javax0.jamal.debugger.JsonConverter Maven / Gradle / Ivy
package javax0.jamal.debugger;
import java.util.List;
import java.util.Map;
/**
* An extremely simple JSON converter for the HTTP debugger.
*/
public class JsonConverter {
/*
* Note about why I do not use a well-established, external JSON library:
*
* When you are developing an application, you should usually opt for the use of a library. Writing a simple class
* like this takes no more than 30 minutes at the start. In an application, however, there comes a time when you
* need more and more features. At a certain point in time, the cumulated maintenance effort will become more than
* the difference between the initial 30min development time of the simple class and tasks needed to utilize an
* external library. These are careful library research, selection, learning, integration and library
* version change, and security screening and follow-up.
*
* The two costs considering the Total Cost of Ownership have to be carefully measured. Using the external library
* almost always wins.
*
* When you are developing a library, you should consider the same costs. However, there is a multiplication factor
* when you think of the library version change and security screening and follow-up in this case. This part of the
* cost, which uses an external library heavier, should be multiplied by the number of installation users will
* utilize your library. It means that you should consider using an external library
*
if you intend to use a lot of features (the development is not 30min),
* you expect the library to be highly stable, rarely changing, not even for security reasons,
* you wish only a very few users for your library.
*/
static String object2Json(Object in) {
final var sb = new StringBuilder();
if (in instanceof Map) {
final var map = (Map) in;
String sep = "";
sb.append("{");
for (final var e : map.entrySet()) {
sb.append(sep);
sb.append("\"");
sb.append(escape(e.getKey().toString()));
sb.append("\": ");
sb.append(object2Json(e.getValue()));
sep = ", ";
}
sb.append("}");
return sb.toString();
}
if (in instanceof List) {
final var list = (List) in;
String sep = "";
sb.append("[");
for (final var e : list) {
sb.append(sep);
sb.append(object2Json(e));
sep = ", ";
}
sb.append("]");
return sb.toString();
}
return "\"" + escape(in.toString()) + "\"";
}
private static String escape(String s) {
return s.replace("\\", "\\\\")
.replace("\t", "\\t")
.replace("\b", "\\b")
.replace("\n", "\\n")
.replace("\r", "\\r")
.replace("\f", "\\f")
.replace("\"", "\\\"");
}
}