Spring学习笔记-注入实战篇

 

spring对各种数据类型都提供了注入支持，像java基本类型，对象，集合等，这篇文章以代码实践为主，代码注释中会解释注入的细节

测试类中包含了我们编程中最常见的数据结构

package com.crazycoder2010.spring.injection;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class Student {private int age;private double weight;private String name;private boolean registed;private Properties properties;private Map<?, ?> attributes;private List<?> scores;private Set<?> sets;public int getAge() {return age;}public void setAge(int age) {this.age = age;}public double getWeight() {return weight;}public void setWeight(double weight) {this.weight = weight;}public String getName() {return name;}public void setName(String name) {this.name = name;}public boolean isRegisted() {return registed;}public void setRegisted(boolean registed) {this.registed = registed;}public Properties getProperties() {return properties;}public void setProperties(Properties properties) {this.properties = properties;}public Map<?, ?> getAttributes() {return attributes;}public void setAttributes(Map<?, ?> attributes) {this.attributes = attributes;}public List<?> getScores() {return scores;}public void setScores(List<?> scores) {this.scores = scores;}public Set<?> getSets() {return sets;}public void setSets(Set<?> sets) {this.sets = sets;}@Overridepublic String toString() {StringBuilder builder = new StringBuilder();builder.append("age=").append(this.age).append("/n").append("weight=").append(this.weight).append("/n").append("name=").append(this.name).append("/n").append("registed=").append(this.registed).append("/n").append("properties={");StringBuilder tmp = new StringBuilder();for (Object key : this.properties.keySet()) {tmp.append(key).append("=").append(properties.get(key)).append(",");}builder.append(tmp).append("}/n");builder.append("attributes={");StringBuilder map = new StringBuilder();for (Object key : attributes.keySet()) {map.append(key).append("=").append(attributes.get(key)).append(",");}builder.append(map).append("}/n");builder.append("scores={");for (Object obj : scores) {builder.append(obj).append(",");}builder.append("}/n");builder.append("sets={");for (Object obj : sets) {builder.append(obj).append(",");}builder.append("}/n");return builder.toString();}} 

看下在配置文件中如何对各种类型注入

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"><bean id="student" class="com.crazycoder2010.spring.injection.Student"><!-- 整形普通属性直接写入值即可 --><property name="age" value="20"></property><!-- 也可以搞个value标签 --><property name="name"><value>张三</value></property><!-- 布尔型 --><property name="registed" value="true"></property><!-- double类型 --><property name="weight" value="142.5"></property><!-- list类型注入 --><property name="scores"><list><!-- 这个地方是个list --><value>90</value><value>98</value><value>87</value></list></property><!-- 注入map --><property name="attributes"><map><!--这个地方是map,注意内嵌的标签是entry,是一个键值对 --><entry key="a1"><value>12345</value></entry><entry key="a2" value="hello-world"></entry></map></property><!-- Properties注入 --><property name="properties"><props><!-- 雷同与map,但是注意prop标签只有key属性，因为value只能是String类型，prop对应的值直接写在标签内部 --><prop key="p1">789</prop><prop key="p2">567</prop></props></property><!-- 集合注入 --><property name="sets"><set><value>你好</value><value>123</value><null></null><!-- 这个地方我们注入一个null进去 --></set></property></bean></beans> 

打印输出

 

age=20

weight=142.5

name=张三

registed=true

properties={p2=567,p1=789,}

attributes={a1=12345,a2=hello-world,}

scores={90,98,87,}

sets={你好,123,null,}

 

附BaseSpring类

package com.crazycoder2010.spring;import org.springframework.beans.factory.BeanFactory;import org.springframework.context.support.ClassPathXmlApplicationContext;public class BaseSpring {BeanFactory beanFactory = null;public Object getBean(String beanName) {init();//确保spring容器已经启动return beanFactory.getBean(beanName);}private void init() {if (beanFactory == null) {beanFactory = new ClassPathXmlApplicationContext(configFiles());//这个地方}}protected String[] configFiles() {//这里作了个约定，默认的spring文件都放在与当前类平行的目录下，名称为applicationContex.xml//如要测试的类为com.crazycoder2010.spring.injection.StudentTest//则该测试的spring配置文件路径为com/crazycoder2010/spring/injection/applicationContex.xml//子类可以复写这个方法类实现定制化需求String folder = getClass().getPackage().getName().replaceAll("//.", "/")+ "/";String file = "applicationContext.xml";return new String[] { folder + file };}}