auto-string-formatter is a string formatting library for Java, generating optimized formatter methods at compile time with annotation processing.
auto-string-formatter has the following features:
- Fast as hand-written code with
StringBuilder. - (Mostly) compatible for
String.format.
auto-string-formatter requires JDK 8 (1.8.0_65 or later) to run annotation processors.
Just define a format with @AutoStringFormatter and @Format, and use it.
package com.github.imasahiro.stringformatter.example;
import com.github.imasahiro.stringformatter.annotation.AutoStringFormatter;
import com.github.imasahiro.stringformatter.annotation.Format;
public class Example {
@AutoStringFormatter
interface Formatter {
@Format("Hi %s, my name is %s.")
String formatTo(String friendName, String myName);
}
public static void main(String... args) {
System.out.println(new Example_Formatter().formatTo("Alice", "Bob"));
}
}Then the annotation processor generate following java code based on AutoStringFormatter annotation.
package com.github.imasahiro.stringformatter.example;
import java.lang.String;
import javax.annotation.Generated;
import javax.inject.Inject;
import javax.inject.Named;
@Generated({"com.github.imasahiro.stringformatter.processor.StringFormatterProcessor"})
@Named
public final class Example_Formatter implements Example.Formatter {
@Inject
Example_Formatter() {
}
public final String formatTo(final String arg0, final String arg1) {
final StringBuilder sb = new StringBuilder(16);
sb.append("Hi ");
sb.append(String.valueOf(arg0));
sb.append(", my name is ");
sb.append(String.valueOf(arg1));
sb.append(".");
return sb.toString();
}
}