Spring框架学习之第8节
<bean id=”foo” class=”…Foo”>
<property name=”属性”>
<!—第一方法引用-->
<ref bean=”bean对象名”>
<!—内部bean—>
<bean>
<property></property>
</bean>
</property>
</bean>
④集成配置
public class Student
public class Graduate extends Student
在beans.xml文件中配置
思考：目前我们都是通过set的方式给bean注入值的，spring还提供了其他的方式注入值，通过构造函数注入值
- 通过构造函数注入值
beans.xml文件关键代码
<!-- 配置一个雇员对象 -->
<bean id="employee" class="com.litao.constructor.Employee">
<!-- 通过构造函数来注入属性值 index代表第几个参数，type是类型 -->
<constructor-arg index="0" type="java.lang.String" value="大明"/>
<constructor-arg index="1" type="int" value="23"/>
</bean>
set注入的缺点是无法清晰表达哪些属性是必须的，哪些是可选的，构造注入的优势是通过构造强制依赖关系，不可能实例化不完全的或无法使用的bean。
- 自动装配bean的属性值
（1） byName的用法
<!-- 配置一个master对象 -->
<bean id="master" class="com.litao.autowire.Master" autowire="byName">
<property name="name">
<value>顺平</value>
</property>
<!--
/* 传统的方法 */
<property name="dog" ref="dog" />
-->
</bean>
<!-- 配置dog对象 -->
<bean id="dog" class="com.litao.autowire.Dog">
<property name="name" value="小黄" />
<property name="age" value="3" />
</bean>
原理图：
（1） byType
寻找和属性类型相同的bean,找不到,装不上,找到多个抛异常
（2） constructor：autowire="constructor"
说明：
查找和bean的构造参数一致的一个或多个bean，若找不到或找到多个，抛异常。按照参数的类型装配。
（3） autodetect：autowire="autodetect"
说明：(3)和(2)之间选一个方式。不确定
性的处理与(3)和(2)一致。
（4） defualt
这个需要在<beans defualt-autorwire=“指定” />
当你在<beans>指定了default-autowire后，所有的bean的默认的autowire就是指定的装配方法
如果没有在<beans defualt-autorwire=“指定” />，没有default-autowire=”指定”，则默认是default-autowire=”no”.
（5） no：不自动装配
使用spring的特殊bean,完成分散配置
beans.xml
说明：当通过context:property-placeholder引入多个属性文件的时候使用逗号间隔
<!-- 引入我们的db.properties文件 -->
<context:property-placeholder location="classpath:com/litao/dispatch/db.properties,classpath:com/litao/dispatch/db2.properties"/>
<!-- 配置一个DButil对象 -->
<bean id="dbutil" class="com.litao.dispatch.DBUtil">
<property name="name" value="${name}" />
<property name="drivername" value="${drivername}" />
<property name="url" value="${url}" />
<property name="pwd" value="${pwd}" />
</bean>
<!-- 配置一个DButil2对象 -->
<bean id="dbutil2" class="com.litao.dispatch.DBUtil">
<property name="name" value="${db2.name}" />
<property name="drivername" value="${db2.drivername}" />
<property name="url" value="${db2.url}" />
<property name="pwd" value="${db2.pwd}" />
</bean>
db.properties
name=scott
drivername=oracle:jdbc:driver:OracleDriver
url=jdbc:oracle:thin:@127.0.0.1:1521:hsp
pwd=tiger
#key=value
项目结构：
/******************************com.litao.autowire包***************************************************/
com.litao.autowire.App1.java
package com.litao.autowire;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/autowire/beans.xml");
//通过容器获取主人
Master master = (Master) ac.getBean("master");
System.out.println(master.getName()+" "+master.getDog().getName());
}
}
com.litao.autowire.Dog.java
package com.litao.autowire;
import javax.annotation.Resource;
public class Dog {
private String name;
private int age;
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;
}
}
com.litao.autowire.Master.java
package com.litao.autowire;
public class Master {
private String name;
private Dog dog;
public Master(Dog dog){
System.out.println("Master(Dog dog)构造函数被调用");
this.dog = dog;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Dog getDog() {
return dog;
}
public void setDog(Dog dog) {
this.dog = dog;
}
}
com.litao.autowire.beans.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:context="http://www.springframework.org/schema/context" 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/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" default-autowire="no" > <!-- 配置一个master对象 --> <bean id="master" class="com.litao.autowire.Master"> <property name="name"> <value>顺平</value> </property> <!-- /* 传统的方法 */ <property name="dog" ref="dog" /> --> </bean> <!-- 配置dog对象 --> <bean id="dog11" class="com.litao.autowire.Dog"> <property name="name" value="小黄" /> <property name="age" value="3" /> </bean> </beans>
/******************************com.litao.collection包***************************************************/
App1.java
package com.litao.collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Map.Entry;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/collection/beans.xml");
