com.google.protobuf.MessageLiteToString Maven / Gradle / Ivy
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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package com.google.protobuf;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
/** Helps generate {@link String} representations of {@link MessageLite} protos. */
final class MessageLiteToString {
private static final String LIST_SUFFIX = "List";
private static final String BUILDER_LIST_SUFFIX = "OrBuilderList";
private static final String MAP_SUFFIX = "Map";
private static final String BYTES_SUFFIX = "Bytes";
private MessageLiteToString() {
// Classes which are not intended to be instantiated should be made non-instantiable with a
// private constructor. This includes utility classes (classes with only static members).
}
/**
* Returns a {@link String} representation of the {@link MessageLite} object. The first line of
* the {@code String} representation includes a comment string to uniquely identify
* the object instance. This acts as an indicator that this should not be relied on for
* comparisons.
*/
static String toString(MessageLite messageLite, String commentString) {
StringBuilder buffer = new StringBuilder();
buffer.append("# ").append(commentString);
reflectivePrintWithIndent(messageLite, buffer, 0);
return buffer.toString();
}
/**
* Reflectively prints the {@link MessageLite} to the buffer at given {@code indent} level.
*
* @param buffer the buffer to write to
* @param indent the number of spaces to indent the proto by
*/
private static void reflectivePrintWithIndent(
MessageLite messageLite, StringBuilder buffer, int indent) {
// Build a map of method name to method. We're looking for methods like getFoo(), hasFoo(),
// getFooList() and getFooMap() which might be useful for building an object's string
// representation.
Map nameToNoArgMethod = new HashMap<>();
Map nameToMethod = new HashMap<>();
Set getters = new TreeSet<>();
for (Method method : messageLite.getClass().getDeclaredMethods()) {
nameToMethod.put(method.getName(), method);
if (method.getParameterTypes().length == 0) {
nameToNoArgMethod.put(method.getName(), method);
if (method.getName().startsWith("get")) {
getters.add(method.getName());
}
}
}
for (String getter : getters) {
String suffix = getter.startsWith("get") ? getter.substring(3) : getter;
if (suffix.endsWith(LIST_SUFFIX)
&& !suffix.endsWith(BUILDER_LIST_SUFFIX)
// Sometimes people have fields named 'list' that aren't repeated.
&& !suffix.equals(LIST_SUFFIX)) {
String camelCase =
suffix.substring(0, 1).toLowerCase()
+ suffix.substring(1, suffix.length() - LIST_SUFFIX.length());
// Try to reflectively get the value and toString() the field as if it were repeated. This
// only works if the method names have not been proguarded out or renamed.
Method listMethod = nameToNoArgMethod.get(getter);
if (listMethod != null && listMethod.getReturnType().equals(List.class)) {
printField(
buffer,
indent,
camelCaseToSnakeCase(camelCase),
GeneratedMessageLite.invokeOrDie(listMethod, messageLite));
continue;
}
}
if (suffix.endsWith(MAP_SUFFIX)
// Sometimes people have fields named 'map' that aren't maps.
&& !suffix.equals(MAP_SUFFIX)) {
String camelCase =
suffix.substring(0, 1).toLowerCase()
+ suffix.substring(1, suffix.length() - MAP_SUFFIX.length());
// Try to reflectively get the value and toString() the field as if it were a map. This only
// works if the method names have not been proguarded out or renamed.
Method mapMethod = nameToNoArgMethod.get(getter);
if (mapMethod != null
&& mapMethod.getReturnType().equals(Map.class)
// Skip the deprecated getter method with no prefix "Map" when the field name ends with
// "map".
&& !mapMethod.isAnnotationPresent(Deprecated.class)
// Skip the internal mutable getter method.
&& Modifier.isPublic(mapMethod.getModifiers())) {
printField(
buffer,
indent,
camelCaseToSnakeCase(camelCase),
GeneratedMessageLite.invokeOrDie(mapMethod, messageLite));
continue;
}
}
Method setter = nameToMethod.get("set" + suffix);
if (setter == null) {
continue;
}
if (suffix.endsWith(BYTES_SUFFIX)
&& nameToNoArgMethod.containsKey(
"get" + suffix.substring(0, suffix.length() - "Bytes".length()))) {
// Heuristic to skip bytes based accessors for string fields.
continue;
}
String camelCase = suffix.substring(0, 1).toLowerCase() + suffix.substring(1);
// Try to reflectively get the value and toString() the field as if it were optional. This
// only works if the method names have not been proguarded out or renamed.
