
}
/**
* Return the static obecjt mapper.
*/
public static ObjectMapper getObjectMapper() {
return mapper;
}
/**
* Convert a byte array to hex string
*/
public static String convertBytesToHex(byte[] byteArray) {
final char[] hexValue = new char[byteArray.length * 2];
final char[] hexSymbols = HEX.toCharArray();
for (int i = 0; i < byteArray.length; i++) {
final int current = byteArray[i] & 0xff;
/* determine the Hex symbol for the last 4 bits */
hexValue[i*2 + 1] = hexSymbols[current & 0x0f];
/* determine the Hex symbol for the first 4 bits */
hexValue[i*2] = hexSymbols[current >> 4];
}
return new String(hexValue);
}
/**
* Convert a hex string to byte array
*/
public static byte[] convertHexToBytes(String hexString) {
if (hexString.length() % 2 != 0) {
throw new IllegalArgumentException("Invalid hex string length");
}
final byte[] result = new byte[hexString.length()/2];
final int n = hexString.length();
for (int i = 0; i < n; i += 2) {
/* high bits */
final int hb = HEX.indexOf(hexString.charAt(i));
/* low bits */
final int lb = HEX.indexOf(hexString.charAt(i + 1));
result[i/2] = (byte)((hb << 4 ) | lb);
}
return result;
}
}
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