Lab4--关于log的使用

日志框架提供了包含可配置日志记录的功能，可以在运行时和单个功能部件中启用、禁用或增加详细信息。
在lab4中使用log4j2完成基本日志功能

关于log4j2的下载

Apache官网下载Log4j2，http://logging.apache.org/log4j/2.x/download.html
向项目中导入jar包，基本上只需要导入一下两个包,xx为版本号：
log4j-core-xx.jar
log4j-api-xx.jar
在lab4中使用的版本为log4j2-2.11.2
接下来需要配置文件，与log4j1不同，2的版本中配置文件不能是properties，只能采用.xml、.json或者.jsn格式，以下相当于缺省配置文件

<?xml version="1.0" encoding="UTF-8"?>  
    <configuration status="OFF">  
        <appenders>  
            <Console name="Console" target="SYSTEM_OUT">  
                <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>  
            </Console>  
        </appenders>  
        <loggers>  
            <root level="error">  
                <appender-ref ref="Console"/>  
            </root>  
        </loggers>  
    </configuration>

关于lab4中日志的使用

在lab4中将配置文件设置为如下形式：

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Appenders>
 
        <File name="File" filename="src\log.log"
            filepattern="%d{YYYY-MM-dd HH:mm:ss}-fargo.log">
            <PatternLayout pattern="%d{YYYY-MM-dd HH:mm:ss} %l [%t] %-5p %c{1}:%L - %msg%n" />
        </File>
 
    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="File" />
        </Root>
    </Loggers>
</Configuration>

以AtomStructure为例展示log和异常的配合使用

package CircularOrbit;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import centralObject.CentralObject;
import exception.AtomNameException;
import exception.AtomTrackNumException;
import exception.AtomTrackNumMatchException;
import exception.ElectronFormatException;
import exception.ElectronNumLabelException;
import exception.StellarTrackRadiusException;
import physicalObject.PhysicalObject;
import track.Track;

public class AtomStructure<L,E> extends ConcreteCircularOrbit<L,E>{
 
 public static Logger logger = LogManager.getLogger(AtomStructure.class.getName());
 @Override
 public void readFile(String filename) throws IOException,AtomNameException, AtomTrackNumException,AtomTrackNumMatchException,ElectronFormatException,ElectronNumLabelException, StellarTrackRadiusException{
  String format1 = "(ElementName ::= )([A-Z][a-z]+)";
  String format2 = "(NumberOfElectron ::= )(\\d+/\\d+;?)+";
  String format3 = "(NumberOfTracks ::= )(\\d+)";
  
  String pathname = "test\\txt\\"+filename;
  Matcher m1,m2,m3;
  String atomName = null;
  int trackNum=0;
  String[]trackNumber = null;
  String[]tracks = null;
  File file = new File(pathname);
  InputStreamReader reader = new InputStreamReader(new FileInputStream(file));
  BufferedReader br = new BufferedReader(reader);
  String line;
  boolean f = false,ff=false,fff=false;
  while((line = br.readLine())!=null) {
   m1 = Pattern.compile(format1).matcher(line);
   m2 = Pattern.compile(format2).matcher(line);
   m3 = Pattern.compile(format3).matcher(line);
   String format4 = "(NumberOfElctron ::= )([\\s\\S]*)";
   Matcher m4 = Pattern.compile(format4).matcher(line);
   while(m1.find()) {
    atomName = m1.group(2);
    
    char[] atomNameChar = atomName.toCharArray();
    if (atomNameChar.length>2||atomNameChar.length<=0||atomNameChar==null) {
     logger.error("异常类型:AtomNameException"+
        "操作错误:AtomName不规范"+
        "停止读取文件");
     throw new AtomNameException("the name of the atom is illegal!");
    }
    if (atomNameChar.length==1) {
     if (!Character.isUpperCase(atomNameChar[0])) {
      logger.error("异常类型:AtomNameException"+
        "操作错误:AtomName不规范"+
        "停止读取文件");
      throw new AtomNameException("the name of the atom's first character is not uppercase");
     }
    }
    if (atomNameChar.length==2) {
     if (!Character.isUpperCase(atomNameChar[0])||!Character.isLowerCase(atomNameChar[1])) {
      logger.error("异常类型:AtomNameException"+
        "操作错误:AtomName不规范"+
        "停止读取文件");
      throw new AtomNameException("the name of the atom's first character should be uppercase and the second one should be lowercase");
     }
    }
    
    f = true;
    CentralObject central = CentralObject.createAtom(atomName);
    super.addCentralObject((L)central);
   }
   while(m3.find()) {
    trackNum = Integer.valueOf(m3.group(2));
     if (trackNum<=0) {
      logger.error("异常类型:AtomTrackNumException"+
        "操作错误:TrackNumber数值不规范"+
        "停止读取文件");
      throw new AtomTrackNumException("the number of tracks is zero!");
     }
    ff = true;
   }
   while(m2.find()) {
    tracks = m2.group().split("NumberOfElectron ::= |;");
    for (int i=1;i<tracks.length;i++) {
     trackNumber = tracks[i].split("/");
     if (trackNumber.length!=2) {
      logger.error("异常类型:ElectronFormatException"+
        "操作错误:电子和轨道的格式不规范"+
        "停止读取文件");
       throw new ElectronFormatException("the electrons on the track should use '/' to split");
     }
     if (trackNumber.length==2) {
      Track t = new Track(Integer.valueOf(trackNumber[0]));
      super.addTrack(t);
      int electronNum = Integer.valueOf(trackNumber[1]);
      for (int j=1;j<=electronNum;j++) {
       PhysicalObject p = PhysicalObject.createElectron();
       super.addPhysicalObject(t, (E)p);
      }
     }
    }
    fff = true;
   }
   
  }
   
  if ((!fff)||(!f)||(!ff)) {
   logger.error("异常类型:ElectronNumLabelException"+
     "操作错误:标签NumberOfElectron或者NumberOfTracks或者ElementName不规范"+
     "停止读取文件");
   throw new ElectronNumLabelException("the label of 'NumberOfElectron ::= ' or 'NumberOfTracks ::= '"
     + " or 'ElementName ::= ' does'n match!");
  }
  if (tracks.length-1 != trackNum) {
   logger.error("异常类型:AtomTrackNumMatchException"+
     "操作错误:输入的TrackNumber和电子所在轨道总和不匹配"+
     "停止读取文件");
   throw new AtomTrackNumMatchException("the number of tracks does'n match!");
  }
  if ((fff)&&(ff)&&(f)) {
    CentralObject central = CentralObject.createAtom(atomName);
    super.addCentralObject((L)central);
  }
  
  
 }
 @Override
 public boolean check() {
  return true;
 }
 @Override
 public int getInfo(E e) {
  throw new UnsupportedOperationException();
 }
}

如此实现每当异常发生时日志有记录。