org.apache.commons.beanutils.PropertyUtils使用

yuandan

org.apache.commons.beanutils.PropertyUtils 利用反射操作bean的属性。
getSimpleProperty()通过反射读取属性

Person person=new Person();
person.setName=("heis");
String name=(String)PropertyUtils.getSimpleProperty(person,"name");->heis

getNestedProperty()检索嵌套的bean属性

Book book=new Book();
book.setAuthor(person);
String authorName=(String)PropertyUtils.getNestedProperty(book,"author.name");//得到person的name

getIndexedProperty()访问数组或List型内Object的属性

Chapter chapter1=new Chapter();
Chapter chapter2=new Chapter();
book.getChapters().add(chapter1);
book.getChapters().add(chapter2);
Chapter chapter=(Chapter)PropertyUtils.getIndexedProperty(book,"chapter[0]");

getMappedProperty()访问Map型bean属性的值

Person person=new Person();
person.setName=("heis");
Map favorites=new HashMap();
favorites.put("food","rice");
person.setFavorite(favorites);
String favorFood=(String)PropertyUtils.getMappedProperty(person,"favorites(food)");->rice

getProperty()和setProperty()可以访问任何bean属性，通过表达式可以完成上面方法的功能

这是一个树型的Bean属性视图
Book book
|--List authors
|--[0]->Person person
|--Map favorites
|--Entry(key->"food",value->"")
PropertyUtils.setProperty(book,"authors[0].favorites(food)","rice");
String favorFood=(String)PropertyUtils.getProperty(book,"authors[0].favorites(food)");->rice

isReadable()和isWritable()检查bean是否可读（有getter）或可写（有setter）

PropertyUtils.isReadable(book,"name");
PropertyUtils.isWritable(book,"name");

getPropertyType()获取属性类型

System.out.println(PropertyUtils.getPropertyType(person,"favorites"));->java.util.Map

copyProperty()复制Bean属性,只复制引用，final类型和原始类型（primitive type）

Book book1=new Book();
book1.setName("Commons Cookbook Notes");
Book book2=new Book();
PropertyUtils.copyProperty(book2,book1);//将book1的name属性copy到book2

describe()创建包含Bean属性的Map

Person person=new Person();
person.setName("heis");
Book book=new Book();
book.setName("Commons Cookbook Notes");
book.setAuthor(person);
Map propMap=PropertyUtils.describe(book);
propMap.get("name");->Commons Cookbook Notes
propMap.get("author");->person