關於Spring-IoC的簡單使用參考:
Spring-IoC的簡單使用
1、通過set方法注入不同數據類型
- 測試類代碼(set方式注入的屬性一定要加set方法)
/**通過set方法注入示例*/
public class IoC_By_Set {
/**注入Integer類型參數*/
private Integer id;
/**注入String類型參數*/
private String name;
/**注入實體Bean*/
private User user;
/**注入數組*/
private Object[] array;
/**注入List集合*/
private List<Object> list;
/**注入Set集合*/
private Set<Object> set;
/**注入Map鍵值對*/
private Map<Object, Object> map;
/**注入properties類型*/
private Properties properties;
/**注入空字符串*/
private String emptyValue;
/**注入null值*/
private String nullValue = "";
/**檢測注入的屬性是否全部正確*/
public boolean checkAttr() {
if(id == null) {
return false;
}else {
System.out.println("id:" + id);
}
System.out.println("--------------------------");
if(name == null) {
return false;
}else {
System.out.println("name:" + name);
}
System.out.println("--------------------------");
if(user == null) {
return false;
}else {
System.out.println("Bean:" + user.getId() + "|" +
user.getUserName() + "|" + user.getPassWord());
}
System.out.println("--------------------------");
if(array == null) {
return false;
}else {
System.out.println("array:");
for (Object object : array) {
System.out.println(object.toString());
}
}
System.out.println("--------------------------");
if(list == null) {
return false;
}else {
System.out.println("list:");
for (Object object : list) {
System.out.println(object.toString());
}
}
System.out.println("--------------------------");
if(set == null) {
return false;
}else {
System.out.println("set:");
for (Object object : set) {
System.out.println(object.toString());
}
}
System.out.println("--------------------------");
if(map == null) {
return false;
}else {
Set<Entry<Object, Object>> set = map.entrySet();
System.out.println("map:");
for (Entry<Object, Object> entry : set) {
System.out.println(entry.getKey() + "|" + entry.getValue());
}
}
System.out.println("--------------------------");
if(properties == null) {
return false;
}else {
Set<Entry<Object, Object>> set = properties.entrySet();
System.out.println("properties:");
for (Entry<Object, Object> entry : set) {
System.out.println(entry.getKey() + "|" + entry.getValue());
}
}
System.out.println("--------------------------");
if(!"".equals(emptyValue))
return false;
System.out.println("--------------------------");
if(!(null == nullValue))
return false;
System.out.println("--------------------------");
System.out.println("全部正確!!!");
return true;
}
public void setId(Integer id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setUser(User user) {
this.user = user;
}
public void setArray(Object[] array) {
this.array = array;
}
public void setList(List<Object> list) {
this.list = list;
}
public void setSet(Set<Object> set) {
this.set = set;
}
public void setMap(Map<Object, Object> map) {
this.map = map;
}
public void setProperties(Properties properties) {
this.properties = properties;
}
public void setEmptyValue(String emptyValue) {
this.emptyValue = emptyValue;
}
public void setNullValue(String nullValue) {
this.nullValue = nullValue;
}
}
- applicationContext.xml配置
<!-- set方式注入 -->
<bean id="ioC_By_Set" class="com.bc.ioc.demo01.IoC_By_Set">
<!-- 注入id屬性 -->
<property name="id" value="1"/>
<!-- 使用<![CDATA[]]>標記處理XML特 殊字符 -->
<property name="name">
<!-- 也可以使用P&G -->
<value><![CDATA[P&G]]></value>
</property>
<!-- 定義內部Bean注入 -->
<property name="user">
<bean class="com.bc.pojo.User">
<property name="id" value="1"/>
<property name="userName" value="內部Bean"/>
<property name="passWord" value="233"/>
</bean>
</property>
<!-- 注入數組類型 -->
<property name="array">
<array>
<!-- 定義數組元素 -->
<value>array01</value>
<value>array02</value>
<value>array03</value>
</array>
</property>
<!-- 注入List類型 -->
<property name="list">
<list>
<!-- 定義list中元素 -->
<value>list01</value>
<value>list02</value>
<value>list03</value>
</list>
</property>
<!-- 注入Set類型 -->
<property name="set">
<set>
<!-- 定義set中元素 -->
<value>set01</value>
<value>set02</value>
<value>set03</value>
</set>
</property>
<!-- 注入Map類型 -->
<property name="map">
<map>
<!-- 定義map中的鍵值對 -->
<entry>
<key>
<value>mapKey01</value>
</key>
<value>mapValue01</value>
</entry>
<entry>
<key>
<value>mapKey02</value>
</key>
<value>mapValue02</value>
</entry>
</map>
</property>
<!-- 注入properties類型 -->
<property name="properties">
<props>
<!-- 定義properties中的鍵值對 -->
<prop key="propKey1">propValue1</prop>
<prop key="propKey2">propValue2</prop>
</props>
</property>
<!-- 注入空字符串 -->
<property name="emptyValue">
<value></value>
</property>
<!-- 注入null值 -->
<property name="nullValue">
<null/>
</property>
</bean>
- 測試代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void SetTest() {
IoC_By_Set ioc = (IoC_By_Set) ctx.getBean("ioC_By_Set");
ioc.checkAttr();
}
}
- 控制檯結果:
id:1
--------------------------
name:P&G
--------------------------
Bean:1|內部Bean|233
--------------------------
array:
array01
array02
array03
--------------------------
list:
list01
list02
list03
--------------------------
set:
set01
set02
set03
--------------------------
map:
mapKey01|mapValue01
mapKey02|mapValue02
--------------------------
properties:
propKey2|propValue2
propKey1|propValue1
--------------------------
--------------------------
--------------------------
全部正確!!!
