IOC注入

一 屬性注入介紹
1 創建對象時候,向類里面屬性設置值。
2 Java設置屬性的三種方法
(1) 使用set方法注入

public class User {
 private  String name;
 public void setName(String name){
     this.name = name;
 }
}


User user = new User();
user.setName("abcd");

(2) 有參構造注入

public class User {
 private  String name;
 public User(String name){
     this.name = name;
 }
}

User user = new User("Jack");

(3) 使用接口注入

public interface User {
 public void delete(String name);
}


public class UserImpl implements User{
    private String name;
    public void delete(String name) {
    this.name = name;
    }
}

3 在Spring框架里面,支持前兩種方式
(1)set方法注入(重點)
(2)有參構造注入
二 Spring框架屬性注入
1 有參構造注入
(1) 有參構造

package IOC;

/**
 * Created by pc on 2017/9/9.
 */
public class PropertyDemo1 {
    private String username;

    public PropertyDemo1(String username) {
        this.username = username;
    }
    public void test1(){
        System.out.println("demo.........."+username);
    }
}

(2).xml配置

  • constructor-arg
    • name屬性值:類里面定義的屬性名稱
    • value屬性值: 設置具體的值
    <!--使用有參構造注入屬性-->
    <bean id="demo1" class="IOC.PropertyDemo1">
        <!-- 使用有參構造注入-->
    <constructor-arg name="username" value="小王"></constructor-arg></bean>

(3)測試

import Bean.User;
import IOC.PropertyDemo1;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by pc on 2017/9/7.
 */
public class TextIOC {
    public static void main(String[] args) {
        //加載Spring配置文件,并創建對象
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
        //得到配置的對象
        PropertyDemo1 demo1 = (PropertyDemo1) context.getBean("demo1");
        demo1.test1();
    }
}
結果顯示

2 set方法注入
(1)測試setBook類

package IOC;

/**
 * Created by pc on 2017/9/9.
 */
public class Book {
    private String bookname;

    public void setBookname(String bookname) {
        this.bookname = bookname;
    }

    public void demobook(){
        System.out.println("book.........."+bookname);
    }
}

(2).xml配置

  • property
    • name屬性值:類里面定義的屬性名稱
    • value屬性值: 設置具體的值
    <!--使用set方法注入屬性-->
    <bean id="book" class="IOC.Book">
        <!-- 注入屬性值
         name 屬性值:類里面定義的屬性名稱
         value 屬性值: 設置具體的值
        -->
        <property name="bookname" value="天龍八部"></property>
    </bean>

(3)測試代碼

import Bean.User;
import IOC.Book;
import IOC.PropertyDemo1;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by pc on 2017/9/7.
 */
public class TextIOC {
    public static void main(String[] args) {
        //加載Spring配置文件,并創建對象
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
        //得到配置的對象
        Book book = (Book) context.getBean("book");
        book.demobook();
    }
}
運行結果

三 注入對象類型屬性(重點)
1 UserDao

package IOC;
public class UserDao {
    public void dao(){
        System.out.println("dao.................");
    }
}

2 UserService

package IOC;
public class UserService {
    //1.定義dao類型屬性
    private UserDao userDao;
    //2.生成set方法
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }

    public void add(){
        System.out.println("servie.................");
        userDao.dao();
    }
}

3 .xml

   <bean id="userdao" class="IOC.UserDao"></bean>
    <bean id="userService" class="IOC.UserService">
        <!--注入dao對象
            name屬性;service類里面屬性名稱
            ref屬性(要注入哪個對象):dao配置bean標簽中id值(不要寫value屬性,因為剛才是字符串,現在是對象)
        -->
        <property name="userDao" ref="userdao"></property>
    </bean>

注釋:
(1)先配置UserDAO和UserService兩個對象
(2)在要被注入的UserService配置中,配置注入UserDao

  • name屬性;service類里面屬性名稱
  • ref屬性(要注入哪個對象):dao配置bean標簽中id值(不要寫value屬性,因為剛才是字符串,現在是對象)
    4 測試
import Bean.User;
import IOC.Book;
import IOC.PropertyDemo1;
import IOC.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TextIOC {
    public static void main(String[] args) {
        //加載Spring配置文件,并創建對象
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
        //得到配置的對象
        UserService us = (UserService) context.getBean("userService");
        us.add();
    }
}

運行結果

結果顯示

四 P名稱空間注入
1 Person

package IOC;
public class Person {
    private String pname;

    public void setPname(String pname) {
        this.pname = pname;
    }
    public void test(){
        System.out.println("person........."+pname);
    }
}

2 .xml配置

    <!--p名稱空間注入-->
    <bean id="person" class="IOC.Person" p:pname="Jack"></bean>

3 測試

import Bean.User;
import IOC.Book;
import IOC.Person;
import IOC.PropertyDemo1;
import IOC.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TextIOC {
    public static void main(String[] args) {
        //加載Spring配置文件,并創建對象
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
        //得到配置的對象
       Person person= (Person) context.getBean("person");
       person.test();
    }
}
結果顯示

五 注入復雜類型

  • 數組
  • list集合
  • map集合
  • properties
    1 Person
package IOC;

import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 * Created by pc on 2017/9/9.
 */
public class Person {
    private String pname;
    private String arrs[];
    private List<String> list;
    private Map<String,String> map;
    private Properties properties;

    public void setArrs(String[] arrs) {
        this.arrs = arrs;
    }

    public void setList(List<String> list) {
        this.list = list;
    }

    public void setMap(Map<String, String> map) {
        this.map = map;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }

    public void setPname(String pname) {
        this.pname = pname;
    }
    public void test(){
        System.out.println("person........."+pname);
        System.out.println("arrs...."+arrs);
        System.out.println("list...."+list);
        System.out.println("map...."+map);
        System.out.println("properties......"+properties);
    }
}

2 .xml配置

<bean id="person" class="IOC.Person">
        <!--數組-->
        <property name="arrs">
            <list>
                <value>張三</value>
                <value>李四</value>
                <value>王麻子</value>
            </list>
        </property>
        <!--list-->
        <property name="list">
            <list>
                <value>張三list</value>
                <value>李四list</value>
                <value>王麻子list</value>
            </list>
        </property>
        <!--map-->
        <property name="map">
            <map>
                <entry key="1" value="張三map"></entry>
                <entry key="2" value="李四map"></entry>
                <entry key="3" value="王麻子map"></entry>
            </map>
        </property>
        <!--properties-->
        <property name="properties">
            <props>
                <prop key="driverclass">com.mysql.jdbc.Driver</prop>
                <prop key="username">root</prop>
            </props>
        </property>
    </bean>

3 測試

import Bean.User;
import IOC.Book;
import IOC.Person;
import IOC.PropertyDemo1;
import IOC.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TextIOC {
    public static void main(String[] args) {
        //加載Spring配置文件,并創建對象
        ApplicationContext context = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
        //得到配置的對象
      Person person= (Person) context.getBean("person");
      person.test();
    }
}
結果顯示

六 IOC和DI區別
1 IOC:控制反轉,把對象創建交給spring進行配置
2 DI:依賴注入,向類里面的屬性中設置值
3 關系:依賴注入不能單獨存在,需要在IOC基礎之上完成操作

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