将一些JSON文件加载到Spring Boot应用程序的最佳方法

时间:2015-12-14 21:58:23

标签: java json spring-boot

我即将创建一个Rest webservice应用程序,我需要在应用程序启动时加载存在于作为参数传递的文件夹中的所有JSON文件(在application.yml中先验),以便稍后在方法中使用它们webservices作为bean列表(每个JSON文件对应一个bean)。

进一步解释我的要求的样本:

application.yml

json.config.folder: /opt/my_application/json_configs

MyApplication.java

package com.company;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }
}

具有以下结构的JSON文件:

    {  
   "key":"YYYYY",
   "operator_list":[  
        {  
           "name":"operator1",
           "configs":{  
               "id":"XXXXX1",
               "path":"xxxx2"
           }
        },
        {  
            "name":"operator2",
            "configs":{  
                "id":"XXXXX1",
                "passphrase":"xxxx2",
                "user_id":"XXXX3",
                "password":"XXXXX"
            }
        },
        {  
            "name":"operator3",
            "configs":{  
                "user_id":"XXXXX1"
            }
        }
    ]
    }

RestAPI.java

@RestController
@RequestMapping("/my_app_url")
@PropertySource(value={"classpath:application.yml"})
public class RestAPI {
    //Some fields
    ....

    //Some methods
    ....

    //Method that return operator list of a given context (correspond to the field "key" of the json file)
    @RequestMapping("/getOperatorList")
    public List<Operator> getOperatorList(@RequestParam(value = "context", defaultValue = "YYYYY") String context) throws Exception{
        List<Operator> result = null;
        //Here, i need to loop the objects , that are supposed to be initialized during application startup 
        //(but i I do not know yet how to do it) with data from JSON files
        //to find the one that correspond to the context in parameter and return its operator list

        return result;
    }
}

ContextOperatorBean.java ,它将包含先验的JSON文件信息:

package com.company.models;

import java.util.List;

public class ContextOperatorBean {
    String key;
    List<Operator> operator_list;

    public ContextOperatorBean() {
    }

    public ContextOperatorBean(String key, List<PaymentMethod> operator_list) {
        this.key = key;
        this.operator_list = operator_list;
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public List<Operator> getOperator_list() {
        return operator_list;
    }

    public void setOperator_list(List<Operator> operator_list) {
        this.operator_list = operator_list;
    }
}

另一个名为Operator.java的类,包含所有运算符信息。

是否有方法在应用程序启动时初始化包含所有JSON文件信息的ContextOperatorBean对象列表,并在我的Web服务方法(RestAPI.java类)中使用它们?

1 个答案:

答案 0 :(得分:12)

不知道以下天真的实现是否满足“最佳”的标准,但您可以创建一个处理此责任的新服务,例如:

@Service
public class OperatorsService {

    @Value("${json.config.folder}")
    String jsonConfigFolder;

    List<ContextOperatorBean> operators = new ArrayList<>();

    @PostConstruct
    public void init() throws IOException {
        ObjectMapper jsonMapper = new ObjectMapper();
        for (File jsonFile : getFilesInFolder(jsonConfigFolder)) {
            // deserialize contents of each file into an object of type
            ContextOperatorBean operator = jsonMapper.readValue(jsonFile, new TypeReference<List<ContextOperatorBean>>() {});
            operators.add(operator);
        }
    }

    public List<ContextOperatorBean> getMatchingOperators(String context) {
        return operators.stream().filter(operator -> checkIfMatches(operator, context)).collect(Collectors.toList());
    }

    private boolean checkIfMatches(ContextOperatorBean operator, String context) {
        // TODO implement
        return false;
    }

    private File[] getFilesInFolder(String path) {
        // TODO implement
        return null;
    }
}

注意:遗漏处理失败或意外情况以及一些实施细节。

然后在您的控制器中@Autowire,并调用getMatchingOperators()仅过滤匹配的条目。