Improved ThreaDumpFilter tool

h2/src/tools/org/h2/dev/util/ThreadDumpFilter.java

@@ -5,8 +5,12 @@
  */
 package org.h2.dev.util;
 
-import java.io.InputStreamReader;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
 import java.io.LineNumberReader;
+import java.io.PrintWriter;
 
 /**
  * Filter full thread dumps from a log file.
@@ -15,14 +19,19 @@ public class ThreadDumpFilter {
 
     /**
      * Usage: java ThreadDumpFilter <log.txt >threadDump.txt
-     * @param a ignored
+     *
+     * @param a the file name
      */
     public static void main(String... a) throws Exception {
-        LineNumberReader in = new LineNumberReader(new InputStreamReader(System.in));
+        String fileName = a[0];
+        LineNumberReader in = new LineNumberReader(
+                new BufferedReader(new FileReader(fileName)));
+        PrintWriter writer = new PrintWriter(new BufferedWriter(
+                new FileWriter(fileName + ".filtered.txt")));
         for (String s; (s = in.readLine()) != null;) {
             if (s.startsWith("Full thread")) {
                 do {
-                    System.out.println(s);
+                    writer.println(s);
                     s = in.readLine();
                 } while(s != null && (s.length() == 0 || " \t\"".indexOf(s.charAt(0)) >= 0));
             }