最近在写往公司产品里添加Tomcat适配器，以支持Tomcat。有一些功能需要摘取到Tomcat的部分日志。没有合适的工具，也不想去网上找了，就自己写了一个。
简单的画了一下设计方案：
下面直接上代码了：
日志阅读器：
package com.fjn.tools.log.reader; import java.io.File;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner; import com.fjn.tools.log.reader.parser.CatalinaSimpleFormatterParser; public class LogReader {
private String logFile;
private List<LogFilter> logFilterChain = new LinkedList<LogFilter>();
private final ContinueRead continueRead = new ContinueRead();
private LogParser parser;
private final boolean doFilter(LogRecord record) {
for (LogFilter filter : logFilterChain) {
if (!filter.accept(record)) {
return false;
}
}
return true;
} public void addFilter(LogFilter filter) {
if(filter!=null){
logFilterChain.add(filter);
}
} public final String readLogRecords(String startTime, String endTime) {
if (parser == null) {
return null;
}
StringBuilder buff = new StringBuilder();
Scanner scanner = null; try {
scanner = new Scanner(new File(logFile)); NewLine newLine = null;
if (startTime != null) {
StartTimeFilter filter = new StartTimeFilter();
filter.startTime = startTime;
addFilter(filter);
}
if (endTime != null) {
EndTimeFilter filter = new EndTimeFilter();
filter.endTime = endTime;
filter.continueRead = this.continueRead;
addFilter(filter);
}
while (scanner.hasNextLine() && continueRead.value) {
LogRecord record = null;
if (newLine == null) {
newLine = new NewLine();
}
if (!newLine.hasGetNewLine) {
newLine.line = scanner.nextLine();
newLine.hasGetNewLine = true;
}
record = parser.getLogRecord(scanner, newLine, continueRead);
if (record != null) {
if (doFilter(record)) {
buff.append(record.toString());
}
}
}
} catch (Exception ex) {
// Ignore it
} finally {
if (scanner != null) {
scanner.close();
}
}
return buff.toString();
} public static interface LogParser {
public LogRecord getLogRecord(Scanner scanner, NewLine newLine,
ContinueRead continueRead);
} public static interface LogFilter {
public boolean accept(LogRecord record);
} public static abstract class LogRecord {
public String prefix;
public String message;
public String threadStack;
public String datetime;
} public static class NewLine {
public boolean hasGetNewLine = false;
public String line = "";
} public static class ContinueRead {
public boolean value = true;
} private class StartTimeFilter implements LogFilter {
private String startTime; @Override
public boolean accept(LogRecord record) {
if (startTime == null) {
return true;
} if (startTime.compareTo(record.datetime) <= 0) {
return true;
}
return false;
}
} private class EndTimeFilter implements LogFilter {
private String endTime = "";
private ContinueRead continueRead; @Override
public boolean accept(LogRecord record) {
if (endTime == null || endTime.isEmpty()) {
return true;
}
if (endTime.compareTo(record.datetime) < 0) {
if (continueRead.value) {
continueRead.value = false;
}
return false;
}
return true;
}
} public String getLogFile() {
return logFile;
} public void setLogFile(String logFile) {
this.logFile = logFile;
} public LogParser getParser() {
return parser;
} public void setParser(LogParser parser) {
this.parser = parser;
} public static void main(String[] args) {
LogReader logReader=new LogReader();
logReader.setLogFile("E:\\Program Files\\apache/tomcat/apache-tomcat-6.0.41/logs/catalina.2015-05-12.log");
logReader.setParser(new CatalinaSimpleFormatterParser());
System.out.println(logReader.readLogRecords("2015-10-12 01:53:10", null));
}
}
LogReader
接下来是一个Tomcat日志分析器：
package com.fjn.tools.log.reader.parser; import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer; import com.fjn.tools.log.reader.LogReader.ContinueRead;
import com.fjn.tools.log.reader.LogReader.LogParser;
import com.fjn.tools.log.reader.LogReader.LogRecord;
import com.fjn.tools.log.reader.LogReader.NewLine; public class CatalinaSimpleFormatterParser implements LogParser { @Override
public LogRecord getLogRecord(Scanner scanner, NewLine newLine,
ContinueRead continueRead) {
String line1 = newLine.line;
if (!line1.matches(SimpleFormatterLogRecord.prefixPattern)) {
newLine.hasGetNewLine = false;
return null;
}
boolean toNextRecord = false;
String nextLine = null;
List<String> messageLines = new LinkedList<String>();
while (!toNextRecord) {
if (scanner.hasNextLine()) {
nextLine = scanner.nextLine();
if (!nextLine.matches(SimpleFormatterLogRecord.prefixPattern)) {
messageLines.add(nextLine);
} else {
toNextRecord = true;
newLine.hasGetNewLine = true;
newLine.line = nextLine;
break;
}
} else {
break;
}
}
SimpleFormatterLogRecord record = new SimpleFormatterLogRecord();
record.prefix = line1 + "\n";
StringBuilder messageBuilder = new StringBuilder();
StringBuilder threadStackBuilder = new StringBuilder();
boolean toThreadStack = false;
for (String lineN : messageLines) {
if (!toThreadStack
&& lineN.matches(SimpleFormatterLogRecord.threadStackStartPattern)) {
toThreadStack = true;
}
if (toThreadStack) {
threadStackBuilder.append(lineN).append("\n");
} else {
messageBuilder.append(lineN).append("\n");
}
} record.message = messageBuilder.toString();
record.threadStack = threadStackBuilder.toString(); StringTokenizer stk = new StringTokenizer(record.prefix);
String date = stk.nextToken();
String time = stk.nextToken();
record.datetime = dateTimeFormat(date + " " + time); return record;
} private class SimpleFormatterLogRecord extends LogRecord {
private static final String prefixPattern = "^(\\d{4}-\\d{1,2}-\\d{1,2} \\d{1,2}:\\d{1,2}:\\d{1,2} ).*";
private static final String threadStackStartPattern = "^((\\w+\\.)*\\w*Exception: ).*"; public String toString() {
return this.prefix + this.message + this.threadStack;
}
} private static String dateTimeFormat(String datetime){
StringTokenizer stk = new StringTokenizer(datetime, "- :");
int i = 0;
StringBuilder dateTimeBuilder = new StringBuilder();
while (stk.hasMoreTokens()) {
i++;
String token = stk.nextToken();
if (i < 7 && token.length() < 2) {
token = "0" + token;
}
if (i < 3) {
token += "-";
} else if (i < 4) {
token += " ";
} else if (i < 6) {
token += ":";
}
dateTimeBuilder.append(token);
}
return dateTimeBuilder.toString();
} public static void main(String[] args) {
System.out.println(dateTimeFormat("2015-5-12 1:53:10 "));
}
}
CatalinaSimpleFormatterLogParser
1) 如果想要分析其它格式的日志，只需要做相应的扩展LogParser就行了。
2) 如果想要只找包含某些关键字的日志，只需要扩展LogFilter就可以了。
3) 如果想要取得某个时间段的日志，只需要指定相应的startTime,endTime参数就可以了。