Example usage for java.lang StringBuilder charAt

List of usage examples for java.lang StringBuilder charAt

Introduction

In this page you can find the example usage for java.lang StringBuilder charAt.

Prototype

char charAt(int index);

Source Link

Document

Returns the char value at the specified index.

Usage

From source file:Main.java

public static void main(String args[]) {
    StringBuilder buffer = new StringBuilder("hello java2s.com");

    System.out.println(buffer.charAt(0));
    System.out.println(buffer.charAt(4));

}

From source file:Main.java

public static void main(String args[]) {
    StringBuilder sb = new StringBuilder("java2s.com");
    System.out.println("buffer before = " + sb);
    System.out.println("charAt(1) before = " + sb.charAt(1));

    sb.setCharAt(1, 'i');
    System.out.println("buffer after = " + sb);
    System.out.println("charAt(1) after = " + sb.charAt(1));

}

From source file:com.mijecu25.sqlplus.SQLPlus.java

public static void main(String[] args) throws IOException {
    // Create and load the properties from the application properties file
    Properties properties = new Properties();
    properties.load(SQLPlus.class.getClassLoader().getResourceAsStream(SQLPlus.APPLICATION_PROPERTIES_FILE));

    SQLPlus.logger.info("Initializing " + SQLPlus.PROGRAM_NAME + " version "
            + properties.getProperty(SQLPlus.APPLICATION_PROPERTIES_FILE_VERSION));

    // Check if the user is using a valid console (i.e. not from Eclipse)
    if (System.console() == null) {
        // The Console object for the JVM could not be found. Alert the user 
        SQLPlus.logger.fatal(Messages.FATAL + "A JVM Console object was not found. Try running "
                + SQLPlus.PROGRAM_NAME + "from the command line");
        System.out.println(/*from w w w  .  j a va2s.c o m*/
                Messages.FATAL + SQLPlus.PROGRAM_NAME + " was not able to find your JVM's Console object. "
                        + "Try running " + SQLPlus.PROGRAM_NAME + " from the command line.");

        SQLPlus.exitSQLPlus();

        SQLPlus.logger.fatal(Messages.FATAL + Messages.QUIT_PROGRAM_ERROR(PROGRAM_NAME));
        return;
    }

    // UI intro
    System.out.println("Welcome to " + SQLPlus.PROGRAM_NAME
            + "! This program has a DSL to add alerts to various SQL DML events.");
    System.out.println("Be sure to use " + SQLPlus.PROGRAM_NAME + " from the command line.");
    System.out.println();

    // Get the version
    System.out.println("Version: " + properties.getProperty(SQLPlus.APPLICATION_PROPERTIES_FILE_VERSION));
    System.out.println();

    // Read the license file
    BufferedReader bufferedReader;
    bufferedReader = new BufferedReader(new FileReader(SQLPlus.LICENSE_FILE));

    // Read a line
    String line = bufferedReader.readLine();

    // While the line is not null
    while (line != null) {
        System.out.println(line);

        // Read a new lines
        line = bufferedReader.readLine();
    }

    // Close the buffer
    bufferedReader.close();
    System.out.println();

    // Create the jline console that allows us to remember commands, use arrow keys, and catch interruptions
    // from the user
    SQLPlus.console = new ConsoleReader();
    SQLPlus.console.setHandleUserInterrupt(true);

    try {
        // Get credentials from the user
        SQLPlus.logger.info("Create SQLPlusConnection");
        SQLPlus.createSQLPlusConnection();
    } catch (NullPointerException | SQLException | IllegalArgumentException e) {
        // NPE: This exception can occur if the user is running the program where the JVM Console
        // object cannot be found.
        // SQLE: TODO should I add here the error code?
        // This exception can occur when trying to establish a connection
        // IAE: This exception can occur when trying to establish a connection
        SQLPlus.logger
                .fatal(Messages.FATAL + Messages.FATAL_EXIT(SQLPlus.PROGRAM_NAME, e.getClass().getName()));
        System.out.println(Messages.FATAL + Messages.FATAL_EXCEPTION_ACTION(e.getClass().getSimpleName()) + " "
                + Messages.CHECK_LOG_FILES);
        SQLPlus.exitSQLPlus();

