Java tutorial
/* * @(#)VMMetrics.java 1.3 04/01/05 * * Copyright (c) 2000-2003 Sun Microsystems, Inc. All Rights Reserved. * * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use, * modify and redistribute this software in source and binary code form, * provided that i) this copyright notice and license appear on all copies of * the software; and ii) Licensee does not utilize the software in a manner * which is disparaging to Sun. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE * POSSIBILITY OF SUCH DAMAGES. * * This software is not designed or intended for use in on-line control of * aircraft, air traffic, aircraft navigation or aircraft communications; or in * the design, construction, operation or maintenance of any nuclear * facility. Licensee represents and warrants that it will not use or * redistribute the Software for such purposes. */ /* * @(#)MultiColumnPrinter.java 1.3 04/09/15 * * Copyright 2003 Sun Microsystems, Inc. All Rights Reserved * SUN PROPRIETARY/CONFIDENTIAL * Use is subject to license terms. * */ import java.util.Enumeration; import java.util.Vector; import java.util.Map; import java.util.TreeMap; import java.util.Iterator; /** * Utility class for printing aligned collumns of text. How/where * the text is printed is determined by the abstract methods * doPrint(String) and doPrintln(String). The typical case is to * create a subclass and make these methods print the string to standard * out or error. * <P> * This class allows you to specify: * <UL> * <LI>The number of collumns in the output. This will determine * the dimension of the string arrays passed to add(String[]) * or addTitle(String[]). * <LI>spacing/gap between columns * <LI>character to use for title border (null means no border) * <LI>column alignment. Only LEFT/CENTER is supported for now. * </UL> * * <P> * Example usage: * <PRE> * MyPrinter mp = new MyPrinter(3, 2, "-"); * String oneRow[] = new String [ 3 ]; * oneRow[0] = "User Name"; * oneRow[1] = "Email Address"; * oneRow[2] = "Phone Number"; * mp.addTitle(oneRow); * * oneRow[0] = "Bob"; * oneRow[1] = "bob@foo.com"; * oneRow[2] = "123-4567"; * mp.add(oneRow); * * oneRow[0] = "John"; * oneRow[1] = "john@foo.com"; * oneRow[2] = "456-7890"; * mp.add(oneRow); * mp.print(); * </PRE> * * <P> * The above would print: * <P> * <PRE> * -------------------------------------- * User Name Email Address Phone Number * -------------------------------------- * Bob bob@foo.com 123-4567 * John john@foo.com 456-7890 * </PRE> * *<P> * This class also supports multi-row titles and having title * strings spanning multiple collumns. Example usage: * <PRE> * TestPrinter tp = new TestPrinter(4, 2, "-"); * String oneRow[] = new String [ 4 ]; * int[] span = new int[ 4 ]; * * span[0] = 2; // spans 2 collumns * span[1] = 0; // spans 0 collumns * span[2] = 2; // spans 2 collumns * span[3] = 0; // spans 0 collumns * * tp.setTitleAlign(CENTER); * oneRow[0] = "Name"; * oneRow[1] = ""; * oneRow[2] = "Contact"; * oneRow[3] = ""; * tp.addTitle(oneRow, span); * * oneRow[0] = "First"; * oneRow[1] = "Last"; * oneRow[2] = "Email"; * oneRow[3] = "Phone"; * tp.addTitle(oneRow); * * oneRow[0] = "Bob"; * oneRow[1] = "Jones"; * oneRow[2] = "bob@foo.com"; * oneRow[3] = "123-4567"; * tp.add(oneRow); * * oneRow[0] = "John"; * oneRow[1] = "Doe"; * oneRow[2] = "john@foo.com"; * oneRow[3] = "456-7890"; * tp.add(oneRow); * * tp.println(); * </PRE> * * <P> * The above would print: * <P> * <PRE> * ------------------------------------ * Name Contact * First Last Email Phone * ------------------------------------ * Bob Jones bob@foo.com 123-4567 * John Doe john@foo.com 456-7890 * </PRE> * */ public abstract class MultiColumnPrinter { final public static int LEFT = 0; final public static int CENTER = 1; /* * Sets the default sorting behavior. * When set to true, the table entries are sorted unless otherwise * specified in a constructor. */ final private static boolean DEFAULT_SORT = true; private int numCol = 2; private int gap = 4; private int align = CENTER; private int titleAlign = CENTER; private String border = null; private Vector table = null; private Vector titleTable = null; private Vector titleSpanTable = null; private int curLength[]; private boolean sortNeeded = DEFAULT_SORT; private int[] keyCriteria = null; /** * Creates a new MultiColumnPrinter class. * * @param numCol number of columns * @param gap gap between each column * @param border character used to frame the titles * @param align type of alignment within columns * @param sort true if the output is sorted; false otherwise * * REVISIT: Possibly adding another argument that specifies which ones can * be truncated (xxx...) */ public MultiColumnPrinter(int numCol, int gap, String border, int align, boolean sort) { table = new Vector(); titleTable = new Vector(); titleSpanTable = new Vector(); curLength = new int[numCol]; this.numCol = numCol; this.gap = gap; this.border = border; this.align = align; this.titleAlign = LEFT; this.sortNeeded = sort; } /** * Creates a new sorted MultiColumnPrinter class. * * @param