如何用java jackson库编写json消息

Question

我想写以下类型字符串到yaml文件，path是键和'abc'、'def'、'ghi'是映射到同一个键的多个值。

路径：-abc-def-ghi

Answer 1

首先，您需要一个paths.class

public class Paths {
private List<String> paths;

public Paths(List<String> paths) {
    super();
    this.paths = paths;
}

public Paths() {
    super();
}

public List<String> getPaths() {
    return paths;
}

public void setPaths(List<String> paths) {
    this.paths = paths;
}

@Override
public String toString() {
    return "Paths [pathList=" + paths + "]";
}

}

然后将其写入yaml文件，如下所示：

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.Feature;

public class App
{
    public static void main(String[] args) 
    {
        ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
        mapper.findAndRegisterModules();
        

        
        //Writing Values to YAML
        
        //turning off the three Dashes
        mapper = new ObjectMapper(new YAMLFactory().disable(Feature.WRITE_DOC_START_MARKER));
        
        List<String> values = new ArrayList<>();
        values.add("abc");
        values.add("def");
        values.add("ghi");
        
        Paths paths = new Paths();
        paths.setPaths(values);
        
        try {
            mapper.writeValue(new File("src/main/resources/pathInput.yaml"), paths);
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        //Reading Values from YAML
        try {
            Paths path = mapper.readValue(new File("src/main/resources/pathInput.yaml"), Paths.class);
            System.out.println(path.getPaths().get(1));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
}

 paths:
- "abc"
- "def"
- "ghi"