package com.xxx.beancopier; import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier; /**
* @Type BeanCopier
* @Desc 属性copy类
* @author
* @date 2017-01-06
* @Version V1.0
*/
public class BeanCopier {
private BeanCopier() {
} public static <DestType> DestType propertiesCopy(Object orig, DestType dest) {
if (orig == null || dest == null) {
throw new RuntimeException("参数不能为null");
} Method[] destMethods = dest.getClass().getMethods();
for (Method destMethod : destMethods) {
if (needCopy(destMethod)) {
MethodCopy methodCopy = new MethodCopy(destMethod);
methodCopy.copy(orig, dest);
}
}
return dest;
} private static boolean needCopy(Method method) {
PropertyCopy annotation = method.getAnnotation(PropertyCopy.class);
if (annotation != null && annotation.ignore())
return false;
return method.getName().startsWith("set") && method.getParameterTypes().length == 1
&& Modifier.isPublic(method.getModifiers()) && !Modifier.isStatic(method.getModifiers());
} static class MethodCopy {
private Method method;
private String methodName;
private Method getterMethod; public MethodCopy(Method destMethod) {
method = destMethod;
methodName = destMethod.getName();
} private void copy(Object orig, Object dest) {
try {
this.getterMethod = orig.getClass().getMethod("get" + methodName.substring(3));
} catch (NoSuchMethodException e) {
throw new RuntimeException("对象【" + orig + "】中缺失【" + methodName.replaceFirst("set", "get") + "()】方法!");
}
Object propertyValue = invokeMethod(orig, getterMethod);
if (propertyValue != null) {
invokeMethod(dest, method, propertyValue);
}
} private Object invokeMethod(Object targerObject, Method method, Object... args) {
if (method == null) {
throw new RuntimeException("被调用方法不能为空!");
}
// 验证参数数量
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length != args.length) {
throw new RuntimeException("方法【" + method + "】的参数数量【" + parameterTypes.length + "】和反射调用时的参数数量【"
+ args.length + "】不相符,无法完成调用!");
} try {
method.setAccessible(true);
return method.invoke(targerObject, args);
} catch (Throwable e) {
throw new RuntimeException("调用对象【" + targerObject + "】的【" + method + "】方法,参数为【" + args + "】时发生异常:", e);
}
} }
} @Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.METHOD })
@Documented
@interface PropertyCopy {
/**
* 被标注方法是否被忽略拷贝
* @return
*/
boolean ignore() default false;
}
使用如下:
StudentDTO studentDTO1 = BeanCopier.propertiesCopy(student, new StudentDTO());