Changeset 38850 for main/trunk/greenstone2/build-src/src

Timestamp:

2024-03-19T16:00:34+13:00 (2 months ago)

Author:

davidb

Message:

How this Java code was determining end-of-input was found to be incorrect; having read the docs more carefully, this is an updated version that works even if there is a delay in input arriving on standard-in

File:

• main/trunk/greenstone2/build-src/src/java/org/nzdl/gsdl/ApplyXSLT.java (modified) (8 diffs)

main/trunk/greenstone2/build-src/src/java/org/nzdl/gsdl/ApplyXSLT.java

@@ -101 +101 @@
     }
 
+    /*
+    private boolean isOpen(BufferedReader br) {
+    // The code used to rely on br.ready() to determine whether it should
+    // continue looping to read input (from standard-in).  However on
+    // closer read of the JavaDoc, br.ready() can return false even
+    // when the input stream is still open -- it's just that there isn't
+    // any input lines to read in at the moment.
+
+    // If the input stream has been closed (from the external calling Perl code),
+    // then the only sure way to determine that this condition has arise is
+    // to ask br.ready() and catch the Exception that occurs ... because the
+    // input stream is not closed!
+
+    boolean is_open = true;
+    
+    try {
+        boolean is_ready = br.ready();
+    }
+    catch (Exception e) {  // Could be more selective and go for IOException ??
+        //System.err.println("ApplyXSLT::isOpen() encountered an exception => so input is closed");
+        is_open = false;
+    }
+
+    return is_open;
+    }
+    */
+    
   private boolean process()
   {
@@ -114 +141 @@
 
 
-      while (br.ready()) {
-                           
-    String this_line = br.readLine();
+      String this_line;      
+      while ((this_line = br.readLine()) != null) {
+        
+    //System.err.println("Read in from pipe, line: " + this_line);
+    
     if(system_status == BEFORE_READING){
       if(this_line.compareTo(DOC_START) == 0){
+          // If this_line is DOC_START then we require the next line of input to be
+          // the filename
         output_file = br.readLine(); // read the next line as the output file name
+        if (output_file == null) {
+        // A problem of some form occurred
+        return false;
+        }
+        //System.err.println("Read in from pipe, next line: " + output_file);
         system_status = IS_READING;
         a_doc = new StringBuffer();
@@ -127 +163 @@
       }
       else{
-        System.err.println("Undefined process status:" + this_line);
         system_status = BEFORE_READING;
       }
@@ -143 +178 @@
             
         if (!result){
-          System.err.println("Translation Failed!!");
           return false;
         }
@@ -161 +195 @@
       }
 
+      return true;
+      
       //if(br != null) {
       //  br.close();
       //  br = null;
-      //}
-      
-    }catch (Exception e)
-      {
+      //}      
+    }
+    catch (Exception e) {
     System.err.println("Receiving piped data error!" + e.toString());
-      }
+    e.printStackTrace();
+    }
                 
     return false;
@@ -206 +242 @@
       }catch (Exception e) {
       System.err.println("Receiving piped data error!" + e.toString());
+      e.printStackTrace();
       } 
       return false;
@@ -474 +511 @@
   public static void main(String[] args) 
   { 
-
     String xml_file="";
     String xsl_file="";
@@ -636 +672 @@
         ioe.printStackTrace();  
         } finally {
+        System.err.println("ReadStreamGobbler:run() finished.  Closing resource");
         closeResource(br);
         }