1. publicclasstest{
3. /**
4. *@paramargs
5. */
6. publicstaticvoidmain(String[]args){
7. //TODOAuto-generatedmethodstub
8. longn=30000;
9. System.out.
11. longstart1=System.currentTimeMillis();
12. Strings1=newString("hello");
13. for(longi=0;i<n;i++)
14. {
15. s1+="拼接字符串的時(shí)間";
16. }
17. longend1=System.currentTimeMillis();
18. longtime1=end1-start1;
19. System.out.println("用String+=拼接字符串的時(shí)間"+time1);
21. longstart2=System.currentTimeMillis();
22. Strings2=newString("hello");
23. for(longi=0;i<n;i++)
24. {
25. s2=s2+"拼接字符串的時(shí)間";
26. }
27. longend2=System.currentTimeMillis();
28. longtime2=end2-start2;
29. System.out.println("用String=String+拼接字符串的時(shí)間"+time2);
31. longstart3=System.currentTimeMillis();
32. Strings3=newString("hello");
33. for(longi=0;i<n;i++)
34. {
35. s3=s3.concat("拼接字符串的時(shí)間");
36. }
37. longend3=System.currentTimeMillis();
38. longtime3=end3-start3;
39. System.out.println("用String.concat拼接字符串的時(shí)間"+time3);
41. longstart4=System.currentTimeMillis();
42. StringBuffers4=newStringBuffer("hello");
43. for(longi=0;i<n;i++)
44. {
45. s4.append("拼接字符串的時(shí)間");
46. }
47. longend4=System.currentTimeMillis();
48. longtime4=end4-start4;
49. System.out.println("用StringBuffer.append拼接字符串的時(shí)間"+time4);
51. longstart5=System.currentTimeMillis();
52. StringBuilders5=newStringBuilder("hello");
53. for(longi=0;i<n;i++)
54. {
55. s5.append("拼接字符串的時(shí)間");
56. }
57. longend5=System.currentTimeMillis();
58. longtime5=end5-start5;
59. System.out.println("用StringBuilder.append拼接字符串的時(shí)間"+time5);
61. System.out.println("End...");
62. }
64. }

貼出一組檢測數(shù)據(jù)如下:

1. 用String+=拼接字符串的時(shí)間27468
2. 用String=String+拼接字符串的時(shí)間25813
3. 用String.concat拼接字符串的時(shí)間12265
4. 用StringBuffer.append拼接字符串的時(shí)間14
5. 用StringBuilder.append拼接字符串的時(shí)間8