jdbccategorydataset.html

jfreechart1。0。2的api。

<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>        /**<a name="line.191"></a>
<FONT color="green">192</FONT>         * Populates the dataset by executing the supplied query against the <a name="line.192"></a>
<FONT color="green">193</FONT>         * existing database connection.  If no connection exists then no action <a name="line.193"></a>
<FONT color="green">194</FONT>         * is taken.<a name="line.194"></a>
<FONT color="green">195</FONT>         * &lt;p&gt;<a name="line.195"></a>
<FONT color="green">196</FONT>         * The results from the query are extracted and cached locally, thus <a name="line.196"></a>
<FONT color="green">197</FONT>         * applying an upper limit on how many rows can be retrieved successfully.<a name="line.197"></a>
<FONT color="green">198</FONT>         *<a name="line.198"></a>
<FONT color="green">199</FONT>         * @param con  the connection.<a name="line.199"></a>
<FONT color="green">200</FONT>         * @param query  the query.<a name="line.200"></a>
<FONT color="green">201</FONT>         * <a name="line.201"></a>
<FONT color="green">202</FONT>         * @throws SQLException if there is a problem executing the query.<a name="line.202"></a>
<FONT color="green">203</FONT>         */<a name="line.203"></a>
<FONT color="green">204</FONT>        public void executeQuery(Connection con, String query) throws SQLException {<a name="line.204"></a>
<FONT color="green">205</FONT>    <a name="line.205"></a>
<FONT color="green">206</FONT>            Statement statement = null;<a name="line.206"></a>
<FONT color="green">207</FONT>            ResultSet resultSet = null;<a name="line.207"></a>
<FONT color="green">208</FONT>            try {<a name="line.208"></a>
<FONT color="green">209</FONT>                statement = con.createStatement();<a name="line.209"></a>
<FONT color="green">210</FONT>                resultSet = statement.executeQuery(query);<a name="line.210"></a>
<FONT color="green">211</FONT>                ResultSetMetaData metaData = resultSet.getMetaData();<a name="line.211"></a>
<FONT color="green">212</FONT>    <a name="line.212"></a>
<FONT color="green">213</FONT>                int columnCount = metaData.getColumnCount();<a name="line.213"></a>
<FONT color="green">214</FONT>    <a name="line.214"></a>
<FONT color="green">215</FONT>                if (columnCount &lt; 2) {<a name="line.215"></a>
<FONT color="green">216</FONT>                    throw new SQLException(<a name="line.216"></a>
<FONT color="green">217</FONT>                        "JDBCCategoryDataset.executeQuery() : insufficient columns "<a name="line.217"></a>
<FONT color="green">218</FONT>                        + "returned from the database.");<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>
<FONT color="green">221</FONT>                // Remove any previous old data<a name="line.221"></a>
<FONT color="green">222</FONT>                int i = getRowCount();<a name="line.222"></a>
<FONT color="green">223</FONT>                while (--i &gt;= 0) {<a name="line.223"></a>
<FONT color="green">224</FONT>                    removeRow(i);<a name="line.224"></a>
<FONT color="green">225</FONT>                }<a name="line.225"></a>
<FONT color="green">226</FONT>    <a name="line.226"></a>
<FONT color="green">227</FONT>                while (resultSet.next()) {<a name="line.227"></a>
<FONT color="green">228</FONT>                    // first column contains the row key...<a name="line.228"></a>
<FONT color="green">229</FONT>                    Comparable rowKey = resultSet.getString(1);<a name="line.229"></a>
<FONT color="green">230</FONT>                    for (int column = 2; column &lt;= columnCount; column++) {<a name="line.230"></a>
<FONT color="green">231</FONT>    <a name="line.231"></a>
<FONT color="green">232</FONT>                        Comparable columnKey = metaData.getColumnName(column);<a name="line.232"></a>
<FONT color="green">233</FONT>                        int columnType = metaData.getColumnType(column);<a name="line.233"></a>
<FONT color="green">234</FONT>    <a name="line.234"></a>
<FONT color="green">235</FONT>                        switch (columnType) {<a name="line.235"></a>
<FONT color="green">236</FONT>                            case Types.TINYINT:<a name="line.236"></a>
<FONT color="green">237</FONT>                            case Types.SMALLINT:<a name="line.237"></a>
<FONT color="green">238</FONT>                            case Types.INTEGER:<a name="line.238"></a>
<FONT color="green">239</FONT>                            case Types.BIGINT:<a name="line.239"></a>
<FONT color="green">240</FONT>                            case Types.FLOAT:<a name="line.240"></a>
<FONT color="green">241</FONT>                            case Types.DOUBLE:<a name="line.241"></a>
<FONT color="green">242</FONT>                            case Types.DECIMAL:<a name="line.242"></a>
<FONT color="green">243</FONT>                            case Types.NUMERIC:<a name="line.243"></a>
<FONT color="green">244</FONT>                            case Types.REAL: {<a name="line.244"></a>
<FONT color="green">245</FONT>                                Number value = (Number) resultSet.getObject(column);<a name="line.245"></a>
<FONT color="green">246</FONT>                                if (this.transpose) {<a name="line.246"></a>
<FONT color="green">247</FONT>                                    setValue(value, columnKey, rowKey);<a name="line.247"></a>
<FONT color="green">248</FONT>                                }<a name="line.248"></a>
<FONT color="green">249</FONT>                                else {<a name="line.249"></a>
<FONT color="green">250</FONT>                                    setValue(value, rowKey, columnKey);<a name="line.250"></a>
<FONT color="green">251</FONT>                                }<a name="line.251"></a>
<FONT color="green">252</FONT>                                break;<a name="line.252"></a>
