架构探险——学到的知识

一.常用到的工具类

1.用于编码和解码的工具类

/**
 * 编码与解码操作工具类
 *
 * @author solverpeng
 * @create 2016-06-23-21:54
 */
public final class CodecUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(CodecUtil.class);

    /**
     * 将 URL 编码
     */
    public static String encodeURL(String source) {
        String target;
        try {
            target = URLEncoder.encode(source, "UTF-8");
        } catch(UnsupportedEncodingException e) {
            LOGGER.error("encode url failure", e);
            throw new RuntimeException(e);
        }
        return target;
    }

    /**
     * 将URL解码
     */
    public static String decodeURL(String source) {
        String target;

        try {
            target = URLDecoder.decode(source, "UTF-8");
        } catch(UnsupportedEncodingException e) {
            LOGGER.error("decode url failure", e);
            throw new RuntimeException(e);
        }

        return target;
    }
}

2.POJO 和 JSON 之间的相互转换

/**
 * JSON工具类
 *
 * @author solverpeng
 * @create 2016-06-24-11:54
 */
public final class JsonUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(JsonUtil.class);

    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();

    /**
     * 将 POJO 转换为 JSON
     */
    public static <T> String toJson(T obj) {
        String json;

        try {
            json = OBJECT_MAPPER.writeValueAsString(obj);
        } catch(JsonProcessingException e) {
            LOGGER.error("convert POJO to JSON failure", e);
            throw new RuntimeException(e);
        }

        return json;
    }

    /**
     * 将 JSON 转换为 POJO
     */
    public static <T> T fromJson(String json, Class<T> type) {
        T pojo;
        try {
            pojo = OBJECT_MAPPER.readValue(json, type);
        } catch(IOException e) {
            LOGGER.error("convert JSON to POJO failure", e);
            throw new RuntimeException(e);
        }
        return pojo;
    }

}

3.反射工具类

/**
 * 反射工具类
 *
 * @author solverpeng
 * @create 2016-06-23-18:06
 */
public final class ReflectionUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ReflectionUtil.class);

    /**
     * 创建实例
     */
    public static Object newInstance(Class<?> cls) {
        Object instance;

        try {
            instance = cls.newInstance();
        } catch(Exception e) {
            LOGGER.error("new instance failure", e);
            throw new RuntimeException(e);
        }

        return instance;
    }

    /**
     * 调用方法
     */
    public static Object invokeMethod(Object obj, Method method, Object... args) {
        Object result;

        try {
            method.setAccessible(true);
            result = method.invoke(obj, args);
        } catch(Exception e) {
            LOGGER.error("invoke method failure", e);
            throw new RuntimeException(e);
        }
        return result;
    }

    /**
     * 设置属性
     */
    public static void setField(Object obj, Field field, Object value) {
        try {
            field.setAccessible(true);
            field.set(obj, value);
        } catch(IllegalAccessException e) {
            LOGGER.error("set field failure", e);
            throw new RuntimeException(e);
        }

    }

}

二.其他的知识

1.注解开发

/**
 * Action方法注解
 *
 * @author solverpeng
 * @create 2016-06-23-16:58
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Action {
    /**
     * 请求类型与路径
     */
    String value();
}

/**
 * 控制器注解
 *
 * @author solverpeng
 * @create 2016-06-23-16:57
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Controller {}

/**
 * 依赖注入注解
 *
 * @author solverpeng
 * @create 2016-06-23-17:02
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Inject {}

/**
 * 服务类注解
 *
 * @author solverpeng
 * @create 2016-06-23-17:00
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Service {}

2.异常和日志的处理

private static final Logger LOGGER = LoggerFactory.getLogger(CodecUtil.class);

    /**
     * 将 URL 编码
     */
    public static String encodeURL(String source) {
        String target;
        try {
            target = URLEncoder.encode(source, "UTF-8");
        } catch(UnsupportedEncodingException e) {
            LOGGER.error("encode url failure", e);
            throw new RuntimeException(e);
        }
        return target;
    }

3.配置文件的定义

smart.framework.jdbc.driver=com.mysql.jdbc.Driver
smart.framework.jdbc.url=jdbc:mysql://localhost:3306/demo
smart.framework.jdbc.username=root
smart.framework.jdbc.password=123456

smart.framework.app.base_package=com.nucsoft.chapter2
smart.framework.app.jsp_path=/WEB-INF/view/
#表示静态资源文件的基础路径
smart.framework.app.asset_path=/asset/

/**
 * 提供相关配置常量类
 *
 * @author solverpeng
 * @create 2016-06-23-14:31
 */
public interface ConfigConstant {
    String CONFIG_FILE = "smart.properties";

    String JDBC_DRIVER = "smart.framework.jdbc.driver";
    String JDBC_URL = "smart.framework.jdbc.url";
    String JDBC_USERNAME = "smart.framework.jdbc.username";
    String JDBC_PASSWORD = "smart.framework.jdbc.password";

    String APP_BASE_PACKAGE = "smart.framework.app.base_package";
    String APP_JSP_PATH = "smart.framework.app.jsp_path";
    String APP_ASSET_PATH = "smart.framework.app.asset_path";
}

/**
 * 属性文件助手类
 *
 * @author solverpeng
 * @create 2016-06-23-14:37
 */
public final class ConfigHelper {
    private static final Properties CONFIGE_PROPS = PropsUtils.loadProps(ConfigConstant.CONFIG_FILE);

    /**
     * 获取 JDBC 驱动
     */
    public static String getJdbcDriver() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.JDBC_DRIVER);
    }

    /**
     * 获取 JDBC URL
     */
    public static String getJdbcUrl() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.JDBC_URL);
    }

    /**
     * 获取 JDBC 用户名
     */
    public static String getJdbcUsername() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.JDBC_USERNAME);
    }

    /**
     * 获取 JDBC 密码
     */
    public static String getJdbcPassword() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.JDBC_PASSWORD);
    }

    /**
     * 获取应用基础包名
     */
    public static String getAppBasePackage() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.APP_BASE_PACKAGE);
    }

    /**
     * 获取应用 JSP 路径
     */
    public static String getAppJspPath() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.APP_JSP_PATH, "/WEB-INF/view/");
    }

    /**
     * 获取应用静态资源路径
     */
    public static String getAppAssetPath() {
        return PropsUtils.getString(CONFIGE_PROPS, ConfigConstant.APP_ASSET_PATH, "/asset/");
    }

}