package net.hockeyapp.android.metrics;
import net.hockeyapp.android.metrics.model.IJsonSerializable;
import java.io.IOException;
import java.io.Writer;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* This is the helper class to have the json to integer/double/string and ext
* converting.
*/
public final class JsonHelper {
private static final int CONTROL_CHARACTER_RANGE = 0x80;
private static final String[] CONTROL_CHARACTERS;
static {
CONTROL_CHARACTERS = new String[CONTROL_CHARACTER_RANGE];
// per RFC 4627 (JSON specification) section 2.5; escape control characters U+0000 -> U+001F
for (int i = 0; i <= 0x1f; i++) {
CONTROL_CHARACTERS[i] = String.format("\\u%04X", i);
}
// additionally escape quotation mark, reverse solidus, line breaks and whitespace
CONTROL_CHARACTERS['\"'] = "\\\"";
CONTROL_CHARACTERS['\\'] = "\\\\";
CONTROL_CHARACTERS['\b'] = "\\b";
CONTROL_CHARACTERS['\f'] = "\\f";
CONTROL_CHARACTERS['\n'] = "\\n";
CONTROL_CHARACTERS['\r'] = "\\r";
CONTROL_CHARACTERS['\t'] = "\\t";
}
/**
* prevent caller to construct this object.
*/
private JsonHelper() {
}
/**
* Escapes all characters in a string per JSON specification
*
* @param input the string to escape
* @return the input with all characters JSON escaped
*/
private static String escapeJSON(String input) {
StringBuilder builder = new StringBuilder();
builder.append("\"");
for (int i = 0; i < input.length(); i++) {
char charIndex = input.charAt(i);
if (charIndex < CONTROL_CHARACTER_RANGE) {
String replacement = CONTROL_CHARACTERS[charIndex];
if (replacement == null) {
builder.append(charIndex);
} else {
builder.append(replacement);
}
} else if (charIndex == '\u2028') {
// JavaScript interprets '\u2028' as newline
builder.append("\\u2028");
} else if (charIndex == '\u2029') {
// JavaScript interprets '\u2029' as newline
builder.append("\\u2029");
} else {
builder.append(charIndex);
}
}
builder.append("\"");
return builder.toString();
}
/**
* integer to string.
*
* @param value value of the integer.
* @return String to represent the integer
*/
public static String convert(Integer value) {
return Integer.toString(value);
}
/**
* long to string.
*
* @param value value of the integer.
* @return String to represent the long
*/
public static String convert(Long value) {
return Long.toString(value);
}
/**
* character to string.
*
* @param value value of the character.
* @return String to represent the character
*/
public static String convert(char value) {
return Character.toString(value);
}
/**
* float to string.
*
* @param value value of the float.
* @return String to represent the float
*/
public static String convert(Float value) {
return Float.toString(value);
}
/**
* double to string.
*
* @param value value of the double.
* @return String to represent the double
*/
public static String convert(Double value) {
return Double.toString(value);
}
/**
* boolean to string.
*
* @param value value of the boolean.
* @return String to represent the boolean
*/
public static String convert(boolean value) {
return Boolean.toString(value);
}
/**
* String to JSON String
*
* @param value value of the string
* @return JSON string to represent the string input parameter.
*/
public static String convert(String value) {
if (value == null) {
return "null";
} else if (value.length() == 0) {
return "\"\"";
} else {
return escapeJSON(value);
}
}
/**
* serialize the IJsonSerializable to writer
*
* @param writer Writer object
* @param value IJsonSerializable object
* @throws IOException
*/
public static void writeJsonSerializable(Writer writer, IJsonSerializable value)
throws IOException {
if (value != null) {
value.serialize(writer);
}
}
/**
* serialize the map object to writer
*
* @param writer Writer object
* @param map Map object
* @throws IOException
*/
public static <T> void writeDictionary(Writer writer, Map<String, T> map) throws IOException {
if (map == null || map.isEmpty()) {
writer.write("null");
} else {
Set<String> keys = map.keySet();
Iterator<String> iterator = keys.iterator();
// special first case to ensure we have contents and that
if (iterator.hasNext()) {
writer.write("{");
String key = iterator.next();
T item = map.get(key);
writer.write("\"" + key + "\"");
writer.write(":");
writeItem(writer, item);
while (iterator.hasNext()) {
key = iterator.next();
writer.write(",");
writer.write("\"" + key + "\"");
writer.write(":");
item = map.get(key);
writeItem(writer, item);
}
writer.write("}");
}
}
}
/**
* serialize the List object to writer
*
* @param writer Writer object
* @param list List object
* @throws IOException
*/
public static <T extends IJsonSerializable> void writeList(Writer writer, List<T> list) throws IOException {
if (list == null || list.isEmpty()) {
writer.write("null");
} else {
Iterator<T> iterator = list.iterator();
if (iterator.hasNext()) {
writer.write("[");
IJsonSerializable item = iterator.next();
item.serialize(writer);
while (iterator.hasNext()) {
item = iterator.next();
writer.write(",");
item.serialize(writer);
}
writer.write("]");
}
}
}
/**
* Emits a primitive item of unknown type to the writer
*
* @param writer The writer to which this item will be emitted
* @param item The item to write
* @param <T> The type of the item
* @throws IOException if no handler exists for the type
*/
private static <T> void writeItem(Writer writer, T item) throws IOException {
if (item != null) {
if (item instanceof String) {
writer.write(JsonHelper.convert((String) item));
} else if (item instanceof Double) {
writer.write(JsonHelper.convert((Double) item));
} else if (item instanceof Integer) {
writer.write(JsonHelper.convert((Integer) item));
} else if (item instanceof Long) {
writer.write(JsonHelper.convert((Long) item));
} else if (item instanceof IJsonSerializable) {
((IJsonSerializable) item).serialize(writer);
} else {
throw new IOException("Cannot serialize: " + item.toString());
}
} else {
writer.write("null");
}
}
}