// Protocol Buffers - Google's data interchange format
// Copyright 2013 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
// 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,
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package com.google.protobuf.nano;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
/**
* Static helper methods for printing nano protos.
*
* @author flynn@google.com Andrew Flynn
*/
public final class MessageNanoPrinter {
// Do not allow instantiation
private MessageNanoPrinter() {}
private static final String INDENT = " ";
private static final int MAX_STRING_LEN = 200;
/**
* Returns an text representation of a MessageNano suitable for debugging.
*
*
Employs Java reflection on the given object and recursively prints primitive fields,
* groups, and messages.
*/
public static String print(T message) {
if (message == null) {
return "null";
}
StringBuffer buf = new StringBuffer();
try {
print(message.getClass().getSimpleName(), message.getClass(), message,
new StringBuffer(), buf);
} catch (IllegalAccessException e) {
return "Error printing proto: " + e.getMessage();
}
return buf.toString();
}
/**
* Function that will print the given message/class into the StringBuffer.
* Meant to be called recursively.
*/
private static void print(String identifier, Class> clazz, Object message,
StringBuffer indentBuf, StringBuffer buf) throws IllegalAccessException {
if (MessageNano.class.isAssignableFrom(clazz)) {
// Nano proto message
buf.append(indentBuf).append(identifier);
// If null, just print it and return
if (message == null) {
buf.append(": ").append(message).append("\n");
return;
}
indentBuf.append(INDENT);
buf.append(" <\n");
for (Field field : clazz.getFields()) {
// Proto fields are public, non-static variables that do not begin or end with '_'
int modifiers = field.getModifiers();
String fieldName = field.getName();
if ((modifiers & Modifier.PUBLIC) != Modifier.PUBLIC
|| (modifiers & Modifier.STATIC) == Modifier.STATIC
|| fieldName.startsWith("_") || fieldName.endsWith("_")) {
continue;
}
Class > fieldType = field.getType();
Object value = field.get(message);
if (fieldType.isArray()) {
Class> arrayType = fieldType.getComponentType();
// bytes is special since it's not repeated, but is represented by an array
if (arrayType == byte.class) {
print(fieldName, fieldType, value, indentBuf, buf);
} else {
int len = Array.getLength(value);
for (int i = 0; i < len; i++) {
Object elem = Array.get(value, i);
print(fieldName, arrayType, elem, indentBuf, buf);
}
}
} else {
print(fieldName, fieldType, value, indentBuf, buf);
}
}
indentBuf.delete(indentBuf.length() - INDENT.length(), indentBuf.length());
buf.append(indentBuf).append(">\n");
} else {
// Primitive value
identifier = deCamelCaseify(identifier);
buf.append(indentBuf).append(identifier).append(": ");
if (message instanceof String) {
String stringMessage = sanitizeString((String) message);
buf.append("\"").append(stringMessage).append("\"");
} else {
buf.append(message);
}
buf.append("\n");
}
}
/**
* Converts an identifier of the format "FieldName" into "field_name".
*/
private static String deCamelCaseify(String identifier) {
StringBuffer out = new StringBuffer();
for (int i = 0; i < identifier.length(); i++) {
char currentChar = identifier.charAt(i);
if (i == 0) {
out.append(Character.toLowerCase(currentChar));
} else if (Character.isUpperCase(currentChar)) {
out.append('_').append(Character.toLowerCase(currentChar));
} else {
out.append(currentChar);
}
}
return out.toString();
}
/**
* Shortens and escapes the given string.
*/
private static String sanitizeString(String str) {
if (!str.startsWith("http") && str.length() > MAX_STRING_LEN) {
// Trim non-URL strings.
str = str.substring(0, MAX_STRING_LEN) + "[...]";
}
return escapeString(str);
}
/**
* Escape everything except for low ASCII code points.
*/
private static String escapeString(String str) {
int strLen = str.length();
StringBuilder b = new StringBuilder(strLen);
for (int i = 0; i < strLen; i++) {
char original = str.charAt(i);
if (original >= ' ' && original <= '~' && original != '"' && original != '\'') {
b.append(original);
} else {
b.append(String.format("\\u%04x", (int) original));
}
}
return b.toString();
}
}