Don't ignore IOException stupid!

Files may not be accessible if they are read-only, or if the directory
is read-only, or ... whatever. So, let the caller handle IOException
in DataWriter.

Return a set if it can be read.

Do some misc cleanups (remove unused imports, fix docs, remove obsolete
TODOs).

2 files changed, 33 insertions, 39 deletions

diff --git a/src/io/DataWriter.java b/src/io/DataWriter.java
index c26dbf3..42d69f8 100644
--- a/src/io/DataWriter.java
+++ b/src/io/DataWriter.java
@@ -39,28 +39,26 @@ public class DataWriter implements ResultListener {
      * the buffer of profile ids that already exist.
      */
     private final Set<Long> m_profileIdSet;
-    
+
     public final static String CFG_PROFILE_FILENAME = "profiles-filename";
-    public final static String CFG_TWEETS_FILENAME  = "tweets-filename";
+    public final static String CFG_TWEETS_FILENAME = "tweets-filename";
 
     /**
      * Opens a stream to every single file that data will be streamed to.
+     *
      * @param profilesName The file to write the profiles to.
      * @param tweetsName The file to write the tweets to.
+     * @throws java.io.IOException if the files cannot be read or written.
      */
-    public DataWriter(final String profilesName, final String tweetsName) {
-        try {
-            m_profileIdSet = readIds(profilesName);
-            m_profileWriter = new FileWriter(profilesName, true);
+    public DataWriter(final String profilesName, final String tweetsName)
+            throws IOException {
+        m_profileIdSet = readIds(profilesName);
+        m_profileWriter = new FileWriter(profilesName, true);
 
-            m_tweetIdSet = readIds(tweetsName);
-            m_tweetWriter = new FileWriter(tweetsName, true);
-        } catch (IOException ex) {
-            // This should not happen.
-            throw new RuntimeException(ex.getMessage());
-        }
+        m_tweetIdSet = readIds(tweetsName);
+        m_tweetWriter = new FileWriter(tweetsName, true);
     }
-    
+
     public void close() {
         try {
             m_tweetWriter.close();
@@ -82,18 +80,15 @@ public class DataWriter implements ResultListener {
 
     /**
      * Read the current existing tweetName and profileName filenames and fill
-     * the existing id set, it will create the file when it doesn't exist.
+     * the existing id set.
      *
-     * @param filename The file to parse
-     * @return The set of ids
+     * @param filename The file to parse.
+     * @return The set of ids, may be empty if the fill does not exist.
      */
     private Set readIds(String filename) throws IOException {
+        Set<Long> idSet = new HashSet<>();
         try {
             Scanner reader = new Scanner(new File(filename));
-
-            // TODO: Read the file JSON objects and parse the ids.
-            Set idSet = new HashSet();
-
             // parse each line into a JSONObject, read the id and add it to
             // the set of ids.
             while (reader.hasNext()) {
@@ -101,29 +96,23 @@ public class DataWriter implements ResultListener {
                 long id = obj.getLong("id");
                 idSet.add(id);
             }
-
-            return idSet;
         } catch (FileNotFoundException ex) {
-            // File does not exist, so create one.
-            File file = new File(filename);
-            // Return value should always be true.
-            file.createNewFile();
+            // ignore, file will be created if necessary.
         } catch (JSONException ex) {
-            getLogger().log(Level.SEVERE, null, ex);
+            getLogger().log(Level.WARNING, filename
+                    + ": File is only partially processed", ex);
         }
-
-        // return the empty set.
-        return new HashSet();
+        return idSet;
     }
 
     /**
      * Writes the JSONObject to a writer and update the idSet.
-     * 
+     *
      * @param obj The object to write.
      * @param writer The writer object to append the object to.
      * @param idSet The id set to add the obj id to.
      */
-    private void writeObject(JSONObject obj, FileWriter writer, Set idSet) {
+    private void writeObject(JSONObject obj, FileWriter writer, Set<Long> idSet) {
         try {
             long id = obj.getLong("id");
 
@@ -133,11 +122,11 @@ public class DataWriter implements ResultListener {
                     writer.write(obj.toString() + "\n");
                     idSet.add(id);
                 } catch (IOException ex) {
-                    getLogger().log(Level.SEVERE, null, ex);
+                    getLogger().log(Level.WARNING, "Cannot write to file", ex);
                 }
             }
         } catch (JSONException ex) {
-            getLogger().log(Level.SEVERE, null, ex);
+            getLogger().log(Level.WARNING, "ID not found?!", ex);
         }
     }
 
diff --git a/src/main/TweetShell.java b/src/main/TweetShell.java
index 3ab1397..a5114e2 100644
--- a/src/main/TweetShell.java
+++ b/src/main/TweetShell.java
@@ -377,11 +377,16 @@ public class TweetShell implements TwitterApi.PinSupplier {
 
             String profilesFilename = config.getProperty(DataWriter.CFG_PROFILE_FILENAME);
             String tweetsFilename = config.getProperty(DataWriter.CFG_TWEETS_FILENAME);
-
-            resultListeners.register(new DataWriter(profilesFilename, tweetsFilename));
-
-            // save the changes to the config.
-            config.save();
+            try {
+                DataWriter dw = new DataWriter(profilesFilename, tweetsFilename);
+                resultListeners.register(dw);
+                // save the changes to the config.
+                config.save();
+            } catch (IOException ex) {
+                System.err.println("Could not open file for storing tweets:");
+                System.err.println(ex.getMessage());
+                return false;
+            }
         } else if (rlCls == StreamHandler.class) {
             resultListeners.register(new StreamHandler());
         }