04set注入专题/简单类型/数组/List/Set/Map/空字符串/null/特殊符号

1.1注入外部Bean

在之前使用的案例就是注入外部Bean的方式。

<!-- class属性声明要管理哪个类中的对象 property标签的name是提示set方法名ref标签指明注入的bean的id--><bean id="userServiceBean" class="com.powernode.spring6.service.UserService"><property name="userDao" ref="userDaoBean"/></bean></beans>

外部Bean的特点：bean定义到外面，在property标签中使用ref属性进行注入。通常这种方式是常用。

1.2注入内部Bean

内部Bean的特点：在bean标签中嵌套bean标签,以取代property种的ref标签.少用.

<!-- ref标签指明注入的bean的id没有了ref标签,用另一个bean标签的class标签指明注入的bean所在的类(进而找到该bean)--><bean id="userServiceBean" class="com.powernode.spring6.service.UserService"><property name="userDao"><bean class="com.sunsplanter.spring6.dao.UserDao"/></property></bean>

2.1注入简单类型

我们之前在进行注入的时候，是将获取到的对象注入到另一个对象中。

 public void setUserDao(UserDao userDao){this.userDao = userDao;}

对于简单类型,也就是
● 基本数据类型
● 基本数据类型对应的包装类
● String或其他的CharSequence子类
● Number子类
● Date子类
● Enum子类
● URI
● URL
● Temporal子类
● Locale
● Class
● 另外还包括以上简单值类型对应的数组类型
该如何注入?
和对象注入的基本方法完全一致.
即完成spring配置文件,src中定义要注入的类,对象,属性,test中进行单元测试.

项目结构

其中,JDBC测试简单数据类型string;SimpleValue_Array测试数组,且数组中数据是简单数据类型;NonSimpleValue_Array测试数组,且数组中数据是非简单数据类型,这三组测试公用一个set-di.xml的spring配置,共用一个SpringDITest测试类.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns="http://www.springframework.org/schema/beans"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"><!--测试注入JDBC数据源property标签的name属性是提示set方法名。property标签的value属性是要注入的bean对象的直接值(注入简单类型时可用)。property标签的ref属性是要注入的bean对象的id。property标签的ref子标签是声明要注入数组的非简单数据的bean的id。--><bean id="myDataSource" class="com.sunsplanter.JDBC.MyDataSource"><property name="driver" value=""/><property name="url" value="jdbc:mysql.cj.jdbc.Driver"/><property name="username" value="root"/><property name="password" value="Mysql998168"/></bean><!--    测试注入数组,且数组个数据是简单类型,因此在array中使用value子标签注入在property下添加一个array子标签--><bean id="person" class="com.sunsplanter.SimpleValueTest.SimpleValue_Array"><property name="favariteFoods"><array><value>鸡排</value><value>汉堡</value><value>鹅肝</value></array></property></bean><!--    测试注入数组,且数组中数据是非简单类型,因此在array中使用value子标签注入--><bean id="goods1" class="com.sunsplanter.NonSimpleValue_Array.Goods"><property name="name" value="西瓜"/></bean><bean id="goods2" class="com.sunsplanter.NonSimpleValue_Array.Goods"><property name="name" value="苹果"/></bean><bean id="order" class="com.sunsplanter.NonSimpleValue_Array.Order"><property name="goods"><array><!--Order是一个数组.且数组中元素是非简单类型,因此在array中采用ref标签注入--><ref bean="goods1"/><ref bean="goods2"/></array></property></bean><!--    list集合有序可重复set集合无序不可重复--><!--提前在SpringDITest中声明一个set,并指明是String类型private Set<String> phones;<bean id="peopleBean" class="com.powernode.spring6.beans.People"><property name="phones"><set>非简单类型可以使用ref，简单类型使用value<value>110</value><value>110</value><value>120</value></set></property></bean>提前在SpringDITest中声明一个list,并指明是String类型private List<String> names;<bean id="peopleBean" class="com.powernode.spring6.beans.People"><property name="names"><list><ref bean="people1"/><ref bean="people2"/></list></property></bean>--><!--    注入键值对的集合map--><!--提前在SpringDITest中声明一个Map键值对,并指明是键是整数类型,值是String类型private Map<Integer, String> addrs;<bean id="peopleBean" class="com.powernode.spring6.beans.People"><property name="addrs"><map>如果key是非简单类型，使用 key-ref 属性如果value是非简单类型，使用 value-ref 属性<entry key="1" value="北京大兴区"/><entry key="2" value="上海浦东区"/><entry key="3" value="深圳宝安区"/></map></property></bean>-->
<!--    cndata是xml提供的语法,有了这个xml就不解析--><!--    p命名空间注入本质还是set注入,只不过其让Spring配置更简单--></beans>

