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 correct
MSG_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
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。