Java 使用snakeyaml解析yaml

下载依赖

<dependency>
            <groupId>org.yaml</groupId>
            <artifactId>snakeyaml</artifactId>
            <version>1.23</version>
        </dependency>

在项目根目录下创建/etc/conifg.yml 配置文件, 输入一条测试数据

test.param: 3

代码测试

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Map;

import org.yaml.snakeyaml.Yaml;

public class yamlTest {
    public static void main(String[] args) throws FileNotFoundException {
        Map conf = new Yaml().load(new FileInputStream(new File("./etc/config.yml")));
        System.out.println(conf.get("test.param"));  // test_gp2
        System.out.println(conf.getOrDefault("test.param2", "unknown"));  // unknown

    }
}

打包测试

在jar包同级目录下创建/etc/confog.yml文件

root@ubuntu:~/jars# tree etc/ sparktest_gp-1.0-SNAPSHOT.jar 
etc/
└── config.yml
sparktest_gp-1.0-SNAPSHOT.jar

运行jar包

root@ubuntu:~/jars# java -cp sparktest_gp-1.0-SNAPSHOT.jar main.yamlTest
2
unknown

修改/etc/config.yml文件

test.param: 3

重新运行jar包, 参数改变, 可以在jar包外部修改配置

root@ubuntu:~/jars# java -cp sparktest_gp-1.0-SNAPSHOT.jar main.yamlTest
3
unknown

使用单例模式构建读取配置工具类

package main;

import com.ctc.wstx.api.ReaderConfig;
import org.yaml.snakeyaml.Yaml;

import java.io.File;
import java.io.FileInputStream;
import java.util.Map;

public class Config {
    private Map conf;
    private static Config instance;

    private Config() {
        try {
            conf = new Yaml().load(new FileInputStream(new File("./etc/config.yml")));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static Config getInstance() {
        if (instance == null) {
            synchronized (ReaderConfig.class) {
                if (instance == null) {
                    instance = new Config();
                }
            }
        }
        return instance;
    }

    public String getString(String param) {
        return String.valueOf(conf.get(param));
    }

    public String getString(String param, String defaultValue) {
        if (null == conf.get(param)) {
            return defaultValue;
        }
        return String.valueOf(conf.get(param));
    }

    public Map getConfig() {
        return conf;
    }
}

调用测试

import java.util.Map;

public class UseConfig {
    public static void main(String[] args) {
        Map conf = Config.getInstance().getConfig();
        System.out.println(conf);
        String parma1 = Config.getInstance().getString("test.param");
        System.out.println(parma1);
    }
}