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view libs/commons-math-2.1/docs/apidocs/src-html/org/apache/commons/math/util/CompositeFormat.html @ 13:cbf34dd4d7e6
commons-math-2.1 added
| author | dwinter |
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| date | Tue, 04 Jan 2011 10:02:07 +0100 |
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<HTML> <BODY BGCOLOR="white"> <PRE> <FONT color="green">001</FONT> /*<a name="line.1"></a> <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a> <FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a> <FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a> <FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a> <FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a> <FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a> <FONT color="green">008</FONT> *<a name="line.8"></a> <FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a> <FONT color="green">010</FONT> *<a name="line.10"></a> <FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a> <FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a> <FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a> <FONT color="green">014</FONT> * See the License for the specific language governing permissions and<a name="line.14"></a> <FONT color="green">015</FONT> * limitations under the License.<a name="line.15"></a> <FONT color="green">016</FONT> */<a name="line.16"></a> <FONT color="green">017</FONT> package org.apache.commons.math.util;<a name="line.17"></a> <FONT color="green">018</FONT> <a name="line.18"></a> <FONT color="green">019</FONT> import java.text.FieldPosition;<a name="line.19"></a> <FONT color="green">020</FONT> import java.text.Format;<a name="line.20"></a> <FONT color="green">021</FONT> import java.text.NumberFormat;<a name="line.21"></a> <FONT color="green">022</FONT> import java.text.ParsePosition;<a name="line.22"></a> <FONT color="green">023</FONT> import java.util.Locale;<a name="line.23"></a> <FONT color="green">024</FONT> <a name="line.24"></a> <FONT color="green">025</FONT> /**<a name="line.25"></a> <FONT color="green">026</FONT> * Base class for formatters of composite objects (complex numbers, vectors ...).<a name="line.26"></a> <FONT color="green">027</FONT> *<a name="line.27"></a> <FONT color="green">028</FONT> * @version $Revision: 811783 $ $Date: 2009-09-06 04:56:58 -0400 (Sun, 06 Sep 2009) $<a name="line.28"></a> <FONT color="green">029</FONT> */<a name="line.29"></a> <FONT color="green">030</FONT> public abstract class CompositeFormat extends Format {<a name="line.30"></a> <FONT color="green">031</FONT> <a name="line.31"></a> <FONT color="green">032</FONT> /** Serializable version identifier. */<a name="line.32"></a> <FONT color="green">033</FONT> private static final long serialVersionUID = 5358685519349262494L;<a name="line.33"></a> <FONT color="green">034</FONT> <a name="line.34"></a> <FONT color="green">035</FONT> /**<a name="line.35"></a> <FONT color="green">036</FONT> * Create a default number format. The default number format is based on<a name="line.36"></a> <FONT color="green">037</FONT> * {@link NumberFormat#getInstance()} with the only customizing that the<a name="line.37"></a> <FONT color="green">038</FONT> * maximum number of fraction digits is set to 2.<a name="line.38"></a> <FONT color="green">039</FONT> * @return the default number format.<a name="line.39"></a> <FONT color="green">040</FONT> */<a name="line.40"></a> <FONT color="green">041</FONT> protected static NumberFormat getDefaultNumberFormat() {<a name="line.41"></a> <FONT color="green">042</FONT> return getDefaultNumberFormat(Locale.getDefault());<a name="line.42"></a> <FONT color="green">043</FONT> }<a name="line.43"></a> <FONT color="green">044</FONT> <a name="line.44"></a> <FONT color="green">045</FONT> /**<a name="line.45"></a> <FONT color="green">046</FONT> * Create a default number format. The default number format is based on<a name="line.46"></a> <FONT color="green">047</FONT> * {@link NumberFormat#getInstance(java.util.Locale)} with the only<a name="line.47"></a> <FONT color="green">048</FONT> * customizing that the maximum number of fraction digits is set to 2.<a name="line.48"></a> <FONT color="green">049</FONT> * @param locale the specific locale used by the format.<a name="line.49"></a> <FONT color="green">050</FONT> * @return the default number format specific to the given locale.