{"id":1863,"date":"2022-11-28T21:32:32","date_gmt":"2022-11-28T13:32:32","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1863"},"modified":"2022-11-28T21:32:33","modified_gmt":"2022-11-28T13:32:33","slug":"%e6%8f%90%e4%be%9b%e6%93%8d%e4%bd%9c%e6%95%b0%e6%8d%ae%e8%a1%a8%e7%9a%84basedao","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1863","title":{"rendered":"\u63d0\u4f9b\u64cd\u4f5c\u6570\u636e\u8868\u7684BaseDAO"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.P42.dao;\r\n\r\nimport java.lang.reflect.Field;\r\nimport java.sql.Connection;\r\nimport java.sql.PreparedStatement;\r\nimport java.sql.ResultSet;\r\nimport java.sql.ResultSetMetaData;\r\nimport java.sql.SQLException;\r\nimport java.util.ArrayList;\r\nimport java.util.List;\r\n\r\nimport top.qaqaq.P35.util.JDBCUtils;\r\n\r\n\/*\r\n * DAO:\tdata(base) access object\r\n * \u5c01\u88c5\u4e86\u9488\u5bf9\u4e8e\u6570\u636e\u8868\u7684\u901a\u7528\u7684\u64cd\u4f5c\r\n * \r\n *\/\r\npublic abstract class BaseDAO {\r\n\r\n\t\/\/ \u901a\u7528\u7684\u589e\u5220\u6539\u64cd\u4f5c --version 2.0 (\u8003\u8651\u4e0a\u4e8b\u52a1)\r\n\tpublic int update(Connection conn, String sql, Object... args) {\/\/ sql\u4e2d\u5360\u4f4d\u7b26\u7684\u4e2a\u6570\u4e0e\u53ef\u53d8\u5f62\u53c2\u7684\u957f\u5ea6\u76f8\u540c\uff01\r\n\t\tPreparedStatement ps = null;\r\n\t\ttry {\r\n\t\t\t\/\/ 1.\u9884\u7f16\u8bd1sql\u8bed\u53e5\uff0c\u8fd4\u56dePreparedStatement\u5b9e\u4f8b\r\n\t\t\tps = conn.prepareStatement(sql);\r\n\t\t\t\/\/ 2.\u586b\u5145\u5360\u4f4d\u7b26\r\n\t\t\tfor (int i = 0; i &lt; args.length; i++) {\r\n\t\t\t\tps.setObject(i + 1, args&#91;i]);\/\/ \u5c0f\u5fc3\u53c2\u6570\u58f0\u660e\u9519\u8bef\uff01\uff01\r\n\t\t\t}\r\n\t\t\t\/\/ 3.\u6267\u884c\r\n\t\t\treturn ps.executeUpdate();\r\n\t\t} catch (Exception e) {\r\n\t\t\te.printStackTrace();\r\n\t\t} finally {\r\n\r\n\t\t\t\/\/ \u4fee\u6539\u5176\u4e3a\u81ea\u52a8\u63d0\u4ea4\u6570\u636e\r\n\t\t\t\/\/ \u4e3b\u8981\u9488\u5bf9\u4e8e\u4f7f\u7528\u6570\u636e\u5e93\u8fde\u63a5\u6c60\u7684\u4f7f\u7528\r\n\/\/\t\t\t\ttry {\r\n\/\/\t\t\t\t\tconn.setAutoCommit(true);\r\n\/\/\t\t\t\t} catch (SQLException e) {\r\n\/\/\t\t\t\t\te.printStackTrace();\r\n\/\/\t\t\t\t}\r\n\r\n\t\t\t\/\/ 4.