测试分为3个方面：1. 实例化效率；2. 方法调用效率；3. 成员变量GET调用效率；4. 成员变量SET调用
测试环境：
Windows 7
Sun Java 1.6
先写好备测试用的类
import java.util.Date;
public class DemoClass{
public String firstName;
private String endName;
private Date birthDay;
private String email;
private String phone;
private DemoClass parent;
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getEndName() {
return endName;
}
public void setEndName(String endName) {
this.endName = endName;
}
public Date getBirthDay() {
return birthDay;
}
public void setBirthDay(Date birthDay) {
this.birthDay = birthDay;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public DemoClass getParent() {
return parent;
}
public void setParent(DemoClass parent) {
this.parent = parent;
}
}
1. 实例化效率
1) 正常调用
public class TestReflectNew {
public static void main(String[] args) throws Exception{
int i = 0;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
// DemoClass.class.newInstance();
new DemoClass();
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
18 MillSeconds
19 MillSeconds
20 MillSeconds
均值：19
2) 反射调用
public class TestReflectNew {
public static void main(String[] args) throws Exception{
int i = 0;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
DemoClass.class.newInstance();
// new DemoClass();
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
191 MillSeconds
193 MillSeconds
192 MillSeconds
均值：192
2. 方法调用测试
1) 正常调用
public class TestReflectMethod {
public static void main(String[] args) throws Exception{
int i = 0;
DemoClass dc = new DemoClass();
long start = System.currentTimeMillis();
while(i<1000000){
i++;
// DemoClass.class.getMethod("getBirthDay").invoke(dc);
dc.getBirthDay();
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
2 MillSeconds
2 MillSeconds
2 MillSeconds
均值：2
2) 反射调用
public class TestReflectMethod {
public static void main(String[] args) throws Exception{
int i = 0;
DemoClass dc = new DemoClass();
long start = System.currentTimeMillis();
while(i<1000000){
i++;
DemoClass.class.getMethod("getBirthDay").invoke(dc);
// dc.getBirthDay();
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
1223 MillSeconds
1201 MillSeconds
1207 MillSeconds
均值1210
3. 测试成员变量GET
1) 正常调用
public class TestReflectFieldGet {
public static void main(String[] args) throws Exception{
int i = 0;
DemoClass dc = new DemoClass();
String s;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
// s = (String) DemoClass.class.getField("firstName").get(dc);
s = dc.firstName;
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
2 MillSeconds
1 MillSeconds
3 MillSeconds
均值：2
2) 反射调用
public class TestReflectFieldGet {
public static void main(String[] args) throws Exception{
int i = 0;
DemoClass dc = new DemoClass();
String s;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
s = (String) DemoClass.class.getField("firstName").get(dc);
// s = dc.firstName;
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
992 MillSeconds
1000 MillSeconds
1005 MillSeconds
均值：999
4. 测试成员变量SET
1) 正常调用
public class TestReflectFieldSet {
public static void main(String[] args) throws Exception {
int i = 0;
DemoClass dc = new DemoClass();
String s = null;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
dc.firstName = s;
// DemoClass.class.getField("firstName").set(dc, s);
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
}
三次输出：
1 MillSeconds
2 MillSeconds
2 MillSeconds
均值：1.7
2) 反射调用
public class TestReflectFieldSet {
public static void main(String[] args) throws Exception {
int i = 0;
DemoClass dc = new DemoClass();
String s = null;
long start = System.currentTimeMillis();
while(i<1000000){
i++;
// dc.firstName = s;
DemoClass.class.getField("firstName").set(dc, s);
}
long end = System.currentTimeMillis();
System.err.println((end - start) + " MillSeconds");
}
} 三次输出：
998 MillSeconds
1021 MillSeconds
1007 MillSeconds
均值：1009
来个统计
反射平均时间 非反射平均时间 比值
实例化 192 19 10
方法调用 1210 2 605
成员Get 999 2 500
成员Set 1009 1.7 593