目标：通过自定义注解 @Ignore 注解，觉得是否读取指定类的属性。
运行结果：
[main] INFO util.FruitInfoUtil - 水果的名字为：entity.Apple [main] INFO util.FruitInfoUtil - 水果的颜色为：RED [main] INFO util.FruitInfoUtil - 水果的供应商名称为：红富士供应商，供应商地址为：山西红富士产业园 [main] INFO main.MainTest - ==================== [main] INFO util.FieldsUtil - fieldName:fruitColor's ignore is null [main] INFO util.FieldsUtil - fieldName:fruitProvider's ignore is false
[main] INFO util.FieldsUtil - fields: [main] INFO util.FieldsUtil - fruitColor [main] INFO util.FieldsUtil - fruitProvider [main] INFO util.FieldsUtil - END
import java.lang.annotation.*;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface FruitName {
String value() default "";
}
import java.lang.annotation.*;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface FruitColor {
public enum Color {GREND, RED, BLUE}
Color fruitColor() default Color.GREND;
}
import java.lang.annotation.*;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface FruitProvider {
int id() default -1;
String name() default "";
String addr() default "";
}
import java.lang.annotation.*;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Ignore {
boolean ignore() default false;
}
import annotation.FruitColor;
import annotation.FruitName;
import annotation.FruitProvider;
import annotation.Ignore;
public class Apple {
@FruitName("entity.Apple")
@Ignore(ignore = true)
String fruitName;
@FruitColor(fruitColor = FruitColor.Color.RED)
// @Ignore(ignore = true)
String fruitColor;
@FruitProvider(id = 1, name = "红富士供应商", addr = "山西红富士产业园")
@Ignore
String fruitProvider;
public String getFruitName() {
return fruitName;
}
public void setFruitName(String fruitName) {
this.fruitName = fruitName;
}
public String getFruitColor() {
return fruitColor;
}
public void setFruitColor(String fruitColor) {
this.fruitColor = fruitColor;
}
public String getFruitProvider() {
return fruitProvider;
}
public void setFruitProvider(String fruitProvider) {
this.fruitProvider = fruitProvider;
}
public void getAppleName(){
System.out.println("水果的名称为：苹果。");
}
}
import annotation.FruitColor;
import annotation.FruitName;
import annotation.FruitProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.reflect.Field;
public class FruitInfoUtil {
final static Logger logger = LoggerFactory.getLogger(FruitInfoUtil.class);
public static void getAnnotationInfo(Class clazz){
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
if(field.isAnnotationPresent(FruitName.class)){
FruitName fruitName = field.getAnnotation(FruitName.class);
logger.info("水果的名字为："+fruitName.value());
}
else if(field.isAnnotationPresent(FruitColor.class)) {
FruitColor fruitColor = field.getAnnotation(FruitColor.class);
logger.info("水果的颜色为：" + fruitColor.fruitColor());
}
else if(field.isAnnotationPresent(FruitProvider.class)){
FruitProvider fruitProvider = field.getAnnotation(FruitProvider.class);
logger.info("水果的供应商名称为：" + fruitProvider.name()+"，供应商地址为："+fruitProvider.addr());
}
}
}
}
import annotation.Ignore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
public class FieldsUtil {
final static Logger logger = LoggerFactory.getLogger(FieldsUtil.class);
/**
* 本类的所有 Ignore = false的字段集合
* @param clazz
*/
public static void getOneSelfActiveFieldsUtil(Class clazz){
Field[] fields = clazz.getDeclaredFields();
List<String> fileNames = new ArrayList<>();
for (Field field : fields){
String fieldName = field.getName();
Ignore ignoreField = field.getAnnotation(Ignore.class);
if(field.isAnnotationPresent(Ignore.class) && !ignoreField.ignore()){
fileNames.add(field.getName());
logger.info("fieldName:"+fieldName+"'s ignore is false");
}
else if(!field.isAnnotationPresent(Ignore.class)){
fileNames.add(field.getName());
logger.info("fieldName:"+fieldName+"'s ignore is null");
}
}
logger.info("fields:");
if(fileNames != null && fileNames.size() > 0){
// fileNames.stream().forEach(System.out::println);
fileNames.stream().forEach(y -> {
logger.info(y);
});
}else{
logger.info("Size() == 0 ");
}
logger.info("END");
}
/**
* 包括 父类的所有Ignore = false（默认值）的字段信息
* @param clazz
*/
public static List<Field> getAllActiveFieldsUtil(Class clazz){
List<String> fileNames = new ArrayList<>();
List<Field> fieldList = null;
Field[] fields;
do{
fields = clazz.getDeclaredFields();
if(fields != null && fields.length > 0){
for (Field field : fields){
String fieldName = field.getName();
Ignore ignoreField = field.getAnnotation(Ignore.class);
if(field.isAnnotationPresent(Ignore.class) && !ignoreField.ignore()){
fileNames.add(field.getName());
logger.info("fieldName:"+fieldName+"'s ignore is false");
fieldList.add(field);
}
else if(!field.isAnnotationPresent(Ignore.class)){
fileNames.add(field.getName());
logger.info("fieldName:"+fieldName+"'s ignore is null");
fieldList.add(field);
}
}
if(fileNames != null && fileNames.size() > 0){
fileNames.stream().forEach(System.out::println);
}else{
logger.info("Size() == 0 ");
}
logger.info("END");
}
clazz = clazz.getSuperclass();
}while (clazz != Object.class && clazz != null);
return fieldList;
}
}
import entity.Apple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import util.FieldsUtil;
import util.FruitInfoUtil;
public class MainTest {
final static Logger logger = LoggerFactory.getLogger(MainTest.class);
public static void main(String[] args) {
FruitInfoUtil.getAnnotationInfo(Apple.class);
logger.info("====================");
FieldsUtil.getOneSelfActiveFieldsUtil(Apple.class);
}
}
参考资源：