Method getMethod = nameToNoArgMethod.get("get" + suffix);
Method hasMethod = nameToNoArgMethod.get("has" + suffix);
// TODO(dweis): Fix proto3 semantics.
if (getMethod != null) {
Object value = GeneratedMessageLite.invokeOrDie(getMethod, messageLite);
final boolean hasValue =
hasMethod == null
? !isDefaultValue(value)
: (Boolean) GeneratedMessageLite.invokeOrDie(hasMethod, messageLite);
// TODO(dweis): This doesn't stop printing oneof case twice: value and enum style.
if (hasValue) {
printField(buffer, indent, camelCaseToSnakeCase(camelCase), value);
}
continue;
}
}
if (messageLite instanceof GeneratedMessageLite.ExtendableMessage) {
Iterator> iter =
((GeneratedMessageLite.ExtendableMessage) messageLite).extensions.iterator();
while (iter.hasNext()) {
Map.Entry entry = iter.next();
printField(buffer, indent, "[" + entry.getKey().getNumber() + "]", entry.getValue());
}
}
if (((GeneratedMessageLite) messageLite).unknownFields != null) {
((GeneratedMessageLite) messageLite).unknownFields.printWithIndent(buffer, indent);
}
}
private static boolean isDefaultValue(Object o) {
if (o instanceof Boolean) {
return !((Boolean) o);
}
if (o instanceof Integer) {
return ((Integer) o) == 0;
}
if (o instanceof Float) {
return Float.floatToRawIntBits((Float) o) == 0;
}
if (o instanceof Double) {
return Double.doubleToRawLongBits((Double) o) == 0;
}
if (o instanceof String) {
return o.equals("");
}
if (o instanceof ByteString) {
return o.equals(ByteString.EMPTY);
}
if (o instanceof MessageLite) { // Can happen in oneofs.
return o == ((MessageLite) o).getDefaultInstanceForType();
}
if (o instanceof java.lang.Enum) { // Catches oneof enums.
return ((java.lang.Enum) o).ordinal() == 0;
}
return false;
}
/**
* Formats a text proto field.
*
* For use by generated code only.
*
* @param buffer the buffer to write to
* @param indent the number of spaces the proto should be indented by
* @param name the field name (in lower underscore case)
* @param object the object value of the field
*/
static final void printField(StringBuilder buffer, int indent, String name, Object object) {
if (object instanceof List) {
List list = (List) object;
for (Object entry : list) {
printField(buffer, indent, name, entry);
}
return;
}
if (object instanceof Map) {
Map map = (Map) object;
for (Map.Entry entry : map.entrySet()) {
printField(buffer, indent, name, entry);
}
return;
}
buffer.append('\n');
for (int i = 0; i < indent; i++) {
buffer.append(' ');
}
buffer.append(name);
if (object instanceof String) {
buffer.append(": \"").append(TextFormatEscaper.escapeText((String) object)).append('"');
} else if (object instanceof ByteString) {
buffer.append(": \"").append(TextFormatEscaper.escapeBytes((ByteString) object)).append('"');
} else if (object instanceof GeneratedMessageLite) {
buffer.append(" {");
reflectivePrintWithIndent((GeneratedMessageLite) object, buffer, indent + 2);
buffer.append("\n");
for (int i = 0; i < indent; i++) {
buffer.append(' ');
}
buffer.append("}");
} else if (object instanceof Map.Entry) {
buffer.append(" {");
Map.Entry entry = (Map.Entry) object;
printField(buffer, indent + 2, "key", entry.getKey());
printField(buffer, indent + 2, "value", entry.getValue());
buffer.append("\n");
for (int i = 0; i < indent; i++) {
buffer.append(' ');
}
buffer.append("}");
} else {
buffer.append(": ").append(object);
}
}
private static final String camelCaseToSnakeCase(String camelCase) {
StringBuilder builder = new StringBuilder();
for (int i = 0; i < camelCase.length(); i++) {
char ch = camelCase.charAt(i);
if (Character.isUpperCase(ch)) {
builder.append("_");
}
builder.append(Character.toLowerCase(ch));
}
return builder.toString();
}
}