循环使用正则导致进程挂起和CPU使用率达到100%居高不下测试Demo

客官°小女子只卖身不卖艺 2022-08-26 01:20 55阅读 0赞

以下代码为测试代码

import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    public class ErrorDataStatTest {
    	public static Map<String, EntryBean> errorMap = new HashMap<String, EntryBean>();
    
    	public static void main(String[] args) {
    		String dest = "/Users/kevin/Documents/shop.do1";
    		try {
    			new ErrorDataStatTest().statData(new File(dest));
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		for (Map.Entry<String, EntryBean> entry : errorMap.entrySet()) {
    			System.out.println(entry.getKey() + "\t" + entry.getValue().val + "\t" + entry.getValue().num);
    		}
    	}
    
    	public static class EntryBean {
    		String key;
    		String val;
    		int num = 0;
    
    		public EntryBean(String key, String val) {
    			this.key = key;
    			this.val = val;
    		}
    
    		public void add() {
    			this.num++;
    		}
    	}
    
    	public static final String regex_code = ".*?code.*?=.*?\"(-?[\\d]*)\"";
    	public static final Pattern pattern = Pattern.compile(regex_code);
    	public static final String regex_code_1 = ".*?Code\\s?=\\s?(-?[\\d]*).*?";
    	public static final Pattern pattern_1 = Pattern.compile(regex_code_1);
     //解析错误Code
    	private static String parserErrorCode(String error) {
    		Matcher matcher = pattern.matcher(error);
    		if (matcher.find()) {
    			return matcher.group(1);
    		}
    		Matcher matcher1 = pattern_1.matcher(error);
    		if (matcher1.find()) {
    			return matcher1.group(1);
    		}
    		return null;
    	}
    
    	public static final String regex_desc = ".*?description.*?=.*?\"(.*?)\"";
    	public static final Pattern pattern_desc = Pattern.compile(regex_desc);
    	private static final String regex_desc_1 = ".*?Code\\s?=\\s?[-]?[\\d]*\\s*\"(.*?)\".*?";
    	private static final Pattern pattern_desc_1 = Pattern.compile(regex_desc_1);
     //解析错误描述
    	private static String parserErrorDesc(String error) {
    		Matcher matcher = pattern_desc.matcher(error);
    		if (matcher.find()) {
    			return matcher.group(1);
    		}
    		Matcher matcher1 = pattern_desc_1.matcher(error);
    		if (matcher1.find()) {
    			return matcher1.group(1);
    		}
    		return null;
    	}
    
    	private String process(String str) {
    		if (str != null) {
    			String key = parserErrorCode(str), val = parserErrorDesc(str);
    			EntryBean entryBean = errorMap.get(key);
    			if (entryBean == null) {
    				entryBean = new EntryBean(key, val);
    			} else {
    				entryBean.add();
    			}
    			errorMap.put(key, entryBean);
    		}
    		return str;
    	}
    
     /*统计日志文件：按照错误码分类统计汇总*/
    	protected void statData(File srcFile) throws IOException {
    		FileReader reader = new FileReader(srcFile);
    		BufferedReader bReader = new BufferedReader(reader);
    		try {
    			String line = process(bReader.readLine());
    			int num = 0;
    			while (line != null) {
    				line = process(bReader.readLine());
    				System.out.println(num);
    				num++;
    			}
    
    		} catch (FileNotFoundException ex) {
    			throw ex;
    		} finally {
    			bReader.close();
    			bReader = null;
    			reader.close();
    			reader = null;
    		}
    	}
    }

本地测试了几次都是在循环处理到第11497次的时候程序卡住不动，导致进程挂起，CPU消耗在100%左右一直下不来。

localhost:~ kevin$ jstack 675

2014-03-22 11:10:16

Full thread dump Java HotSpot(TM) 64-Bit Server VM (24.45-b08 mixed mode):