Department department = (Department)ac.getBean("department");
System.out.println(department.getName());
for (String emName : department.getEmpName()) {
System.out.println(emName);
}
System.out.println("************通过list集合取出数据**************");
for(Employee e: department.getEmpList()){
System.out.println("name=" + e.getName() + " " + e.getId());
}
//set取得时候不能保证顺序，list取时可以保证顺序
System.out.println("************通过set集合取出数据**************");
for(Employee e: department.getEmpsets()){
System.out.println("name=" + e.getName());
}
System.out.println("************通过map集合取出数据**************");
//1.用迭代器
Map<String,Employee> empmaps = department.getEmpMaps();
Iterator it = empmaps.keySet().iterator();
while (it.hasNext()) {
String key = (String)it.next();
//System.out.println(key);
Employee emp = empmaps.get(key);
System.out.println("key="+key+" "+emp.getName());
}
//2.最简洁的方法
for(Entry<String,Employee> entry1:department.getEmpMaps().entrySet()){
System.out.println(entry1.getKey() + " " + entry1.getValue().getName());
}
System.out.println("**************通过Properties取出数据**************");
Properties pp = department.getPp();
//System.out.println(pp.getProperty("pp1").toString());
for(Entry<Object,Object> entry:pp.entrySet()){
System.out.println(entry.getKey().toString()+" "+ entry.getValue().toString());
}
System.out.println("**************通过Enumeration取出数据**************");
Enumeration en = pp.keys();
while (en.hasMoreElements()) {
//Entry<Object,Object> element = (Entry<Object,Object>) en.nextElement();
//System.out.println(element.getKey()+ " " +element.getValue());
String key = (String)en.nextElement();
System.out.println(key+ " " + pp.getProperty(key));
}
}
}
Department.java
package com.litao.collection;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class Department {
private String name;
private String[] empName;
private List<Employee> empList;
private Set<Employee> empsets;
private Map<String,Employee> empMaps;
private Properties pp;//Properties的配置使用
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String[] getEmpName() {
return empName;
}
public void setEmpName(String[] empName) {
this.empName = empName;
}
public List<Employee> getEmpList() {
return empList;
}
public void setEmpList(List<Employee> empList) {
this.empList = empList;
}
public Set<Employee> getEmpsets() {
return empsets;
}
public void setEmpsets(Set<Employee> empsets) {
this.empsets = empsets;
}
public Map<String, Employee> getEmpMaps() {
return empMaps;
}
public void setEmpMaps(Map<String, Employee> empMaps) {
this.empMaps = empMaps;
}
public Properties getPp() {
return pp;
}
public void setPp(Properties pp) {
this.pp = pp;
}
}
Employee.java
package com.litao.collection;
public class Employee {
private String name;
private int id;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
beans.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="department" class="com.litao.collection.Department">
<property name="name" value="财务部" />
<!-- 给数组注入值 -->
<property name="empName">
<list>
<value>小明</value>
<value>小明小明</value>
<value>小明小明小明小明</value>
</list>
</property>
<!-- 给list注入值 list中可以有相同的对象 -->
<property name="empList">
<list>
<ref bean="emp1"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
</list>
</property>
<!-- 给set注入值 set中不能有相同的对象 -->
<property name="empsets">
<set>
<ref bean="emp1"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
<ref bean="emp2"/>
</set>
</property>
<!-- 给map注入值 map中也不能有相同的对象，后面的会把前面的覆盖，map只要key一样就可以装配value对应的bean -->
<property name="empMaps">
<map>
<entry key="1" value-ref="emp1"></entry>
<entry key="2" value-ref="emp2"></entry>
<entry key="2" value-ref="emp2"></entry>
</map>
</property>
<!-- 给属性集合配置 -->
<property name="pp">
<props>
<prop key="pp1">abcd</prop>
<prop key="pp2">hello</prop>
</props>
</property>
</bean>
<bean id="emp1" class="com.litao.collection.Employee">
<property name="name" value="北京" />
<property name="id" value="1" />
</bean>
<bean id="emp2" class="com.litao.collection.Employee">
<property name="name" value="天津" />
<property name="id" value="2" />
</bean>
</beans>
/******************************com.litao.constructor包************************************************/
App1.java