        SQLPlus.logger.fatal(Messages.FATAL + Messages.QUIT_PROGRAM_ERROR(SQLPlus.PROGRAM_NAME));
        return;
    } catch (UserInterruptException uie) {
        SQLPlus.logger.warn(Messages.WARNING + "The user typed an interrupt instruction.");
        SQLPlus.exitSQLPlus();

        return;
    }

    System.out.println("Connection established! Commands end with " + SQLPlus.END_OF_COMMAND);
    System.out.println("Type " + SQLPlus.EXIT + " or " + SQLPlus.QUIT + " to exit the application ");

    try {
        // Execute the input scanner
        while (true) {
            // Get a line from the user until the hit enter (carriage return, line feed/ new line).
            System.out.print(SQLPlus.PROMPT);
            try {
                line = SQLPlus.console.readLine().trim();
            } catch (NullPointerException npe) {
                // TODO test this behavior
                // If this exception is catch, it is very likely that the user entered the end of line command.
                // This means that the program should quit.
                SQLPlus.logger.warn(Messages.WARNING + "The input from the user is null. It is very likely that"
                        + "the user entered the end of line command and they want to quit.");
                SQLPlus.exitSQLPlus();

                return;
            }

            // If the user did not enter anything
            if (line.isEmpty()) {
                // Continue to the next iteration
                continue;
            }

            if (line.equals(".")) {
                line = "use courses;";
            }

            if (line.equals("-")) {
                line = "select created_at from classes;";
            }

            if (line.equals("--")) {
                line = "select name, year from classes;";
            }

            if (line.equals("*")) {
                line = "select * from classes;";
            }

            if (line.equals("x")) {
                line = "select name from classes, classes;";
            }

            if (line.equals("e")) {
                line = "select * feom classes;";
            }

            // Logic to quit
            if (line.equals(SQLPlus.QUIT) || line.equals(SQLPlus.EXIT)) {
                SQLPlus.logger.info("The user wants to quit " + SQLPlus.PROGRAM_NAME);
                SQLPlus.exitSQLPlus();
                break;
            }

            // Use a StringBuilder since jline works weird when it has read a line. The issue we were having was with the
            // end of command logic. jline does not keep the input from the user in the variable that was stored in. Each
            // time jline reads a new line, the variable is empty
            StringBuilder query = new StringBuilder();
            query.append(line);

            // While the user does not finish the command with the SQLPlus.END_OF_COMMAND
            while (query.charAt(query.length() - 1) != SQLPlus.END_OF_COMMAND) {
                // Print the wait for command prompt and get the next line for the user
                System.out.print(SQLPlus.WAIT_FOR_END_OF_COMMAND);
                query.append(" ");
                line = StringUtils.stripEnd(SQLPlus.console.readLine(), null);
                query.append(line);
            }

            SQLPlus.logger.info("Raw input from the user: " + query);

            try {
                Statement statement;

                try {
                    // Execute the antlr code to parse the user input
                    SQLPlus.logger.info("Will parse the user input to determine what to execute");
                    ANTLRStringStream input = new ANTLRStringStream(query.toString());
                    SQLPlusLex lexer = new SQLPlusLex(input);
                    CommonTokenStream tokens = new CommonTokenStream(lexer);
                    SQLPlusParser parser = new SQLPlusParser(tokens);

                    statement = parser.sqlplus();
                } catch (RecognitionException re) {
                    // TODO move this to somehwere else
                    //                        String message = Messages.WARNING + "You have an error in your SQL syntax. Check the manual"
                    //                                + " that corresponds to your " + SQLPlus.sqlPlusConnection.getCurrentDatabase()
                    //                                + " server or " + SQLPlus.PROGRAM_NAME + " for the correct syntax";
                    //                        SQLPlus.logger.warn(message);
                    //                        System.out.println(message);
                    statement = new StatementDefault();
                }

                statement.setStatement(query.toString());
                SQLPlus.sqlPlusConnection.execute(statement);
            } catch (UnsupportedOperationException uoe) {
                // This exception can occur when the user entered a command allowed by the parsers, but not currently
                // supported by SQLPlus. This can occur because the parser is written in such a way that supports
                // the addition of features.
                SQLPlus.logger.warn(Messages.WARNING + uoe);
                System.out.println(
                        Messages.WARNING + Messages.FATAL_EXCEPTION_ACTION(uoe.getClass().getSimpleName()) + " "
                                + Messages.CHECK_LOG_FILES);
                SQLPlus.logger.warn(Messages.WARNING + "The previous command is not currently supported.");
            }

        }
    } catch (IllegalArgumentException iae) {
        // This exception can occur when a command is executed but it had illegal arguments. Most likely
        // it is a programmer's error and should be addressed by the developer.
        SQLPlus.logger
                .fatal(Messages.FATAL + Messages.FATAL_EXIT(SQLPlus.PROGRAM_NAME, iae.getClass().getName()));
        SQLPlus.exitSQLPlus();

