使用配置文件引用服务的spring控制器

我有一个SpringMVC项目。我有一个控制器，定义如下：

public class HelloController {

    private HelloService helloService;

    @RequestMapping("/hello")
    public void sayHello() {
        helloService.sayHello();
    }
}

public class HelloServiceImpl implements HelloService {

public void sayHello() {
    System.out.println("Hello Spring !");
}
}

public interface HelloService {

void sayHello();
}

<mvc:annotation-driven/>
<context:component-scan base-package="com.pack"/>

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <property name="helloService" ref="HelloService"></property>
</bean>
<bean id="HelloService" class="com.pack.services.HelloServiceImpl"/>

我的服务如下：

public class HelloController {

    private HelloService helloService;

    @RequestMapping("/hello")
    public void sayHello() {
        helloService.sayHello();
    }
}

public class HelloServiceImpl implements HelloService {

public void sayHello() {
    System.out.println("Hello Spring !");
}
}

public interface HelloService {

void sayHello();
}

<mvc:annotation-driven/>
<context:component-scan base-package="com.pack"/>

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <property name="helloService" ref="HelloService"></property>
</bean>
<bean id="HelloService" class="com.pack.services.HelloServiceImpl"/>

界面如下：

public class HelloController {

    private HelloService helloService;

    @RequestMapping("/hello")
    public void sayHello() {
        helloService.sayHello();
    }
}

public class HelloServiceImpl implements HelloService {

public void sayHello() {
    System.out.println("Hello Spring !");
}
}

public interface HelloService {

void sayHello();
}

<mvc:annotation-driven/>
<context:component-scan base-package="com.pack"/>

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <property name="helloService" ref="HelloService"></property>
</bean>
<bean id="HelloService" class="com.pack.services.HelloServiceImpl"/>

我的配置文件如下：

public class HelloController {

    private HelloService helloService;

    @RequestMapping("/hello")
    public void sayHello() {
        helloService.sayHello();
    }
}

public class HelloServiceImpl implements HelloService {

public void sayHello() {
    System.out.println("Hello Spring !");
}
}

public interface HelloService {

void sayHello();
}

<mvc:annotation-driven/>
<context:component-scan base-package="com.pack"/>

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <property name="helloService" ref="HelloService"></property>
</bean>
<bean id="HelloService" class="com.pack.services.HelloServiceImpl"/>

---

错误是您需要为bean helloService生成get和set

Bean属性“helloService”不可写或具有无效的setter方法。setter的参数类型与getter的返回类型匹配吗

但是，如果您尝试注入bean，甚至手动进行配置，则需要在@Autowire中添加注释

@Autowire
private HelloService helloService;

---

错误是您需要为bean helloService生成get和set

Bean属性“helloService”不可写或具有无效的setter方法。setter的参数类型与getter的返回类型匹配吗

但是，如果您尝试注入bean，甚至手动进行配置，则需要在@Autowire中添加注释

@Autowire
private HelloService helloService;

---

在HelloController类中添加helloservice的setter和getter可以解决这个问题。应该不需要添加@autowired注释，这样做之后

在HelloController类中添加helloservice的setter和getter就可以了。应该不需要添加@autowired注释，然后添加@autowired注释您可以通过提供用于注入helloService的setter方法来实现，如下所示
//塞特注射

  public void setHelloService(HelloService helloService) {
    this.helloService = helloService;
  }

或者您可以通过使用构造函数注入为注入helloService提供构造函数来实现它，如下所示
//构造函数注入

 public HelloController (HelloService helloService) {
   this.helloService = helloService;
}

//配置文件中的更改

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <constructor-arg ref="HelloService"/>

---

您可以通过提供用于注入helloService的setter方法来实现它，如下所示
//塞特注射

  public void setHelloService(HelloService helloService) {
    this.helloService = helloService;
  }

或者您可以通过使用构造函数注入为注入helloService提供构造函数来实现它，如下所示
//构造函数注入

 public HelloController (HelloService helloService) {
   this.helloService = helloService;
}

//配置文件中的更改

<bean id="HelloController" class="com.pack.controllers.HelloController">
    <constructor-arg ref="HelloService"/>

---

如果您有XML配置，则添加

@Autowired

是毫无意义的。如果您有XML配置，则添加

@Autowired

是毫无意义的。将

@Autowired

放在字段上是一种糟糕的做法。现在，您已经了解了为什么它不好了。将

@Autowired

放在字段上是一种不好的做法。现在你已经经历了为什么它不好。