"Attach Listener" daemon prio=5 tid=0x00007f96638e9000 nid=0x3c0b waiting on condition \[0x0000000000000000\]

java.lang.Thread.State: RUNNABLE

"Service Thread" daemon prio=5 tid=0x00007f966301e000 nid=0x4b03 runnable \[0x0000000000000000\]

java.lang.Thread.State: RUNNABLE

"C2 CompilerThread1" daemon prio=5 tid=0x00007f966301d000 nid=0x4903 waiting on condition \[0x0000000000000000\]

java.lang.Thread.State: RUNNABLE

"C2 CompilerThread0" daemon prio=5 tid=0x00007f966300d000 nid=0x4703 waiting on condition \[0x0000000000000000\]

java.lang.Thread.State: RUNNABLE

"Signal Dispatcher" daemon prio=5 tid=0x00007f9663014000 nid=0x4503 runnable \[0x0000000000000000\]

java.lang.Thread.State: RUNNABLE

"Finalizer" daemon prio=5 tid=0x00007f9664827000 nid=0x3103 in Object.wait() \[0x000000011108c000\]

java.lang.Thread.State: WAITING (on object monitor)

at java.lang.Object.wait(Native Method)

\- waiting on <0x00000007eaa85568> (a java.lang.ref.ReferenceQueue$Lock)

at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:135)

\- locked <0x00000007eaa85568> (a java.lang.ref.ReferenceQueue$Lock)

at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:151)

at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:189)

"Reference Handler" daemon prio=5 tid=0x00007f9664029000 nid=0x2f03 in Object.wait() \[0x0000000110f89000\]

java.lang.Thread.State: WAITING (on object monitor)

at java.lang.Object.wait(Native Method)

\- waiting on <0x00000007eaa850f0> (a java.lang.ref.Reference$Lock)

at java.lang.Object.wait(Object.java:503)

at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133)

\- locked <0x00000007eaa850f0> (a java.lang.ref.Reference$Lock)

"main" prio=5 tid=0x00007f9664800000 nid=0x1903 runnable \[0x0000000109753000\]

java.lang.Thread.State: RUNNABLE

at java.util.regex.Pattern$Curly.match1(Pattern.java:4198)

at java.util.regex.Pattern$Curly.match(Pattern.java:4134)

at java.util.regex.Pattern$Start.match(Pattern.java:3408)

at java.util.regex.Matcher.search(Matcher.java:1199)

at java.util.regex.Matcher.find(Matcher.java:592)

at com.ishopping.sign.controller.ErrorDataStatTest.parserErrorDesc(ErrorDataStatTest.java:72)

at com.ishopping.sign.controller.ErrorDataStatTest.process(ErrorDataStatTest.java:84)

at com.ishopping.sign.controller.ErrorDataStatTest.statData(ErrorDataStatTest.java:140)

at com.ishopping.sign.controller.ErrorDataStatTest.main(ErrorDataStatTest.java:24)

"VM Thread" prio=5 tid=0x00007f9664028800 nid=0x2d03 runnable

"GC task thread\#0 (ParallelGC)" prio=5 tid=0x00007f966300f800 nid=0x2503 runnable

"GC task thread\#1 (ParallelGC)" prio=5 tid=0x00007f9663010800 nid=0x2703 runnable

"GC task thread\#2 (ParallelGC)" prio=5 tid=0x00007f9663011000 nid=0x2903 runnable

"GC task thread\#3 (ParallelGC)" prio=5 tid=0x00007f9663011800 nid=0x2b03 runnable

"VM Periodic Task Thread" prio=5 tid=0x00007f9663019800 nid=0x4d03 waiting on condition

JNI global references: 181

ORACLE:

[http://bugs.sun.com/bugdatabase/view\_bug.do?bug\_id=5050507][http_bugs.sun.com_bugdatabase_view_bug.do_bug_id_5050507] 和 [http://bugs.sun.com/bugdatabase/view\_bug.do?bug\_id=6988218][http_bugs.sun.com_bugdatabase_view_bug.do_bug_id_6988218]

\#总结

建议在高频度执行的代码或高并发的系统中尽量少的使用正则。

[http_bugs.sun.com_bugdatabase_view_bug.do_bug_id_5050507]: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5050507
[http_bugs.sun.com_bugdatabase_view_bug.do_bug_id_6988218]: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6988218