C3PO数据库连接池

Posted 2020-11-08 traveller-hzq

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 
 3 -<c3p0-config>
 4 
 5 
 6 -<default-config>
 7 
 8 <property name="driverClass">com.mysql.jdbc.Driver</property>
 9 
10 <property name="jdbcUrl">jdbc:mysql://localhost:3306/dataSourceDemo?characterEncoding=UTF8</property>
11 
12 <property name="user">root</property>
13 
14 <property name="password">root</property>
15 
16 <property name="maxPoolSize">15</property>
17 
18 <property name="minPoolSize">3</property>
19 
20 <property name="initialPoolSize">3</property>
21 
22 <property name="acquireIncrement">3</property>
23 
24 <property name="maxIdleTime">600</property>
25 
26 <property name="checkoutTimeout">0</property>
27 
28 </default-config>
29 
30 </c3p0-config>

c3po-config.xml

1.导入XML文件

2.使用jdbcutils获取连接池对象

  1 import java.beans.BeanInfo;
  2 import java.beans.Introspector;
  3 import java.beans.PropertyDescriptor;
  4 import java.sql.Connection;
  5 import java.sql.PreparedStatement;
  6 import java.sql.ResultSet;
  7 import java.sql.ResultSetMetaData;
  8 import java.sql.SQLException;
  9 import java.sql.Statement;
 10 import java.util.ArrayList;
 11 import java.util.List;
 12 
 13 import javax.sql.DataSource;
 14 
 15 import com.mchange.v2.c3p0.ComboPooledDataSource;
 16 
 17 public class JDBCUtils {
 18 
 19     // 使用C3P0数据库连接池管理数据库连接
 20     private static DataSource dataSource = new ComboPooledDataSource();
 21 
 22     // 获取连接
 23     public static Connection getConnection() throws SQLException {
 24         return dataSource.getConnection();
 25     }
 26 
 27     // 关闭连接
 28     public static void close(Connection conn) {
 29         if (conn != null) {
 30             try {
 31                 conn.close();
 32             } catch (SQLException e) {
 33             }
 34         }
 35     }
 36 
 37     // 关闭statement
 38     public static void close(Statement stmt) {
 39         if (stmt != null) {
 40             try {
 41                 stmt.close();
 42             } catch (SQLException e) {
 43             }
 44         }
 45     }
 46 
 47     // 关闭结果集
 48     public static void close(ResultSet rs) {
 49         if (rs != null) {
 50             try {
 51                 rs.close();
 52             } catch (SQLException e) {
 53             }
 54         }
 55     }
 56 
 57     // 关闭结果集、statement、连接
 58     public static void closeAll(ResultSet rs) {
 59         if (rs == null) {
 60             return;
 61         }
 62         try {
 63             close(rs);
 64             // 如果先关掉statement再关conn，会抛出“You cannot operate on a closed
 65             // Statement!”的异常，导致conn没有关闭
 66             close(rs.getStatement().getConnection());
 67             close(rs.getStatement());
 68 
 69         } catch (SQLException e) {
 70             e.printStackTrace();
 71         }
 72     }
 73 
 74     // 关闭结果集、statement
 75     public static void closeResultSetAndStatement(ResultSet rs) {
 76         if (rs == null) {
 77             return;
 78         }
 79         try {
 80             close(rs);
 81             close(rs.getStatement());
 82         } catch (SQLException e) {
 83 
 84         }
 85     }
 86 
 87     // 执行insert、update、delete等sql语句
 88     public static int executeUpdate(String sql, Object... parameters) throws SQLException {
 89         Connection conn = null;
 90         try {
 91             conn = getConnection();
 92             return executeUpdate(conn, sql, parameters);
 93         } finally {
 94             close(conn);
 95         }
 96     }
 97 
 98     // 执行insert、update、delete等sql语句
 99     public static int executeUpdate(Connection conn, String sql, Object... parameters) throws 
100     SQLException {
101         PreparedStatement ps = null;
102         try {
103             ps = conn.prepareStatement(sql);
104             for (int i = 0; i < parameters.length; i++) {
105                 ps.setObject(i + 1, parameters[i]);
106             }
107             return ps.executeUpdate();
108         } finally {
109             close(ps);
110         }
111     }
112 
113     // 执行查询
114     public static ResultSet executeQuery(String sql, Object... parameters) throws SQLException {
115         Connection conn = null;
116         try {
117             conn = getConnection();
118             return executeQuery(conn, sql, parameters);
119         } catch (SQLException ex) {
120             close(conn);
121             throw ex;
122         }
123     }
124 
125     // 执行查询
126     public static ResultSet executeQuery(Connection conn, String sql, Object... parameters) throws 
127     SQLException {
128         PreparedStatement ps = null;
129         try {
130             ResultSet rs = null;
131             ps = conn.prepareStatement(sql);
132             for (int i = 0; i < parameters.length; i++) {
133                 ps.setObject(i + 1, parameters[i]);
134             }
135             rs = ps.executeQuery();
136             return rs;
137         } catch (SQLException ex) {
138             close(ps);
139             throw ex;
140         }
141     }
142 
143     // 回滚
144     public static void rollback(Connection conn) {
145         try {
146             conn.rollback();
147         } catch (SQLException e) {
148 
149         }
150     }
151 }

JDBCUtils

jar包  c3p0