功能说明: 顾名思义,Bean Utility就是Bean小工具,主要是封装了反射(reflection)和自省(introspection)的API(可以查看java.lang.reflect和java.beans文档),对bean进行操作。
主要功能: 操作Bean的属性,针对Bean属性排序,Bean和Map的转换,创建动态的Bean等
Apache提供的架包:commons-beanutils-1.7.jar
2.1 org.apache.commons.beanutils.PropertyUtils 利用反射操作bean的属性
getSimpleProperty()通过反射读取属性
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Person person= new Person(); |
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person.setName=( "heis" ); |
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String name=(String)PropertyUtils.getSimpleProperty(person, "name" );->heis |
getNestedProperty()检索嵌套的bean属性
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book.setAuthor(person); |
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String authorName=(String)PropertyUtils.getNestedProperty(book, "author.name" ); |
getIndexedProperty()访问数组或List型内Object的属性
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Chapter chapter1= new Chapter(); |
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Chapter chapter2= new Chapter(); |
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book.getChapters().add(chapter1); |
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book.getChapters().add(chapter2); |
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Chapter chapter=(Chapter)PropertyUtils.getIndexedProperty(book, "chapter[0]" ); |
getMappedProperty()访问Map型bean属性的值
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Person person= new Person(); |
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person.setName=( "heis" ); |
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Map favorites= new HashMap(); |
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favorites.put( "food" , "rice" ); |
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person.setFavorite(favorites); |
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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
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|--Entry(key-> "food" ,value-> "" ) |
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PropertyUtils.setProperty(book, "authors[0].favorites(food)" , "rice" ); |
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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)
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PropertyUtils.isReadable(book, "name" ); |
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PropertyUtils.isWritable(book, "name" ); |
getPropertyType()获取属性类型
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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)
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book1.setName( "Commons Cookbook Notes" ); |
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PropertyUtils.copyProperty(book2,book1); |
describe()创建包含Bean属性的Map
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Person person= new Person(); |
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person.setName( "heis" ); |
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book.setName( "Commons Cookbook Notes" ); |
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book.setAuthor(person); |
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Map propMap=PropertyUtils.describe(book); |
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propMap.get( "name" );->Commons Cookbook Notes |
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propMap.get( "author" );->person |