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<FONT color="green">001</FONT>    /**<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<FONT color="green">003</FONT>     * or more contributor license agreements.  See the NOTICE file<a name="line.3"></a>
<FONT color="green">004</FONT>     * distributed with this work for additional information<a name="line.4"></a>
<FONT color="green">005</FONT>     * regarding copyright ownership.  The ASF licenses this file<a name="line.5"></a>
<FONT color="green">006</FONT>     * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<FONT color="green">007</FONT>     * "License"); you may not use this file except in compliance<a name="line.7"></a>
<FONT color="green">008</FONT>     * with the License.  You may obtain a copy of the License at<a name="line.8"></a>
<FONT color="green">009</FONT>     *<a name="line.9"></a>
<FONT color="green">010</FONT>     *     http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<FONT color="green">011</FONT>     *<a name="line.11"></a>
<FONT color="green">012</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<FONT color="green">013</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<FONT color="green">014</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<FONT color="green">015</FONT>     * See the License for the specific language governing permissions and<a name="line.15"></a>
<FONT color="green">016</FONT>     * limitations under the License.<a name="line.16"></a>
<FONT color="green">017</FONT>     */<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    package org.apache.hadoop.lib.lang;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    import org.apache.hadoop.lib.util.Check;<a name="line.21"></a>
<FONT color="green">022</FONT>    <a name="line.22"></a>
<FONT color="green">023</FONT>    import java.text.MessageFormat;<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>     * Generic exception that requires error codes and uses the a message<a name="line.26"></a>
<FONT color="green">027</FONT>     * template from the error code.<a name="line.27"></a>
<FONT color="green">028</FONT>     */<a name="line.28"></a>
<FONT color="green">029</FONT>    public class XException extends Exception {<a name="line.29"></a>
<FONT color="green">030</FONT>    <a name="line.30"></a>
<FONT color="green">031</FONT>      /**<a name="line.31"></a>
<FONT color="green">032</FONT>       * Interface to define error codes.<a name="line.32"></a>
<FONT color="green">033</FONT>       */<a name="line.33"></a>
<FONT color="green">034</FONT>      public static interface ERROR {<a name="line.34"></a>
<FONT color="green">035</FONT>    <a name="line.35"></a>
<FONT color="green">036</FONT>        /**<a name="line.36"></a>
<FONT color="green">037</FONT>         * Returns the template for the error.<a name="line.37"></a>
<FONT color="green">038</FONT>         *<a name="line.38"></a>
<FONT color="green">039</FONT>         * @return the template for the error, the template must be in JDK<a name="line.39"></a>
<FONT color="green">040</FONT>         *         &lt;code&gt;MessageFormat&lt;/code&gt; syntax (using {#} positional parameters).<a name="line.40"></a>
<FONT color="green">041</FONT>         */<a name="line.41"></a>
<FONT color="green">042</FONT>        public String getTemplate();<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>      private ERROR error;<a name="line.46"></a>
<FONT color="green">047</FONT>    <a name="line.47"></a>
<FONT color="green">048</FONT>      /**<a name="line.48"></a>
<FONT color="green">049</FONT>       * Private constructor used by the public constructors.<a name="line.49"></a>
<FONT color="green">050</FONT>       *<a name="line.50"></a>
<FONT color="green">051</FONT>       * @param error error code.<a name="line.51"></a>
<FONT color="green">052</FONT>       * @param message error message.<a name="line.52"></a>
<FONT color="green">053</FONT>       * @param cause exception cause if any.<a name="line.53"></a>
<FONT color="green">054</FONT>       */<a name="line.54"></a>
<FONT color="green">055</FONT>      private XException(ERROR error, String message, Throwable cause) {<a name="line.55"></a>
<FONT color="green">056</FONT>        super(message, cause);<a name="line.56"></a>
<FONT color="green">057</FONT>        this.error = error;<a name="line.57"></a>
<FONT color="green">058</FONT>      }<a name="line.58"></a>
<FONT color="green">059</FONT>    <a name="line.59"></a>
<FONT color="green">060</FONT>      /**<a name="line.60"></a>
<FONT color="green">061</FONT>       * Creates an XException using another XException as cause.<a name="line.61"></a>
<FONT color="green">062</FONT>       * &lt;p/&gt;<a name="line.62"></a>
<FONT color="green">063</FONT>       * The error code and error message are extracted from the cause.<a name="line.63"></a>
<FONT color="green">064</FONT>       *<a name="line.64"></a>
<FONT color="green">065</FONT>       * @param cause exception cause.<a name="line.65"></a>
<FONT color="green">066</FONT>       */<a name="line.66"></a>
<FONT color="green">067</FONT>      public XException(XException cause) {<a name="line.67"></a>
<FONT color="green">068</FONT>        this(cause.getError(), cause.getMessage(), cause);<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>       * Creates an XException using the specified error code. The exception<a name="line.72"></a>
<FONT color="green">073</FONT>       * message is resolved using the error code template and the passed<a name="line.73"></a>