        SQLPlus.logger.fatal(Messages.FATAL + Messages.QUIT_PROGRAM_ERROR(SQLPlus.PROGRAM_NAME));
    } catch (UserInterruptException uie) {
        SQLPlus.logger.warn(Messages.WARNING + "The user typed an interrupt instruction.");
        SQLPlus.exitSQLPlus();
    }
}

From source file:com.admc.jcreole.JCreole.java

/**
 * Run this method with no parameters to see syntax requirements and the
 * available parameters.//w w  w  .  java2s. c o m
 *
 * N.b. do not call this method from a persistent program, because it
 * may call System.exit!
 * <p>
 * Any long-running program should use the lower-level methods in this
 * class instead (or directly use CreoleParser and CreoleScanner
 * instances).
 * </p> <p>
 * This method executes with all JCreole privileges.
 * </p> <p>
 * This method sets up the following htmlExpander mappings (therefore you
 * can reference these in both Creole and boilerplate text).<p>
 * <ul>
 *   <li>sys|*: mappings for Java system properties
 *   <li>isoDateTime
 *   <li>isoDate
 *   <li>pageTitle: Value derived from the specified Creole file name.
 * </ul>
 *
 * @throws IOException for any I/O problem that makes it impossible to
 *         satisfy the request.
 * @throws CreoleParseException
 *         if can not generate output, or if the run generates 0 output.
 *         If the problem is due to input formatting, in most cases you
 *         will get a CreoleParseException, which is a RuntimException, and
 *         CreoleParseException has getters for locations in the source
 *         data (though they will be offset for \r's in the provided
 *         Creole source, if any).
 */
public static void main(String[] sa) throws IOException {
    String bpResPath = null;
    String bpFsPath = null;
    String outPath = null;
    String inPath = null;
    boolean debugs = false;
    boolean troubleshoot = false;
    boolean noBp = false;
    int param = -1;
    try {
        while (++param < sa.length) {
            if (sa[param].equals("-d")) {
                debugs = true;
                continue;
            }
            if (sa[param].equals("-t")) {
                troubleshoot = true;
                continue;
            }
            if (sa[param].equals("-r") && param + 1 < sa.length) {
                if (bpFsPath != null || bpResPath != null || noBp)
                    throw new IllegalArgumentException();
                bpResPath = sa[++param];
                continue;
            }
            if (sa[param].equals("-f") && param + 1 < sa.length) {
                if (bpResPath != null || bpFsPath != null || noBp)
                    throw new IllegalArgumentException();
                bpFsPath = sa[++param];
                continue;
            }
            if (sa[param].equals("-")) {
                if (noBp || bpFsPath != null || bpResPath != null)
                    throw new IllegalArgumentException();
                noBp = true;
                continue;
            }
            if (sa[param].equals("-o") && param + 1 < sa.length) {
                if (outPath != null)
                    throw new IllegalArgumentException();
                outPath = sa[++param];
                continue;
            }
            if (inPath != null)
                throw new IllegalArgumentException();
            inPath = sa[param];
        }
        if (inPath == null)
            throw new IllegalArgumentException();
    } catch (IllegalArgumentException iae) {
        System.err.println(SYNTAX_MSG);
        System.exit(1);
    }
    if (!noBp && bpResPath == null && bpFsPath == null)
        bpResPath = DEFAULT_BP_RES_PATH;
    String rawBoilerPlate = null;
    if (bpResPath != null) {
        if (bpResPath.length() > 0 && bpResPath.charAt(0) == '/')
            // Classloader lookups are ALWAYS relative to CLASSPATH roots,
            // and will abort if you specify a beginning "/".
            bpResPath = bpResPath.substring(1);
        InputStream iStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(bpResPath);
        if (iStream == null)
            throw new IOException("Boilerplate inaccessible: " + bpResPath);
        rawBoilerPlate = IOUtil.toString(iStream);
    } else if (bpFsPath != null) {
        rawBoilerPlate = IOUtil.toString(new File(bpFsPath));
    }
    String creoleResPath = (inPath.length() > 0 && inPath.charAt(0) == '/') ? inPath.substring(1) : inPath;
    // Classloader lookups are ALWAYS relative to CLASSPATH roots,
    // and will abort if you specify a beginning "/".
    InputStream creoleStream = Thread.currentThread().getContextClassLoader()
            .getResourceAsStream(creoleResPath);
    File inFile = (creoleStream == null) ? new File(inPath) : null;
    JCreole jCreole = (rawBoilerPlate == null) ? (new JCreole()) : (new JCreole(rawBoilerPlate));
    if (debugs) {
        jCreole.setInterWikiMapper(new InterWikiMapper() {
            // This InterWikiMapper is just for prototyping.
            // Use wiki name of "nil" to force lookup failure for path.
            // Use wiki page of "nil" to force lookup failure for label.
            public String toPath(String wikiName, String wikiPage) {
                if (wikiName != null && wikiName.equals("nil"))
                    return null;
                return "{WIKI-LINK to: " + wikiName + '|' + wikiPage + '}';
            }

