Spring Set注入：基本类型、List、Map、Set、Array、Date类型注入
Spring依赖注入有两种：构造器注入与Set注入
其中以Set注入为首选。下面演示几个示例。
Bean类：User
package com.lwf.bean;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class User {
private String name;
private int age;
private List listValues;
private Map map ;
private Set set;
private String [] array;
private Date date;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public List getListValues() {
return listValues;
}
public void setListValues(List listValues) {
this.listValues = listValues;
}
public Map getMap() {
return map;
}
public void setMap(Map map) {
this.map = map;
}
public Set getSet() {
return set;
}
public void setSet(Set set) {
this.set = set;
}
public String[] getArray() {
return array;
}
public void setArray(String[] array) {
this.array = array;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
}
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> <bean id="userDaoImp4MySql" class="com.lwf.dao.UserDaoImp4MySql"/> <bean id="userDaoImp4Oracle" class="com.lwf.dao.UserDaoImp4Oracle"/> <bean id="userManager" class="com.lwf.manager.UserManagerImp"> <property name="userDao" ref="userDaoImp4Oracle"/> </bean> <bean id="upperAction" class="com.lwf.action.UpperAction"> <property name="message" value="good"/> </bean> <bean id="lowerAction" class="com.lwf.action.LowerAction"/> <bean id="user" class="com.lwf.bean.User"> <property name="name"><value>zhangdong</value></property> <property name="age" value="23" /> <property name="listValues"> <list> <value>list1</value> <value>list2</value> </list> </property> <property name="array"> <list> <value>array1</value> <value>array2</value> </list> </property> <property name="map"> <map> <entry> <key ><value>testCaseName</value></key> <value>testSpring</value> </entry> <entry> <key ><value>testCaseName1</value></key> <value>testSpring1</value> </entry> </map> </property> <property name="set"> <set> <value>set1</value> <value>set2</value> </set> </property> </bean> </beans>
测试类：
package com.lwf.client;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import com.lwf.bean.User;
public class Client {
public static void main(String[] args) {
ApplicationContext ctx2 = new FileSystemXmlApplicationContext("/src/applicationContext.xml");
User user = (User)ctx2.getBean("user");
System.out.println(user.getName() +":"+ user.getAge());
List list = user.getListValues();
for (int i = 0; i < list.size(); i++) {
System.out.println(list.get(i));
}
Map map = user.getMap();
for (Iterator iter = map.entrySet().iterator(); iter.hasNext();) {
Map.Entry object = (Map.Entry) iter.next();
System.out.println((String)object.getKey() +":"+ (String)object.getValue());
}
Set set = user.getSet();
for(Iterator iter = set.iterator();iter.hasNext();){
String str = (String)iter.next();
System.out.println(str);
}
String[] array = user.getArray();
System.out.println(array);
}
}
说明：上例测试了普通属性的注入，List,Map,Array,Set属性的注入。
测试打印出内容：
2010-05-18 15:56:16,794 INFO [org.springframework.context.support.FileSystemXmlApplicationContext] - Refreshing org.springframework.context.support.FileSystemXmlApplicationContext@3e86d0: display name [org.springframework.context.support.FileSystemXmlApplicationContext@3e86d0]; startup date [Tue May 18 15:56:16 CST 2010]; root of context hierarchy 2010-05-18 15:56:16,997 INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - Loading XML bean definitions from file [D:\workdirlocal\spring_start\src\applicationContext.xml] 2010-05-18 15:56:17,388 INFO [org.springframework.context.support.FileSystemXmlApplicationContext] - Bean factory for application context [org.springframework.context.support.FileSystemXmlApplicationContext@3e86d0]: org.springframework.beans.factory.support.DefaultListableBeanFactory@184ec44 2010-05-18 15:56:17,450 INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@184ec44: defining beans [userDaoImp4MySql,userDaoImp4Oracle,userManager,upperAction,lowerAction,user]; root of factory hierarchy zhangdong:23 list1 list2 testCaseName:testSpring testCaseName1:testSpring1 set1 set2 [Ljava.lang.String;@1d6776d
好，我们的User类中定义了Date date，现在测试Date类型，现在在applicationContext.xml中加入：
<property name="date" value="2010/05/18"></property>
在测试类中加入：
System.out.println(user.getDate());
测试结果：
我们会发现报错：
Caused by: org.springframework.beans.TypeMismatchException: Failed to convert property value of type [java.lang.String] to required type [java.util.Date] for property 'date'; nested exception is java.lang.IllegalArgumentException: Cannot convert value of type [java.lang.String] to required type [java.util.Date] for property 'date': no matching editors or conversion strategy found
显然从字符串类型转换为Date类型出错，那么怎么办？
回忆一下Struts中actionForm怎么处理类型转换问题？
http://quicker.iteye.com/admin/blogs/629603
在spring中。我们采取类似的思路，先自己创建转换器再注册。
转换器继承于java.bean.下面的类：
package com.lwf.bean;
import java.beans.PropertyEditorSupport;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class UtilDatePropertiesEditor extends PropertyEditorSupport {
private String format ;
public void setAsText(String text) throws IllegalArgumentException {
SimpleDateFormat sdf = new SimpleDateFormat(format);
try {
Date dateVal = sdf.parse(text);
this.setValue(dateVal);
} catch (ParseException e) {
e.printStackTrace();
}
}
public void setFormat(String format){
this.format = format;
}
}
那么怎么注册呢？
我们先看在applicationContext.xml中加入
<bean id="customEditorConfigurer" class="org.springframework.beans.factory.config.CustomEditorConfigurer"> </bean>
按F3查找类org.springframework.beans.factory.config.CustomEditorConfigurer，定位spring源代码到src目录，即可看到CustomEditorConfigurer类的源码
/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.beans.factory.config;
import java.beans.PropertyEditor;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.PropertyEditorRegistrar;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.core.Ordered;
import org.springframework.util.ClassUtils;
/**
* {@link BeanFactoryPostProcessor} implementation that allows for convenient
* registration of custom {@link PropertyEditor property editors}.
