net.meku.chameleon.persist.JsonFileHandler Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of chameleon-persist-json Show documentation

A light-weight library to manage the configurations

There is a newer version: 1.0.3

Show newest version

package net.meku.chameleon.persist;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

@Component
public class JsonFileHandler {

    private static final Log LOGGER = LogFactory.getLog(JsonFileHandler.class);

    @Autowired
    private ObjectMapper objectMapper;

    @Value("${chameleon.persist.json.path:configs.json}")
    private String filePath = "configs.json";

    public Map read() {
        File file = new File(filePath);
        if (!file.exists()) {
            return Collections.EMPTY_MAP;
        }

        try {
            return objectMapper.readValue(file, Map.class);
        } catch (IOException e) {
            LOGGER.error("Failed to convert file to Map.", e);
            return Collections.EMPTY_MAP;
        }
    }

    public Map write(String key, String value) throws IOException {
        Map map;
        File file = new File(filePath);
        if (!file.exists()) {
            map = new HashMap<>();
        } else {
            map = objectMapper.readValue(file, Map.class);
        }

        map.put(key, value);
        objectMapper.writeValue(file, map);

        return map;
    }
}