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Java Eclipse Visitor Not Leaving Main() of test file

I'm attempting collect all the methods in a Java file using the Eclipse AST package. I believe that I have the CompilationUnit created successfully. However when I attempt to use a visitor to collect the information it doesn't go past the main() method of the file I'm testing.
public void parseCode(String fileName) {
String strSource = "";
try {
strSource = codeToString(fileName);
} catch (Exception e) {
e.printStackTrace();
}
ASTParser parser = ASTParser.newParser(AST.JLS8);
parser.setSource(strSource.toCharArray());
parser.setKind(ASTParser.K_COMPILATION_UNIT);
final CompilationUnit cu = (CompilationUnit) parser.createAST(new NullProgressMonitor());
SCTVisitor v = new SCTVisitor();
cu.accept(v);
System.out.println(v.m);
}
public class SCTVisitor extends ASTVisitor{
List<SimpleName> m = new ArrayList<SimpleName>();
SCTVisitor(){
System.out.println("What is love");
}
#Override public boolean visit(MethodInvocation node) {
this.m.add(node.getName());
return true;
}
}
This is part of the file I'm using to test:
import java.util.Map;
import java.util.Scanner;
import javax.swing.JFileChooser;
import javax.swing.UIManager;
public class WordCount {
public static void main(String[] args) {
System.out.println("Cheese");
countWordsViaGUI();
}
// allow user to pick file to exam via GUI.
// allow multiple picks
public static void countWordsViaGUI() {
setLookAndFeel();
try {
Scanner key = new Scanner(System.in);
do {
System.out.println("Opening GUI to choose file.");
Scanner fileScanner = new Scanner(getFile());
Stopwatch st = new Stopwatch();
st.start();
ArrayList<String> words = countWordsWithArrayList(fileScanner);
st.stop();
System.out.println("time to count: " + st);
System.out.print("Enter number of words to display: ");
int numWordsToShow = Integer.parseInt(key.nextLine());
showWords(words, numWordsToShow);
fileScanner.close();
System.out.print("Perform another count? ");
} while(key.nextLine().toLowerCase().charAt(0) == 'y');
key.close();
}
catch(FileNotFoundException e) {
System.out.println("Problem reading the data file. Exiting the program." + e);
}
}
My results are:
[println, countWordsViaGUI]
My expected results are:
[println, countWordsViaGUI, setLookAndFeel, scanner, println, getFile, Scanner, ...]
Please let me know if you have any insight into this problem.

How do I fix Illegal Start of Expressions with all of my methods?

I have my code. I think it's all right, but it is not. It keeps telling me at the beginning of each method that there is a ';' expected and it's also an 'illegal start of expression' with the void. I do not know how to fix it. Can someone please help me fix these errors?
Here's an example of the Errors:
F:\COMP SCI\Topic 29 - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:203: error: ';' expected
void arrayList **()** throws FileNotFoundException();
F:\COMP SCI\Topic 29 - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:212: error: illegal start of expression
**void** output()
F:\COMP SCI\Topic 29 - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:212: error: ';' expected
void output **()**
My code:
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import static java.lang.System.out;
import java.util.ArrayList;
import javax.swing.JFrame;
public class RobinHoodApp{
public static void main(String[] args) throws FileNotFoundException, IOException {
RobinHood app = new RobinHood();
app.readFile();
app.arrayList();
app.wordCount();
app.countMenAtArms();
app.writeToFile();
}
}
class RobinHood extends JFrame
{
private static final ArrayList<String>words = new ArrayList<>();
private static Scanner book;
private static int count;
private static int wordCount;
public RobinHood()
{
try {
// scrubber();
//Prints All Words 1 by 1: Works!
book = new Scanner(new File("RobinHood.txt") );
book.useDelimiter("\r\n");
} catch (FileNotFoundException ex)
{
out.println("Where's your text fam?");
}
}
void readFile()
{
while(book.hasNext())
{
String text = book.next();
out.println(text);
}
void arrayList() throws FileNotFoundException();
{
Scanner add = new Scanner(new File("RobinHood.txt"));
while(add.hasNext())
{
words.add(add.next());
}
}
void output()
{
out.println(words);
}
void countMenAtArms()
{
//Shows 23 times
String find = "men-at-arms";
count = 0;
int x;
String text;
for(x=0; x< wordCount; x++ )
{
text = words.get(x);
text = text.replaceAll("\n", "");
text = text.replaceAll("\n", "");
if (text.equals(find))
{
count++;
}
}
out.println("The amount of time 'men-at-arms' appears in the book is: " + count);
}
// void scrubber()
// {
//
// }
//
//
void wordCount()
{
{
wordCount=words.size();
out.println("There are "+wordCount+" words in Robin Hood.");
}
}
public void writeToFile()
{
File file;
file = new File("Dominique.dat");
try (FileOutputStream data = new FileOutputStream(file)) {
if ( !file.exists() )
{
file.createNewFile();
}
String wordCountSentence = "There are "+ wordCount +" words in Robin Hood. \n";
String countTheMen = "The amount of time 'men-at-arms' appears in the book is: " + count;
byte[] strToBytes = wordCountSentence.getBytes();
byte[] menToBytes = countTheMen.getBytes();
data.write(strToBytes);
data.write(menToBytes);
data.flush();
data.close();
}
catch (IOException ioe)
{
System.out.println("Error");
}
}
}
}

