Java 您如何在2016年创建SimpleBeanInfo？

我想为我的JavaBean创建一个属性编辑器。为此，我需要一个实现的类。问题是：我真的不喜欢像这样将属性名声明为字符串（

floodColor

，

fillColor

，

percent

）：

我从一篇关于如何创建自定义属性编辑器的示例文章中了解到了这一点：。这篇文章出自1997年

如何在2016年创建属性编辑器，而不使用变量的字符串声明，一旦有人更改变量名，这显然会导致运行时异常

我的意思是除了使用内省器。有e吗。G对类的属性名提供某种注释支持

---

非常感谢您的专业知识

我尝试了自定义注释，它似乎很管用。至少它现在是类型安全的，并且与字段相连接

代码

ExampleBean.java

import annotations.Descriptor;
import annotations.Property;

@Descriptor(displayName = "Example Bean", shortDescription = "This is an example bean")
public class ExampleBean {

    @Property(displayName = "Integer Value", shortDescription = "This is an integer value")
    int integerValue;

    @Property(displayName = "Double Value", shortDescription = "This is a double value")
    double doubleValue;

    @Property(displayName = "String Value", shortDescription = "This is a string value")
    String stringValue;

    public int getIntegerValue() {
        return integerValue;
    }

    public void setIntegerValue(int integerValue) {
        this.integerValue = integerValue;
    }

    public double getDoubleValue() {
        return doubleValue;
    }

    public void setDoubleValue(double doubleValue) {
        this.doubleValue = doubleValue;
    }

    public String getStringValue() {
        return stringValue;
    }

    public void setStringValue(String stringValue) {
        this.stringValue = stringValue;
    }

}

Descriptor.java

package annotations;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface Descriptor {

    public String displayName() default "";

    public String shortDescription() default "";

}

Property.java

package annotations;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.FIELD, ElementType.METHOD })
public @interface Property {

    public String displayName() default "";

    public String shortDescription() default "";

}

示例beanbeaninfo.java

import java.beans.BeanDescriptor;
import java.beans.PropertyDescriptor;
import java.beans.SimpleBeanInfo;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import annotations.Descriptor;
import annotations.Property;

public class ExampleBeanBeanInfo extends SimpleBeanInfo {

    private final static Class<ExampleBean> myClass = ExampleBean.class;

    public PropertyDescriptor[] getPropertyDescriptors() {

        List<PropertyDescriptor> propertyDescriptors = new ArrayList<>();

        try {

            for (Field field : myClass.getDeclaredFields()) {

                if (field.isAnnotationPresent(Property.class)) {

                    Annotation annotation = field.getAnnotation(Property.class);
                    Property property = (Property) annotation;

                    PropertyDescriptor propertyDescriptor = new PropertyDescriptor(field.getName(), myClass);
                    propertyDescriptor.setDisplayName(property.displayName());
                    propertyDescriptor.setShortDescription(property.shortDescription());

                    propertyDescriptors.add(propertyDescriptor);
                }

            }

            return propertyDescriptors.toArray(new PropertyDescriptor[propertyDescriptors.size()]);
        } catch (Exception iexErr) {
            throw new Error(iexErr.toString());
        }
    }

    public BeanDescriptor getBeanDescriptor() {
        BeanDescriptor desc = new BeanDescriptor(myClass);

        if (myClass.isAnnotationPresent(Descriptor.class)) {

            Annotation annotation = myClass.getAnnotation(Descriptor.class);
            Descriptor descriptor = (Descriptor) annotation;

            desc.setDisplayName(descriptor.displayName());
            desc.setShortDescription(descriptor.shortDescription());

        }

        return desc;
    }

}

控制台输出：

Bean display name = 'Example Bean', description = 'This is an example bean'
Property field name = 'doubleValue', display name = 'Double Value', description = 'This is a double value'
Property field name = 'integerValue', display name = 'Integer Value', description = 'This is an integer value'
Property field name = 'stringValue', display name = 'String Value', description = 'This is a string value'

这个示例公开了displayname和shortdescription方法，其中必须添加bean和属性描述符的其他方法

如果有人有更好的办法，请告诉我

import java.beans.BeanDescriptor;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;

public class Main {

    public static void main(String[] args) throws InstantiationException, IllegalAccessException, IntrospectionException {

        BeanInfo beanInfo = Introspector.getBeanInfo(ExampleBean.class);

        BeanDescriptor beanDescriptor = beanInfo.getBeanDescriptor();

        System.out.printf( "Bean display name = '%s', description = '%s'\n", beanDescriptor.getDisplayName(), beanDescriptor.getShortDescription());

        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

        for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {

            String propertyName = propertyDescriptor.getName();

            System.out.printf("Property field name = '%s', display name = '%s', description = '%s'\n", propertyName, propertyDescriptor.getDisplayName(), propertyDescriptor.getShortDescription());

        }

        System.exit(0);
        ;
    }
}

Bean display name = 'Example Bean', description = 'This is an example bean'
Property field name = 'doubleValue', display name = 'Double Value', description = 'This is a double value'
Property field name = 'integerValue', display name = 'Integer Value', description = 'This is an integer value'
Property field name = 'stringValue', display name = 'String Value', description = 'This is a string value'