            public String toLabel(String wikiName, String wikiPage) {
                if (wikiPage == null)
                    throw new RuntimeException("Null page name sent to InterWikiMapper");
                if (wikiPage.equals("nil"))
                    return null;
                return "{LABEL for: " + wikiName + '|' + wikiPage + '}';
            }
        });
        Expander creoleExpander = new Expander(Expander.PairedDelims.RECTANGULAR);
        creoleExpander.put("testMacro",
                "\n\n<<prettyPrint>>\n{{{\n" + "!/bin/bash -p\n\ncp /etc/inittab /tmp\n}}}\n");
        jCreole.setCreoleExpander(creoleExpander);
    }
    jCreole.setPrivileges(EnumSet.allOf(JCreolePrivilege.class));
    Expander exp = jCreole.getHtmlExpander();
    Date now = new Date();
    exp.putAll("sys", System.getProperties(), false);
    exp.put("isoDateTime", isoDateTimeFormatter.format(now), false);
    exp.put("isoDate", isoDateFormatter.format(now), false);
    exp.put("pageTitle",
            (inFile == null) ? creoleResPath.replaceFirst("[.][^.]*$", "").replaceFirst(".*[/\\\\.]", "")
                    : inFile.getName().replaceFirst("[.][^.]*$", ""));
    if (troubleshoot) {
        // We don't write any HMTL output here.
        // Goal is just to output diagnostics.
        StringBuilder builder = (creoleStream == null) ? IOUtil.toStringBuilder(inFile)
                : IOUtil.toStringBuilder(creoleStream);
        int newlineCount = 0;
        int lastOffset = -1;
        int offset = builder.indexOf("\n");
        for (; offset >= 0; offset = builder.indexOf("\n", offset + 1)) {
            lastOffset = offset;
            newlineCount++;
        }
        // Accommodate input files with no terminating newline:
        if (builder.length() > lastOffset + 1)
            newlineCount++;
        System.out.println("Input lines:  " + newlineCount);
        Exception lastException = null;
        while (true) {
            try {
                jCreole.parseCreole(builder);
                break;
            } catch (Exception e) {
                lastException = e;
            }
            if (builder.charAt(builder.length() - 1) == '\n')
                builder.setLength(builder.length() - 1);
            offset = builder.lastIndexOf("\n");
            if (offset < 1)
                break;
            newlineCount--;
            builder.setLength(builder.lastIndexOf("\n"));
        }
        System.out.println((lastException == null) ? "Input validates"
                : String.format("Error around input line %d:  %s", newlineCount, lastException.getMessage()));
        return;
    }
    String generatedHtml = (creoleStream == null) ? jCreole.parseCreole(inFile)
            : jCreole.parseCreole(IOUtil.toStringBuilder(creoleStream));
    String html = jCreole.postProcess(generatedHtml, SystemUtils.LINE_SEPARATOR);
    if (outPath == null) {
        System.out.print(html);
    } else {
        FileUtils.writeStringToFile(new File(outPath), html, "UTF-8");
    }
}

From source file:org.eclipse.swt.snippets.Snippet179.java

public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("Snippet 179");
    shell.setLayout(new GridLayout());
    final Text text = new Text(shell, SWT.BORDER);
    text.setText("YYYY/MM/DD");
    final Calendar calendar = Calendar.getInstance();
    text.addListener(SWT.Verify, new Listener() {
        boolean ignore;

        @Override//from   ww  w.j  av a2s. c o  m
        public void handleEvent(Event e) {
            if (ignore)
                return;
            e.doit = false;
            StringBuilder buffer = new StringBuilder(e.text);
            char[] chars = new char[buffer.length()];
            buffer.getChars(0, chars.length, chars, 0);
            if (e.character == '\b') {
                for (int i = e.start; i < e.end; i++) {
                    switch (i) {
                    case 0: /* [Y]YYY */
                    case 1: /* Y[Y]YY */
                    case 2: /* YY[Y]Y */
                    case 3: /* YYY[Y] */ {
                        buffer.append('Y');
                        break;
                    }
                    case 5: /* [M]M*/
                    case 6: /* M[M] */ {
                        buffer.append('M');
                        break;
                    }
                    case 8: /* [D]D */
                    case 9: /* D[D] */ {
                        buffer.append('D');
                        break;
                    }
                    case 4: /* YYYY[/]MM */
                    case 7: /* MM[/]DD */ {
                        buffer.append('/');
                        break;
                    }
                    default:
                        return;
                    }
                }
                text.setSelection(e.start, e.start + buffer.length());
                ignore = true;
                text.insert(buffer.toString());
                ignore = false;
                text.setSelection(e.start, e.start);
                return;
            }