\u8d44\u6e90\u7684\u5173\u95ed\r\n\t\t\tJDBCUtils.closeResource(null, ps);\r\n\t\t}\r\n\r\n\t\treturn 0;\r\n\t}\r\n\r\n\t\/\/ \u901a\u7528\u7684\u67e5\u8be2\u64cd\u4f5c\uff0c\u7528\u4e8e\u8fd4\u56de\u6570\u636e\u8868\u4e2d\u7684\u4e00\u6761\u8bb0\u5f55(varsion 2.0,\u8003\u8651\u4e0a\u4e8b\u52a1)\r\n\tpublic &lt;T> T getInstance(Connection conn, Class&lt;T> clazz, String sql, Object... args) {\r\n\t\tPreparedStatement ps = null;\r\n\t\tResultSet rs = null;\r\n\t\ttry {\r\n\r\n\t\t\tps = conn.prepareStatement(sql);\r\n\t\t\tfor (int i = 0; i &lt; args.length; i++) {\r\n\t\t\t\tps.setObject(i + 1, args&#91;i]);\r\n\t\t\t}\r\n\r\n\t\t\trs = ps.executeQuery();\r\n\t\t\t\/\/ \u83b7\u53d6\u7ed3\u679c\u96c6\u7684\u5143\u6570\u636e : ResultSetMetaData\r\n\t\t\tResultSetMetaData rsmd = rs.getMetaData();\r\n\t\t\t\/\/ \u901a\u8fc7ResultSetMetaData\u83b7\u53d6\u7ed3\u679c\u96c6\u4e2d\u7684\u5217\u6570\r\n\t\t\tint columnCount = rsmd.getColumnCount();\r\n\r\n\t\t\tif (rs.next()) {\r\n\t\t\t\tT t = clazz.newInstance();\r\n\t\t\t\t\/\/ \u5904\u7406\u7ed3\u679c\u96c6\u4e00\u884c\u6570\u636e\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5217\r\n\t\t\t\tfor (int i = 0; i &lt; columnCount; i++) {\r\n\t\t\t\t\t\/\/ \u83b7\u53d6\u5217\u503c\r\n\t\t\t\t\tObject columnvalue = rs.getObject(i + 1);\r\n\r\n\t\t\t\t\t\/\/ \u83b7\u53d6\u6bcf\u4e2a\u5217\u7684\u5217\u540d\r\n\/\/\t\t\t\t\t\tString columnName = rsmd.getColumnName(i + 1);\r\n\t\t\t\t\tString columnLabel = rsmd.getColumnLabel(i + 1);\r\n\r\n\t\t\t\t\t\/\/ \u7ed9t\u5bf9\u8c61\u6307\u5b9a\u7684columnName\u5c5e\u6027\uff0c\u8d4b\u503c\u4e3acolumnvalue\uff1b\u901a\u8fc7\u53cd\u5c04\r\n\t\t\t\t\tField field = clazz.getDeclaredField(columnLabel);\r\n\t\t\t\t\tfield.setAccessible(true);\r\n\t\t\t\t\tfield.set(t, columnvalue);\r\n\r\n\t\t\t\t}\r\n\t\t\t\treturn t;\r\n\t\t\t}\r\n\t\t} catch (Exception e) {\r\n\t\t\te.printStackTrace();\r\n\t\t} finally {\r\n\/\/\t\t\t\tJDBCUtils.closeResource(null, ps, rs);\r\n\t\t}\r\n\r\n\t\treturn null;\r\n\t}\r\n\r\n\t\/\/ \u901a\u7528\u7684\u67e5\u8be2\u64cd\u4f5c\uff0c\u7528\u4e8e\u8fd4\u56de\u6570\u636e\u8868\u4e2d\u591a\u6761\u8bb0\u5f55\u6784\u6210\u7684\u96c6\u5408(varsion 2.0,\u8003\u8651\u4e0a\u4e8b\u52a1)\r\n\tpublic &lt;T> List&lt;T> getForList(Connection conn, Class&lt;T> clazz, String sql, Object... args) {\r\n\t\tPreparedStatement ps = null;\r\n\t\tResultSet rs = null;\r\n\t\ttry {\r\n\r\n\t\t\tps = conn.prepareStatement(sql);\r\n\t\t\tfor (int i = 0; i &lt; args.length; i++) {\r\n\t\t\t\tps.setObject(i + 1, args&#91;i]);\r\n\t\t\t}\r\n\r\n\t\t\trs = ps.executeQuery();\r\n\t\t\t\/\/ \u83b7\u53d6\u7ed3\u679c\u96c6\u7684\u5143\u6570\u636e : ResultSetMetaData\r\n\t\t\tResultSetMetaData rsmd = rs.getMetaData();\r\n\t\t\t\/\/ \u901a\u8fc7ResultSetMetaData\u83b7\u53d6\u7ed3\u679c\u96c6\u4e2d\u7684\u5217\u6570\r\n\t\t\tint