项目上中logger、message错误信息的配置

申明：在一个项目中必不可少的是Logger和错误信息的配置，现在给出在我们常用的处理方法。

—、创建一个ConfigUtils类和他对应的rah.properties文件和Test测试类

ConfigUtis:

package com.rah;

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

public class ConfigUtils {

    private static final String PROPERTIES_FILE = "com/rah/rah.properties";

    private static Properties prop = null;

    static{
        InputStream propStream = ConfigUtils.class.getClassLoader().getResourceAsStream(PROPERTIES_FILE);
        prop = new Properties();
        try {
            prop.load(propStream);
        } catch (IOException e) {
            System.out.println("读取文件失败");
        }
    }

    public static  String getProperty(String key){
        return prop.getProperty(key);
    }
}

rah.properties

photoDir=d:/temp/photo
videoDir=d:/temp/video

test

package com.rah;

public class Test {
    public static void main(String[] args) {
        String photoDir = ConfigUtils.getProperty("photoDir");
        String videoDir = ConfigUtils.getProperty("videoDir");
        System.out.println("photoDir Path is: " + photoDir);
        System.out.println("videoDir path is: " + videoDir);
    }
}

测试结果：

photoDir Path is: d:/temp/photo
videoDir path is: d:/temp/video

二、创建MessageManager类、message.properties和测试类Test.

MessageManager

package com.rah;

import java.io.IOException;import java.io.InputStream;import java.text.MessageFormat;import java.util.Properties;

public class MessageManager {    private static final String PROPERTIES_FILE = "/properties/message.properties";    private static Properties prop = null;    static{        InputStream propStream = MessageManager.class.getResourceAsStream(PROPERTIES_FILE);        prop = new Properties();        try {            prop.load(propStream);        } catch (IOException e) {            // TODO Auto-generated catch block            System.out.println("读取文件失败");        }    }        public static String getProperty(String messageCode){        return prop.getProperty(messageCode);    }        public static String getProperty(String messageCode, String arg1){        Object[] args = new Object[1];        args[0] = arg1;                return getFormatMessage(messageCode, args);    }        public static String getProperty(String messageCode, String arg1, String arg2){        Object[] args = new Object[2];        args[0] = arg1;        args[1] = arg2;                return getFormatMessage(messageCode, args);    }        public static String getProperty(String messageCode, String arg1, String arg2, String arg3){        Object[] args = new Object[3];        args[0] = arg1;        args[1] = arg2;        args[2] = arg3;                return getFormatMessage(messageCode, args);    }        private static String getFormatMessage(String messageCode, Object[] args) {        String argMessage = getProperty(messageCode);                return MessageFormat.format(argMessage, args);    }

}

Message.properties

MSG_E00001=password is not correctMSG_E00002=country is {0}MSG_E00003=country is {0} provice is {1} MSG_E00004=country is {0} provice is {1} city is {2} 

Test

package com.rah;

public class Test {
    public static void main(String[] args) {
        System.out.println("MSG_E00001 data is: " +  MessageManager.getProperty("MSG_E00001"));
        System.out.println("MSG_E00002 data is: " +  MessageManager.getProperty("MSG_E00002", "CHINA"));
        System.out.println("MSG_E00003 data is: " +  MessageManager.getProperty("MSG_E00003", "CHINA", "JIANGXI"));
        System.out.println("MSG_E00004 data is: " +  MessageManager.getProperty("MSG_E00004", "CHINA", "JIANGXI", "SHANGRAO"));
    }
}

测试结果:

MSG_E00001 data is: password is not correct
MSG_E00002 data is: country is CHINA
MSG_E00003 data is: country is CHINA provice is JIANGXI
MSG_E00004 data is: country is CHINA provice is JIANGXI city is SHANGRAO 

三、Loger日志输出，其实就是对log4j的一点封装，方便开发人员使用

log4j-1.2.13.jar下载

public class Logger {

    private static org.apache.log4j.Logger logger = org.apache.log4j.Logger
            .getLogger(org.apache.log4j.Logger.class);

    public static void debug(String message) {
        logger.debug(message);
    }

    public static void debug(String message, Throwable ex) {
        logger.debug(message, ex);
    }

    public static void info(String message) {
        logger.info(message);
    }

    public static void info(String message, Throwable ex) {
        logger.info(message, ex);
    }

    public static void error(String message) {
        logger.error(message);
    }

    public static void error(String message, Throwable ex) {
        logger.error(message, ex);
    }

    public static void fatal(String message) {
        logger.fatal(message);
    }

    public static void fatal(String message, Throwable ex) {
        logger.fatal(message, ex);
    }

    public static void warn(String message) {http://i.cnblogs.com/EditPosts.aspx?opt=1
        logger.warn(message);
    }

    public static void warn(String message, Throwable ex) {http://i.cnblogs.com/EditPosts.aspx?opt=1
        logger.warn(message, ex);
    }
}

四、对class.getResourceAsStream()、class.getClassLoader().getResourceAsStream()区别的分析

　　思心的网友肯定会发现我上面的两个测试分别采用了class.getResourceAsStream()，和class.getClassLoader().getResourceAsStream().其实一开始我也没有注意，是在查API的时候发现有不同的方法，于是为了试试他们的用法特地采用了不同的写法。

class.getResourceAsStream()会指定的加载的资源路径与当前类所在的包的路径一致

　　像上面的MessageManager类如果写成getResourceAsStream("message.properties")则他就只会在ciom.rah包下寻找，此时我们采用"/"开头，那么就会从classpath的根路径开始查找（SRC根目录）getResourceAsStream("/properties/message.properties")就是在SRC目录下创建了properties目录接着创建了message.properties文件。

ClassLoader.gettResourceAsStream()无论要查找的资源前面是否有"/"都是从classpath的根路径下查找。

　　像上面的ConfigUtil类getResourceAsStream("/rah.properties")和("rah.properties")都是直接从SRC目录下找rah.properties文件。

最后补充:

程序运行的是最后编译成.class的文件。这个SRC目录下的所有东西都会编译在bin目录下。