2、通過構造方法注入各種類型屬性
注意:使用JDK1.8版本請將spring相關jar包升級到4.x版本以上,否則不兼容構造方法注入
- 測試類代碼
/** 通過構造方法注入示例 */
public class IoC_By_Constructor {
private Integer id;
private String name;
private User user;
private List<Object> list;
public IoC_By_Constructor() {
}
public IoC_By_Constructor(Integer id, String name, User user,
List<Object> list) {
this.id = id;
this.name = name;
this.user = user;
this.list = list;
}
/**檢查是否注入成功*/
public boolean checkAttr() {
if(id == null) {
return false;
}else {
System.out.println("id:" + id);
}
System.out.println("----------------------------");
if(name == null) {
return false;
}else {
System.out.println("name:" + name);
}
System.out.println("----------------------------");
if(user == null) {
return false;
}else {
System.out.println("user:" + user.getId() + "|" +
user.getUserName() + "|" + user.getPassWord());
}
System.out.println("----------------------------");
if(list == null) {
return false;
}else {
System.out.println("list:");
for (Object object : list) {
System.out.println(object.toString());
}
}
System.out.println("----------------------------");
System.out.println("全部正確!!!");
return true;
}
}
- applicationContext.xml配置
<!-- 構造方法注入 演示幾種類型-->
<bean id="ioC_By_Constructor" class="com.bc.ioc.demo02.IoC_By_Constructor">
<!-- 注入Integer屬性,可以選擇使用index指定參數位置,也可以選擇使用type指定參數類型 -->
<constructor-arg index="0" value="1" type="java.lang.Integer"/>
<!-- 注入字符串 -->
<constructor-arg value="P&G"/>
<!-- 注入對象 -->
<constructor-arg>
<!-- 內建對象 -->
<bean class="com.bc.pojo.User">
<constructor-arg value="1"/>
<constructor-arg value="構造內部Bean"/>
<constructor-arg value="666"/>
</bean>
</constructor-arg>
<!-- 注入集合 -->
<constructor-arg>
<list>
<value>list01</value>
<value>list02</value>
<value>list03</value>
</list>
</constructor-arg>
</bean>
- 測試代碼:
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void constructorTest() {
IoC_By_Constructor ioc = (IoC_By_Constructor) ctx.getBean("ioC_By_Constructor");
ioc.checkAttr();
}
}
- 控制檯結果:
id:1
----------------------------
name:P&G
----------------------------
user:1|構造內部Bean|666
----------------------------
list:
list01
list02
list03
----------------------------
全部正確!!!
3、自動注入(自動裝配)
自動裝配雖然能節省一些代碼但是不推薦使用
- 測試類代碼:
/**自動裝配注入*/
public class IoC_By_Auto {
private User user;
/**檢查是否注入成功*/
public boolean checkAttr() {
if(user == null) {
return false;
}else {
System.out.println("user:" + user.getId() + "|" +
user.getUserName() + "|" + user.getPassWord());
}
System.out.println("正確!!!");
return true;
}
/**自動裝配的屬性需要設置set方法*/
public void setUser(User user) {
this.user = user;
}
}
- applicationContext.xml配置
<!-- 被自動裝配獲取的bean -->
<bean id="user" class="com.bc.pojo.User">
<property name="id" value="1"/>
<property name="userName" value="自動裝配"/>
<property name="passWord" value="233"/>
</bean>
<!-- 自動裝配的bean
autowire:byName 根據類的屬性名查找與之命名相同的id的bean進行裝配
byType 根據類的屬性類型查找唯一一個匹配類型的bean,如果有多個bean匹配則拋出異常
constructor 根據類的構造方法參數類型匹配對應的bean
no 默認,表示不使用自動裝配
default:由上級標籤<beans>的default-autowire屬性確定 -->
<bean id="ioC_By_Auto" class="com.bc.ioc.demo03.IoC_By_Auto" autowire="byName"></bean>
- 測試代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void AutoTest() {
IoC_By_Auto ioc = (IoC_By_Auto) ctx.getBean("ioC_By_Auto");
ioc.checkAttr();
}
}
- 控制檯結果
user:1|自動裝配|233
正確!!!
