Spring-读取属性（java.lang.IllegalArgumentException:无法解析字符串值“${name}”中的占位符'name'）

Question

我看到下面的错误，当我试图读取属性从类路径在我的Spring项目中使用的@属性源注释。我已经粘贴了我的代码下面，请你帮助让我知道我错过了什么？谢谢。

警告：在上下文初始化期间遇到异常-取消刷新尝试：org.springframework.beans.factory.BeanCreation异常：创建名称为“客户仓库”的bean时出错：自动构建依赖项注入失败；嵌套异常java.lang.IllegalArgument异常：无法解析字符串值“${name}”中的占位符“name”

线程“main”组织中出现异常。springframework。豆。工厂BeanCreationException:创建名为“customerRepository”的bean时出错：自动连线依赖项的注入失败；嵌套的例外是java。lang.IllegalArgumentException:无法解析字符串值“${name}”中的占位符“name”

AppConfig。JAVA

import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.annotation.Scope;

import com.vivek.service.CustomerService;
import com.vivek.service.CustomerServiceImpl;

@Configuration
@ComponentScan("com.vivek")
@PropertySource("app.properties")
public class AppConfig {

    @Bean
    public static PropertyPlaceholderConfigurer getPropertyPlaceholderConfigurer(){
        PropertyPlaceholderConfigurer p = new PropertyPlaceholderConfigurer();
        //p.setIgnoreUnresolvablePlaceholders(true);
        return p;
    }

    @Bean(name="customerService")
    @Scope("prototype")
    public CustomerService getCustomerService(){
        CustomerServiceImpl service = new CustomerServiceImpl();
        //service.setRepository(getCustomerRepository());
        return service;
    }

/*  @Bean(name="customerRepository")
    public CustomerRepository getCustomerRepository(){
        CustomerRepository repository = new HibernateCustomerRepository();
        return repository;
    }*/
}

应用JAVA

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.vivek.service.CustomerService;
import com.vivek.service.CustomerServiceImpl;

public class Application {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
        CustomerService service = context.getBean("customerService",CustomerService.class);
        System.out.println(service);
        CustomerService service1 = context.getBean("customerService",CustomerService.class);
        System.out.println(service1);

        System.out.println(service.findAll().get(0).getFirstName());
        System.out.println(service.findAll().get(0).getLastName());
    }

}

HibernateCustomerRepository。JAVA

package com.vivek.repository;

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Repository;

import com.vivek.model.Customer;

@Repository("customerRepository")
public class HibernateCustomerRepository implements CustomerRepository {

    /* (non-Javadoc)
     * @see com.vivek.repository.CustomerRepository#findAll()
     */
    @Value("${name}")
    private String name;

    @Override
    public List<Customer> findAll(){
        List<Customer> customerList = new ArrayList<Customer>();

        Customer customer = new Customer();
        customer.setFirstName(name);
        customer.setLastName("Shah");

        customerList.add(customer);

        return customerList;
    }
}

CustomerServiceImpl。JAVA

package com.vivek.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import com.vivek.model.Customer;
import com.vivek.repository.CustomerRepository;
import com.vivek.repository.HibernateCustomerRepository;

public class CustomerServiceImpl implements CustomerService {

    /* (non-Javadoc)
     * @see com.vivek.service.CustomerService#findAll()
     * 
     */

    private CustomerRepository repository;

    @Autowired
    public void setRepository(CustomerRepository repository) {
        this.repository = repository;
    }

    @Override
    public List<Customer> findAll(){
        CustomerRepository repository = new HibernateCustomerRepository();
        return repository.findAll();
    }



}

app.properties

name=Arnold

Answer 1

可能您需要在spring配置文件中声明PropertySourcesPlaceholderConfigurer。

 <bean 
    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>config.properties</value>
    </property>
 </bean>