*
* <p>As of Spring 2.0, the recommended usage is to use custom
* {@link PropertyEditorRegistrar} implementations that in turn register
* any desired editors on a given
* {@link org.springframework.beans.PropertyEditorRegistry registry}.
* Each PropertyEditorRegistrar can register any number of custom editors.
*
* <pre class="code">
* <bean id="customEditorConfigurer" class="org.springframework.beans.factory.config.CustomEditorConfigurer">
* <property name="propertyEditorRegistrars">
* <list>
* <bean class="mypackage.MyCustomDateEditorRegistrar"/>
* <bean class="mypackage.MyObjectEditorRegistrar"/>
* </list>
* </property>
* </bean></pre>
*
* <p>Alternative configuration example with custom editor classes:
*
* <pre class="code">
* <bean id="customEditorConfigurer" class="org.springframework.beans.factory.config.CustomEditorConfigurer">
* <property name="customEditors">
* <map>
* <entry key="java.util.Date" value="mypackage.MyCustomDateEditor"/>
* <entry key="mypackage.MyObject" value="mypackage.MyObjectEditor"/>
* </map>
* </property>
* </bean></pre>
*
* <p>Also supports "java.lang.String[]"-style array class names and primitive
* class names (e.g. "boolean"). Delegates to {@link ClassUtils} for actual
* class name resolution.
*
* <p><b>NOTE:</b> Custom property editors registered with this configurer do
* <i>not</i> apply to data binding. Custom editors for data binding need to
* be registered on the {@link org.springframework.validation.DataBinder}:
* Use a common base class or delegate to common PropertyEditorRegistrar
* implementations to reuse editor registration there.
*
* @author Juergen Hoeller
* @since 27.02.2004
* @see java.beans.PropertyEditor
* @see org.springframework.beans.PropertyEditorRegistrar
* @see ConfigurableBeanFactory#addPropertyEditorRegistrar
* @see ConfigurableBeanFactory#registerCustomEditor
* @see org.springframework.validation.DataBinder#registerCustomEditor
* @see org.springframework.web.servlet.mvc.BaseCommandController#setPropertyEditorRegistrars
* @see org.springframework.web.servlet.mvc.BaseCommandController#initBinder
*/
public class CustomEditorConfigurer implements BeanFactoryPostProcessor, BeanClassLoaderAware, Ordered {
protected final Log logger = LogFactory.getLog(getClass());
private int order = Ordered.LOWEST_PRECEDENCE; // default: same as non-Ordered
private PropertyEditorRegistrar[] propertyEditorRegistrars;
private Map customEditors;
private boolean ignoreUnresolvableEditors = false;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
public void setOrder(int order) {
this.order = order;
}
public int getOrder() {
return this.order;
}
/**
* Specify the {@link PropertyEditorRegistrar PropertyEditorRegistrars}
* to apply to beans defined within the current application context.
* <p>This allows for sharing <code>PropertyEditorRegistrars</code> with
* {@link org.springframework.validation.DataBinder DataBinders}, etc.
* Furthermore, it avoids the need for synchronization on custom editors:
* A <code>PropertyEditorRegistrar</code> will always create fresh editor
* instances for each bean creation attempt.
* @see ConfigurableListableBeanFactory#addPropertyEditorRegistrar
*/
public void setPropertyEditorRegistrars(PropertyEditorRegistrar[] propertyEditorRegistrars) {
this.propertyEditorRegistrars = propertyEditorRegistrars;
}
/**
* Specify the custom editors to register via a {@link Map}, using the
* class name of the required type as the key and the class name of the
* associated {@link PropertyEditor} as value.
