（1）创建两个Class：
ReflectTest类如下：
package cn.itcast.day01;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
public class ReflectTest {
public static void main(String[] args) throws Exception {
changeStringValue(pt1);
System.out.println(pt1);
}
private static void changeStringValue(Object obj) throws Exception{
Field[] fields = obj.getClass().getFields();
for(Field field :fields){
//if(field.getType().equals(String.class)){
if(field.getType() == String.class){ //同一个字节码用等号 而不是用equal
String oldValue = (String) field.get(obj);
String newValue = oldValue.replace('b','a');
field.set(obj, newValue);
}
}
}
}
ReflectPoint类如下：
package cn.itcast.day01;
public class ReflectPoint {
public String str1 = "ball";
public String str2 = "basketball";
public String str3 = "itcast";
public ReflectPoint(int x, int y) {
super();
this.x = x;
this.y = y;
}
public String toString(){
return str1+":"+str2+":"+str3;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
}
}
结果为：aall:aasketaall:itcast