📄 jdbccategorydataset.html
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<HTML><BODY BGCOLOR="white"><PRE><FONT color="green">001</FONT> /* ===========================================================<a name="line.1"></a><FONT color="green">002</FONT> * JFreeChart : a free chart library for the Java(tm) platform<a name="line.2"></a><FONT color="green">003</FONT> * ===========================================================<a name="line.3"></a><FONT color="green">004</FONT> *<a name="line.4"></a><FONT color="green">005</FONT> * (C) Copyright 2000-2006, by Object Refinery Limited and Contributors.<a name="line.5"></a><FONT color="green">006</FONT> *<a name="line.6"></a><FONT color="green">007</FONT> * Project Info: http://www.jfree.org/jfreechart/index.html<a name="line.7"></a><FONT color="green">008</FONT> *<a name="line.8"></a><FONT color="green">009</FONT> * This library is free software; you can redistribute it and/or modify it <a name="line.9"></a><FONT color="green">010</FONT> * under the terms of the GNU Lesser General Public License as published by <a name="line.10"></a><FONT color="green">011</FONT> * the Free Software Foundation; either version 2.1 of the License, or <a name="line.11"></a><FONT color="green">012</FONT> * (at your option) any later version.<a name="line.12"></a><FONT color="green">013</FONT> *<a name="line.13"></a><FONT color="green">014</FONT> * This library is distributed in the hope that it will be useful, but <a name="line.14"></a><FONT color="green">015</FONT> * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY <a name="line.15"></a><FONT color="green">016</FONT> * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public <a name="line.16"></a><FONT color="green">017</FONT> * License for more details.<a name="line.17"></a><FONT color="green">018</FONT> *<a name="line.18"></a><FONT color="green">019</FONT> * You should have received a copy of the GNU Lesser General Public<a name="line.19"></a><FONT color="green">020</FONT> * License along with this library; if not, write to the Free Software<a name="line.20"></a><FONT color="green">021</FONT> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, <a name="line.21"></a><FONT color="green">022</FONT> * USA. <a name="line.22"></a><FONT color="green">023</FONT> *<a name="line.23"></a><FONT color="green">024</FONT> * [Java is a trademark or registered trademark of Sun Microsystems, Inc. <a name="line.24"></a><FONT color="green">025</FONT> * in the United States and other countries.]<a name="line.25"></a><FONT color="green">026</FONT> *<a name="line.26"></a><FONT color="green">027</FONT> * ------------------------<a name="line.27"></a><FONT color="green">028</FONT> * JDBCCategoryDataset.java<a name="line.28"></a><FONT color="green">029</FONT> * ------------------------<a name="line.29"></a><FONT color="green">030</FONT> * (C) Copyright 2002-2006, by Bryan Scott and Contributors.<a name="line.30"></a><FONT color="green">031</FONT> *<a name="line.31"></a><FONT color="green">032</FONT> * Original Author: Bryan Scott; Andy;<a name="line.32"></a><FONT color="green">033</FONT> * Contributor(s): David Gilbert (for Object Refinery Limited);<a name="line.33"></a><FONT color="green">034</FONT> * Thomas Morgner;<a name="line.34"></a><FONT color="green">035</FONT> *<a name="line.35"></a><FONT color="green">036</FONT> * Changes<a name="line.36"></a><FONT color="green">037</FONT> * -------<a name="line.37"></a><FONT color="green">038</FONT> * 26-Apr-2002 : Creation based on JdbcXYDataSet, using code contributed from <a name="line.38"></a><FONT color="green">039</FONT> * Andy;<a name="line.39"></a><FONT color="green">040</FONT> * 13-Aug-2002 : Updated Javadocs, import statements and formatting (DG);<a name="line.40"></a><FONT color="green">041</FONT> * 03-Sep-2002 : Added fix for bug 591385 (DG);<a name="line.41"></a><FONT color="green">042</FONT> * 18-Sep-2002 : Updated to support BIGINT (BS);<a name="line.42"></a><FONT color="green">043</FONT> * 16-Oct-2002 : Added fix for bug 586667 (DG);<a name="line.43"></a><FONT