numCol number of columns * @param gap gap between each column * @param border character used to frame the titles * @param align type of alignment within columns */ public MultiColumnPrinter(int numCol, int gap, String border, int align) { this(numCol, gap, border, align, DEFAULT_SORT); } /** * Creates a sorted new MultiColumnPrinter class using LEFT alignment. * * @param numCol number of columns * @param gap gap between each column * @param border character used to frame the titles */ public MultiColumnPrinter(int numCol, int gap, String border) { this(numCol, gap, border, LEFT); } /** * Creates a sorted new MultiColumnPrinter class using LEFT alignment * and with no title border. * * @param numCol number of columns * @param gap gap between each column */ public MultiColumnPrinter(int numCol, int gap) { this(numCol, gap, null, LEFT); } /** * Adds to the row of strings to be used as the title for the table. * * @param row Array of strings to print in one row of title. */ public void addTitle(String[] row) { if (row == null) return; int[] span = new int[row.length]; for (int i = 0; i < row.length; i++) { span[i] = 1; } addTitle(row, span); } /** * Adds to the row of strings to be used as the title for the table. * Also allows for certain title strings to span multiple collumns * The span parameter is an array of integers which indicate how * many collumns the corresponding title string will occupy. * For a row that is 4 collumns wide, it is possible to have some * title strings in a row to 'span' multiple collumns: * * <P> * <PRE> * ------------------------------------ * Name Contact * First Last Email Phone * ------------------------------------ * Bob Jones bob@foo.com 123-4567 * John Doe john@foo.com 456-7890 * </PRE> * * In the example above, the title row has a string 'Name' that * spans 2 collumns. The string 'Contact' also spans 2 collumns. * The above is done by passing in to addTitle() an array that * contains: * * <PRE> * span[0] = 2; // spans 2 collumns * span[1] = 0; // spans 0 collumns, ignore * span[2] = 2; // spans 2 collumns * span[3] = 0; // spans 0 collumns, ignore * </PRE> * <P> * A span value of 1 is the default. * The method addTitle(String[] row) basically does: * * <PRE> * int[] span = new int [ row.length ]; * for (int i = 0; i < row.length; i++) { * span[i] = 1; * } * addTitle(row, span); * </PRE> * * @param row Array of strings to print in one row of title. * @param span Array of integers that reflect the number of collumns * the corresponding title string will occupy. */ public void addTitle(String[] row, int span[]) { // Need to create a new instance of it, otherwise the new values will // always overwrite the old values. String[] rowInstance = new String[(row.length)]; for (int i = 0; i < row.length; i++) { rowInstance[i] = row[i]; } titleTable.addElement(rowInstance); titleSpanTable.addElement(span); } /** * Set alignment for title strings * * @param titleAlign */ public void setTitleAlign(int titleAlign) { this.titleAlign = titleAlign; } /** * Adds one row of text to output. * * @param row Array of strings to print in one row. */ public void add(String[] row) { // Need to create a new instance of it, otherwise the new values will // always overwrite the old values. String[] rowInstance = new String[(row.length)]; for (int i = 0; i < row.length; i++) { rowInstance[i] = row[i]; } table.addElement(rowInstance); } /** * Clears title strings. */ public void clearTitle() { titleTable.clear(); titleSpanTable.clear(); } /** * Clears strings. */ public void clear() { table.clear(); if (curLength != null) { for (int i = 0; i < curLength.length; ++i) { curLength[i] = 0; } } } /** * Prints the multi-column table, including the title. */ public void print() { print(true); } /** * Prints the multi-column table. * * @param printTitle Specifies if the title rows should be printed. */ public void print(boolean printTitle) { // REVISIT: // Make sure you take care of curLength and row being null value cases. // Get the longest string for each column and store in curLength[] // Scan through title rows Enumeration elm = titleTable.elements(); Enumeration spanEnum = titleSpanTable.elements(); int rowNum = 0; while (elm.hasMoreElements()) { String[] row = (String[]) elm.nextElement(); int[] curSpan = (int[]) spanEnum.nextElement(); for (int i = 0; i < numCol; i++) { // Fix for 4627901: NullPtrException seen when // execute 'jmqcmd list dur' // This happens when a field to be listed is null. // None of the fields should be null, but if it // happens to be so, replace it with "-". if (row[i] == null) row[i] = "-"; int len = row[i].length(); /* * If a title string spans multiple collumns, then * the space it occupies in each collumn is at most * len/span (since we have gap to take into account * as well). */ int span = curSpan[i], rem = 0; if (span > 1) { rem = len % span; len = len / span; } if (curLength[i] < len) { curLength[i] = len; if ((span > 1) && ((i + span) <= numCol)) { for (int j = i + 1; j < (i + span); ++j) { curLength[j] = len; } /* * Add