You should use a Java IDE like Eclipse when programming Java, it would point out to you the most obvious mistakes in your code.
You missed a } after the while loop for your readFile() method (thanks to Sweeper for this one).
The syntax in your arrayList() method is wrong.
void arrayList() throws FileNotFoundException(); {
No semicolon at the end of this defintion, no parenthesis at the end too, you are describing the class, not a method. Here is the correct way:
void arrayList() throws FileNotFoundException {
1 useless } at the end of your class file.
Find below your code, with a proper layout and without syntax errors. Please use an IDE next time, that would avoid you an awful lot of trouble.
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import static java.lang.System.out;
import java.util.ArrayList;
import javax.swing.JFrame;
public class RobinHoodApp {
public static void main(String[] args) throws FileNotFoundException, IOException {
RobinHood app = new RobinHood();
app.readFile();
app.arrayList();
app.wordCount();
app.countMenAtArms();
app.writeToFile();
}
}
class RobinHood extends JFrame
{
private static final ArrayList<String>words = new ArrayList<>();
private static Scanner book;
private static int count;
private static int wordCount;
public RobinHood()
{
try {
// Prints All Words 1 by 1: Works!
book = new Scanner(new File("RobinHood.txt") );
book.useDelimiter("\r\n");
} catch (FileNotFoundException ex)
{
out.println("Where's your text fam ?");
}
}
void readFile()
{
while(book.hasNext())
{
String text = book.next();
out.println(text);
}
}
void arrayList() throws FileNotFoundException
{
Scanner add = new Scanner(new File("RobinHood.txt"));
while(add.hasNext())
{
words.add(add.next());
}
}
void output()
{
out.println(words);
}
void countMenAtArms()
{
// Shows 23 times
String find = "men-at-arms";
count = 0;
int x;
String text;
for(x=0; x< wordCount; x++ )
{
text = words.get(x);
text = text.replaceAll("\n", "");
text = text.replaceAll("\n", "");
if (text.equals(find))
{
count++;
}
}
out.println("The amount of time 'men-at-arms' appears in the book is: " + count);
}
void wordCount()
{
{
wordCount=words.size();
out.println("There are "+wordCount+" words in Robin Hood.");
}
}
public void writeToFile()
{
File file;
file = new File("Dominique.dat");
try (FileOutputStream data = new FileOutputStream(file)) {
if ( !file.exists() )
{
file.createNewFile();
}
String wordCountSentence = "There are "+ wordCount +" words in Robin Hood. \n";
String countTheMen = "The amount of time 'men-at-arms' appears in the book is: " + count;
byte[] strToBytes = wordCountSentence.getBytes();
byte[] menToBytes = countTheMen.getBytes();
data.write(strToBytes);
data.write(menToBytes);
data.flush();
data.close();
}
catch (IOException ioe)
{
System.out.println("Error");
}
}
}

throws FileNotFoundException();
This should be
throws FileNotFoundException
and similarly in all cases.
Rather trivial. Don't just make up the syntax. Look it up.

Saving Vectors In Java

How would I go about saving a String Vector to a file every time it is edited?
So let's say I have usernames in a vector, after I add or delete a username I'd like it to save that vector so if the program is closed, it will show the most recent elements.

