來至:gotesting軟件測試聯盟論壇 http://www.78test.com
public class TestCharacter {
public TestCharacter(){
}
public void test(String s){
long begin = System.currentTimeMillis();
for(int i=0; i<time; i++){
s += "add";
}
long over = System.currentTimeMillis();
System.out.println("操作"+s.getClass().getName()+"類型使用的時間爲:"+(over-begin)+"毫秒");
}
public void test(StringBuffer s){
long begin = System.currentTimeMillis();
for(int i=0; i<time; i++){
s.append("add");
}
long over = System.currentTimeMillis();
System.out.println("操作"+s.getClass().getCanonicalName()+"類型使用的時間爲:"+(over-begin)+"毫秒");
}
public void test(StringBuilder s){
long begin = System.currentTimeMillis();
for(int i=0; i<time; i++){
s.append("add");
}
long over = System.currentTimeMillis();
System.out.println("操作"+s.getClass().getName()+"類型使用的時間爲:"+(over-begin)+"毫秒");
}
/*對 String 直接進行字符串拼接的測試*/
public void test2(){
String s2 = "abcd";
long begin = System.currentTimeMillis();
for(int i=0; i<time; i++){
String s = s2 + s2 +s2;
}
long over = System.currentTimeMillis();
System.out.println("操作字符串對象引用相加類型使用的時間爲:"+(over-begin)+"毫秒");
}
public void test3(){
long begin = System.currentTimeMillis();
for(int i=0; i<time; i++){
String s ="abcd" + "abcd" + "abcd";
}
long over = System.currentTimeMillis();
System.out.println("操作字符串相加使用的時間爲:"+(over-begin)+"毫秒");
}
public static void main(String[] args){
String s1 = "abcd";
StringBuffer st1 = new StringBuffer("abcd");
StringBuilder st2 = new StringBuilder("abcd");
TestCharacter tc = new TestCharacter();
tc.test(s1);
tc.test(st1);
tc.test(st2);
tc.test2();
tc.test3();
}
}
1)myeclipse下循環10000次時: