Java tutorial
//package com.java2s; //License from project: Apache License import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class Main { /** * The maximum length of a display line. * * @parameter expression="${lineLength}" default-value="80" */ private int lineLength; /** * The number of spaces per indentation level. * * @parameter expression="${indentSize}" default-value="2" */ private int indentSize; /** * <p>Repeat a String <code>n</code> times to form a new string.</p> * * @param str String to repeat * @param repeat number of times to repeat str * @return String with repeated String * @throws NegativeArraySizeException if <code>repeat < 0</code> * @throws NullPointerException if str is <code>null</code> */ private static String repeat(String str, int repeat) { StringBuffer buffer = new StringBuffer(repeat * str.length()); for (int i = 0; i < repeat; i++) { buffer.append(str); } return buffer.toString(); } private void append(StringBuffer sb, String description, int indent) { for (Iterator it = toLines(description, indent).iterator(); it.hasNext();) { sb.append(it.next().toString()).append('\n'); } } /** * Splits the specified text into lines of convenient display length. * * @param text The text to split into lines, must not be <code>null</code>. * @param indent The base indentation level of each line, must not be negative. * @return The sequence of display lines, never <code>null</code>. */ private List toLines(String text, int indent) { List lines = new ArrayList(); String ind = repeat("\t", indent); String[] plainLines = text.split("(\r\n)|(\r)|(\n)"); for (int i = 0; i < plainLines.length; i++) { toLines(lines, ind + plainLines[i]); } return lines; } /** * Adds the specified line to the output sequence, performing line wrapping if necessary. * * @param lines The sequence of display lines, must not be <code>null</code>. * @param line The line to add, must not be <code>null</code>. */ private void toLines(List lines, String line) { int lineIndent = getIndentLevel(line); StringBuffer buf = new StringBuffer(256); String[] tokens = line.split(" +"); for (int i = 0; i < tokens.length; i++) { String token = tokens[i]; if (i > 0) { if (buf.length() + token.length() >= lineLength) { lines.add(buf.toString()); buf.setLength(0); buf.append(repeat(" ", lineIndent * indentSize)); } else { buf.append(' '); } } for (int j = 0; j < token.length(); j++) { char c = token.charAt(j); if (c == '\t') { buf.append(repeat(" ", indentSize - buf.length() % indentSize)); } else if (c == '\u00A0') { buf.append(' '); } else { buf.append(c); } } } lines.add(buf.toString()); } /** * Gets the indentation level of the specified line. * * @param line The line whose indentation level should be retrieved, must not be <code>null</code>. * @return The indentation level of the line. */ private static int getIndentLevel(String line) { int level = 0; for (int i = 0; i < line.length() && line.charAt(i) == '\t'; i++) { level++; } for (int i = level + 1; i <= level + 4 && i < line.length(); i++) { if (line.charAt(i) == '\t') { level++; break; } } return level; } }