This should help you get started.
As JB Nizet said, you should use an ArrayList.
I also went ahead and used Java 7 autocloseable functionality, which ensures you close file handles appropriately.
Of course, you will need to validate your input, and you will want to take care about what you persist. I suspect that you will soon want to consider a better storage strategy, however, this will get you started.
In addition, since this is acting like a collection, you should add hashcode and equals. For brevity sake, I did not add those.
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
public class PersistedCollection {
private static final String NEWLINE_SEPARATOR = System.getProperty("line.separator");
private final List<String> values;
private final File file;
public PersistedCollection(File file) {
this.values = new ArrayList<>();
this.file = file;
}
public void add(String value) {
// You should validate this value. Remove carriage returns, make sure it meets your value specifications.
values.add(value);
persist();
}
public void remove(String value) {
values.remove(value);
persist();
}
private void persist() {
// Using Java 7 autocloseable to ensure that the output stream is closed, even in exceptional circumstances.
try (OutputStream outputStream = new BufferedOutputStream(new FileOutputStream(this.file), 8192); Writer writer = new PrintWriter(outputStream)) {
for (String value : values) {
writer.append(value);
writer.append(NEWLINE_SEPARATOR);
}
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("PersistedCollection [values=");
builder.append(values);
builder.append(", file=");
builder.append(file);
builder.append("]");
return builder.toString();
}
public static void main(String[] arguments) {
PersistedCollection persistedCollection = new PersistedCollection(new File("/tmp/test.txt"));
persistedCollection.add("jazeee");
persistedCollection.add("temporary user");
persistedCollection.add("user402442");
persistedCollection.add("JB Nizet");
persistedCollection.remove("temporary user");
System.out.println(persistedCollection);
}
}

Another solution would be to create a class where you add all the methods required to read from a file of usernames (one username per line). Then you can refer to this class from anywhere (as the modifier is public) and call the methods such that you will add or remove usernames from that file.
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.io.File;
public class Test {
private static BufferedWriter bw;
private static ArrayList<String> vector=new ArrayList<String>();
private static String everything;
//add an username
public static void add(String x){
vector.add(x);
}
//remove an username
public static void remove(String x){
vector.remove(x);
}
//update the file with the new vector of usernames
public static void updateToFile() throws IOException{
File username = new File("/home/path/to/the/file");
FileWriter fw = new FileWriter(username.getAbsoluteFile());
bw= new BufferedWriter(fw);
for (String x:vector){
bw.write(x.toString());
bw.write("\n");
}
bw.close();
}
//you call this method to initialise your vector of usernames
//this implies that you already have a file of usernames
//one username per line
public static void setUsername() throws IOException{
vector=new ArrayList<String>();
BufferedReader br = new BufferedReader(new FileReader("/home/path/to/the/file"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
sb.append(System.lineSeparator());
line = br.readLine();
}
everything = sb.toString();
} finally {
br.close();
}
String lines[] = everything.split("\\r?\\n");
for (String x:lines){
vector.add(x);
}
}
//print your usernames in the console
public static void printUsers(){
for (String User:vector){
System.out.println(User);
}
}
}
Then it gets as easy as this:
import java.io.IOException;
public class MainTest {
public static void main(String[] args) throws IOException{
Test.setUsername();
Test.printUsers();
Test.add("username5");
Test.remove("username2");
System.out.println("// add username5; remove username2");
Test.printUsers();
System.out.println("// file has been updated with the new state");
Test.updateToFile();
System.out.println("// veryfing update");
Test.setUsername();
Test.printUsers();
}
}
The output:
(this first 4 users is what I have in the file)
username1
username2
username3
username4
// add username5; remove username2
username1
username3
username4
username5
// file has been updated with the new state
// verifying update
username1
username3
username4
username5

