zipkin2.internal.JsonEscaper Maven / Gradle / Ivy
/*
* Copyright 2015-2019 The OpenZipkin Authors
*
* Licensed 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 zipkin2.internal;
public final class JsonEscaper {
/** Exposed for ElasticSearch HttpBulkIndexer */
public static CharSequence jsonEscape(CharSequence v) {
int length = v.length();
if (length == 0) return v;
int afterReplacement = 0;
StringBuilder builder = null;
for (int i = 0; i < length; i++) {
char c = v.charAt(i);
String replacement;
if (c < 0x80) {
replacement = REPLACEMENT_CHARS[c];
if (replacement == null) continue;
} else if (c == '\u2028') {
replacement = U2028;
} else if (c == '\u2029') {
replacement = U2029;
} else {
continue;
}
if (afterReplacement < i) { // write characters between the last replacement and now
if (builder == null) builder = new StringBuilder(length);
builder.append(v, afterReplacement, i);
}
if (builder == null) builder = new StringBuilder(length);
builder.append(replacement);
afterReplacement = i + 1;
}
if (builder == null) return v; // then we didn't escape anything
if (afterReplacement < length) {
builder.append(v, afterReplacement, length);
}
return builder;
}
/*
* Escaping logic adapted from Moshi, which we couldn't use due to language level
*
* From RFC 7159, "All Unicode characters may be placed within the
* quotation marks except for the characters that must be escaped:
* quotation mark, reverse solidus, and the control characters
* (U+0000 through U+001F)."
*
* We also escape '\u2028' and '\u2029', which JavaScript interprets as
* newline characters. This prevents eval() from failing with a syntax
* error. http://code.google.com/p/google-gson/issues/detail?id=341
*/
private static final String[] REPLACEMENT_CHARS;
static {
REPLACEMENT_CHARS = new String[128];
for (int i = 0; i <= 0x1f; i++) {
REPLACEMENT_CHARS[i] = String.format("\\u%04x", (int) i);
}
REPLACEMENT_CHARS['"'] = "\\\"";
REPLACEMENT_CHARS['\\'] = "\\\\";
REPLACEMENT_CHARS['\t'] = "\\t";
REPLACEMENT_CHARS['\b'] = "\\b";
REPLACEMENT_CHARS['\n'] = "\\n";
REPLACEMENT_CHARS['\r'] = "\\r";
REPLACEMENT_CHARS['\f'] = "\\f";
}
private static final String U2028 = "\\u2028";
private static final String U2029 = "\\u2029";
public static int jsonEscapedSizeInBytes(CharSequence v) {
boolean ascii = true;
int escapingOverhead = 0;
for (int i = 0, length = v.length(); i < length; i++) {
char c = v.charAt(i);
if (c == '\u2028' || c == '\u2029') {
escapingOverhead += 5;
} else if (c >= 0x80) {
ascii = false;
} else {
String maybeReplacement = REPLACEMENT_CHARS[c];
if (maybeReplacement != null) escapingOverhead += maybeReplacement.length() - 1;
}
}
if (ascii) return v.length() + escapingOverhead;
return WriteBuffer.utf8SizeInBytes(v) + escapingOverhead;
}
}