<a name="line.50"></a> <FONT color="green">051</FONT> */<a name="line.51"></a> <FONT color="green">052</FONT> protected static NumberFormat getDefaultNumberFormat(final Locale locale) {<a name="line.52"></a> <FONT color="green">053</FONT> final NumberFormat nf = NumberFormat.getInstance(locale);<a name="line.53"></a> <FONT color="green">054</FONT> nf.setMaximumFractionDigits(2);<a name="line.54"></a> <FONT color="green">055</FONT> return nf;<a name="line.55"></a> <FONT color="green">056</FONT> }<a name="line.56"></a> <FONT color="green">057</FONT> <a name="line.57"></a> <FONT color="green">058</FONT> /**<a name="line.58"></a> <FONT color="green">059</FONT> * Parses <code>source</code> until a non-whitespace character is found.<a name="line.59"></a> <FONT color="green">060</FONT> *<a name="line.60"></a> <FONT color="green">061</FONT> * @param source the string to parse<a name="line.61"></a> <FONT color="green">062</FONT> * @param pos input/ouput parsing parameter. On output, <code>pos</code><a name="line.62"></a> <FONT color="green">063</FONT> * holds the index of the next non-whitespace character.<a name="line.63"></a> <FONT color="green">064</FONT> */<a name="line.64"></a> <FONT color="green">065</FONT> protected void parseAndIgnoreWhitespace(final String source,<a name="line.65"></a> <FONT color="green">066</FONT> final ParsePosition pos) {<a name="line.66"></a> <FONT color="green">067</FONT> parseNextCharacter(source, pos);<a name="line.67"></a> <FONT color="green">068</FONT> pos.setIndex(pos.getIndex() - 1);<a name="line.68"></a> <FONT color="green">069</FONT> }<a name="line.69"></a> <FONT color="green">070</FONT> <a name="line.70"></a> <FONT color="green">071</FONT> /**<a name="line.71"></a> <FONT color="green">072</FONT> * Parses <code>source</code> until a non-whitespace character is found.<a name="line.72"></a> <FONT color="green">073</FONT> *<a name="line.73"></a> <FONT color="green">074</FONT> * @param source the string to parse<a name="line.74"></a> <FONT color="green">075</FONT> * @param pos input/ouput parsing parameter.<a name="line.75"></a> <FONT color="green">076</FONT> * @return the first non-whitespace character.<a name="line.76"></a> <FONT color="green">077</FONT> */<a name="line.77"></a> <FONT color="green">078</FONT> protected char parseNextCharacter(final String source,<a name="line.78"></a> <FONT color="green">079</FONT> final ParsePosition pos) {<a name="line.79"></a> <FONT color="green">080</FONT> int index = pos.getIndex();<a name="line.80"></a> <FONT color="green">081</FONT> final int n = source.length();<a name="line.81"></a> <FONT color="green">082</FONT> char ret = 0;<a name="line.82"></a> <FONT color="green">083</FONT> <a name="line.83"></a> <FONT color="green">084</FONT> if (index < n) {<a name="line.84"></a> <FONT color="green">085</FONT> char c;<a name="line.85"></a> <FONT color="green">086</FONT> do {<a name="line.86"></a> <FONT color="green">087</FONT> c = source.charAt(index++);<a name="line.87"></a> <FONT color="green">088</FONT> } while (Character.isWhitespace(c) && index < n);<a name="line.88"></a> <FONT color="green">089</FONT> pos.setIndex(index);<a name="line.89"></a> <FONT color="green">090</FONT> <a name="line.90"></a> <FONT color="green">091</FONT> if (index < n) {<a name="line.91"></a> <FONT color="green">092</FONT> ret = c;<a name="line.92"></a> <FONT color="green">093</FONT> }<a name="line.93"></a> <FONT color="green">094</FONT> }<a name="line.94"></a> <FONT color="green">095</FONT> <a name="line.95"></a> <FONT color="green">096</FONT> return ret;<a name="line.96"></a> <FONT color="green">097</FONT> }<a name="line.97"></a> <FONT color="green">098</FONT> <a name="line.98"></a> <FONT color="green">099</FONT> /**<a name="line.99"></a> <FONT color="green">100</FONT> * Parses <code>source</code> for special double values. These values<a name="line.100"></a> <FONT color="green">101</FONT> * include Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY.<a name="line.101"></a> <FONT color="green">102</FONT> *<a name="line.102"></a> <FONT color="green">103</FONT> * @param source the string to parse<a name="line.103"></a> <FONT color="green">104</FONT> * @param value the special value to parse.<a name="line.104"></a> <FONT color="green">105</FONT> * @param pos input/ouput parsing parameter.<a name="line.105"></a> <FONT color="green">106</FONT> * @return the special number.