remainder to last collumn in span * to avoid round-off errors. */ curLength[(i + span) - 1] += rem; } } } ++rowNum; } // Scan through rest of rows elm = table.elements(); while (elm.hasMoreElements()) { String[] row = (String[]) elm.nextElement(); for (int i = 0; i < numCol; i++) { // Fix for 4627901: NullPtrException seen when // execute 'jmqcmd list dur' // This happens when a field to be listed is null. // None of the fields should be null, but if it // happens to be so, replace it with "-". if (row[i] == null) row[i] = "-"; if (curLength[i] < row[i].length()) curLength[i] = row[i].length(); } } /* * Print title */ if (printTitle) { printBorder(); elm = titleTable.elements(); spanEnum = titleSpanTable.elements(); while (elm.hasMoreElements()) { String[] row = (String[]) elm.nextElement(); int[] curSpan = (int[]) spanEnum.nextElement(); for (int i = 0; i < numCol; i++) { int availableSpace = 0, span = curSpan[i]; if (span == 0) continue; availableSpace = curLength[i]; if ((span > 1) && ((i + span) <= numCol)) { for (int j = i + 1; j < (i + span); ++j) { availableSpace += gap; availableSpace += curLength[j]; } } if (titleAlign == CENTER) { int space_before, space_after; space_before = (availableSpace - row[i].length()) / 2; space_after = availableSpace - row[i].length() - space_before; printSpaces(space_before); doPrint(row[i]); printSpaces(space_after); if (i < numCol - 1) printSpaces(gap); } else { doPrint(row[i]); if (i < numCol - 1) printSpaces(availableSpace - row[i].length() + gap); } } doPrintln(""); } printBorder(); } if (sortNeeded) printSortedTable(); else printUnsortedTable(); } /* * Prints the table entries in the sorted order. */ private void printSortedTable() { // Sort the table entries TreeMap sortedTable = new TreeMap(); Enumeration elm = table.elements(); while (elm.hasMoreElements()) { String[] row = (String[]) elm.nextElement(); // If keyCriteria contains valid info use that // to create the key; otherwise, use the default row[0] // for the key. if (keyCriteria != null && keyCriteria.length > 0) { String key = getKey(row); if (key != null) sortedTable.put(key, row); else sortedTable.put(row[0], row); } else { sortedTable.put(row[0], row); } } // Iterate through the table entries Iterator iterator = sortedTable.entrySet().iterator(); while (iterator.hasNext()) { Map.Entry entry = (Map.Entry) iterator.next(); String[] row = ((String[]) entry.getValue()); printRow(row); } } /* * Creates the key for the current row based on the * criteria specified by setKeyCriteria(). * If key cannot be created by the criteria, it simply returns * null. * * Examples: * String[] row = {"foo", "bar", "hello"); * * int[] keyCriteria = {0}; * key = "foo"; * * int[] keyCriteria = {0, 1}; * key = "foobar"; * * int[] keyCriteria = {2, 1}; * key = "hellobar"; * * int[] keyCriteria = {4}; * key = null; */ private String getKey(String[] row) { String key = ""; for (int i = 0; i < keyCriteria.length; i++) { int content = keyCriteria[i]; try { key = key + row[content]; } catch (ArrayIndexOutOfBoundsException ae) { // Happens when keyCriteria[] contains an index that // does not exist in 'row'. return null; } } return key; } /* * Prints the table entries in the order they were entered. */ private void printUnsortedTable() { Enumeration elm = table.elements(); while (elm.hasMoreElements()) { String[] row = (String[]) elm.nextElement(); printRow(row); } } private void printRow(String[] row) { for (int i = 0; i < numCol; i++) { if (align == CENTER) { int space1, space2; space1 = (curLength[i] - row[i].length()) / 2; space2 = curLength[i] - row[i].length() - space1; printSpaces(space1); doPrint(row[i]); printSpaces(space2); if (i < numCol - 1) printSpaces(gap); } else { doPrint(row[i]); if (i < numCol - 1) printSpaces(curLength[i] - row[i].length() + gap); } } doPrintln(""); } /** * Prints the multi-column table, with a carriage return. */ public void println() { print(); doPrintln(""); } private void printSpaces(int count) { for (int i = 0; i < count; ++i) { doPrint(" "); } } private void printBorder() { int colNum = 1; if (border == null) return; // For the value in each column for (int i = 0; i < numCol; i++) { for (int j = 0; j < curLength[i]; j++) { doPrint(border); } } // For the gap between each column for (int i = 0; i < numCol - 1; i++) { for (int j = 0; j < gap; j++) { doPrint(border); } } doPrintln(""); } /* * Sets the criteria for the key. * new int[] {0, 1} means use the first and the second * elements of the array. */ public void setKeyCriteria(int[] criteria) { this.keyCriteria = criteria; } /** * Method that does the actual printing. Override this method to * print to your destination of choice (stdout, stream, etc). * * @param str String to print. */ public abstract void doPrint(String str); /** * Method that does the actual printing. Override this method to * print to your destination of choice (stdout, stream, etc). * * This method also prints a newline at the end of the string. * * @param str String to print. */ public abstract void doPrintln(String str); }