Spring Learning in the Java family--Dependency injection (II.)

One, three ways to rely on injection

interface injection, set injection, constructor injection

Ii. Constructor Injection 2.1, test class

Package Test;public class Test01 {public String msg=null;public test01 (String msg) {System.out.println (msg);} public void Prints () {System.out.println ("prints");}}

2.2. Edit Applicationcontext.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" xsi:schemalocation= "Http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/ Spring-beans.xsd Http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-m Vc.xsd Http://www.springframework.org/schema/context Http://www.springframework.org/schema/context/spring-co         Ntext.xsd HTTP://WWW.SPRINGFRAMEWORK.ORG/SCHEMA/AOP http://www.springframework.org/schema/aop/spring-aop.xsd       Http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd "> <!--constructor injection--<bean id= "test01" class= "test.test01" > <constructor-arg index= "0" > <val Ue>dirk</value> </constructor-arg> <constructor-arg index= "1" > <value>dirk2</value> </constructor-arg> </bean> </beans>

2.3. Testing

Package Test;public class Test01 {public string Msg=null;public string Msg1=null;public test01 (String msg,string msg1) {Sy Stem.out.println (MSG+MSG1);} public void Prints () {System.out.println ("prints");}}

Package Test;import Java.io.ioexception;import Java.io.printwriter;import javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Org.springframework.context.applicationcontext;import Org.springframework.context.support.classpathxmlapplicationcontext;public class Aservlet extends HttpServlet { public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { ApplicationContext context=new classpathxmlapplicationcontext ("Applicationcontext.xml"); test02 test01= (test02) Context.getbean ("test02"); Test01.getmsg ();}}

Third, set injection 　　3.1 Test class

Package Test;public class test02 {public string Msg;public string getmsg () {return msg;} public void Setmsg (String msg) {this.msg = msg;}}

3.2. Configuration file Modification

<?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" xsi:schemalocation= "Http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/ Spring-beans.xsd Http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-m Vc.xsd Http://www.springframework.org/schema/context Http://www.springframework.org/schema/context/spring-co         Ntext.xsd HTTP://WWW.SPRINGFRAMEWORK.ORG/SCHEMA/AOP http://www.springframework.org/schema/aop/spring-aop.xsd         Http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd "> <bean id= "test02" class= "test.test02" > <property name= "msg" > <value>drik.wang</value&gt    ; </property> </bean></beanS> 

Package Test;import Java.io.ioexception;import Java.io.printwriter;import javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Org.springframework.context.applicationcontext;import Org.springframework.context.support.classpathxmlapplicationcontext;public class Aservlet extends HttpServlet { public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { ApplicationContext context=new classpathxmlapplicationcontext ("Applicationcontext.xml"); test02 test01= (test02) Context.getbean ("test02"); Test01.getmsg ();}}

3.3. Testing

Package Test;import Java.io.ioexception;import Java.io.printwriter;import javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Org.springframework.context.applicationcontext;import Org.springframework.context.support.classpathxmlapplicationcontext;public class Aservlet extends HttpServlet { public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { ApplicationContext context=new classpathxmlapplicationcontext ("Applicationcontext.xml"); test02 test02= (test02) Context.getbean ("test02"); System.out.println (Test02.getmsg ());}}

Iv. Example 4.1, project structure

4.2. Data layer Interface

4.2, the data layer is the implementation of the class

4.4, Business Layer Interface

4.5. Business Layer Implementation Class

4.5. Call the business layer

4.6. Configuration files

4.7. Results

Spring Learning in the Java family--Dependency injection (II.)