<a name="line.106"></a> <FONT color="green">107</FONT> */<a name="line.107"></a> <FONT color="green">108</FONT> private Number parseNumber(final String source, final double value,<a name="line.108"></a> <FONT color="green">109</FONT> final ParsePosition pos) {<a name="line.109"></a> <FONT color="green">110</FONT> Number ret = null;<a name="line.110"></a> <FONT color="green">111</FONT> <a name="line.111"></a> <FONT color="green">112</FONT> StringBuffer sb = new StringBuffer();<a name="line.112"></a> <FONT color="green">113</FONT> sb.append('(');<a name="line.113"></a> <FONT color="green">114</FONT> sb.append(value);<a name="line.114"></a> <FONT color="green">115</FONT> sb.append(')');<a name="line.115"></a> <FONT color="green">116</FONT> <a name="line.116"></a> <FONT color="green">117</FONT> final int n = sb.length();<a name="line.117"></a> <FONT color="green">118</FONT> final int startIndex = pos.getIndex();<a name="line.118"></a> <FONT color="green">119</FONT> final int endIndex = startIndex + n;<a name="line.119"></a> <FONT color="green">120</FONT> if (endIndex < source.length()) {<a name="line.120"></a> <FONT color="green">121</FONT> if (source.substring(startIndex, endIndex).compareTo(sb.toString()) == 0) {<a name="line.121"></a> <FONT color="green">122</FONT> ret = Double.valueOf(value);<a name="line.122"></a> <FONT color="green">123</FONT> pos.setIndex(endIndex);<a name="line.123"></a> <FONT color="green">124</FONT> }<a name="line.124"></a> <FONT color="green">125</FONT> }<a name="line.125"></a> <FONT color="green">126</FONT> <a name="line.126"></a> <FONT color="green">127</FONT> return ret;<a name="line.127"></a> <FONT color="green">128</FONT> }<a name="line.128"></a> <FONT color="green">129</FONT> <a name="line.129"></a> <FONT color="green">130</FONT> /**<a name="line.130"></a> <FONT color="green">131</FONT> * Parses <code>source</code> for a number. This method can parse normal,<a name="line.131"></a> <FONT color="green">132</FONT> * numeric values as well as special values. These special values include<a name="line.132"></a> <FONT color="green">133</FONT> * Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY.<a name="line.133"></a> <FONT color="green">134</FONT> *<a name="line.134"></a> <FONT color="green">135</FONT> * @param source the string to parse<a name="line.135"></a> <FONT color="green">136</FONT> * @param format the number format used to parse normal, numeric values.<a name="line.136"></a> <FONT color="green">137</FONT> * @param pos input/ouput parsing parameter.<a name="line.137"></a> <FONT color="green">138</FONT> * @return the parsed number.<a name="line.138"></a> <FONT color="green">139</FONT> */<a name="line.139"></a> <FONT color="green">140</FONT> protected Number parseNumber(final String source, final NumberFormat format,<a name="line.140"></a> <FONT color="green">141</FONT> final ParsePosition pos) {<a name="line.141"></a> <FONT color="green">142</FONT> final int startIndex = pos.getIndex();<a name="line.142"></a> <FONT color="green">143</FONT> Number number = format.parse(source, pos);<a name="line.143"></a> <FONT color="green">144</FONT> final int endIndex = pos.getIndex();<a name="line.144"></a> <FONT color="green">145</FONT> <a name="line.145"></a> <FONT color="green">146</FONT> // check for error parsing number<a name="line.146"></a> <FONT color="green">147</FONT> if (startIndex == endIndex) {<a name="line.147"></a> <FONT color="green">148</FONT> // try parsing special numbers<a name="line.148"></a> <FONT color="green">149</FONT> final double[] special = {<a name="line.149"></a> <FONT color="green">150</FONT> Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY<a name="line.150"></a> <FONT color="green">151</FONT> };<a name="line.151"></a> <FONT color="green">152</FONT> for (int i = 0; i < special.length; ++i) {<a name="line.152"></a> <FONT color="green">153</FONT> number = parseNumber(source, special[i], pos);<a name="line.153"></a> <FONT color="green">154</FONT> if (number != null) {<a name="line.154"></a> <FONT color="green">155</FONT> break;<a name="line.155"></a> <FONT color="green">156</FONT> }<a name="line.156"></a> <FONT color="green">157</FONT> }<a name="line.157"></a> <FONT color="green">158</FONT> }<a name="line.158"></a> <FONT color="green">159</FONT> <a name="line.159"></a> <FONT color="green">160</FONT> return number;<a name="line.160"></a> <FONT color="green">161</FONT> }<a name="line.161"></a> <FONT color="green">162</FONT> <a name="line.162"></a> <FONT color="green">163</FONT> /**<a name="line.163"></a> <FONT color="green">164</FONT> * Parse <code>source</code> for an expected fixed string.<a name="line.164"></a> <FONT color="green">165</FONT> * @param source the string to parse<a name="line.165"></a> <FONT color="green">166</FONT> * @param expected expected string<a name="line.166"></a> <FONT color="green">167</FONT> * @param pos input/ouput parsing parameter.