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1, If the constructor can be called
2. The spring XML file is configured as follows:
2, Assign values to different types of parameters of the constructor
1, If the constructor can be called
1. Write a UserInfo class:
public class UserInfo {
public UserInfo(int age,String name) {
System.out.println(age+","+name);
}
}2. The spring XML file is configured as follows:
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean> <context:component-scan base-package="com.jd"></context:component-scan> <!-- How to call a constructor --> <bean class="com.jd.vo.UserInfo"><!--Set up Bean--> <constructor-arg name="age" value="12"></constructor-arg><!--Set parameters passed in by construction method--> <constructor-arg name="name" value="Tim"></constructor-arg> </bean> </beans>
3. Write a Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation, observation results:
2, Assign values to different types of parameters of the constructor
1. Custom object
1) Write UserInfo class
import java.util.Date;
public class UserInfo {
public UserInfo(Date birth) {
System.out.println(birth);
}
}
2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean><!--To configure Date object--> <context:component-scan base-package="com.jd"></context:component-scan> <!-- Assign value to constructor parameter: custom object --> <bean class="com.jd.vo.UserInfo"> <constructor-arg ref="date"></constructor-arg><!--utilize ref Attribute will Date Object afferent--> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
The run result indicates that the Date object has been passed in as a parameter to the constructor.
2, array
1) Write UserInfo class
public class UserInfo {
public UserInfo(String [] mobiles) {//Pass in an array in the argument of the constructor
for (String mobile : mobiles) {
System.out.println(mobile);//Output each value in the collection to verify our operation
}
}
}2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean> <context:component-scan base-package="com.jd"></context:component-scan> <!-- Assign value to constructor parameter: array --> <bean class="com.jd.vo.UserInfo"> <constructor-arg> <array> <value>119</value><!--The first way: assign values directly to array elements--> <bean class="java.lang.String"><!--The second way: through configuration Bean Establish String Class object to assign values to array elements--> <constructor-arg value="120"></constructor-arg> </bean> </array> </constructor-arg> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
As you can see from the observation results, the String array has been passed in as a parameter construction method.
3. List collection
1) Write UserInfo class
import java.util.List;
public class UserInfo {
public UserInfo(List<Double> moneys) {//In the constructor parameter, a List collection is passed in, and the generic type is Double
for (Double money : moneys) {//Output each element in the collection to verify our operation
System.out.println(money);
}
}
}2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean> <context:component-scan base-package="com.jd"></context:component-scan> <!-- Assign a value to the constructor parameter: List aggregate --> <bean class="com.jd.vo.UserInfo"> <constructor-arg> <list> <value>21000</value> <value>23222</value> <value>42455</value> </list> </constructor-arg> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
As you can see from the observation, the List set has been used as the parameter input constructor.
4. Set set
1) Write UserInfo class
import java.util.Date;
import java.util.Set;
public class UserInfo {
public UserInfo(Set<Date> births) {//In the constructor parameter, a List collection is passed in, and the generic type is Date
for (Date birth : births) {//Output each element in the collection to verify our operation
System.out.println(birth);
}
}
}
2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean> <context:component-scan base-package="com.jd"></context:component-scan> <!-- Assign a value to the constructor parameter: set aggregate --> <bean class="com.jd.vo.UserInfo"> <constructor-arg> <set> <ref bean="date"/><!--Two different ways to assign values to elements--> <bean class="java.util.Date"></bean> </set> </constructor-arg> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
As can be seen from the observation results, the Set set has been used as the parameter input construction method.
5. Map set
1) Write UserInfo class
import java.util.Map;
import java.util.Properties;
public class UserInfo {
public UserInfo(Map<String,Integer> map) {
for (String name : map.keySet()) {//Output each pair of key and value in the collection to verify our operation
System.out.println(name+","+map.get(name));
}
}
}2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <bean id="date" class="java.util.Date"></bean> <context:component-scan base-package="com.jd"></context:component-scan> <bean id="xiaogang" class="java.lang.String"><!--Through use Bean Establish String Object in map In set key assignment--> <constructor-arg value="Xiaogang"></constructor-arg> </bean> <!-- Assign a value to the constructor parameter: map aggregate --> <bean id="ui" class="com.jd.vo.UserInfo"> <constructor-arg> <map> <entry key="Xiao Ming" value="12"></entry> <entry key-ref="xiaogang" value="23"></entry><!--utilize key-ref Attribute call String object--> </map> </constructor-arg> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
As can be seen from the observation results, the Map set has been used as the parameter input construction method.
6. Properties object
1) Write UserInfo class
import java.util.Properties;
public class UserInfo {
public UserInfo(Properties properties) {
System.out.println(properties.getProperty("driver"));
System.out.println(properties.getProperty("url"));
System.out.println(properties.getProperty("username"));
System.out.println(properties.getProperty("password"));
}
}
2) Configuration XML file
<?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:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd"> <context:component-scan base-package="com.jd"></context:component-scan> <bean class="com.jd.vo.UserInfo" > <constructor-arg> <props> <prop key="driver">com.mysql.jdbc.Driver</prop> <prop key="url">jdbc://127.0.0.1:3306/test</prop> <prop key="username">root</prop> <prop key="password">root</prop> </props> </constructor-arg> </bean> </beans>
3) Write Test class
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jd.vo.UserInfo;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
UserInfo userInfo = applicationContext.getBean(UserInfo.class);
applicationContext.close();
}
}Operation result:
As you can see from the observation, the Properties object has passed in the constructor as a parameter.
