com.squareup.moshi.JsonUtf8Writer Maven / Gradle / Ivy
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/*
* Copyright (C) 2010 Google Inc.
*
* 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 com.squareup.moshi;
import com.jn.langx.annotation.Nullable;
import okio.*;
import java.io.IOException;
import static com.squareup.moshi.JsonScope.*;
final class JsonUtf8Writer extends JsonWriter {
/*
* 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";
}
/**
* The output data, containing at most one top-level array or object.
*/
private final BufferedSink sink;
/**
* The name/value separator; either ":" or ": ".
*/
private String separator = ":";
private String deferredName;
JsonUtf8Writer(BufferedSink sink) {
if (sink == null) {
throw new NullPointerException("sink == null");
}
this.sink = sink;
pushScope(EMPTY_DOCUMENT);
}
@Override
public void setIndent(String indent) {
super.setIndent(indent);
this.separator = !indent.isEmpty() ? ": " : ":";
}
@Override
public JsonWriter beginArray() throws IOException {
if (promoteValueToName) {
throw new IllegalStateException(
"Array cannot be used as a map key in JSON at path " + getPath());
}
writeDeferredName();
return open(EMPTY_ARRAY, NONEMPTY_ARRAY, '[');
}
@Override
public JsonWriter endArray() throws IOException {
return close(EMPTY_ARRAY, NONEMPTY_ARRAY, ']');
}
@Override
public JsonWriter beginObject() throws IOException {
if (promoteValueToName) {
throw new IllegalStateException(
"Object cannot be used as a map key in JSON at path " + getPath());
}
writeDeferredName();
return open(EMPTY_OBJECT, NONEMPTY_OBJECT, '{');
}
@Override
public JsonWriter endObject() throws IOException {
promoteValueToName = false;
return close(EMPTY_OBJECT, NONEMPTY_OBJECT, '}');
}
/**
* Enters a new scope by appending any necessary whitespace and the given
* bracket.
*/
private JsonWriter open(int empty, int nonempty, char openBracket) throws IOException {
if (stackSize == flattenStackSize
&& (scopes[stackSize - 1] == empty || scopes[stackSize - 1] == nonempty)) {
// Cancel this open. Invert the flatten stack size until this is closed.
flattenStackSize = ~flattenStackSize;
return this;
}
beforeValue();
checkStack();
pushScope(empty);
pathIndices[stackSize - 1] = 0;
sink.writeByte(openBracket);
return this;
}
/**
* Closes the current scope by appending any necessary whitespace and the
* given bracket.
*/
private JsonWriter close(int empty, int nonempty, char closeBracket) throws IOException {
int context = peekScope();
if (context != nonempty && context != empty) {
throw new IllegalStateException("Nesting problem.");
}
if (deferredName != null) {
throw new IllegalStateException("Dangling name: " + deferredName);
}
if (stackSize == ~flattenStackSize) {
// Cancel this close. Restore the flattenStackSize so we're ready to flatten again!
flattenStackSize = ~flattenStackSize;
return this;
}
stackSize--;
pathNames[stackSize] = null; // Free the last path name so that it can be garbage collected!
pathIndices[stackSize - 1]++;
if (context == nonempty) {
newline();
}
sink.writeByte(closeBracket);
return this;
}
@Override
public JsonWriter name(String name) throws IOException {
if (name == null) {
throw new NullPointerException("name == null");
}
if (stackSize == 0) {
throw new IllegalStateException("JsonWriter is closed.");
}
int context = peekScope();
if ((context != EMPTY_OBJECT && context != NONEMPTY_OBJECT) || deferredName != null) {
throw new IllegalStateException("Nesting problem.");
}
deferredName = name;
pathNames[stackSize - 1] = name;
promoteValueToName = false;
return this;
}
private void writeDeferredName() throws IOException {
if (deferredName != null) {
beforeName();
string(sink, deferredName);
deferredName = null;
}
}
@Override
public JsonWriter value(String value) throws IOException {
if (value == null) {
return nullValue();
}
if (promoteValueToName) {
return name(value);
}
writeDeferredName();
beforeValue();
string(sink, value);
pathIndices[stackSize - 1]++;
return this;
}
@Override
public JsonWriter nullValue() throws IOException {
if (promoteValueToName) {
throw new IllegalStateException(
"null cannot be used as a map key in JSON at path " + getPath());
}
if (deferredName != null) {
if (serializeNulls) {
writeDeferredName();
} else {
deferredName = null;
return this; // skip the name and the value
}
}
beforeValue();
sink.writeUtf8("null");
pathIndices[stackSize - 1]++;
return this;
}
@Override
public JsonWriter value(boolean value) throws IOException {
if (promoteValueToName) {
throw new IllegalStateException(
"Boolean cannot be used as a map key in JSON at path " + getPath());
}
writeDeferredName();
beforeValue();
sink.writeUtf8(value ? "true" : "false");
pathIndices[stackSize - 1]++;
return this;
}
@Override
public JsonWriter value(Boolean value) throws IOException {
if (value == null) {
return nullValue();
}
return value(value.booleanValue());
