说明：为应付上级无脑需求，特地写出无脑代码。
自定义注解:
/**
* @Author wen.jie
* @Description 用于日期格式化
* @Date 2021/2/1 21:04
**/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface FieldMapping {
public String formatter() default "";
}
java实体类：
@Data
public class Dog {
private String name;
private Integer age;
private long num;
@FieldMapping(formatter = "yyyy/MM/dd HH:mm:ss")
private Date date;
private BigDecimal money;
private char t;
}
配置文件file.properties：
dog.name=0
dog.age=1
dog.num=2
dog.date=3
dog.money=4
dog.t=5
BeanUtil工具类：
@Slf4j
@Component
public class BeanUtil implements InitializingBean {
private static Properties prop = new Properties();
@Override
public void afterPropertiesSet() throws Exception {
FileInputStream fis = new FileInputStream(ResourceUtils.getFile("classpath:file.properties"));
prop.load(fis);
fis.close();
}
/**
* @Author wen.jie
* @Description 我的代码不需要有可读性,自己能看懂就行了
* @Date 2021/2/1 20:30
**/
public static<T> T newInstance(Class<T> clazz, List<String> filedList){
T instance = null;
try {
instance = clazz.newInstance();
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
String key = encapsulatingKey(field, clazz);
if(!prop.containsKey(key)) continue;
String property = prop.getProperty(key);
field.setAccessible(true);
Class type = field.getType();
String value = filedList.get(Integer.valueOf(property));
if(type.equals(String.class)){
Method method = clazz.getMethod(getSetter(field.getName()), String.class);
method.invoke(instance, value);
}else if(type.equals(Integer.class) || type == Integer.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Integer.TYPE ? Integer.TYPE : Integer.class);
method.invoke(instance, Integer.valueOf(value));
}else if(type.equals(Date.class)){
FieldMapping annotation = field.getAnnotation(FieldMapping.class);
String formatter = annotation.formatter();
SimpleDateFormat sdf = new SimpleDateFormat(formatter);
Date date = sdf.parse(value);
Method method = clazz.getMethod(getSetter(field.getName()), Date.class);
method.invoke(instance, date);
}else if(type.equals(Long.class) || type == Long.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Long.TYPE ? Long.TYPE : Long.class);
method.invoke(instance, Long.valueOf(value));
}else if(type.equals(Boolean.class) || type == Boolean.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Boolean.TYPE ? Boolean.TYPE : Boolean.class);
Boolean flag = false;
if(value.equals("1") || "true".equals(value)) flag = true;
method.invoke(instance,flag);
}else if(type.equals(Float.class) || type == Float.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Float.TYPE ? Float.TYPE : Float.class);
method.invoke(instance, Float.valueOf(value));
}else if (type.equals(Double.class) || type == Double.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Double.TYPE ? Double.TYPE : Double.class);
method.invoke(instance, Double.valueOf(value));
}else if(type.equals(Character.class) || type == Character.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Character.TYPE ? Character.TYPE : Character.class);
method.invoke(instance, value.charAt(0));
}else if(type.equals(Short.class) || type == Short.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Short.TYPE ? Short.TYPE : Short.class);
method.invoke(instance, Short.valueOf(value));
}else if(type.equals(Byte.class) || type == Byte.TYPE){
Method method = clazz.getMethod(getSetter(field.getName()), type == Byte.TYPE ? Byte.TYPE : Byte.class);
method.invoke(instance, Byte.valueOf(value));
}else if(type.equals(BigDecimal.class)){
Class<BigDecimal> bigDecimalClazz = BigDecimal.class;
Constructor<BigDecimal> constructor = bigDecimalClazz.getConstructor(String.class);
BigDecimal bigDecimal = constructor.newInstance(value);
Method method = clazz.getMethod(getSetter(field.getName()), BigDecimal.class);
method.invoke(instance, bigDecimal);
}
}
} catch (InstantiationException | NoSuchMethodException |IllegalAccessException | InvocationTargetException e) {
log.error("reflect find exception");
} catch (ParseException e) {
log.error("date format find exception");
}
return instance;
}
private static <T> String encapsulatingKey(Field field, Class<T> clazz) {
return clazz.getSimpleName().toLowerCase()+"."+field.getName();
}
private static String getSetter(String filedName){
char[] cs= filedName.toCharArray();
cs[0] = upper(cs[0]);
return "set" + String.valueOf(cs);
}
private static char upper(char chars) {
if (chars >= 97 && chars <= 122)
chars ^= 32;
return chars;
}
}
测试：
@Test
void contextLoads() {
ArrayList<String> list = new ArrayList<>();
list.add("aaa");
list.add("12");
list.add("123213412");
list.add("2020/01/02 21:23:56");
list.add("12.3");
list.add("o");
Dog dog = BeanUtil.newInstance(Dog.class, list);
System.out.println(dog);
}
测试结果：
