大家好，又见面了，我是全栈君，今天给大家准备了Idea注册码。
通用查询数据库辅助类，可实现任意查询语句的查询，还可以进行多结果集查询。
类的代码：
1 package com.hongyuan.db; 2 3 import java.math.BigDecimal; 4 import java.net.URL; 5 import java.sql.Array; 6 import java.sql.Blob; 7 import java.sql.Clob; 8 import java.sql.Connection; 9 import java.sql.Date; 10 import java.sql.PreparedStatement; 11 import java.sql.ResultSet; 12 import java.sql.SQLException; 13 import java.sql.SQLXML; 14 import java.sql.Statement; 15 import java.sql.Time; 16 import java.sql.Timestamp; 17 import java.util.ArrayList; 18 import java.util.List; 19 20 import javax.sql.DataSource; 21 import javax.sql.rowset.CachedRowSet; 22 23 import com.sun.rowset.CachedRowSetImpl; 24 25 public class DBUtil { 26 private DataSource ds = null; 27 28 public DataSource getDs() { 29 return ds; 30 } 31 32 public void setDs(DataSource ds) { 33 this.ds = ds; 34 } 35 36 public DBUtil() { 37 } 38 39 public DBUtil(DataSource ds) { 40 this.ds = ds; 41 } 42 43 public Connection getConnection() throws SQLException { 44 return ds.getConnection(); 45 } 46 47 public static void close(Connection conn, Statement s, ResultSet rs) 48 throws SQLException { 49 if (rs != null) 50 rs.close(); 51 if (s != null) 52 s.close(); 53 if (conn != null) 54 conn.close(); 55 } 56 57 public Object query(String sql) throws SQLException { 58 return this.query(sql, null); 59 } 60 61 public Object query(String sql, List params) throws SQLException { 62 Connection conn = null; 63 PreparedStatement ps = null; 64 ResultSet rs = null; 65 try { 66 conn = this.getConnection(); 67 ps = conn.prepareStatement(sql); 68 69 if (null != params) { 70 //初始化查询参数 71 this.initParam(ps, params); 72 } 73 //处理结果集 http://www.cnblogs.com/roucheng/ 74 boolean isResultSet = ps.execute(); 75 List result = new ArrayList(); 76 do { 77 if (isResultSet) { 78 CachedRowSet crs = new CachedRowSetImpl(); 79 crs.populate(ps.getResultSet()); 80 result.add(crs); 81 } else { 82 result.add(new Integer(ps.getUpdateCount())); 83 } 84 } while ((isResultSet = ps.getMoreResults()) == true 85 || ps.getUpdateCount() != -1); 86 87 if (result.size() == 0) { 88 return null; 89 } else if (result.size() == 1) { 90 return result.get(0); 91 } else { 92 return result; 93 } 94 } catch (SQLException e) { 95 throw new SQLException("无法执行的sql语句!"); 96 } finally { 97 DBUtil.close(conn, ps, rs); 98 } 99 } 100 //初始化查询参数 101 private void initParam(PreparedStatement ps, List params) 102 throws SQLException { 103 for (int i = 0; i < params.size(); i++) { 104 Object param = params.get(i); 105 if (param instanceof Byte) { 106 ps.setByte(i + 1, (Byte) param); 107 } else if (param instanceof Short) { 108 ps.setShort(i + 1, (Short) param); 109 } else if (param instanceof Integer) { 110 ps.setInt(i + 1, (Integer) param); 111 } else if (param instanceof Long) { 112 ps.setLong(i + 1, (Long) param); 113 } else if (param instanceof Float) { 114 ps.setFloat(i + 1, (Float) param); 115 } else if (param instanceof Double) { 116 ps.setDouble(i + 1, (double) param); 117 } else if (param instanceof BigDecimal) { 118 ps.setBigDecimal(i + 1, (BigDecimal) param); 119 } else if (param instanceof Boolean) { 120 ps.setBoolean(i + 1, (Boolean) param); 121 } else if (param instanceof String) { 122 ps.setString(i + 1, (String) param); 123 } else if (param instanceof Time) { 124 ps.setTime(i + 1, (Time) param); 125 } else if (param instanceof Date) { 126 ps.setDate(i + 1, (Date) param); 127 } else if (param instanceof Timestamp) { 128 ps.setTimestamp(i + 1, (Timestamp) param); 129 } else if (param instanceof Array) { 130 ps.setArray(i + 1, (Array) param); 131 } else if (param instanceof Blob) { 132 ps.setBlob(i + 1, (Blob) param); 133 } else if (param instanceof Clob) { 134 ps.setClob(i + 1, (Clob) param); 135 } else if (param instanceof SQLXML) { 136 ps.setSQLXML(i + 1, (SQLXML) param); 137 } else if (param instanceof URL) { 138 ps.setURL(i, (URL) param); 139 } else { 140 ps.setObject(i + 1, param); 141 } 142 } 143 } 144 }
上面类的使用 DBUtilTest.java：
1 package com.hongyuan.db; 2 3 import java.sql.ResultSet; 4 import java.sql.SQLException; 5 import java.util.ArrayList; 6 import java.util.List; 7 8 import javax.sql.DataSource; 9 10 import org.junit.BeforeClass; 11 import org.junit.Test; 12 13 import com.mysql.jdbc.jdbc2.optional.MysqlDataSource; 14 15 public class DBUtilTest { 16 17 private static DataSource ds=null; 18 19 @BeforeClass 20 public static void setUpBeforeClass() throws Exception { 21 MysqlDataSource mds=new MysqlDataSource(); 22 mds.setURL("jdbc:mysql://127.0.0.1:3306/test"); 23 mds.setUser("root"); 24 mds.setPassword("123456"); 25 ds=mds; 26 } 27 28 @Test 29 public void testQuery() throws SQLException { 30 DBUtil util=new DBUtil(ds); 31 List params=new ArrayList(); 32 params.add(2); 33 Object obj=util.query("select * from emp where id=?",params); 34 if(obj instanceof ResultSet){ 35 ResultSet rs=(ResultSet)obj; 36 while(rs.next()){ 37 for(int i=0;i<rs.getMetaData().getColumnCount();i++){ 38 System.out.print(rs.getObject(i+1)+"\t"); 39 } 40 System.out.println(); 41 } 42 }else{ 43 System.out.println(obj); 44 } 45 } 46 47 }
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