<FONT color="green">253</FONT>                            }<a name="line.253"></a>
<FONT color="green">254</FONT>                            case Types.DATE:<a name="line.254"></a>
<FONT color="green">255</FONT>                            case Types.TIME:<a name="line.255"></a>
<FONT color="green">256</FONT>                            case Types.TIMESTAMP: {<a name="line.256"></a>
<FONT color="green">257</FONT>                                Date date = (Date) resultSet.getObject(column);<a name="line.257"></a>
<FONT color="green">258</FONT>                                Number value = new Long(date.getTime());<a name="line.258"></a>
<FONT color="green">259</FONT>                                if (this.transpose) {<a name="line.259"></a>
<FONT color="green">260</FONT>                                    setValue(value, columnKey, rowKey);<a name="line.260"></a>
<FONT color="green">261</FONT>                                }<a name="line.261"></a>
<FONT color="green">262</FONT>                                else {<a name="line.262"></a>
<FONT color="green">263</FONT>                                    setValue(value, rowKey, columnKey);<a name="line.263"></a>
<FONT color="green">264</FONT>                                }<a name="line.264"></a>
<FONT color="green">265</FONT>                                break;<a name="line.265"></a>
<FONT color="green">266</FONT>                            }<a name="line.266"></a>
<FONT color="green">267</FONT>                            case Types.CHAR:<a name="line.267"></a>
<FONT color="green">268</FONT>                            case Types.VARCHAR:<a name="line.268"></a>
<FONT color="green">269</FONT>                            case Types.LONGVARCHAR: {<a name="line.269"></a>
<FONT color="green">270</FONT>                                String string <a name="line.270"></a>
<FONT color="green">271</FONT>                                    = (String) resultSet.getObject(column);<a name="line.271"></a>
<FONT color="green">272</FONT>                                try {<a name="line.272"></a>
<FONT color="green">273</FONT>                                    Number value = Double.valueOf(string);<a name="line.273"></a>
<FONT color="green">274</FONT>                                    if (this.transpose) {<a name="line.274"></a>
<FONT color="green">275</FONT>                                        setValue(value, columnKey, rowKey);<a name="line.275"></a>
<FONT color="green">276</FONT>                                    }<a name="line.276"></a>
<FONT color="green">277</FONT>                                    else {<a name="line.277"></a>
<FONT color="green">278</FONT>                                        setValue(value, rowKey, columnKey);<a name="line.278"></a>
<FONT color="green">279</FONT>                                    }<a name="line.279"></a>
<FONT color="green">280</FONT>                                }<a name="line.280"></a>
<FONT color="green">281</FONT>                                catch (NumberFormatException e) {<a name="line.281"></a>
<FONT color="green">282</FONT>                                    // suppress (value defaults to null)<a name="line.282"></a>
<FONT color="green">283</FONT>                                }<a name="line.283"></a>
<FONT color="green">284</FONT>                                break;<a name="line.284"></a>
<FONT color="green">285</FONT>                            }<a name="line.285"></a>
<FONT color="green">286</FONT>                            default:<a name="line.286"></a>
<FONT color="green">287</FONT>                                // not a value, can't use it (defaults to null)<a name="line.287"></a>
<FONT color="green">288</FONT>                                break;<a name="line.288"></a>
<FONT color="green">289</FONT>                        }<a name="line.289"></a>
<FONT color="green">290</FONT>                    }<a name="line.290"></a>
<FONT color="green">291</FONT>                }<a name="line.291"></a>
<FONT color="green">292</FONT>    <a name="line.292"></a>
<FONT color="green">293</FONT>                fireDatasetChanged();<a name="line.293"></a>
<FONT color="green">294</FONT>            }<a name="line.294"></a>
<FONT color="green">295</FONT>            finally {<a name="line.295"></a>
<FONT color="green">296</FONT>                if (resultSet != null) {<a name="line.296"></a>
<FONT color="green">297</FONT>                    try {<a name="line.297"></a>
<FONT color="green">298</FONT>                        resultSet.close();<a name="line.298"></a>
<FONT color="green">299</FONT>                    }<a name="line.299"></a>
<FONT color="green">300</FONT>                    catch (Exception e) {<a name="line.300"></a>
<FONT color="green">301</FONT>                        // report this?<a name="line.301"></a>
<FONT color="green">302</FONT>                    }<a name="line.302"></a>
<FONT color="green">303</FONT>                }<a name="line.303"></a>
<FONT color="green">304</FONT>                if (statement != null) {<a name="line.304"></a>
<FONT color="green">305</FONT>                    try {<a name="line.305"></a>
<FONT color="green">306</FONT>                        statement.close();<a name="line.306"></a>
<FONT color="green">307</FONT>                    }<a name="line.307"></a>
<FONT color="green">308</FONT>                    catch (Exception e) {<a name="line.308"></a>
<FONT color="green">309</FONT>                        // report this?<a name="line.309"></a>
<FONT color="green">310</FONT>                    }<a name="line.310"></a>
<FONT color="green">311</FONT>                }<a name="line.311"></a>
<FONT color="green">312</FONT>            }<a name="line.312"></a>
<FONT color="green">313</FONT>        }<a name="line.313"></a>
<FONT color="green">314</FONT>    <a name="line.314"></a>
<FONT color="green">315</FONT>    }<a name="line.315"></a>




























































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