求救高手！急
import java.lang.ref.WeakReference;
/**
* Class to research strings.
* constant string like "AAA " won 't be reclaimed while instance created by new will.
*/
public class StringResearch {

public static void main(String[] args) {
String a = "AAA ";
String b = new String( "AAA ");

WeakReference wra = new WeakReference(a);
WeakReference wrb = new WeakReference(b);

a = null;
b = null;

System.gc();

System.out.println(wra.get());
System.out.println(wrb.get());
}

}

程序输出如下
AAA
null

根据以上结果，请说明通常情况下如何定义新的String变量比较好，并说明理由。


[解决办法]
我记得应该是String a = "AAA "; 这个方法比较好，两个对象a, "AAA "。
String b = new String( "AAA "); 据说是多创建一个对象,3个对象a, "AAA "和引用 "AAA "的对象。

[解决办法]
1楼正解
[解决办法]
String a = "AAA ";
String b = new String( "AAA ");
一般前面的好
a是一个引用
b是个内存空间