- 以上使用的是byName模式,其他模式配置代碼已經註明,不做測試。
4、使用P命名空間注入屬性
- 測試類代碼
/**使用P命名空間注入*/
public class IoC_By_P {
private Integer id;
private String name;
private User user;
/**檢查是否注入成功*/
public boolean checkAttr() {
if(id == null) {
return false;
}else {
System.out.println("id:" + id);
}
System.out.println("----------------------------");
if(name == null) {
return false;
}else {
System.out.println("name:" + name);
}
System.out.println("----------------------------");
if(user == null) {
return false;
}else {
System.out.println("user:" + user.getId() + "|" +
user.getUserName() + "|" + user.getPassWord());
}
System.out.println("----------------------------");
System.out.println("全部正確!!!");
return true;
}
//使用P命名空間注入屬性需要設置set方法
public void setId(Integer id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setUser(User user) {
this.user = user;
}
}
- applicationContext.xml配置
<!-- 使用P命名空間注入各種類型屬性 -->
<bean id="user2" class="com.bc.pojo.User">
<property name="id" value="1"/>
<property name="userName" value="P"/>
<property name="passWord" value="233"/>
</bean>
<bean id="ioC_By_P" class="com.bc.ioc.demo04.IoC_By_P" p:id="1"
p:name="命名空間" p:user-ref="user2"></bean>
- 測試代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void PTest() {
IoC_By_P ioc = (IoC_By_P) ctx.getBean("ioC_By_P");
ioc.checkAttr();
}
}
- 控制檯結果
id:1
----------------------------
name:命名空間
----------------------------
user:1|P|233
----------------------------
全部正確!!!
5、使用註解方式注入
Spring在3.0以後,提供了基於Annotation(註解)的注入。
1.@Autowired -對成員變量、方法和構造函數進行標註,來完成自動裝配的工作,不推薦使用
2.@Qualifier -配合@Autowired來解決裝配多個同類型的bean
3.@Resource -JSR-250標準註解,作用相當於@Autowired,只不過@Autowired按byType自動注入,而@Resource默認按byName自動注入
4.@PostConstruct -在方法上加上註解@PostConstruct,這個方法就會在Bean初始化之後被Spring容器執行
5.@PreDestroy -在方法上加上註解@PreDestroy,這個方法就會在Bean初始化之後被Spring容器執行
6.@Component -只需要在對應的類上加上一個@Component註解,就將該類定義爲一個Bean,不推薦使用,推薦使用更加細化的三種:@Repository、@Service、@Controller
- @Repository 存儲層Bean
- @Service 業務層Bean
- @Controller 展示層Bean
7.@Scope -定義Bean的作用範圍
- 首先配置applicationContext.xml開啓註解
<!-- 掃描包中註解標註的類 -->
<context:component-scan base-package="com.bc.ioc.demo05"/>
- 實體Bean加註解
@Repository
public class User {
private Integer id = 1;
private String userName = "註解注入";
private String passWord = "233";
public User() {
super();
}
public User(Integer id, String userName, String passWord) {
super();
this.id = id;
this.userName = userName;
this.passWord = passWord;
}
public Integer getId() {
return id;
}
public String getUserName() {
return userName;
}
public String getPassWord() {
return passWord;
}
public void setId(Integer id) {
this.id = id;
}
public void setUserName(String userName) {
this.userName = userName;
}
public void setPassWord(String passWord) {
this.passWord = passWord;
}
}
- 測試類代碼加註解
/**使用註解注入屬性*/
@Service("ioC_By_Annotation")
public class IoC_By_Annotation {
@Resource
private User user;
public void setUser(User user) {
this.user = user;
}
/**檢查是否注入成功*/
public boolean checkAttr() {
if(user == null) {
return false;
}else {
System.out.println("user:" + user.getId() + "|" +
user.getUserName() + "|" + user.getPassWord());
}
System.out.println("正確!!!");
return true;
}
}
- 測試代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void annotationTest() {
IoC_By_Annotation ioc = (IoC_By_Annotation) ctx.getBean("ioC_By_Annotation");
ioc.checkAttr();
}
}
- 控制檯輸出
經測試使用註解注入如果applicationContext.xml配置有其他注入方式會報錯,也會導致其他注入方式異常。
user:1|註解注入|233
正確!!!
