java中的c3p0和proxool都分别是什么能详细介绍一下么

发布网友发布时间：2022-05-01 17:14

共3个回答

懂视网时间：2022-05-01 21:36

proxool>  <alias>localmysqldb</alias>  <driver-url><![CDATA[jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf-8]]></driver-url>  <driver-class>com.mysql.jdbc.Driver</driver-class> <driver-properties> <property name="user" value="root"/> <property name="password" value="ROOT"/> </driver-properties>  <house-keeping-sleep-time>900000</house-keeping-sleep-time>  <maximum-active-time>500000</maximum-active-time>  <maximum-connection-count>10</maximum-connection-count>  <minimum-connection-count>4</minimum-connection-count>  <house-keeping-test-sql>select 1</house-keeping-test-sql> <prop key="hibernate.connection.release_mode">after_transaction</prop> </proxool> </proxool-config>

2。工具类

public class ClassUtil {
 
 /**
 * @param c
 * @return
 * @Author: 
 * @Description: 返回class文件所在的目录
 */
 public static String getClassPath(Class<?> c) {
 return c.getResource("").getPath().replaceAll("%20", " ");
 }
 
 /**
 * @param c
 * @return
 * @Author:
 * @Description: 返回class文件所在项目的根目录
 */
 public static String getClassRootPath(Class<?> c) {
 return c.getResource("/").getPath().replaceAll("%20", " ");
 }
 
 /**
 * @param c
 * @param hasName 是否包括class名
 * @return
 * @Author:lulei 
 * @Description: 返回class文件所在的目录
 */
 public static String getClassPath(Class<?> c, boolean hasName) {
 String name = c.getSimpleName() + ".class";
 String path = c.getResource(name).getPath().replaceAll("%20", " ");
 if (hasName) {
  return path;
 } else {
  return path.substring(0, path.length() - name.length());
 }
 }

}

3.数据库连接池配置加载类

public class DBPool {
 private String poolPath;//数据库连接池的配置文件路径
 
 private DBPool() {
 }
 
 /**
 * @return
 * @Author: 
 * @Description: 返回DBPool对象
 */
 public static DBPool getDBPool() {
 return DBPoolDao.dbPool;
 }

 /**
 *@Description: 静态内部类实现单例模式
 *@Author:
 *@Version:1.1.0
 */
 private static class DBPoolDao{
 private static DBPool dbPool = new DBPool();
 }
 
 public String getPoolPath() {
 if (poolPath == null) {
  //如果poolPath为空，赋值为默认值
  poolPath = ClassUtil.getClassRootPath(DBPool.class) + "proxool.xml";
 }
 return poolPath;
 }

 /**
 * @param poolPath
 * @Author: 
 * @Description: 设置数据库连接池的配置文件路径
 */
 public void setPoolPath(String poolPath) {
 this.poolPath = poolPath;
 }

}

4.数据库连接池管理类

public class DBManager {
 
 private DBManager(){
 try {
  //数据库连接池配置文件
  JAXPConfigurator.configure(DBPool.getDBPool().getPoolPath(), false);
  //数据库加载驱动类
  Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");
 } catch (Exception e) {
  // TODO Auto-generated catch block 
  e.printStackTrace();
 }
 }
 
 /**
 * @param poolName
 * @return
 * @throws SQLException
 * @Author:
 * @Description: 获取数据库连接
 */
 public Connection getConnection(String poolName) throws SQLException {
 return DriverManager.getConnection(poolName);
 }
 
 /**
 *@Description: 内部静态类实现单例模式 
 *@Author:
 *@Version:1.1.0
 */
 private static class DBManagerDao {
 private static DBManager dbManager = new DBManager();
 }
 
 /**
 * @return
 * @Author:
 * @Description: 返回数据库连接池管理类
 */
 public static DBManager getDBManager() {
 return DBManagerDao.dbManager;
 }

}

5. sql语句参数转化

public class DBOperation {
 private String poolName;//数据库连接池别名
 private Connection con = null;//数据库连接
 
 public DBOperation(String poolName) {
 this.poolName = poolName;
 }
 
 /**
 * @Author: 
 * @Description:关闭数据库连接
 */
 public void close() {
 try {
  if (this.con != null) {
  this.con.close();
  }
 } catch (Exception e) {
  e.printStackTrace();
 }
 }
 