package com.litao.constructor;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/constructor/beans.xml");
Employee ee = (Employee)ac.getBean("employee");
System.out.println(ee.getName());
}
}
Employee.java
package com.litao.constructor;
public class Employee {
private String name;
private int age;
public Employee() {
}
public Employee(String name, int age) {
System.out.println("Employee(String name, int age)构造函数被调用");
this.name = name;
this.age = age;
}
public Employee(String name) {
System.out.println("Employee(String name)构造函数被调用");
this.name = name;
}
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;
}
}
beans.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:context="http://www.springframework.org/schema/context" 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/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> <!-- 配置一个雇员对象 --> <bean id="employee" class="com.litao.constructor.Employee"> <!-- 通过构造函数来注入属性值 index代表第几个参数，type是类型 --> <constructor-arg index="0" type="java.lang.String" value="大明"/> <constructor-arg index="1" type="int" value="23"/> </bean> </beans>
/******************************com.litao.dispatch包************************************************/
App1.java
package com.litao.dispatch;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/dispatch/beans.xml");
DBUtil dbUtil = (DBUtil)ac.getBean("dbutil2");
System.out.println(dbUtil.getDrivername()+" "+ dbUtil.getPwd());
}
}
DBUtil.java
package com.litao.dispatch;
public class DBUtil {
private String drivername;
private String url;
private String name;
private String pwd;
public String getDrivername() {
return drivername;
}
public void setDrivername(String drivername) {
this.drivername = drivername;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
}
beans.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:context="http://www.springframework.org/schema/context"
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/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
<!-- 引入我们的db.properties文件 -->
<context:property-placeholder location="classpath:com/litao/dispatch/db.properties,classpath:com/litao/dispatch/db2.properties"/>
<!-- 配置一个DButil对象 -->
<bean id="dbutil" class="com.litao.dispatch.DBUtil">
<property name="name" value="${name}" />
<property name="drivername" value="${drivername}" />
<property name="url" value="${url}" />
<property name="pwd" value="${pwd}" />
</bean>
<!-- 配置一个DButil2对象 -->
<bean id="dbutil2" class="com.litao.dispatch.DBUtil">
<property name="name" value="${db2.name}" />
<property name="drivername" value="${db2.drivername}" />
<property name="url" value="${db2.url}" />
<property name="pwd" value="${db2.pwd}" />
</bean>
</beans>
db.properties
name=scott drivername=oracle:jdbc:driver:OracleDriver url=jdbc:oracle:thin:@127.0.0.1:1521:hsp pwd=tiger #key=value
db.properties2
db2.name=scott3 db2.drivername=oracle:jdbc:driver:OracleDriver3 db2.url=jdbc:oracle:thin:@127.0.0.1:1521:hsp3 db2.pwd=tiger3 #key=value
/******************************com.litao.inherit包************************************************/
App1.java
package com.litao.inherit;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/inherit/beans.xml");
Graduate graduate = (Graduate)ac.getBean("graduate");
System.out.println(graduate.getName() + " " + graduate.getAge() + " " + graduate.getDegree());
}
}
Graduate.java
package com.litao.inherit;
public class Graduate extends Student {
private String degree;
public String getDegree() {
return degree;
}
public void setDegree(String degree) {
this.degree = degree;
}
}
Student.java
package com.litao.inherit;
public class Student {
protected String name;
protected String age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
}
beans.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">
<!-- 配置一个学生对象 -->
<bean id="student" class="com.litao.inherit.Student">
<property name="name" value=" 李涛" />
<property name="age" value="30" />
</bean>
<!-- 配置一个Graduate对象 -->
<bean id="graduate" parent="student" class="com.litao.inherit.Graduate">
<!-- 如果自己配置属性name,age,则会替换从父对象集成的数据 -->
<property name="name" value="小明" />
<property name="degree" value="学士" />
</bean>
</beans>
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