NullPointerException error in Main

Trying to read a file when the user enters the file name into the console. The program compiles and runs with no errors. Once you enter the file name and press enter, you get this error. Can't figure out why. Any help would be appreciated.
Exception in thread "main" java.lang.NullPointerException
at java.io.Writer.<init>(Writer.java:88)
at java.io.PrintWriter.<init>(PrintWriter.java:113)
at java.io.PrintWriter.<init>(PrintWriter.java:100)
at propertylistings.propertylistings.main(propertylistings.java:34)
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.TreeSet;
public class propertylistings {
public static void main(String[] args)
throws FileNotFoundException
{
// Prompt for the input file name
Scanner console = new Scanner(System.in);
System.out.print("Input file: ");
String inputFileName = console.next();
BufferedWriter pwfo = null;
try {
pwfo = new BufferedWriter(new FileWriter("C:\\agentReport.txt",
true));
} catch (IOException e) {
}
//next line is LINE 34
PrintWriter pwo = new PrintWriter(pwfo);
// Construct property type treeSet
Set<String> propertyTypes = pTypes(inputFileName);
// Print property types from treeSet
for (String type : propertyTypes) {
System.out.println(type);
pwo.println(type);
}
// Construct agent ids and values treeSet
Set<String> agentRpt = agentValue(inputFileName);
// Print agent Ids and values from key set
for (String tail : agentRpt) {
{
System.out.println(tail);
pwo.println(tail);
}
}
pwo.flush();
pwo.close();
}
// Reads the input file.
// #return the alphabetized property types in uppercase.
public static Set<String> pTypes(String inputFileName)
throws FileNotFoundException
// Construct a tree set to return property types
{
Set<String> type = new TreeSet<String>();
Scanner in = new Scanner(new File(inputFileName));
// Use delimiters to select specific chars for set
in.useDelimiter("[1234567890. ]");
while (in.hasNext()) {
type.add(in.next().toUpperCase());
}
in.close();
return type;
}
// Reads the input file.
// #returns the Agent id's and corresponding property values.
public static Set<String> agentValue(String inputFileName)
throws FileNotFoundException {
TreeSet<String> tail = new TreeSet<String>();
SortedMap<String, Number> agentValues = new TreeMap<String, Number>();
Scanner in = new Scanner(new File(inputFileName));
String line = inputFileName;
while (in.hasNextLine()) {
try {
line = in.nextLine();
String[] fields = line.split("[\\s}]");
String agentId = (fields[3]);
Double pValue = Double.parseDouble(fields[2]);
if (agentValues.containsKey(agentId)) {
pValue += agentValues.get(agentId).doubleValue();
}
agentValues.put(agentId, pValue);
} catch (Exception e) {
}
// Create keyMap with all keys and values
Set<String> keySet = agentValues.keySet();
for (String key : keySet) {
Number value = agentValues.get(key);
// System.out.println(key + ":" + value);
tail.add(key + ":" + value);
}
}
return tail;
}
}

Put a stacktrace in your catch block and you'll know the exact error.
try {
pwfo = new BufferedWriter(new FileWriter("C:\\agentReport.txt", true));
} catch (IOException e) {
e.printstacktrace();
}

File always seems to be empty

Ok, I'm really confused by some code I wrote. It's a DataSetter (didn't know a better name for it...), and has methods to change the data in my data file (data.txt). This data has the following format: #key=value (eg. #version=1.0). Now, I tried to run this line of code:
new DataSetter().setValue("version", "1.1");
It just clears the file. That's pretty much all it does. Now, I think it clears the file because it makes a new File, which is completely empty but has the same name. Here's my code:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;
/**
* This class contains methods to set specific data in the data.txt file. <br>
* The data is rewritten every time a new value is set.
*
* #author Casper van Battum
*
*/
public class DataSetter {
private static final File DATA_FILE = new File("resources/data.txt");
private static final String lineFormat = "#%s=%s";
private FileOutputStream out;
private DataReader reader = new DataReader();
private HashMap<String, String> dataMap = reader.getDataMap();
private Scanner scanner;
public DataSetter() {
try {
out = new FileOutputStream(DATA_FILE, false);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public void setValue(String key, String newValue) {
openDataFile();
String oldLine = String.format(lineFormat, key, dataMap.get(key));
dataMap.put(key, newValue);
String newLine = String.format(lineFormat, key, newValue);
try {
replace(oldLine, newLine);
} catch (IOException e) {
e.printStackTrace();
}
closeDataFile();
}
private void replace(String oldLine, String newLine) throws IOException {
ArrayList<String> tmpData = new ArrayList<String>();
while (scanner.hasNextLine()) {
String currentLine = scanner.nextLine();
tmpData.add((currentLine == oldLine) ? newLine : currentLine);
}
out.write(new String().getBytes());
String sep = System.getProperty("line.separator");
StringBuffer sb = new StringBuffer();
for (String string : tmpData) {
sb.append(string + sep);
}
FileWriter writer = new FileWriter(DATA_FILE);
String outString = sb.toString();
writer.write(outString);
writer.close();
}
private void openDataFile() {
try {
scanner = new Scanner(DATA_FILE);
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
}
private void closeDataFile() {
scanner.close();
}
}
So after running the setValue() method, I just have an empty file...
Im really out of idea's on how to solve this...

You are truncating your data file with the
new FileOutputStream(DATA_FILE, false)
so no nothing is written when you go to output your the elements in the tmpData ArrayList read from Scanner.
ArrayList<String> tmpData = new ArrayList<String>();
while (scanner.hasNextLine()) {
String currentLine = scanner.nextLine(); // never gets called
...
}
The typical strategy for updating a text file is to create a temporary file with old file's contents (File#renameTo), write the data to file, then delete the temporary file after closing any open streams to the file being read.