 /**
 * @throws SQLException
 * @Author:lulei 
 * @Description: 打开数据库连接
 */
 private void open() throws SQLException {
 //先关闭后打开，防止数据库连接溢出
 close();
 this.con = DBManager.getDBManager().getConnection(this.poolName);
 }
 
 /**
 * @param sql
 * @param params
 * @return
 * @throws SQLException
 * @throws ClassNotFoundException
 * @Author: 
 * @Description: sql语句参数转化
 */
 private PreparedStatement setPres(String sql, HashMap<Integer, Object> params) throws SQLException, ClassNotFoundException{
 if (null == params || params.size() < 1) {
  return null;
 }
 PreparedStatement pres = this.con.prepareStatement(sql);
 for (int i = 1; i <= params.size(); i++) {
  if (params.get(i) == null) {
  pres.setString(i, "");
  } else if (params.get(i).getClass() == Class.forName("java.lang.String")) {
  pres.setString(i, params.get(i).toString());
  } else if (params.get(i).getClass() == Class.forName("java.lang.Integer")) {
  pres.setInt(i, (Integer) params.get(i));
  } else if (params.get(i).getClass() == Class.forName("java.lang.Long")) {
  pres.setLong(i, (Long) params.get(i));
  } else if (params.get(i).getClass() == Class.forName("java.lang.Double")) {
  pres.setDouble(i, (Double) params.get(i));
  } else if (params.get(i).getClass() == Class.forName("java.lang.Flaot")) {
  pres.setFloat(i, (Float) params.get(i));
  } else if (params.get(i).getClass() == Class.forName("java.lang.Boolean")) {
  pres.setBoolean(i, (Boolean) params.get(i));
  } else if (params.get(i).getClass() == Class.forName("java.sql.Date")) {
  pres.setDate(i, java.sql.Date.valueOf(params.get(i).toString()));
  } else {
  return null;
  }
 }
 return pres;
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author: 
 * @Description: 执行SQL语句，返回影响行数
 */
 public int executeUpdate(String sql) throws SQLException {
 this.open();
 Statement state = this.con.createStatement();
 return state.executeUpdate(sql);
 }
 
 /**
 * @param sql
 * @param params
 * @return
 * @throws SQLException
 * @throws ClassNotFoundException
 * @Author:
 * @Description: 执行sql语句，返回影响行数
 */
 public int executeUpdate(String sql, HashMap<Integer, Object> params) throws SQLException, ClassNotFoundException {
 this.open();
 PreparedStatement pres = setPres(sql, params);
 if (null == pres) {
  return 0;
 }
 return pres.executeUpdate();
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author: 
 * @Description: 执行sql语句，返回结果集
 */
 public ResultSet executeQuery(String sql) throws SQLException {
 this.open();
 Statement state = this.con.createStatement();
 return state.executeQuery(sql);
 }
 
 /**
 * @param sql
 * @param params
 * @return
 * @throws SQLException
 * @throws ClassNotFoundException
 * @Author:
 * @Description:执行sql语句，返回结果集
 */
 public ResultSet executeQuery(String sql, HashMap<Integer, Object> params) throws SQLException, ClassNotFoundException {
 this.open();
 PreparedStatement pres = setPres(sql, params);
 if (null == pres) {
  return null;
 }
 return pres.executeQuery();
 }

}

6.数据基本操作

public class DBServer {
 private DBOperation dbOperation;
 
 public DBServer(String poolName) {
 dbOperation = new DBOperation(poolName);
 }
 
 /**
 * @Author: 
 * @Description: 关闭数据库连接
 */
 public void close() {
 dbOperation.close();
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author:
 * @Description: 数据库新增操作
 */
 public int insert(String sql) throws SQLException {
 return dbOperation.executeUpdate(sql);
 }
 
 /**
 * @param tableName
 * @param columns
 * @param params
 * @return
 * @throws SQLException
 * @throws ClassNotFoundException
 * @Author: 
 * @Description: 数据库新增操作
 */
 public int insert(String tableName, String columns, HashMap<Integer, Object> params) throws SQLException, ClassNotFoundException {
 String sql = insertSql(tableName, columns);
 return dbOperation.executeUpdate(sql, params);
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author: 
 * @Description: 数据库删除操作
 */
 public int delete(String sql) throws SQLException {
 return dbOperation.executeUpdate(sql);
 }
 
