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import java.util.Vector;
class CEL {
void method (Vector vector) {
for (int i = 0; i < vector.size (); i++) // Violation
; // ...
}
}
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class CEL_fixed {
void method (Vector vector) {
int size = vector.size ()
for (int i = 0; i < size; i++)
; // ...
}
}
¶þ¡¢Îª'Vectors' ºÍ 'Hashtables'¶¨Òå³õʼ´óС
JVMΪVectorÀ©³ä´óСµÄʱºòÐèÒªÖØÐ´´½¨Ò»¸ö¸ü´óµÄÊý×飬½«ÔÔÏÈÊý×éÖеÄÄÚÈݸ´ÖƹýÀ´£¬×îºó£¬ÔÏȵÄÊý×éÔÙ±»»ØÊÕ¡£¿É¼ûVectorÈÝÁ¿µÄÀ©´óÊÇÒ»¸öÆÄ·Ñʱ¼äµÄÊ¡£
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import java.util.Vector;
public class DIC {
public void addObjects (Object[] o) {
// if length > 10, Vector needs to expand
for (int i = 0; i< o.length;i++) {
v.add(o); // capacity before it can add more elements.
}
}
public Vector v = new Vector(); // no initialCapacity.
}
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public Vector v = new Vector(20);
public Hashtable hash = new Hashtable(10);
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Dov Bulka, "Java Performance and Scalability Volume 1: Server-Side Programming
Techniques" Addison Wesley, ISBN: 0-201-70429-3 pp.55 – 57
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