columnCount = rsmd.getColumnCount();\r\n\t\t\t\/\/ \u521b\u5efa\u96c6\u5408\u5bf9\u8c61\r\n\t\t\tArrayList&lt;T> list = new ArrayList&lt;T>();\r\n\t\t\twhile (rs.next()) {\r\n\t\t\t\tT t = clazz.newInstance();\r\n\t\t\t\t\/\/ \u5904\u7406\u7ed3\u679c\u96c6\u4e00\u884c\u6570\u636e\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5217:\u7ed9t\u5bf9\u8c61\u6307\u5b9a\u7684\u5c5e\u6027\u8d4b\u503c\r\n\t\t\t\tfor (int i = 0; i &lt; columnCount; i++) {\r\n\t\t\t\t\t\/\/ \u83b7\u53d6\u5217\u503c\r\n\t\t\t\t\tObject columnvalue = rs.getObject(i + 1);\r\n\r\n\t\t\t\t\t\/\/ \u83b7\u53d6\u6bcf\u4e2a\u5217\u7684\u5217\u540d\r\n\/\/\t\t\t\t\tString columnName = rsmd.getColumnName(i + 1);\r\n\t\t\t\t\tString columnLabel = rsmd.getColumnLabel(i + 1);\r\n\r\n\t\t\t\t\t\/\/ \u7ed9t\u5bf9\u8c61\u6307\u5b9a\u7684columnName\u5c5e\u6027\uff0c\u8d4b\u503c\u4e3acolumnvalue\uff1b\u901a\u8fc7\u53cd\u5c04\r\n\t\t\t\t\tField field = clazz.getDeclaredField(columnLabel);\r\n\t\t\t\t\tfield.setAccessible(true);\r\n\t\t\t\t\tfield.set(t, columnvalue);\r\n\r\n\t\t\t\t}\r\n\t\t\t\tlist.add(t);\r\n\t\t\t}\r\n\r\n\t\t\treturn list;\r\n\t\t} catch (Exception e) {\r\n\t\t\te.printStackTrace();\r\n\t\t} finally {\r\n\t\t\tJDBCUtils.closeResource(null, ps, rs);\r\n\t\t}\r\n\r\n\t\treturn null;\r\n\t}\r\n\r\n\t\/\/\u7528\u4e8e\u67e5\u8be2\u7279\u6b8a\u503c\u7684\u901a\u7528\u7684\u65b9\u6cd5\r\n\tpublic &lt;E> E getValue(Connection conn, String sql, Object... args) {\r\n\t\tPreparedStatement ps = null;\r\n\t\tResultSet rs = null;\r\n\t\ttry {\r\n\t\t\tps = conn.prepareStatement(sql);\r\n\t\t\tfor(int i = 0; i&lt; args.length; i++) {\r\n\t\t\t\tps.setObject(i + 1, args&#91;i]);\r\n\t\t\t}\r\n\t\t\t\r\n\t\t\trs = ps.executeQuery();\r\n\t\t\tif(rs.next()) {\r\n\t\t\t\treturn (E) rs.getObject(1);\r\n\t\t\t}\r\n\t\t} catch (SQLException e) {\r\n\t\t\te.printStackTrace();\r\n\t\t} finally {\r\n\t\t\tJDBCUtils.closeResource(null, ps, rs);\r\n\t\t}\r\n\t\t\r\n\t\treturn null;\r\n\t\t\r\n\t}\r\n\r\n}\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[38],"tags":[48],"class_list":["post-1863","post","type-post","status-publish","format-standard","hentry","category-jdbc-code","tag-jdbc"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1863"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1863"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1863\/revisions"}],"predecessor-version":[{"id":1864,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1863\/revisions\/1864"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}