 /**
 * @param tableName
 * @param condition
 * @return
 * @throws SQLException
 * @Author:lulei 
 * @Description: 数据库删除操作
 */
 public int delete(String tableName, String condition) throws SQLException {
 if (null == tableName) {
  return 0;
 }
 String sql = "delete from " + tableName + " " + condition;
 return dbOperation.executeUpdate(sql);
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author: 
 * @Description: 数据库更新操作
 */
 public int update(String sql) throws SQLException {
 return dbOperation.executeUpdate(sql);
 }
 
 /**
 * @param tableName
 * @param columns
 * @param condition
 * @param params
 * @return
 * @throws SQLException
 * @throws ClassNotFoundException
 * @Author: 
 * @Description: 数据库更新操作
 */
 public int update(String tableName, String columns, String condition, HashMap<Integer, Object> params) throws SQLException, ClassNotFoundException {
 String sql = updateSql(tableName, columns, condition);
 return dbOperation.executeUpdate(sql, params);
 }
 
 /**
 * @param sql
 * @return
 * @throws SQLException
 * @Author: 
 * @Description: 数据库查询操作 
 */
 public ResultSet select(String sql) throws SQLException {
 return dbOperation.executeQuery(sql);
 }
 
 /**
 * @param tableName
 * @param columns
 * @param condition
 * @return
 * @throws SQLException
 * @Author:lulei 
 * @Description: 数据库查询操作
 */
 public ResultSet select(String tableName, String columns, String condition) throws SQLException {
 String sql = "select " + columns + " from " + tableName + " " + condition;
 return dbOperation.executeQuery(sql);
 }
 
 /**
 * @param tableName
 * @param columns
 * @param condition
 * @return
 * @Author: 
 * @Description: 组装 update sql eg: update tableName set column1=?,column2=? condition 
 */
 private String updateSql(String tableName, String columns, String condition) {
 if (tableName == null || columns == null) {
  return "";
 }
 String[] column = columns.split(",");
 StringBuilder sb = new StringBuilder();
 sb.append("update ");
 sb.append(tableName);
 sb.append(" set ");
 sb.append(column[0]);
 sb.append("=?");
 for (int i = 1; i < column.length; i++) {
  sb.append(", ");
  sb.append(column[i]);
  sb.append("=?");
 }
 sb.append(" ");
 sb.append(condition);
 return sb.toString();
 }
 
 /**
 * @param tableName
 * @param columns
 * @return
 * @Author:
 * @Description: 组装 insert sql eg: insert into tableName (column1, column2) values (?,?)
 */
 private String insertSql(String tableName, String columns) {
 if (tableName == null || columns == null) {
  return "";
 }
 int n = columns.split(",").length;
 StringBuilder sb = new StringBuilder("");
 sb.append("insert into ");
 sb.append(tableName);
 sb.append(" (");
 sb.append(columns);
 sb.append(") values (?");
 for (int i = 1; i < n; i++) {
  sb.append(",?");
 }
 sb.append(")");
 return sb.toString();
 }

}

Java数据库连接池-proxool

标签：jdbc 参考 manager 数据库 long object length resource after

热心网友时间：2022-05-01 18:44

两个都是开源数据库连接池框架， JDBC连接你应该知道.

连接池是为了避免过多的开启数据库链接导致的资源消耗，由连接池在系统创建初始创建一定数量的数据库连接放到连接池中，这些连接的数量是由最小数据库连接数来设定的，
无论这些数据库连接是否被使用，连接池都将一直保证至少拥有这么多的连接数量。连接池的最大数据库连接数量限定了这个连接池能占有的最大连接数，当应用程序向连接池请求的连接数超过最大连接数量时，这些请求将被加入到等待队列中。其实就是为了节约资源

数据库框架hibernate就都支持这两个连接池

热心网友时间：2022-05-01 20:02

c3p0---->http://ke.baidu.com/view/920062.htm
proxool-->http://ke.baidu.com/view/2098784.htm

java中的c3p0和proxool都分别是什么 能详细介绍一下么

java中的c3p0和proxool都分别是什么能详细介绍一下么