SettingLoader.java

package com.xiaoleilu.hutool.setting;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Set;

import com.xiaoleilu.hutool.io.FileUtil;
import com.xiaoleilu.hutool.io.IoUtil;
import com.xiaoleilu.hutool.io.resource.UrlResource;
import com.xiaoleilu.hutool.log.Log;
import com.xiaoleilu.hutool.log.LogFactory;
import com.xiaoleilu.hutool.setting.dialect.BasicSetting;
import com.xiaoleilu.hutool.util.CharsetUtil;
import com.xiaoleilu.hutool.util.ReUtil;
import com.xiaoleilu.hutool.util.StrUtil;

/**
 * Setting文件加载器
 * @author Looly
 *
 */
public class SettingLoader {
	private static Log log = LogFactory.get();
	
	/** 注释符号（当有此符号在行首，表示此行为注释） */
	private final static String COMMENT_FLAG_PRE = "#";
	/** 赋值分隔符（用于分隔键值对） */
	private final static String ASSIGN_FLAG = "=";
	/** 分组行识别的环绕标记 */
	private final static char[] GROUP_SURROUND = { '[', ']' };
	/** 变量名称的正则 */
	private String reg_var = "\\$\\{(.*?)\\}";
	
	/** 本设置对象的字符集 */
	private Charset charset;
	/** 是否使用变量 */
	private boolean isUseVariable;
	/** Setting */
	private BasicSetting setting;
	
	public SettingLoader(BasicSetting setting) {
		this(setting, CharsetUtil.CHARSET_UTF_8, false);
	}
	
	public SettingLoader(BasicSetting setting, Charset charset, boolean isUseVariable) {
		this.setting = setting;
		this.charset = charset;
		this.isUseVariable = isUseVariable;
	}
	
	/**
	 * 加载设置文件
	 * 
	 * @param urlResource 配置文件URL
	 * @return 加载是否成功
	 */
	public boolean load(UrlResource urlResource) {
		if (urlResource == null) {
			throw new NullPointerException("Null setting url define!");
		}
		log.debug("Load setting file [{}]", urlResource);
		InputStream settingStream = null;
		try {
			settingStream = urlResource.getStream();
			load(settingStream);
		} catch (Exception e) {
			log.error(e, "Load setting error!");
			return false;
		} finally {
			IoUtil.close(settingStream);
		}
		return true;
	}

	/**
	 * 加载设置文件。 此方法不会关闭流对象
	 * 
	 * @param settingStream 文件流
	 * @return 加载成功与否
	 * @throws IOException
	 */
	public boolean load(InputStream settingStream) throws IOException {
		setting.clear();
		BufferedReader reader = null;
		try {
			reader = IoUtil.getReader(settingStream, this.charset);
			// 分组
			String group = null;
			
			while (true) {
				String line = reader.readLine();
				if (line == null) {
					break;
				}
				line = line.trim();
				// 跳过注释行和空行
				if (StrUtil.isBlank(line) || line.startsWith(COMMENT_FLAG_PRE)) {
					continue;
				}
				
				// 记录分组名
				if (line.charAt(0) == GROUP_SURROUND[0] && line.charAt(line.length() - 1) == GROUP_SURROUND[1]) {
					group = line.substring(1, line.length() - 1).trim();
					this.setting.getGroups().add(group);
					continue;
				}
				
				String[] keyValue = line.split(ASSIGN_FLAG, 2);
				// 跳过不符合简直规范的行
				if (keyValue.length < 2) {
					continue;
				}
				
				String key = keyValue[0].trim();
				if (false == StrUtil.isBlank(group)) {
					key = group + StrUtil.DOT + key;
				}
				String value = keyValue[1].trim();
				
				// 替换值中的所有变量变量（变量必须是此行之前定义的变量，否则无法找到）
				if (isUseVariable) {
					value = replaceVar(value);
				}
				this.setting.put(key, value);
			}
		} finally {
			IoUtil.close(reader);
		}
		return true;
	}

	/**
	 * 设置变量的正则<br/>
	 * 正则只能有一个group表示变量本身，剩余为字符 例如 \$\{(name)\}表示${name}变量名为name的一个变量表示
	 * 
	 * @param regex 正则
	 */
	public void setVarRegex(String regex) {
		this.reg_var = regex;
	}
	
	/**
	 * 持久化当前设置，会覆盖掉之前的设置<br>
	 * 持久化会不会保留之前的分组
 	 * @param absolutePath 设置文件的绝对路径
	 */
	public void store(String absolutePath) {
		Writer writer = null;
		try {
			writer = FileUtil.getWriter(absolutePath, charset, false);
			for (Entry<Object, Object> entry : this.setting.entrySet()) {
				writer.write(StrUtil.format("{} {} {}", entry.getKey(), ASSIGN_FLAG, entry.getValue()));
			}
		} catch (FileNotFoundException e) {
			throw new RuntimeException(StrUtil.format("Can not find file [{}]!", absolutePath), e);
		} catch (IOException e) {
			throw new RuntimeException("Store Setting error!", e);
		}finally{
			IoUtil.close(writer);
		}
	}
	
	public void autoReload(){
	}

	//----------------------------------------------------------------------------------- Private method start
	/**
	 * 替换给定值中的变量标识
	 * @param value 值
	 * @return 替换后的字符串
	 */
	private String replaceVar(String value) {
		// 找到所有变量标识
		final Set<String> vars = ReUtil.findAll(reg_var, value, 0, new HashSet<String>());
		for (String var : vars) {
			// 查找变量名对应的值
			Object varValue = this.setting.get(ReUtil.get(reg_var, var, 1));
			if (null != varValue && value instanceof CharSequence) {
				// 替换标识
				value = value.replace(var, (CharSequence)varValue);
			}
		}
		return value;
	}
	//----------------------------------------------------------------------------------- Private method end
}