【java基础】读取本地文件赋给Bean或list、Map

 private Map<String, AbstractController> messageTypeControllerMap;

 private static final String CONTROLLERS_CONFIG_PATH = "config/controller/controllers.json";

    /**
     * 从文件中获取 controller的配置：优先级、消息类型、类名
     */
    public void init(ApplicationContext app) {
        this.messageTypeControllerMap = new HashMap<String, AbstractController>();
        try {
            String json = FileUtils.readFileToString(new File(CONTROLLERS_CONFIG_PATH));//gson很方便
            List<Map<String, String>> controllerConfigList = GSON.fromJson(json,
                    new TypeToken<List<Map<String, String>>>() {
                    }.getType());
            for (Map<String, String> map : controllerConfigList) {//遍历文件，取值
                String messageType = map.get("messageType");
                int priority = Integer.parseInt(map.get("priority"));
                String className = map.get("className");
                if (null == messageType || null == className) {
                    throw new Exception("字段缺失!");
                }
                Class<?> cls = Class.forName(className);
                AbstractController controller = (AbstractController) app.getBean(cls);
                controller.setPriority(priority);
                controller.setMessageType(messageType);
                this.messageTypeControllerMap.put(messageType, controller);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

文件输入、输出流：

    https://blog.csdn.net/caixiexin/article/details/6719407

Properties：

    读取java配置文件，继承自hashtable

    方法：

        getProperty（String key）通过key得到value

        load（InputStream inStream）从输入流中读取属性列表（键和元素对）

        setProperty(String key,String value)调用hashtable的put方法，设置键值对

        store（OutputStream out,String comments）将键值对写入到指定文件中

        clear()清除装载的键值对

        https://www.cnblogs.com/bakari/p/3562244.html

        读取文件：https://blog.csdn.net/Senton/article/details/4083127

1/InputStream in = new BufferedInputStream(new FileInputStream(name));
Properties p= new Properties();
p.load(in);

2/ResourceBundle rb = ResourceBundle.getBundle(name,Local.getDefault());

3/InputStream in = new BufferedInputStream(new FileInputStream(name));
ResourceBundle rb = new PropertyResourceBundle(in);

4/InputStream in = JProperties.class.getResourceAsStream(name);
Properties p = new Properties();
p.load(in);

5/InputStream in = JProperties.class.getClassLoader().getResourceAsStream(name);
Properties p = new Properties();
p.load(in);

6/InputStream in = ClassLoader.getSystemResourceAsStream(name);
Properties p =new Properties();
p.load(in);

7/javax.servlet.ServletContext的getResourceAsStream()方法
示例：InputStream in = context.getResourceAsStream(path);
Properties p = new Properties();
p.load(in);

        http://www.runoob.com/java/java-properties-class.html

利用GSON

public void init() {
        this.properties = new Properties();
        try {
            this.properties.load(new FileInputStream(APPLICATION_PROPERTIES_PATH));//路径
        } catch (IOException e) {
            e.printStackTrace();
            GiskaLogger.log(null, GiskaLogger.EXCEPTION, this.getClass().getName() + ":init",
                    "加载文件[" + APPLICATION_PROPERTIES_PATH + "]异常[" + e + "].");
            System.exit(-1);
        }
    }


     String json = FileUtils.readFileToString(new File(ROLE_OPERATIONS_PATH));
            this.roleOperationListMap = Constants.SINGLE_GSON.fromJson(json,
                    new TypeToken<Map<String, List<String>>>() {
                    }.getType());

            String platformJson = FileUtils.readFileToString(new File(PLATFORMS_PATH));
            this.namePlatformMap = Constants.SINGLE_GSON.fromJson(platformJson,
                    new TypeToken<Map<String, Platform>>() {
                    }.getType());