color="green">044</FONT> * 03-Feb-2003 : Added Types.DECIMAL (see bug report 677814) (DG);<a name="line.44"></a><FONT color="green">045</FONT> * 13-Jun-2003 : Added Types.TIME as suggest by Bryan Scott in the forum (DG);<a name="line.45"></a><FONT color="green">046</FONT> * 30-Jun-2003 : CVS Write test (BS);<a name="line.46"></a><FONT color="green">047</FONT> * 30-Jul-2003 : Added empty contructor and executeQuery(connection,string) <a name="line.47"></a><FONT color="green">048</FONT> * method (BS);<a name="line.48"></a><FONT color="green">049</FONT> * 29-Aug-2003 : Added a 'transpose' flag, so that data can be easily <a name="line.49"></a><FONT color="green">050</FONT> * transposed if required (DG);<a name="line.50"></a><FONT color="green">051</FONT> * 10-Sep-2003 : Added support for additional JDBC types (DG);<a name="line.51"></a><FONT color="green">052</FONT> * 24-Sep-2003 : Added clearing results from previous queries to executeQuery<a name="line.52"></a><FONT color="green">053</FONT> * following being highlighted on online forum (BS);<a name="line.53"></a><FONT color="green">054</FONT> * 02-Dec-2003 : Throwing exceptions allows to handle errors, removed default <a name="line.54"></a><FONT color="green">055</FONT> * constructor, as without a connection, a query can never be <a name="line.55"></a><FONT color="green">056</FONT> * executed (TM);<a name="line.56"></a><FONT color="green">057</FONT> * 04-Dec-2003 : Added missing Javadocs (DG);<a name="line.57"></a><FONT color="green">058</FONT> * ------------- JFREECHART 1.0.0 ---------------------------------------------<a name="line.58"></a><FONT color="green">059</FONT> * 08-Mar-2006 : Fixed bug 1445748 where an exception is thrown if <a name="line.59"></a><FONT color="green">060</FONT> * executeQuery() is called more than once (DG);<a name="line.60"></a><FONT color="green">061</FONT> * <a name="line.61"></a><FONT color="green">062</FONT> */<a name="line.62"></a><FONT color="green">063</FONT> <a name="line.63"></a><FONT color="green">064</FONT> package org.jfree.data.jdbc;<a name="line.64"></a><FONT color="green">065</FONT> <a name="line.65"></a><FONT color="green">066</FONT> import java.sql.Connection;<a name="line.66"></a><FONT color="green">067</FONT> import java.sql.Date;<a name="line.67"></a><FONT color="green">068</FONT> import java.sql.DriverManager;<a name="line.68"></a><FONT color="green">069</FONT> import java.sql.ResultSet;<a name="line.69"></a><FONT color="green">070</FONT> import java.sql.ResultSetMetaData;<a name="line.70"></a><FONT color="green">071</FONT> import java.sql.SQLException;<a name="line.71"></a><FONT color="green">072</FONT> import java.sql.Statement;<a name="line.72"></a><FONT color="green">073</FONT> import java.sql.Types;<a name="line.73"></a><FONT color="green">074</FONT> <a name="line.74"></a><FONT color="green">075</FONT> import org.jfree.data.category.CategoryDataset;<a name="line.75"></a><FONT color="green">076</FONT> import org.jfree.data.category.DefaultCategoryDataset;<a name="line.76"></a><FONT color="green">077</FONT> <a name="line.77"></a><FONT color="green">078</FONT> /**<a name="line.78"></a><FONT color="green">079</FONT> * A {@link CategoryDataset} implementation over a database JDBC result set.<a name="line.79"></a><FONT color="green">080</FONT> * The dataset is populated via a call to {@link #executeQuery(String)} with <a name="line.80"></a><FONT color="green">081</FONT> * the string SQL query. The SQL query must return at least two columns. The <a name="line.81"></a><FONT color="green">082</FONT> * first column will be the category name and remaining columns values (each<a name="line.82"></a><FONT color="green">083</FONT> * column represents a series). Subsequent calls to <a name="line.83"></a><FONT color="green">084</FONT> * {@link #executeQuery(String)} will refresh the dataset.<a name="line.84"></a><FONT color="green">085</FONT> * <p><a name="line.85"></a><FONT color="green">086</FONT> * The database connection is read-only and no write back facility exists.