一：spring容器给bean对象注入属性值
1：注入基本属性值
a. 创建MessageBean类：
/**
*
*/
package com.hlcui.dao; /**
* @author Administrator
*
*/
public class MessageBean {
private String name; private int age; private double salary; 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 double getSalary() {
return salary;
} public void setSalary(double salary) {
this.salary = salary;
} public String execute() {
System.out.println("name=" + name + "\nage=" + age
+ "\nsalary=" + salary);
return "success";
} }
b. 在spring容器配置文件中配置MessageBean对象核心代码：
<!-- 配置MessageBean对象 -->
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name" value="Jack"></property>
<property name="age" value="27"></property>
<property name="salary" value="12000"></property>
</bean>
或者将value元素作为property元素的子元素，效果是一样的
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name">
<value>Tom</value>
</property>
<property name="age">
<value>27</value>
</property>
<property name="salary">
<value>12000</value>
</property>
</bean>
c. 运行测试方法
@Test
public void testBaseInject(){
ApplicationContext ac = getApplicationContext();
MessageBean mb = ac.getBean("messageBean", MessageBean.class);
mb.execute();
}
通过运行结果可知属性值已经注入到对象中，这种方式在前面已经总结过，就是setter注入。
2：注入集合属性值(List、Set、Map、Properties)
修改MessageBean类：
/**
*
*/
package com.hlcui.dao; import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.Map.Entry; /**
* @author Administrator
*
*/
public class MessageBean {
private List<String> someList;
19 private Set<Integer> someSet;
20 private Map<String,Object> someMap;
21 private Properties props; private String name; private int age; private double salary; public List<String> getSomeList() {
31 return someList;
32 }
33
34 public void setSomeList(List<String> someList) {
35 this.someList = someList;
36 }
37
38 public Set<Integer> getSomeSet() {
39 return someSet;
40 }
41
42 public void setSomeSet(Set<Integer> someSet) {
43 this.someSet = someSet;
44 }
45
46 public Map<String, Object> getSomeMap() {
47 return someMap;
48 }
49
50 public void setSomeMap(Map<String, Object> someMap) {
51 this.someMap = someMap;
52 }
53
54 public Properties getProps() {
55 return props;
56 }
57
58 public void setProps(Properties props) {
59 this.props = props;
} 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 double getSalary() {
return salary;
} public void setSalary(double salary) {
this.salary = salary;
} public String execute() {
System.out.println("name=" + name + "\nage=" + age
+ "\nsalary=" + salary);
System.out.println("--------List集合结果--------");
90 for(String str:someList){
91 System.out.println(str);
92 }
93 System.out.println("--------Set集合结果--------");
94 for(Iterator<Integer> it = someSet.iterator();it.hasNext();){
95 System.out.println(it.next());
96 }
97 System.out.println("-------Map集合结果--------");
98 for(Entry<String, Object> entry:someMap.entrySet()){
99 String key = entry.getKey();
100 String value = (String) entry.getValue();
101 System.out.println(key+"=="+value);
102 }
103 System.out.println("-------Properties结果------");
104 for(Object obj : props.keySet()){
105 String value = props.getProperty((String) obj);
106 System.out.println(obj+"=="+value);
107 }
return "success";
} }
配置文件修改如下：
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name">
<value>Tom</value>
</property>
<property name="age">
<value>27</value>
</property>
<property name="salary">
<value>12000</value>
</property>
<property name="someList">
<list>
<value>aaaaList</value>
<value>bbbbList</value>
<value>ccccList</value>
</list>
</property>
<property name="someSet">
<set>
<value>111</value>
<value>222</value>
<value>333</value>
</set>
</property>
<property name="someMap">
<map>
<entry key="1" value="java"></entry>
<entry key="2" value="c++"></entry>
<entry key="3" value="c#"></entry>
</map>
</property>
<property name="props">
<props>
<prop key="username">root</prop>
<prop key="password">root</prop>
</props>
</property>
</bean>
运行测试方法：
从结果可以看出，参数注入成功！！！
3：引用方式注入集合属性
修改配置文件内容如下：
<util:list id="someList">
<value>aaaaList</value>
<value>bbbbList</value>
<value>ccccList</value>
</util:list>
<util:set id="someSet">
<value>111</value>
<value>222</value>
<value>333</value>
</util:set>
<util:map id="someMap">
<entry key="1" value="java"></entry>
<entry key="2" value="c++"></entry>
<entry key="3" value="c#"></entry>
</util:map>
<util:properties id="props">
<prop key="username">root</prop>
<prop key="password">root</prop>
</util:properties>
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name">
<value>Tom</value>
</property>
<property name="age">
<value>27</value>
</property>
<property name="salary">
<value>12000</value>
</property>
<property name="someList" ref="someList"></property>
<property name="someSet" ref="someSet"></property>
<property name="someMap" ref="someMap"></property>
<property name="props" ref="props"></property>
</beans>
运行测试方法：
和之前的效果是一样的，只不过这样配置更加明了！
二：利用spring表达式注入属性值
1：在src下添加文件user.properties,内容如下：
name=Jack
age=30
salary=15000
2：在spring容器配置文件中加载配置文件
<!-- 加载配置文件user.properties -->
<util:properties id="user" location="classpath:user.properties"/>
<!-- 配置MessageBean对象 -->
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name" value="#{user.name}"></property>
<property name="age" value="#{user.age}"></property>
<property name="salary" value="#{user.salary}"></property>
</bean>
3：运行测试方法
通过结果可知spring表达式注入成功！
三：spring注入空值
1：修改配置文件
<!-- 配置MessageBean对象 -->
<bean id="messageBean" class="com.hlcui.dao.MessageBean">
<property name="name">
<null/>
</property>
<property name="age" value="#{user.age}"></property>
<property name="salary" value="#{user.salary}"></property>
</bean>
2：运行测试方法
空值注入成功，只有引用数据类型才可以注入空值！