package com.sunsplanter.test;import com.sunsplanter.JDBC.MyDataSource;
import com.sunsplanter.NonSimpleValue_Array.Order;
import com.sunsplanter.SimpleValueTest.SimpleValue_Array;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class SpringDITest {@Test//测试注入JDBC数据源,getBean的name参数即set-di.xml中的bean的idpublic void testMyDataSource(){ApplicationContext applicationContext = new ClassPathXmlApplicationContext("set-di.xml");MyDataSource myDatataSource = applicationContext.getBean("myDataSource", MyDataSource.class);System.out.println(myDatataSource);}@Test//测试注入数组,且数组元素为简单类型public void testArraySimple(){ApplicationContext applicationContext = new ClassPathXmlApplicationContext("set-di.xml");SimpleValue_Array simpleValueArray = applicationContext.getBean("person", SimpleValue_Array.class);System.out.println(simpleValueArray);}@Test//测试注入数组,且数组元素为非简单类型public void testArray(){ApplicationContext applicationContext = new ClassPathXmlApplicationContext("set-di.xml");Order order = applicationContext.getBean("order", Order.class);System.out.println(order);}
}

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package com.sunsplanter.JDBC;import javax.sql.DataSource;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.logging.Logger;//数据源:所有提供connection对象的都是数据源,必须实现DataSource
public class MyDataSource implements DataSource{//获取数据库连接对象需要4个信息//这四个数据都是简单数据,用Spring容器管理他们private String driver;private String url;private String username;private String password;public void setDriver(String driver) {this.driver = driver;}public void setUrl(String url) {this.url = url;}public void setUsername(String username) {this.username = username;}public void setPassword(String password) {this.password = password;}@Overridepublic String toString() {return "MyDataSource{" +"driver='" + driver + '\'' +", url='" + url + '\'' +", username='" + username + '\'' +", password='" + password + '\'' +'}';}@Overridepublic Connection getConnection() throws SQLException {return null;}@Overridepublic Connection getConnection(String username, String password) throws SQLException {return null;}@Overridepublic PrintWriter getLogWriter() throws SQLException {return null;}@Overridepublic void setLogWriter(PrintWriter out) throws SQLException {}@Overridepublic void setLoginTimeout(int seconds) throws SQLException {}@Overridepublic int getLoginTimeout() throws SQLException {return 0;}@Overridepublic Logger getParentLogger() throws SQLFeatureNotSupportedException {return null;}@Overridepublic <T> T unwrap(Class<T> iface) throws SQLException {return null;}@Overridepublic boolean isWrapperFor(Class<?> iface) throws SQLException {return false;}
}

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package com.sunsplanter.NonSimpleValue_Array;//本次测试用set方法注入数组,且数组元素是非简单类型
//具体来说,定义两个类,分别是Goods和Order,其中,每个Order可能包含多个Good
public class Goods {private String name;public Goods() {}public Goods(String name) {this.name = name;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "Goods{" +"name='" + name + '\'' +'}';}
}package com.sunsplanter.NonSimpleValue_Array;
import java.util.Arrays;public class Order {// 一个订单中有多个商品//声明一个数组,将传来的good全部放进数组private Goods[] goods;public Order() {}public Order(Goods[] goods) {this.goods = goods;}public void setGoods(Goods[] goods) {this.goods = goods;}@Overridepublic String toString() {return "Order{" +"goods=" + Arrays.toString(goods) +'}';}
}