* <p>Also supports {@link PropertyEditor} instances as values; however,
* this is deprecated since Spring 2.0.7 and will be removed in Spring 3.0.
* @param customEditors said <code>Map</code> of editors (can be <code>null</code>)
* @see ConfigurableListableBeanFactory#registerCustomEditor
*/
public void setCustomEditors(Map customEditors) {
this.customEditors = customEditors;
}
/**
* Set whether unresolvable editors should simply be skipped.
* Default is to raise an exception in such a case.
* <p>This typically applies to either the editor class or the required type
* class not being found in the classpath. If you expect this to happen in
* some deployments and prefer to simply ignore the affected editors,
* then switch this flag to "true".
*/
public void setIgnoreUnresolvableEditors(boolean ignoreUnresolvableEditors) {
this.ignoreUnresolvableEditors = ignoreUnresolvableEditors;
}
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = beanClassLoader;
}
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
if (this.propertyEditorRegistrars != null) {
for (int i = 0; i < this.propertyEditorRegistrars.length; i++) {
beanFactory.addPropertyEditorRegistrar(this.propertyEditorRegistrars[i]);
}
}
if (this.customEditors != null) {
for (Iterator it = this.customEditors.entrySet().iterator(); it.hasNext();) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
Class requiredType = null;
try {
if (key instanceof Class) {
requiredType = (Class) key;
}
else if (key instanceof String) {
requiredType = ClassUtils.forName((String) key, this.beanClassLoader);
}
else {
throw new IllegalArgumentException(
"Invalid key [" + key + "] for custom editor: needs to be Class or String.");
}
if (value instanceof PropertyEditor) {
beanFactory.registerCustomEditor(requiredType, (PropertyEditor) value);
}
else if (value instanceof Class) {
beanFactory.registerCustomEditor(requiredType, (Class) value);
}
else if (value instanceof String) {
Class editorClass = ClassUtils.forName((String) value, this.beanClassLoader);
beanFactory.registerCustomEditor(requiredType, editorClass);
}
else {
throw new IllegalArgumentException("Mapped value [" + value + "] for custom editor key [" +
key + "] is not of required type [" + PropertyEditor.class.getName() +
"] or a corresponding Class or String value indicating a PropertyEditor implementation");
}
}
catch (ClassNotFoundException ex) {
if (this.ignoreUnresolvableEditors) {
logger.info("Skipping editor [" + value + "] for required type [" + key + "]: " +
(requiredType != null ? "editor" : "required type") + " class not found.");
}
else {
throw new FatalBeanException(
(requiredType != null ? "Editor" : "Required type") + " class not found", ex);
}
}
}
}
}
}
我们可以看前面注释部分其实已经告诉我们怎么做了。
就是注入customEditors属性，注意看源代码customEditors属性是一个Map。
那么在applicationContext.xml前面加入：
<bean id="customEditorConfigurer" class="org.springframework.beans.factory.config.CustomEditorConfigurer"> <property name="customEditors"> <map> <entry key="java.util.Date"> <bean class="com.lwf.bean.UtilDatePropertiesEditor"> <property name="format" value="yyyy/MM/dd"/> </bean> </entry> </map> </property> </bean>
注意在注册的同时，我们为UtilDatePropertiesEditor注入了format属性，这个属性可以指定格式。
后面仍然保持代码：
<property name="date" value="2010/05/18"></property>
测试类代码中打印：System.out.println(user.getDate());
输出为：
Tue May 18 00:00:00 CST 2010
好了，现在我想改变格式如改成：2010-05-19。即
<property name="date" value="2010-05-19"></property>
那么顺便修改
<bean id="customEditorConfigurer" class="org.springframework.beans.factory.config.CustomEditorConfigurer">
<property name="customEditors">
<map>
<entry key="java.util.Date">
<bean class="com.bjsxt.spring.UtilDatePropertyEditor">
<property name="format" value="yyyy-MM-dd"/>
</bean>
</entry>
</map>
</property>
</bean>
那么打印日期输出：
Wed May 19 00:00:00 CST 2010
说明我们的日期转换并注册成功。
以上可得：
什么是属性编辑器，其作用？
* 自定义属性编辑器，是将spring配置文件中的字符串转换成相应的对象进行注入，spring已经内置了很多类型
的编辑器，我们可以自定义自己的属性编辑器
如何自定义属性编辑器？
* 继承PropertyEditorSupport,覆写如下方法（参见UtilDatePropertyEditor.java):
public void setAsText(String text) throws IllegalArgumentException
* 将属性编辑器注册到spring中，参考：applicationContext.xml
对于配置文件有多个，并且名称相似如：
applicationContext-beans.xml
applicationContext-others.xml
那么我们在实例化容器的时候可以这样：
BeanFactory factory = new ClassPathXmlApplicationContext("applicationContext-*.xml");
User user = (User)factory.getBean("user");