<FONT color="green">074</FONT>       * parameters.<a name="line.74"></a>
<FONT color="green">075</FONT>       *<a name="line.75"></a>
<FONT color="green">076</FONT>       * @param error error code for the XException.<a name="line.76"></a>
<FONT color="green">077</FONT>       * @param params parameters to use when creating the error message<a name="line.77"></a>
<FONT color="green">078</FONT>       * with the error code template.<a name="line.78"></a>
<FONT color="green">079</FONT>       */<a name="line.79"></a>
<FONT color="green">080</FONT>      @SuppressWarnings({"ThrowableResultOfMethodCallIgnored"})<a name="line.80"></a>
<FONT color="green">081</FONT>      public XException(ERROR error, Object... params) {<a name="line.81"></a>
<FONT color="green">082</FONT>        this(Check.notNull(error, "error"), format(error, params), getCause(params));<a name="line.82"></a>
<FONT color="green">083</FONT>      }<a name="line.83"></a>
<FONT color="green">084</FONT>    <a name="line.84"></a>
<FONT color="green">085</FONT>      /**<a name="line.85"></a>
<FONT color="green">086</FONT>       * Returns the error code of the exception.<a name="line.86"></a>
<FONT color="green">087</FONT>       *<a name="line.87"></a>
<FONT color="green">088</FONT>       * @return the error code of the exception.<a name="line.88"></a>
<FONT color="green">089</FONT>       */<a name="line.89"></a>
<FONT color="green">090</FONT>      public ERROR getError() {<a name="line.90"></a>
<FONT color="green">091</FONT>        return error;<a name="line.91"></a>
<FONT color="green">092</FONT>      }<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>       * Creates a message using a error message template and arguments.<a name="line.95"></a>
<FONT color="green">096</FONT>       * &lt;p/&gt;<a name="line.96"></a>
<FONT color="green">097</FONT>       * The template must be in JDK &lt;code&gt;MessageFormat&lt;/code&gt; syntax<a name="line.97"></a>
<FONT color="green">098</FONT>       * (using {#} positional parameters).<a name="line.98"></a>
<FONT color="green">099</FONT>       *<a name="line.99"></a>
<FONT color="green">100</FONT>       * @param error error code, to get the template from.<a name="line.100"></a>
<FONT color="green">101</FONT>       * @param args arguments to use for creating the message.<a name="line.101"></a>
<FONT color="green">102</FONT>       *<a name="line.102"></a>
<FONT color="green">103</FONT>       * @return the resolved error message.<a name="line.103"></a>
<FONT color="green">104</FONT>       */<a name="line.104"></a>
<FONT color="green">105</FONT>      private static String format(ERROR error, Object... args) {<a name="line.105"></a>
<FONT color="green">106</FONT>        String template = error.getTemplate();<a name="line.106"></a>
<FONT color="green">107</FONT>        if (template == null) {<a name="line.107"></a>
<FONT color="green">108</FONT>          StringBuilder sb = new StringBuilder();<a name="line.108"></a>
<FONT color="green">109</FONT>          for (int i = 0; i &lt; args.length; i++) {<a name="line.109"></a>
<FONT color="green">110</FONT>            sb.append(" {").append(i).append("}");<a name="line.110"></a>
<FONT color="green">111</FONT>          }<a name="line.111"></a>
<FONT color="green">112</FONT>          template = sb.deleteCharAt(0).toString();<a name="line.112"></a>
<FONT color="green">113</FONT>        }<a name="line.113"></a>
<FONT color="green">114</FONT>        return error + ": " + MessageFormat.format(template, args);<a name="line.114"></a>
<FONT color="green">115</FONT>      }<a name="line.115"></a>
<FONT color="green">116</FONT>    <a name="line.116"></a>
<FONT color="green">117</FONT>      /**<a name="line.117"></a>
<FONT color="green">118</FONT>       * Returns the last parameter if it is an instance of &lt;code&gt;Throwable&lt;/code&gt;<a name="line.118"></a>
<FONT color="green">119</FONT>       * returns it else it returns NULL.<a name="line.119"></a>
<FONT color="green">120</FONT>       *<a name="line.120"></a>
<FONT color="green">121</FONT>       * @param params parameters to look for a cause.<a name="line.121"></a>
<FONT color="green">122</FONT>       *<a name="line.122"></a>
<FONT color="green">123</FONT>       * @return the last parameter if it is an instance of &lt;code&gt;Throwable&lt;/code&gt;<a name="line.123"></a>
<FONT color="green">124</FONT>       *         returns it else it returns NULL.<a name="line.124"></a>
<FONT color="green">125</FONT>       */<a name="line.125"></a>
<FONT color="green">126</FONT>      private static Throwable getCause(Object... params) {<a name="line.126"></a>
<FONT color="green">127</FONT>        Throwable throwable = null;<a name="line.127"></a>
<FONT color="green">128</FONT>        if (params != null &amp;&amp; params.length &gt; 0 &amp;&amp; params[params.length - 1] instanceof Throwable) {<a name="line.128"></a>
<FONT color="green">129</FONT>          throwable = (Throwable) params[params.length - 1];<a name="line.129"></a>
<FONT color="green">130</FONT>        }<a name="line.130"></a>
<FONT color="green">131</FONT>        return throwable;<a name="line.131"></a>
<FONT color="green">132</FONT>      }<a name="line.132"></a>
<FONT color="green">133</FONT>    <a name="line.133"></a>
<FONT color="green">134</FONT>    }<a name="line.134"></a>




























































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