}
@Override
public JsonWriter value(double value) throws IOException {
if (!lenient && (Double.isNaN(value) || Double.isInfinite(value))) {
throw new IllegalArgumentException("Numeric values must be finite, but was " + value);
}
if (promoteValueToName) {
return name(Double.toString(value));
}
writeDeferredName();
beforeValue();
sink.writeUtf8(Double.toString(value));
pathIndices[stackSize - 1]++;
return this;
}
@Override
public JsonWriter value(long value) throws IOException {
if (promoteValueToName) {
return name(Long.toString(value));
}
writeDeferredName();
beforeValue();
sink.writeUtf8(Long.toString(value));
pathIndices[stackSize - 1]++;
return this;
}
@Override
public JsonWriter value(@Nullable Number value) throws IOException {
if (value == null) {
return nullValue();
}
String string = value.toString();
if (!lenient
&& (string.equals("-Infinity") || string.equals("Infinity") || string.equals("NaN"))) {
throw new IllegalArgumentException("Numeric values must be finite, but was " + value);
}
if (promoteValueToName) {
return name(string);
}
writeDeferredName();
beforeValue();
sink.writeUtf8(string);
pathIndices[stackSize - 1]++;
return this;
}
@Override
public BufferedSink valueSink() throws IOException {
if (promoteValueToName) {
throw new IllegalStateException(
"BufferedSink cannot be used as a map key in JSON at path " + getPath());
}
writeDeferredName();
beforeValue();
pushScope(STREAMING_VALUE);
return Okio.buffer(new Sink() {
@Override
public void write(Buffer source, long byteCount) throws IOException {
sink.write(source, byteCount);
}
@Override
public void close() {
if (peekScope() != STREAMING_VALUE) {
throw new AssertionError();
}
stackSize--; // Remove STREAMING_VALUE from the stack.
pathIndices[stackSize - 1]++;
}
@Override
public void flush() throws IOException {
sink.flush();
}
@Override
public Timeout timeout() {
return Timeout.NONE;
}
});
}
/**
* Ensures all buffered data is written to the underlying {@link Sink}
* and flushes that writer.
*/
@Override
public void flush() throws IOException {
if (stackSize == 0) {
throw new IllegalStateException("JsonWriter is closed.");
}
sink.flush();
}
/**
* Flushes and closes this writer and the underlying {@link Sink}.
*
* @throws JsonDataException if the JSON document is incomplete.
*/
@Override
public void close() throws IOException {
sink.close();
int size = stackSize;
if (size > 1 || size == 1 && scopes[size - 1] != NONEMPTY_DOCUMENT) {
throw new IOException("Incomplete document");
}
stackSize = 0;
}
/**
* Writes {@code value} as a string literal to {@code sink}. This wraps the value in double quotes
* and escapes those characters that require it.
*/
static void string(BufferedSink sink, String value) throws IOException {
String[] replacements = REPLACEMENT_CHARS;
sink.writeByte('"');
int last = 0;
int length = value.length();
for (int i = 0; i < length; i++) {
char c = value.charAt(i);
String replacement;
if (c < 128) {
replacement = replacements[c];
if (replacement == null) {
continue;
}
} else if (c == '\u2028') {
replacement = "\\u2028";
} else if (c == '\u2029') {
replacement = "\\u2029";
} else {
continue;
}
if (last < i) {
sink.writeUtf8(value, last, i);
}
sink.writeUtf8(replacement);
last = i + 1;
}
if (last < length) {
sink.writeUtf8(value, last, length);
}
sink.writeByte('"');
}
private void newline() throws IOException {
if (indent == null) {
return;
}
sink.writeByte('\n');
for (int i = 1, size = stackSize; i < size; i++) {
sink.writeUtf8(indent);
}
}
/**
* Inserts any necessary separators and whitespace before a name. Also
* adjusts the stack to expect the name's value.
*/
private void beforeName() throws IOException {
int context = peekScope();
if (context == NONEMPTY_OBJECT) { // first in object
sink.writeByte(',');
} else if (context != EMPTY_OBJECT) { // not in an object!
throw new IllegalStateException("Nesting problem.");
}
newline();
replaceTop(DANGLING_NAME);
}
/**
* Inserts any necessary separators and whitespace before a literal value,
* inline array, or inline object. Also adjusts the stack to expect either a
* closing bracket or another element.
*/
@SuppressWarnings("fallthrough")
private void beforeValue() throws IOException {
int nextTop;
switch (peekScope()) {
case NONEMPTY_DOCUMENT:
if (!lenient) {
throw new IllegalStateException(
"JSON must have only one top-level value.");
}
// fall-through
case EMPTY_DOCUMENT: // first in document
nextTop = NONEMPTY_DOCUMENT;
break;
case NONEMPTY_ARRAY: // another in array
sink.writeByte(',');
// fall-through
case EMPTY_ARRAY: // first in array
newline();
nextTop = NONEMPTY_ARRAY;
break;
case DANGLING_NAME: // value for name
nextTop = NONEMPTY_OBJECT;
sink.writeUtf8(separator);
break;
case STREAMING_VALUE:
throw new IllegalStateException("Sink from valueSink() was not closed");
default:
throw new IllegalStateException("Nesting problem.");
}
replaceTop(nextTop);
}
}