            int start = e.start;
            if (start > 9)
                return;
            int index = 0;
            for (int i = 0; i < chars.length; i++) {
                if (start + index == 4 || start + index == 7) {
                    if (chars[i] == '/') {
                        index++;
                        continue;
                    }
                    buffer.insert(index++, '/');
                }
                if (chars[i] < '0' || '9' < chars[i])
                    return;
                if (start + index == 5 && '1' < chars[i])
                    return; /* [M]M */
                if (start + index == 8 && '3' < chars[i])
                    return; /* [D]D */
                index++;
            }
            String newText = buffer.toString();
            int length = newText.length();
            StringBuilder date = new StringBuilder(text.getText());
            date.replace(e.start, e.start + length, newText);
            calendar.set(Calendar.YEAR, 1901);
            calendar.set(Calendar.MONTH, Calendar.JANUARY);
            calendar.set(Calendar.DATE, 1);
            String yyyy = date.substring(0, 4);
            if (yyyy.indexOf('Y') == -1) {
                int year = Integer.parseInt(yyyy);
                calendar.set(Calendar.YEAR, year);
            }
            String mm = date.substring(5, 7);
            if (mm.indexOf('M') == -1) {
                int month = Integer.parseInt(mm) - 1;
                int maxMonth = calendar.getActualMaximum(Calendar.MONTH);
                if (0 > month || month > maxMonth)
                    return;
                calendar.set(Calendar.MONTH, month);
            }
            String dd = date.substring(8, 10);
            if (dd.indexOf('D') == -1) {
                int day = Integer.parseInt(dd);
                int maxDay = calendar.getActualMaximum(Calendar.DATE);
                if (1 > day || day > maxDay)
                    return;
                calendar.set(Calendar.DATE, day);
            } else {
                if (calendar.get(Calendar.MONTH) == Calendar.FEBRUARY) {
                    char firstChar = date.charAt(8);
                    if (firstChar != 'D' && '2' < firstChar)
                        return;
                }
            }
            text.setSelection(e.start, e.start + length);
            ignore = true;
            text.insert(newText);
            ignore = false;
        }
    });
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();
}

From source file:Main.java

private static String swapChars(String str, int lIdx, int rIdx) {
    StringBuilder sb = new StringBuilder(str);
    char l = sb.charAt(lIdx), r = sb.charAt(rIdx);
    sb.setCharAt(lIdx, r);//from   w w  w .j a va 2 s. co  m
    sb.setCharAt(rIdx, l);
    return sb.toString();
}

From source file:Main.java

private static boolean lastCharIsWhitespace(StringBuilder sb) {
    return sb.length() != 0 && sb.charAt(sb.length() - 1) == ' ';
}

From source file:Main.java

public static String capitalizeFirstChar(String target) {
    StringBuilder capitalized = new StringBuilder(target);
    capitalized.setCharAt(0, Character.toUpperCase(capitalized.charAt(0)));
    return capitalized.toString();
}

From source file:Main.java

/**
 * Trim all occurrences of the supplied trailing character from the given String.
 * @param str the String to check/*from ww w  .  j  ava 2s  . c  o m*/
 * @param trailingCharacter the trailing character to be trimmed
 * @return the trimmed String
 */
public static String trimTrailingCharacter(String str, char trailingCharacter) {
    if (!hasLength(str)) {
        return str;
    }
    StringBuilder sb = new StringBuilder(str);
    while (sb.length() > 0 && sb.charAt(sb.length() - 1) == trailingCharacter) {
        sb.deleteCharAt(sb.length() - 1);
    }
    return sb.toString();
}

From source file:Main.java

public static String getHex(byte[] raw) {
    if (raw == null) {
        return null;
    }/*from   w ww  .  j a va2 s  .  co m*/
    final StringBuilder hex = new StringBuilder(2 * raw.length);
    for (final byte b : raw) {
        hex.append(HEX.charAt((b & 0xF0) >> 4)).append(HEX.charAt((b & 0x0F)));
    }
    return hex.toString();
}