JsonUtil.java
/*
* Portions of this software was developed by employees of the National Institute
* of Standards and Technology (NIST), an agency of the Federal Government and is
* being made available as a public service. Pursuant to title 17 United States
* Code Section 105, works of NIST employees are not subject to copyright
* protection in the United States. This software may be subject to foreign
* copyright. Permission in the United States and in foreign countries, to the
* extent that NIST may hold copyright, to use, copy, modify, create derivative
* works, and distribute this software and its documentation without fee is hereby
* granted on a non-exclusive basis, provided that this notice and disclaimer
* of warranty appears in all copies.
*
* THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
* EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
* THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
* INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
* SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
* OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
* CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
* PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
* OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
*/
package gov.nist.secauto.metaschema.core.model.util;
import com.fasterxml.jackson.core.JsonLocation;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import gov.nist.secauto.metaschema.core.util.CustomCollectors;
import gov.nist.secauto.metaschema.core.util.ObjectUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.json.JSONObject;
import org.json.JSONTokener;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
public final class JsonUtil {
private static final Logger LOGGER = LogManager.getLogger(JsonUtil.class);
private JsonUtil() {
// disable construction
}
@NonNull
public static JSONObject toJsonObject(@NonNull InputStream schemaInputStream) {
return new JSONObject(new JSONTokener(schemaInputStream));
}
@NonNull
public static JSONObject toJsonObject(@NonNull Reader reader) {
return new JSONObject(new JSONTokener(reader));
}
/**
* Generate an informational string describing the token at the current location
* of the provided {@code parser}.
*
* @param parser
* the JSON parser
* @return the informational string
* @throws IOException
* if an error occurred while getting the information from the parser
*/
@SuppressWarnings("null")
@NonNull
public static String toString(@NonNull JsonParser parser) throws IOException {
return new StringBuilder(32)
.append(parser.currentToken().name())
.append(" '")
.append(parser.getText())
.append('\'')
.append(generateLocationMessage(parser))
.toString();
}
/**
* Generate an informational string describing the provided {@code location}.
*
* @param location
* a JSON parser location
* @return the informational string
*/
@SuppressWarnings("null")
@NonNull
public static String toString(@NonNull JsonLocation location) {
return new StringBuilder(8)
.append(location.getLineNr())
.append(':')
.append(location.getColumnNr())
.toString();
}
@Nullable
public static JsonToken advanceTo(@NonNull JsonParser parser, JsonToken token) throws IOException {
JsonToken currentToken = null;
while (parser.hasCurrentToken() && !token.equals(currentToken = parser.currentToken())) {
currentToken = parser.nextToken();
if (LOGGER.isWarnEnabled()) {
LOGGER.warn("skipping over: {}{}",
toString(parser),
generateLocationMessage(parser));
}
}
return currentToken;
}
@SuppressWarnings({
"resource", // parser not owned
"PMD.CyclomaticComplexity" // acceptable
})
@Nullable
public static JsonToken skipNextValue(@NonNull JsonParser parser) throws IOException {
JsonToken currentToken = parser.currentToken();
// skip the field name
if (JsonToken.FIELD_NAME.equals(currentToken)) {
currentToken = parser.nextToken();
}
switch (currentToken) {
case START_ARRAY:
case START_OBJECT:
parser.skipChildren();
break;
case VALUE_FALSE:
case VALUE_NULL:
case VALUE_NUMBER_FLOAT:
case VALUE_NUMBER_INT:
case VALUE_STRING:
case VALUE_TRUE:
// do nothing
break;
default:
// error
String msg = String.format("Unhandled JsonToken %s%s.",
toString(parser),
generateLocationMessage(parser));
LOGGER.error(msg);
throw new UnsupportedOperationException(msg);
}
// advance past the value
return parser.nextToken();
}
@SuppressWarnings("PMD.CyclomaticComplexity") // acceptable
public static boolean checkEndOfValue(@NonNull JsonParser parser, @NonNull JsonToken startToken) {
JsonToken currentToken = parser.getCurrentToken();
boolean retval;
switch (startToken) { // NOPMD - intentional fall through
case START_OBJECT:
retval = JsonToken.END_OBJECT.equals(currentToken);
break;
case START_ARRAY:
retval = JsonToken.END_ARRAY.equals(currentToken);
break;
case VALUE_EMBEDDED_OBJECT:
case VALUE_FALSE:
case VALUE_NULL:
case VALUE_NUMBER_FLOAT:
case VALUE_NUMBER_INT:
case VALUE_STRING:
case VALUE_TRUE:
retval = true;
break;
default:
retval = false;
}
return retval;
}
public static void assertCurrent(
@NonNull JsonParser parser,
@NonNull JsonToken... expectedTokens) {
JsonToken current = parser.currentToken();
assert Arrays.stream(expectedTokens)
.anyMatch(expected -> expected.equals(current)) : getAssertMessage(
parser,
expectedTokens,
parser.currentToken());
}
public static void assertCurrentIsFieldValue(@NonNull JsonParser parser) {
JsonToken token = parser.currentToken();
assert token.isStructStart() || token.isScalarValue() : String.format(
"Expected a START_OBJECT, START_ARRAY, or VALUE_xxx token, but found JsonToken '%s'%s.",
token,
generateLocationMessage(parser));
}
@Nullable
public static JsonToken assertAndAdvance(
@NonNull JsonParser parser,
@NonNull JsonToken expectedToken)
throws IOException {
JsonToken token = parser.currentToken();
assert expectedToken.equals(token) : getAssertMessage(
parser,
expectedToken,
token);
return parser.nextToken();
}
@Nullable
public static JsonToken advanceAndAssert(
@NonNull JsonParser parser,
@NonNull JsonToken expectedToken)
throws IOException {
JsonToken token = parser.nextToken();
assert expectedToken.equals(token) : getAssertMessage(
parser,
expectedToken,
token);
return token;
}
@NonNull
public static String getAssertMessage(
@NonNull JsonParser parser,
@NonNull JsonToken expected,
JsonToken actual) {
return ObjectUtils.notNull(
String.format("Expected JsonToken '%s', but found JsonToken '%s'%s.",
expected,
actual,
generateLocationMessage(parser)));
}
@NonNull
public static String getAssertMessage(
@NonNull JsonParser parser,
@NonNull JsonToken[] expected,
JsonToken actual) {
List<JsonToken> expectedTokens = ObjectUtils.notNull(Arrays.asList(expected));
return getAssertMessage(parser, expectedTokens, actual);
}
@NonNull
public static String getAssertMessage(
@NonNull JsonParser parser,
@NonNull Collection<JsonToken> expected,
JsonToken actual) {
return ObjectUtils.notNull(
String.format("Expected JsonToken(s) '%s', but found JsonToken '%s'%s.",
expected.stream().map(token -> token.name()).collect(CustomCollectors.joiningWithOxfordComma("and")),
actual,
generateLocationMessage(parser)));
}
@NonNull
public static CharSequence generateLocationMessage(@NonNull JsonParser parser) {
JsonLocation location = parser.getCurrentLocation();
return location == null ? "" : generateLocationMessage(location);
}
@SuppressWarnings("null")
@NonNull
public static CharSequence generateLocationMessage(@NonNull JsonLocation location) {
return new StringBuilder()
.append(" at location '")
.append(location.getLineNr())
.append(':')
.append(location.getColumnNr())
.append('\'');
}
}