public class Test {
public void test(){
String ss="aaa"+"bbb"+"ccc";
}
public void yyyy(){
String o="bbb";
String ss="aaa"+o+"ccc";
}
public void xxxx(){
String tt="";
tt+="aaa";
tt+="bbb";
tt+="ccc";
}
}
C:\Users\***>javap -v Test.class
Classfile /C:/Users/***/Test.class
Last modified 2017-7-12; size 635 bytes
MD5 checksum 36f408af7481f6ce1a69797b2b6a3d9b
Compiled from "Test.java"
public class Test
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Methodref #12.#22 // java/lang/Object."<init>":()V
#2 = String #23 // aaabbbccc
#3 = String #24 // bbb
#4 = Class #25 // java/lang/StringBuilder
#5 = Methodref #4.#22 // java/lang/StringBuilder."<init>":()V
#6 = String #26 // aaa
#7 = Methodref #4.#27 // java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#8 = String #28 // ccc
#9 = Methodref #4.#29 // java/lang/StringBuilder.toString:()Ljava/lang/String;
#10 = String #30 //
#11 = Class #31 // Test
#12 = Class #32 // java/lang/Object
#13 = Utf8 <init>
#14 = Utf8 ()V
#15 = Utf8 Code
#16 = Utf8 LineNumberTable
#17 = Utf8 test
#18 = Utf8 yyyy
#19 = Utf8 xxxx
#20 = Utf8 SourceFile
#21 = Utf8 Test.java
#22 = NameAndType #13:#14 // "<init>":()V
#23 = Utf8 aaabbbccc
#24 = Utf8 bbb
#25 = Utf8 java/lang/StringBuilder
#26 = Utf8 aaa
#27 = NameAndType #33:#34 // append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
#28 = Utf8 ccc
#29 = NameAndType #35:#36 // toString:()Ljava/lang/String;
#30 = Utf8
#31 = Utf8 Test
#32 = Utf8 java/lang/Object
#33 = Utf8 append
#34 = Utf8 (Ljava/lang/String;)Ljava/lang/StringBuilder;
#35 = Utf8 toString
#36 = Utf8 ()Ljava/lang/String;
{
public Test();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #1 // Method java/lang/Object."<init>":()V
4: return
LineNumberTable:
line 1: 0
public void test();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=2, args_size=1
0: ldc #2 // String aaabbbccc
2: astore_1
3: return
LineNumberTable:
line 3: 0
line 4: 3
public void yyyy();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=2, locals=3, args_size=1
0: ldc #3 // String bbb
2: astore_1
3: new #4 // class java/lang/StringBuilder
6: dup
7: invokespecial #5 // Method java/lang/StringBuilder."<init>":()V
10: ldc #6 // String aaa
12: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
15: aload_1
16: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
19: ldc #8 // String ccc
21: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
24: invokevirtual #9 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
27: astore_2
28: return
LineNumberTable:
line 6: 0
line 7: 3
line 8: 28
public void xxxx();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=2, locals=2, args_size=1
0: ldc #10 // String
2: astore_1
3: new #4 // class java/lang/StringBuilder
6: dup
7: invokespecial #5 // Method java/lang/StringBuilder."<init>":()V
10: aload_1
11: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
14: ldc #6 // String aaa
16: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
19: invokevirtual #9 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
22: astore_1
23: new #4 // class java/lang/StringBuilder
26: dup
27: invokespecial #5 // Method java/lang/StringBuilder."<init>":()V
30: aload_1
31: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
34: ldc #3 // String bbb
36: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
39: invokevirtual #9 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
42: astore_1
43: new #4 // class java/lang/StringBuilder
46: dup
47: invokespecial #5 // Method java/lang/StringBuilder."<init>":()V
50: aload_1
51: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
54: ldc #8 // String ccc
56: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
59: invokevirtual #9 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
62: astore_1
63: return
LineNumberTable:
line 10: 0
line 11: 3
line 12: 23
line 13: 43
line 14: 63
}
SourceFile: "Test.java"
C:\Users\***>