6、通過配置靜態工廠方法Bean注入
- 靜態工廠代碼
/**靜態工廠*/
public class StaticFactory {
public static Integer getId() {
return 1;
}
public static String getName() {
return "靜態工廠";
}
public static User getUser() {
return new User(1, "工廠User", "666");
}
}
- 測試類代碼
/** 通過靜態工廠方式注入 */
public class IoC_By_StaticFactory {
private Integer id;
private String name;
private User user;
/** 檢查是否注入成功 */
public boolean checkAttr() {
if (id == null) {
return false;
} else {
System.out.println("id:" + id);
}
System.out.println("----------------------------");
if (name == null) {
return false;
} else {
System.out.println("name:" + name);
}
System.out.println("----------------------------");
if (user == null) {
return false;
} else {
System.out.println("user:" + user.getId() + "|"
+ user.getUserName() + "|" + user.getPassWord());
}
System.out.println("----------------------------");
System.out.println("全部正確!!!");
return true;
}
/**需要爲需要注入的屬性設置set方法*/
public void setId(Integer id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setUser(User user) {
this.user = user;
}
}
- applicationContext.xml配置
<!-- 配置靜態工廠方法Bean 其實就是將工廠方法返回的數值配置成Bean -->
<bean id="factory_id" class="com.bc.ioc.demo06.StaticFactory" factory-method="getId"/>
<bean id="factory_name" class="com.bc.ioc.demo06.StaticFactory" factory-method="getName"/>
<bean id="factory_user" class="com.bc.ioc.demo06.StaticFactory" factory-method="getUser"/>
<!-- 注入對應的靜態工廠方法Bean -->
<bean id="ioC_By_StaticFactory" class="com.bc.ioc.demo06.IoC_By_StaticFactory">
<property name="id" ref="factory_id"/>
<property name="name" ref="factory_name"/>
<property name="user" ref="factory_user"/>
</bean>
- 測試代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void staticFactoryTest() {
IoC_By_StaticFactory ioc = (IoC_By_StaticFactory) ctx.getBean("ioC_By_StaticFactory");
ioc.checkAttr();
}
}
- 控制檯輸出結果
id:1
----------------------------
name:靜態工廠
----------------------------
user:1|工廠User|666
----------------------------
全部正確!!!
7、通過實例工廠方法注入
與靜態工廠區別在於實例工廠不是靜態的,需要先new 一個實例工廠對象,纔可以配置其方法,而new 的這個對象也由spring來管理
- 工廠代碼
/**實例工廠*/
public class Factory {
public Integer getId() {
return 1;
}
public String getName() {
return "實例工廠";
}
public User getUser() {
return new User(1, "實例工廠User", "233");
}
}
- 測試類代碼
/**實例工廠注入*/
public class IoC_By_Factory {
private Integer id;
private String name;
private User user;
/** 檢查是否注入成功 */
public boolean checkAttr() {
if (id == null) {
return false;
} else {
System.out.println("id:" + id);
}
System.out.println("----------------------------");
if (name == null) {
return false;
} else {
System.out.println("name:" + name);
}
System.out.println("----------------------------");
if (user == null) {
return false;
} else {
System.out.println("user:" + user.getId() + "|"
+ user.getUserName() + "|" + user.getPassWord());
}
System.out.println("----------------------------");
System.out.println("全部正確!!!");
return true;
}
/**需要爲需要注入的屬性設置set方法*/
public void setId(Integer id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setUser(User user) {
this.user = user;
}
}
- applicationContext.xml配置
<!-- 配置實例工廠Bean -->
<bean id="factory" class="com.bc.ioc.demo07.Factory"/>
<!-- 配置實例工廠方法Bean -->
<bean id="f_id" factory-bean="factory" factory-method="getId"/>
<bean id="f_name" factory-bean="factory" factory-method="getName"/>
<bean id="f_user" factory-bean="factory" factory-method="getUser"/>
<!-- 注入對應的實例工廠方法Bean -->
<bean id="ioC_By_Factory" class="com.bc.ioc.demo07.IoC_By_Factory">
<property name="id" ref="f_id"/>
<property name="name" ref="f_name"/>
<property name="user" ref="f_user"/>
</bean>
- 測試類代碼
public class IoC_Test {
private ApplicationContext ctx;
@Before
public void load() {
//讀取applicationContext.xml配置文件
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@Test
public void factoryTest() {
IoC_By_Factory ioc = (IoC_By_Factory) ctx.getBean("ioC_By_Factory");
ioc.checkAttr();
}
}
- 控制檯輸出
id:1
----------------------------
name:實例工廠
----------------------------
user:1|實例工廠User|233
----------------------------
全部正確!!!