Gson

JSON 的 serialization 库，挺好用。

import com.google.gson.Gson ;
import java.util.List ;
import java.util.Map ;
import java.util.HashMap ;
import java.util.Arrays ;

public class TestGson {
    public static class Foo {
        public int a ;
        public String b ;
        public int[] c ;
        public List d ;
        public Map e ;
    }

    public static void main (String[] args) {
        Foo bar = new Foo ();
        bar.a = 1 ;
        bar.b = "abc" ;
        bar.c = new int[] {6,7,8} ;
        bar.d = Arrays.asList ("hello", "world") ;
        bar.e = new HashMap () ;
        bar.e.put ("zoo", 3) ;
        bar.e.put ("keeper", 5) ;

        Gson gson = new Gson () ;
        String s = gson.toJson (bar) ;
        System.out.println (s) ;
        Foo bb = gson.fromJson (s, Foo.class) ;
        System.out.println (gson.toJson (bb)) ;
    }
}

文档见此。