Databases
StackOverflow2013
Postsdbo
POHow to match against multiple regular expressions and determine which expression matched in Java
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to match against multiple regular expressions and determine which expression matched in Java
    primarykey
    data
    text
    <p>I've got a Java program that goes through a file line by line, and tries to match each line against one of four regular expressions. Depending on which expression matched, the program performs a certain action. Here's what I have:</p> <pre><code>private void processFile(ArrayList&lt;String&gt; lines) { ArrayList&lt;Component&gt; Components = new ArrayList&lt;&gt;(); Pattern pattern = Pattern.compile( "Object name\\.{7}: (.++)|" + "\\{CAT=([^\\}]++)\\}|" + "\\{CODE=([^\\}]++)\\}|" + "\\{DESC=([^\\}]++)\\}"); Matcher matcher; // Go through each line and see if the line matches the any of the regexes // defined Component currentComponent = null; for (String line : lines) { matcher = pattern.matcher(line); if (matcher.find()) { // We found a tag. Find out which one String match = matcher.group(); if (match.startsWith("Obj")) { // We've got the object name if (currentComponent != null) { Components.add(currentComponent); } currentComponent = new Component(); currentComponent.setName(matcher.group(1)); } else if (currentComponent != null) { if (match.startsWith("{CAT")) { currentComponent.setCategory(matcher.group(2)); } else if (match.startsWith("{CODE")) { currentComponent.setOrderCode(matcher.group(3)); } else if (match.startsWith("{DESC")) { currentComponent.setDescription(matcher.group(4)); } } } } if (currentComponent != null) { Components.add(currentComponent); } } </code></pre> <p>As you can see, I've combined the four regular expressions into one and apply the whole regex on the line. If a match is found, I check the start of the string to determine which expression was matched and then extract the data from the group. In case anyone is interested in running the code, some sample data is presented below:</p> <pre><code>Object name.......: PMF3800SN Last modified.....: Wednesday 9 November 2011 11:55:04 AM File offset (hex).: 00140598 (Hex). Checksum (hex)....: C1C0 (Hex). Size (bytes)......: 1,736 Properties........: {*DEVICE} {PREFIX=Q} {*PROPDEFS} {PACKAGE="PCB Package",PACKAGE,1,SOT-323 MOSFET} {*INDEX} {CAT=Transistors} {SUBCAT=MOSFET} {MFR=NXP} {DESC=N-channel TrenchMOS standard level FET with ESD protection} {CODE=1894711} {*COMPONENT} {PACKAGE=SOT-323 MOSFET} *PINOUT SOT-323 MOSFET {ELEMENTS=1} {PIN "D" = D} {PIN "G" = G} {PIN "S" = S} </code></pre> <p>Although my code works, I don't like the fact that I repeat part of the string later on when calling the startsWith routines.</p> <p>I'm curious to see how others would have written this.</p> <p>Amr</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USAmr Bekhit
    plurals
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. USYoussef G.
      1. VTFavorite
    3. VO
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIs there a reason why you didn't create four distinct regex instances and run them one after the other on each line until one matches?
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. USDaniel Hilgarth
    2. CO@DanielHilgarth It is not going to be a feasible solution I think.
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. USPhani
    3. COThis might solve your problem. http://stackoverflow.com/questions/895279/regular-expression-to-match-multiple-query-string-parameter-value-pairs
      singulars
      1. POHow to match against multiple regular expressions and determine which expression matched in Java
      1. USPhani
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload