cn.cdwx.jpa.utils.PropertiesLoader.java Source code

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Here is the source code for cn.cdwx.jpa.utils.PropertiesLoader.java

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/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
package cn.cdwx.jpa.utils;

import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.util.Properties;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;

/**
 * Properties. ?properties, ???SystemProperty.
 * 
 * @author calvin
 */
public class PropertiesLoader {

    private static Logger logger = LoggerFactory.getLogger(PropertiesLoader.class);

    private static ResourceLoader resourceLoader = new DefaultResourceLoader();

    private final Properties properties;

    public PropertiesLoader(String... resourcesPaths) {
        properties = loadProperties(resourcesPaths);
    }

    public Properties getProperties() {
        return properties;
    }

    /**
     * ?Property
     */
    private String getValue(String key) {
        String systemProperty = System.getProperty(key);
        if (systemProperty != null) {
            return systemProperty;
        }
        return properties.getProperty(key);
    }

    /**
     * ?StringProperty,Null.
     */
    public String getProperty(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return value;
    }

    /**
     * ?StringProperty.NullDefault.
     */
    public String getProperty(String key, String defaultValue) {
        String value = getValue(key);
        return value != null ? value : defaultValue;
    }

    /**
     * ?IntegerProperty.Null.
     */
    public Integer getInteger(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Integer.valueOf(value);
    }

    /**
     * ?IntegerProperty.NullDefault
     */
    public Integer getInteger(String key, Integer defaultValue) {
        String value = getValue(key);
        return value != null ? Integer.valueOf(value) : defaultValue;
    }

    /**
     * ?DoubleProperty.Null.
     */
    public Double getDouble(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Double.valueOf(value);
    }

    /**
     * ?DoubleProperty.NullDefault
     */
    public Double getDouble(String key, Integer defaultValue) {
        String value = getValue(key);
        return value != null ? Double.valueOf(value) : defaultValue;
    }

    /**
     * ?BooleanProperty.Null,?true/falsefalse.
     */
    public Boolean getBoolean(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Boolean.valueOf(value);
    }

    /**
     * ?BooleanPropert.NullDefault,?true/falsefalse.
     */
    public Boolean getBoolean(String key, boolean defaultValue) {
        String value = getValue(key);
        return value != null ? Boolean.valueOf(value) : defaultValue;
    }

    /**
     * , Spring Resource?.
     */
    private Properties loadProperties(String... resourcesPaths) {
        Properties props = new Properties();

        for (String location : resourcesPaths) {

            logger.debug("Loading properties file from path:{}", location);

            InputStream is = null;
            try {
                Resource resource = resourceLoader.getResource(location);
                is = resource.getInputStream();
                props.load(is);
            } catch (IOException ex) {
                logger.info("Could not load properties from path:{}, {} ", location, ex.getMessage());
            } finally {
                IOUtils.closeQuietly(is);
            }
        }
        return props;
    }
}