Converting Text to Speech

The SpeakText.java file converts the text in the Java tutorial to speech. Listing 7-2 shows the contents of the SpeakText.java file:

Listing 7-2: The SpeakText.java File

 /*Import required io classes*/ import java.io.File; /*Import required util classes*/ import java.util.Locale; import java.util.Vector; import javax.speech.synthesis.SynthesizerAdapter; import javax.speech.synthesis.SynthesizerEvent; /*Import required speech classes*/ import javax.speech.Central; import javax.speech.Engine; import javax.speech.EngineList; import javax.speech.synthesis.Synthesizer; import javax.speech.synthesis.SynthesizerModeDesc; import javax.speech.synthesis.SynthesizerProperties; import javax.speech.synthesis.Voice; /* Class:SpeakText-Speaks the text Fields: voiceName:Represents the voice selected by the end user. synthesizer:Represents an object of Synthesizer class. Methods: speakSelText():Uses the object of Synthesizer class to speak the text. closeSynthesizer():Closes the synthesizer and stops the speaking operation. pauseSynthesizer():Pauses the synthesizer. resumeSynthesizer():Resumes the paused speaking operation of the synthesizer. */ public class SpeakText extends SynthesizerAdapter {    /*Declare variables*/    String l;    String voiceName;    SynthesizerModeDesc desc;    Synthesizer synthesizer;    Tutorial textpad;    /*    SpeakText():    Parameters:    k:String representing the text that the synthesizer speaks.    selvoice:String representing the voice selected by the end user.    Return Type:NA    */    public SpeakText(String k, String selvoice)    {       /*       Set the value of l to the text that the synthesizer speaks       */       l=k;       /*       Set the value of voiceName to the voice selected by the user       */       txtpad=new Tutorial();       voiceName = selvoice;       System.out.println("Using voice: " + voiceName);       try       {          /*          Initialize an object of SynthesizerModeDesc class          */          desc = new SynthesizerModeDesc(          null,          "general",          Locale.US,          null,          null);          synthesizer = Central.createSynthesizer(desc);          /*          Prints the message if no synthesizer is available          */          if (synthesizer == null)          {          String message = "\nCan't find synthesizer.\n"          + "Make sure that there is a \"speech.properties\" file"          + "at either of these locations: \n";          message += "user.home    : "          + System.getProperty("user.home") + "\n";          message += "java.home/lib: " + System.getProperty("java.home")          + File.separator + "lib\n";          System.err.println(message);          System.exit(1);       }       /*       Allocate a synthesizer to speak text.       */       synthesizer.allocate();       synthesizer.resume();       desc = (SynthesizerModeDesc) synthesizer.getEngineModeDesc();       /*       Retrieve all the available voices in an array       */       Voice[] voices = desc.getVoices();       Voice voice = null;       for (int i = 0; i < voices.length; i++)        {          if (voices[i].getName().equals(voiceName))           {             voice = voices[i];             break;          }       }       /*       Print error message if selected voice is not available       */       if(voice == null)       {          System.err.println("Synthesizer does not have a voice named "          + voiceName + ".");          System.exit(1);       }       /*       Set the selected voice for the synthesizer       */       synthesizer.getSynthesizerProperties().setVoice(voice);    }    catch(Exception e)    {       System.out.println(e);    } } /* speakSelText():Speaks the text Parameters:NA Return Value:NA */ public void speakSelText(Tutorial st) {    try    {       txtpad=st;       /*       Invoke speakPlainText() method to speak the text.       */       synthesizer.cancelAll();       synthesizer.speakPlainText(l, null);       System.out.println("Speaking Text");    }    catch (Exception e)    {       e.printStackTrace();    }    try    {       /*       Invoke waitEngineState() method to wait end of speech.       */ synthesizer.waitEngineState(Synthesizer.QUEUE_EMPTY);    }    catch(Exception e)    {    } } /* closeSynthesizer():Close the synthesizer and stop the speaking operation. Parameters:NA Return Type:NA */ public void closeSynthesizer() {    try    {       /*       Stop the synthesizer and cancel the speaking operation       */       synthesizer.cancelAll();       System.out.println("Speaking Operation Cancelled");    }    catch (Exception e)    {       e.printStackTrace();    } } /* pauseSynthesizer():Pause the synthesizer. This pauses the text that the synthesizer is currently speaking. Parameters:NA Return Value:NA */ public void pauseSynthesizer() {    try    {       /*       Pause the synthesizer       */       synthesizer.pause();       System.out.println("Speaking Operation Paused");    }    catch(Exception e)    {       e.printStackTrace();    } } /* resumeSynthesizer():Resumes the speaking operation that is paused by the end user. Parameters:NA Return Value:NA */ public void resumeSynthesizer() {    try    {       /*       Resume the synthesizer that speaks the text.       */       synthesizer.resume();       System.out.println("Speaking Operation Resumed");    }    catch(Exception e)    {       e.printStackTrace();    } } } 

 

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In the above code, the constructor of the SpeakText class takes two strings as input parameters. The k string represents the text that the synthesizer reads out. The selvoice string represents the voice that an end user selects to read out the text.

The methods defined in Listing 7-2 are:

• speakSelText(): Uses the object of the Synthesizer class to read out the text in the selected tutorial.

• closeSynthesizer(): Closes the synthesizer and stops the audio operation.

• pauseSynthesizer(): Pauses the synthesizer.

• resumeSynthesizer(): Resumes the paused synthesizer.