【属性值的各种数据类型转换】 -买球官网平台

前提条件，先构造一个properties文件

properties properties = new properties();

// 使用classloader加载properties配置文件生成对应的输入流

inputstream in = propertiesmain.class.getclassloader().getresourceasstream("config/config.properties");

// 使用properties对象加载输入流 ,注意最后释放资源关闭文件流

properties.load(in);

代码详解

/**
 * get property value
 *
 * @param key property name
 * @return property value
 */
public static string getstring(string key) {
    return properties.getproperty(key.trim());
}
/**
 * get property value with upper case
 *
 * @param key property name
 * @return property value  with upper case
 */
public static string getuppercasestring(string key) {
    return properties.getproperty(key.trim()).touppercase();
}
/**
 * get property value
 *
 * @param key property name
 * @param defaultval default value
 * @return property value
 */
public static string getstring(string key, string defaultval) {
    string val = properties.getproperty(key.trim());
    return val == null ? defaultval : val;
}
/**
 * get property value
 *
 * @param key property name
 * @return  get property int value , if key == null, then return -1
 */
public static int getint(string key) {
    return getint(key, -1);
}
/**
 *
 * @param key key
 * @param defaultvalue default value
 * @return property value
 */
public static int getint(string key, int defaultvalue) {
    string value = getstring(key);
    if (value == null) {
        return defaultvalue;
    }
    try {
        return integer.parseint(value);
    } catch (numberformatexception e) {
        logger.info(e.getmessage(),e);
    }
    return defaultvalue;
}
/**
 * get property value
 *
 * @param key property name
 * @return property value
 */
public static boolean getboolean(string key) {
    string value = properties.getproperty(key.trim());
    if(null != value){
        return boolean.parseboolean(value);
    }
    return false;
}
/**
 * get property value
 *
 * @param key property name
 * @param defaultvalue default value
 * @return property value
 */
public static boolean getboolean(string key, boolean defaultvalue) {
    string value = properties.getproperty(key.trim());
    if(null != value){
        return boolean.parseboolean(value);
    }
    return defaultvalue;
}
/**
 * get property long value
 * @param key key
 * @param defaultval default value
 * @return property value
 */
public static long getlong(string key, long defaultval) {
    string val = getstring(key);
    return val == null ? defaultval : long.parselong(val);
}
/**
 *
 * @param key key
 * @return property value
 */
public static long getlong(string key) {
    return getlong(key,-1);
}
/**
 *
 * @param key key
 * @param defaultval default value
 * @return property value
 */
public double getdouble(string key, double defaultval) {
    string val = getstring(key);
    return val == null ? defaultval : double.parsedouble(val);
}
/**
 *  get array
 * @param key       property name
 * @param splitstr  separator
 * @return property value through array
 */
public static string[] getarray(string key, string splitstr) {
    string value = getstring(key);
    if (value == null) {
        return new string[0];
    }
    try {
        string[] propertyarray = value.split(splitstr);
        return propertyarray;
    } catch (numberformatexception e) {
        logger.info(e.getmessage(),e);
    }
    return new string[0];
}
/**
 *
 * @param key key
 * @param type type
 * @param defaultvalue default value
 * @param  t
 * @return  get enum value
 */
public <t extends enum<t>> t getenum(string key, class<t> type,
                                     t defaultvalue) {
    string val = getstring(key);
    return val == null ? defaultvalue : enum.valueof(type, val);
}
/**
 * get all properties with specified prefix, like: fs.
 * @param prefix prefix to search
 * @return all properties with specified prefix
 */
public static map getprefixedproperties(string prefix) {
    map matchedproperties = new hashmap<>();
    for (string propname : properties.stringpropertynames()) {
        if (propname.startswith(prefix)) {
            matchedproperties.put(propname, properties.getproperty(propname));
        }
    }
    return matchedproperties;
}
代码来自dolphinscheduler的1.36版本