invokevirtual:类对象的方法
invokespecial：私有方法，构造函数，super类的方法
invokestatic：静态方法
invokeinterface：接口方法
示例代码
public class SimpleInvokeBenchMark implements Itest {
@Override
public void test() {
}
private void testPrivate() {
}
public static void testStatic() {
}
public static void main(String[] args) {
SimpleInvokeBenchMark simpleInvokeBenchMark = new SimpleInvokeBenchMark();
Itest iface = simpleInvokeBenchMark;
//warm up
int count = 10000000;
for (int i = 0; i < count; i++) {
simpleInvokeBenchMark.test();
simpleInvokeBenchMark.testPrivate();
SimpleInvokeBenchMark.testStatic();
iface.test();
}
//start
count = 100000000;
//invokevirtual
long startTime = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
simpleInvokeBenchMark.test();
}
System.out.println("invokevirtual: " + (System.currentTimeMillis() - startTime));
//invokespecial
startTime = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
simpleInvokeBenchMark.testPrivate();
}
System.out.println("invokespecial: " + (System.currentTimeMillis() - startTime));
//invokestatic
startTime = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
SimpleInvokeBenchMark.testStatic();
}
System.out.println("invokestatic: " + (System.currentTimeMillis() - startTime));
//invokeinterface
startTime = System.currentTimeMillis();
for (int i = 0; i < count; i++) {
iface.test();
}
System.out.println("invokeinterface: " + (System.currentTimeMillis() - startTime));
}
}
字节码
public class test.zk.instrumentset.SimpleInvokeBenchMark implements test.zk.instrumentset.Itest {
public test.zk.instrumentset.SimpleInvokeBenchMark();
Code:
0: aload_0
1: invokespecial #10 // Method java/lang/Object."<init>":()V
4: return
public void test();
Code:
0: return
public static void testStatic();
Code:
0: return
public static void main(java.lang.String[]);
Code:
0: new #1 // class test/zk/instrumentset/SimpleInvokeBenchMark
3: dup
4: invokespecial #21 // Method "<init>":()V
7: astore_1
8: aload_1
9: astore_2
10: ldc #22 // int 10000000
12: istore_3
13: iconst_0
14: istore 4
16: goto 39
19: aload_1
20: invokevirtual #23 // Method test:()V
23: aload_1
24: invokespecial #25 // Method testPrivate:()V
27: invokestatic #27 // Method testStatic:()V
30: aload_2
31: invokeinterface #29, 1 // InterfaceMethod test/zk/instrumentset/Itest.test:()V
36: iinc 4, 1
39: iload 4
41: iload_3
42: if_icmplt 19
45: ldc #30 // int 100000000
47: istore_3
48: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
51: lstore 4
53: iconst_0
54: istore 6
56: goto 66
59: aload_1
60: invokevirtual #23 // Method test:()V
63: iinc 6, 1
66: iload 6
68: iload_3
69: if_icmplt 59
72: getstatic #37 // Field java/lang/System.out:Ljava/io/PrintStream;
75: new #41 // class java/lang/StringBuilder
78: dup
79: ldc #43 // String invokevirtual:
81: invokespecial #45 // Method java/lang/StringBuilder."<init>":(Ljava/lang/String;)V
84: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
87: lload 4
89: lsub
90: invokevirtual #48 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
93: invokevirtual #52 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
96: invokevirtual #56 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
99: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
102: lstore 4
104: iconst_0
105: istore 6
107: goto 117
110: aload_1
111: invokespecial #25 // Method testPrivate:()V
114: iinc 6, 1
117: iload 6
119: iload_3
120: if_icmplt 110
123: getstatic #37 // Field java/lang/System.out:Ljava/io/PrintStream;
126: new #41 // class java/lang/StringBuilder
129: dup
130: ldc #61 // String invokespecial:
132: invokespecial #45 // Method java/lang/StringBuilder."<init>":(Ljava/lang/String;)V
135: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
138: lload 4
140: lsub
141: invokevirtual #48 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
144: invokevirtual #52 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
147: invokevirtual #56 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
150: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
153: lstore 4
155: iconst_0
156: istore 6
158: goto 167
161: invokestatic #27 // Method testStatic:()V
164: iinc 6, 1
167: iload 6
169: iload_3
170: if_icmplt 161
173: getstatic #37 // Field java/lang/System.out:Ljava/io/PrintStream;
176: new #41 // class java/lang/StringBuilder
179: dup
180: ldc #63 // String invokestatic:
182: invokespecial #45 // Method java/lang/StringBuilder."<init>":(Ljava/lang/String;)V
185: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
188: lload 4
190: lsub
191: invokevirtual #48 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
194: invokevirtual #52 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
197: invokevirtual #56 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
200: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
203: lstore 4
205: iconst_0
206: istore 6
208: goto 220
211: aload_2
212: invokeinterface #29, 1 // InterfaceMethod test/zk/instrumentset/Itest.test:()V
217: iinc 6, 1
220: iload 6
222: iload_3
223: if_icmplt 211
226: getstatic #37 // Field java/lang/System.out:Ljava/io/PrintStream;
229: new #41 // class java/lang/StringBuilder
232: dup
233: ldc #65 // String invokeinterface:
235: invokespecial #45 // Method java/lang/StringBuilder."<init>":(Ljava/lang/String;)V
238: invokestatic #31 // Method java/lang/System.currentTimeMillis:()J
241: lload 4
243: lsub
244: invokevirtual #48 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
247: invokevirtual #52 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
250: invokevirtual #56 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
253: return
}
BenchMark(ms)
count=100000000
invokevirtual: 3
invokespecial: 6
invokestatic: 6
invokeinterface: 5
count = 1000000000L
invokevirtual: 348
invokespecial: 682
invokestatic: 351
invokeinterface: 351
参考
java虚拟机规范-invokespecial
java虚拟机规范-invokevirtual
java虚拟机规范-invokestatic
java虚拟机规范-invokeinterface
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