<a name="line.86"></a><FONT color="green">087</FONT> * <p><a name="line.87"></a><FONT color="green">088</FONT> * NOTE: Many people have found this class too restrictive in general use. <a name="line.88"></a><FONT color="green">089</FONT> * For the greatest flexibility, please consider writing your own code to read <a name="line.89"></a><FONT color="green">090</FONT> * data from a <code>ResultSet</code> and populate a <a name="line.90"></a><FONT color="green">091</FONT> * {@link DefaultCategoryDataset} directly.<a name="line.91"></a><FONT color="green">092</FONT> */<a name="line.92"></a><FONT color="green">093</FONT> public class JDBCCategoryDataset extends DefaultCategoryDataset {<a name="line.93"></a><FONT color="green">094</FONT> <a name="line.94"></a><FONT color="green">095</FONT> /** The database connection. */<a name="line.95"></a><FONT color="green">096</FONT> private transient Connection connection;<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 flag the controls whether or not the table is transposed. The default <a name="line.99"></a><FONT color="green">100</FONT> * is 'true' because this provides the behaviour described in the <a name="line.100"></a><FONT color="green">101</FONT> * documentation.<a name="line.101"></a><FONT color="green">102</FONT> */<a name="line.102"></a><FONT color="green">103</FONT> private boolean transpose = true;<a name="line.103"></a><FONT color="green">104</FONT> <a name="line.104"></a><FONT color="green">105</FONT> <a name="line.105"></a><FONT color="green">106</FONT> /**<a name="line.106"></a><FONT color="green">107</FONT> * Creates a new dataset with a database connection.<a name="line.107"></a><FONT color="green">108</FONT> *<a name="line.108"></a><FONT color="green">109</FONT> * @param url the URL of the database connection.<a name="line.109"></a><FONT color="green">110</FONT> * @param driverName the database driver class name.<a name="line.110"></a><FONT color="green">111</FONT> * @param user the database user.<a name="line.111"></a><FONT color="green">112</FONT> * @param passwd the database user's password.<a name="line.112"></a><FONT color="green">113</FONT> * <a name="line.113"></a><FONT color="green">114</FONT> * @throws ClassNotFoundException if the driver cannot be found.<a name="line.114"></a><FONT color="green">115</FONT> * @throws SQLException if there is an error obtaining a connection to the <a name="line.115"></a><FONT color="green">116</FONT> * database.<a name="line.116"></a><FONT color="green">117</FONT> */<a name="line.117"></a><FONT color="green">118</FONT> public JDBCCategoryDataset(String url,<a name="line.118"></a><FONT color="green">119</FONT> String driverName,<a name="line.119"></a><FONT color="green">120</FONT> String user,<a name="line.120"></a><FONT color="green">121</FONT> String passwd)<a name="line.121"></a><FONT color="green">122</FONT> throws ClassNotFoundException, SQLException {<a name="line.122"></a><FONT color="green">123</FONT> <a name="line.123"></a><FONT color="green">124</FONT> Class.forName(driverName);<a name="line.124"></a><FONT color="green">125</FONT> this.connection = DriverManager.getConnection(url, user, passwd);<a name="line.125"></a><FONT color="green">126</FONT> }<a name="line.126"></a><FONT color="green">127</FONT> <a name="line.127"></a><FONT color="green">128</FONT> /**<a name="line.128"></a><FONT color="green">129</FONT> * Create a new dataset with the given database connection.<a name="line.129"></a><FONT color="green">130</FONT> *<a name="line.130"></a><FONT color="green">131</FONT> * @param connection the database connection.<a name="line.131"></a><FONT color="green">132</FONT> */<a name="line.132"></a><FONT color="green">133</FONT> public JDBCCategoryDataset(Connection connection) {<a name="line.133"></a><FONT color="green">134</FONT> if (connection == null) {<a name="line.134"></a><FONT color="green">135</FONT> throw new NullPointerException("A connection must be supplied.");<a name="line.135"></a><FONT color="green">136</FONT> }<a name="line.136"></a><FONT color="green">137</FONT> this.connection = connection;<a name="line.137"></a><FONT color="green">138</FONT> }<a name="line.138"></a><FONT color="green">139</FONT> <a name="line.139"></a><FONT color="green">140</FONT> /**<a name="line.140"></a><FONT color="green">141</FONT> * Creates a new dataset with the given database connection, and executes <a name="line.141"></a><FONT color="green">142</FONT> * the supplied query to populate the dataset.