<a name="line.167"></a> <FONT color="green">168</FONT> * @return true if the expected string was there<a name="line.168"></a> <FONT color="green">169</FONT> */<a name="line.169"></a> <FONT color="green">170</FONT> protected boolean parseFixedstring(final String source, final String expected,<a name="line.170"></a> <FONT color="green">171</FONT> final ParsePosition pos) {<a name="line.171"></a> <FONT color="green">172</FONT> <a name="line.172"></a> <FONT color="green">173</FONT> final int startIndex = pos.getIndex();<a name="line.173"></a> <FONT color="green">174</FONT> final int endIndex = startIndex + expected.length();<a name="line.174"></a> <FONT color="green">175</FONT> if ((startIndex >= source.length()) ||<a name="line.175"></a> <FONT color="green">176</FONT> (endIndex > source.length()) ||<a name="line.176"></a> <FONT color="green">177</FONT> (source.substring(startIndex, endIndex).compareTo(expected) != 0)) {<a name="line.177"></a> <FONT color="green">178</FONT> // set index back to start, error index should be the start index<a name="line.178"></a> <FONT color="green">179</FONT> pos.setIndex(startIndex);<a name="line.179"></a> <FONT color="green">180</FONT> pos.setErrorIndex(startIndex);<a name="line.180"></a> <FONT color="green">181</FONT> return false;<a name="line.181"></a> <FONT color="green">182</FONT> }<a name="line.182"></a> <FONT color="green">183</FONT> <a name="line.183"></a> <FONT color="green">184</FONT> // the string was here<a name="line.184"></a> <FONT color="green">185</FONT> pos.setIndex(endIndex);<a name="line.185"></a> <FONT color="green">186</FONT> return true;<a name="line.186"></a> <FONT color="green">187</FONT> <a name="line.187"></a> <FONT color="green">188</FONT> }<a name="line.188"></a> <FONT color="green">189</FONT> <a name="line.189"></a> <FONT color="green">190</FONT> /**<a name="line.190"></a> <FONT color="green">191</FONT> * Formats a double value to produce a string. In general, the value is<a name="line.191"></a> <FONT color="green">192</FONT> * formatted using the formatting rules of <code>format</code>. There are<a name="line.192"></a> <FONT color="green">193</FONT> * three exceptions to this:<a name="line.193"></a> <FONT color="green">194</FONT> * <ol><a name="line.194"></a> <FONT color="green">195</FONT> * <li>NaN is formatted as '(NaN)'</li><a name="line.195"></a> <FONT color="green">196</FONT> * <li>Positive infinity is formatted as '(Infinity)'</li><a name="line.196"></a> <FONT color="green">197</FONT> * <li>Negative infinity is formatted as '(-Infinity)'</li><a name="line.197"></a> <FONT color="green">198</FONT> * </ol><a name="line.198"></a> <FONT color="green">199</FONT> *<a name="line.199"></a> <FONT color="green">200</FONT> * @param value the double to format.<a name="line.200"></a> <FONT color="green">201</FONT> * @param format the format used.<a name="line.201"></a> <FONT color="green">202</FONT> * @param toAppendTo where the text is to be appended<a name="line.202"></a> <FONT color="green">203</FONT> * @param pos On input: an alignment field, if desired. On output: the<a name="line.203"></a> <FONT color="green">204</FONT> * offsets of the alignment field<a name="line.204"></a> <FONT color="green">205</FONT> * @return the value passed in as toAppendTo.<a name="line.205"></a> <FONT color="green">206</FONT> */<a name="line.206"></a> <FONT color="green">207</FONT> protected StringBuffer formatDouble(final double value, final NumberFormat format,<a name="line.207"></a> <FONT color="green">208</FONT> final StringBuffer toAppendTo,<a name="line.208"></a> <FONT color="green">209</FONT> final FieldPosition pos) {<a name="line.209"></a> <FONT color="green">210</FONT> if( Double.isNaN(value) || Double.isInfinite(value) ) {<a name="line.210"></a> <FONT color="green">211</FONT> toAppendTo.append('(');<a name="line.211"></a> <FONT color="green">212</FONT> toAppendTo.append(value);<a name="line.212"></a> <FONT color="green">213</FONT> toAppendTo.append(')');<a name="line.213"></a> <FONT color="green">214</FONT> } else {<a name="line.214"></a> <FONT color="green">215</FONT> format.format(value, toAppendTo, pos);<a name="line.215"></a> <FONT color="green">216</FONT> }<a name="line.216"></a> <FONT color="green">217</FONT> return toAppendTo;<a name="line.217"></a> <FONT color="green">218</FONT> }<a name="line.218"></a> <FONT color="green">219</FONT> <a name="line.219"></a> <FONT color="green">220</FONT> }<a name="line.220"></a> </PRE> </BODY> </HTML>