<a name="line.142"></a><FONT color="green">143</FONT> *<a name="line.143"></a><FONT color="green">144</FONT> * @param connection the connection.<a name="line.144"></a><FONT color="green">145</FONT> * @param query the query.<a name="line.145"></a><FONT color="green">146</FONT> * <a name="line.146"></a><FONT color="green">147</FONT> * @throws SQLException if there is a problem executing the query.<a name="line.147"></a><FONT color="green">148</FONT> */<a name="line.148"></a><FONT color="green">149</FONT> public JDBCCategoryDataset(Connection connection, String query) <a name="line.149"></a><FONT color="green">150</FONT> throws SQLException {<a name="line.150"></a><FONT color="green">151</FONT> this(connection);<a name="line.151"></a><FONT color="green">152</FONT> executeQuery(query);<a name="line.152"></a><FONT color="green">153</FONT> }<a name="line.153"></a><FONT color="green">154</FONT> <a name="line.154"></a><FONT color="green">155</FONT> /**<a name="line.155"></a><FONT color="green">156</FONT> * Returns a flag that controls whether or not the table values are <a name="line.156"></a><FONT color="green">157</FONT> * transposed when added to the dataset.<a name="line.157"></a><FONT color="green">158</FONT> *<a name="line.158"></a><FONT color="green">159</FONT> * @return A boolean.<a name="line.159"></a><FONT color="green">160</FONT> */<a name="line.160"></a><FONT color="green">161</FONT> public boolean getTranspose() {<a name="line.161"></a><FONT color="green">162</FONT> return this.transpose;<a name="line.162"></a><FONT color="green">163</FONT> }<a name="line.163"></a><FONT color="green">164</FONT> <a name="line.164"></a><FONT color="green">165</FONT> /**<a name="line.165"></a><FONT color="green">166</FONT> * Sets a flag that controls whether or not the table values are transposed<a name="line.166"></a><FONT color="green">167</FONT> * when added to the dataset.<a name="line.167"></a><FONT color="green">168</FONT> *<a name="line.168"></a><FONT color="green">169</FONT> * @param transpose the flag.<a name="line.169"></a><FONT color="green">170</FONT> */<a name="line.170"></a><FONT color="green">171</FONT> public void setTranspose(boolean transpose) {<a name="line.171"></a><FONT color="green">172</FONT> this.transpose = transpose;<a name="line.172"></a><FONT color="green">173</FONT> }<a name="line.173"></a><FONT color="green">174</FONT> <a name="line.174"></a><FONT color="green">175</FONT> /**<a name="line.175"></a><FONT color="green">176</FONT> * Populates the dataset by executing the supplied query against the <a name="line.176"></a><FONT color="green">177</FONT> * existing database connection. If no connection exists then no action <a name="line.177"></a><FONT color="green">178</FONT> * is taken.<a name="line.178"></a><FONT color="green">179</FONT> * <p><a name="line.179"></a><FONT color="green">180</FONT> * The results from the query are extracted and cached locally, thus <a name="line.180"></a><FONT color="green">181</FONT> * applying an upper limit on how many rows can be retrieved successfully.<a name="line.181"></a><FONT color="green">182</FONT> *<a name="line.182"></a><FONT color="green">183</FONT> * @param query the query.<a name="line.183"></a><FONT color="green">184</FONT> * <a name="line.184"></a><FONT color="green">185</FONT> * @throws SQLException if there is a problem executing the query.<a name="line.185"></a><FONT color="green">186</FONT> */<a name="line.186"></a><FONT color="green">187</FONT> public void executeQuery(String query) throws SQLException {<a name="line.187"></a><FONT color="green">188</FONT> executeQuery(this.connection, query);<a name="line.188"></a>⌨️ 快捷键说明
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