适用,简单的数据库连接与sql操作的封装(JDBC,数据库连接池,c3p0)

import java.sql.ResultSet;
import java.sql.SQLException;

public interface DB {

public void doPstm(String sql, Object[] params);

public ResultSet getRs() throws SQLException;

public int getCount() throws SQLException;

public void closed();
}

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.sun.org.apache.bcel.internal.util.ClassPath;

public class DBConn implements DB {
private static Logger logger = Logger.getLogger(DBConn.class.getName());

private Connection conn;
private PreparedStatement pstm;

private String propFileName = "DB.properties";
private Properties prop = new Properties();

private String user = "root";
private String password = "123456";
private String className = "com.mysql.jdbc.Driver";
private String url = "jdbc:mysql://localhost:3306/lesogo_game?user=root&password=123456&useUnicode=true&characterEncoding=UTF-8";

public static final String CLASSPATH = ClassPath.getClassPath().substring(
0, ClassPath.getClassPath().indexOf(";"));

/** 构造方法，在该方法中加载数据库驱动 */
public DBConn(String... propFileNames) {
checkPropFileNames(propFileNames);

try {
InputStream in = getClass().getResourceAsStream("/" + propFileName);
prop.load(in);

this.user = prop.getProperty("DB_USER", this.user);
this.password = prop.getProperty("DB_PASSWORD", this.password);
this.className = prop.getProperty("DB_CLASSNAME", this.className);
this.url = prop.getProperty("DB_URL", this.url);

Class.forName(this.className);
} catch (ClassNotFoundException e) {
logger.log(Level.WARNING, "加载数据库驱动失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
} catch (IOException e) {
logger.log(Level.WARNING, "读取数据库配置失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}

private void checkPropFileNames(String... propFileNames) {
if (propFileNames != null && propFileNames.length > 0) {
for (int i = 0; i < propFileNames.length; i++) {
File file = new File(CLASSPATH + "/" + propFileNames[i]);
if (file.exists()) {
propFileName = propFileNames[i];
return;
}
}
}
}

/** 创建数据库连接 */
public Connection getCon() {
if (conn == null) {
try {
conn = DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
conn = null;
logger.log(Level.WARNING, "创建数据库连接失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}
return conn;
}

/**
* @功能：对数据库进行增、删、改、查操作
* @参数：sql为SQL语句；params为Object数组，里面存储的是为sql表示的SQL语句中"?"占位符赋值的数据
*/
public void doPstm(String sql, Object[] params) {
if (sql != null && !sql.equals("")) {
if (params == null)
params = new Object[0];
getCon();
if (conn != null) {
try {
System.out.println(sql);
pstm = conn.prepareStatement(sql,
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
for (int i = 0; i < params.length; i++) {
pstm.setObject(i + 1, params[i]);
}
pstm.execute();
} catch (SQLException e) {
logger.log(Level.WARNING, "doPstm()方法出错！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}
}
}

/**
* @功能：获取调用doPstm()方法执行查询操作后返回的ResultSet结果集
* @返回值：ResultSet
* @throws SQLException
*/
public ResultSet getRs() throws SQLException {
return pstm.getResultSet();
}

/**
* @功能：获取调用doPstm()方法执行更新操作后返回影响的记录数
* @返回值：int
* @throws SQLException
*/
public int getCount() throws SQLException {
return pstm.getUpdateCount();
}

/**
* @功能：释放PrepareStatement对象与Connection对象
*/
public void closed() {
try {
if (pstm != null)
pstm.close();
} catch (SQLException e) {
logger.log(Level.WARNING, "关闭pstm对象失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
try {
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
logger.log(Level.WARNING, "关闭Connection对象失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}
}

public class DBPool implements DB {

private static Logger logger = Logger.getLogger(DBPool.class.getName());

private PreparedStatement pstm;
private Connection conn = null;
private String lookup = "jdbc/lesogo";

public DBPool(String... propFileNames) {

try {
Context ctx = new InitialContext();
ctx = (Context) ctx.lookup("java:comp/env");
DataSource ds = (DataSource) ctx.lookup(lookup);
conn = ds.getConnection();
} catch (NamingException e) {
logger.log(Level.WARNING, "数据库连接池lookup错误！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
} catch (SQLException e) {
logger.log(Level.WARNING, "数据库连接池连接失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}

/**
* @功能：对数据库进行增、删、改、查操作
* @参数：sql为SQL语句；params为Object数组，里面存储的是为sql表示的SQL语句中"?"占位符赋值的数据
*/
public void doPstm(String sql, Object[] params) {
System.out.println(params.length);
if (sql != null && !sql.equals("")) {
if (params == null)
params = new Object[0];
if (conn != null) {
try {
System.out.println(sql);
pstm = conn.prepareStatement(sql,
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
for (int i = 0; i < params.length; i++) {
pstm.setObject(i + 1, params[i]);
}
pstm.execute();
} catch (SQLException e) {
logger.log(Level.WARNING, "doPstm()方法出错！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}
}
}

/**
* @功能：获取调用doPstm()方法执行查询操作后返回的ResultSet结果集
* @返回值：ResultSet
* @throws SQLException
*/
public ResultSet getRs() throws SQLException {
return pstm.getResultSet();
}

/**
* @功能：获取调用doPstm()方法执行更新操作后返回影响的记录数
* @返回值：int
* @throws SQLException
*/
public int getCount() throws SQLException {
return pstm.getUpdateCount();
}

/**
* @功能：释放PrepareStatement对象与Connection对象
*/
public void closed() {
try {
if (pstm != null)
pstm.close();
} catch (SQLException e) {
logger.log(Level.WARNING, "关闭pstm对象失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
try {
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
logger.log(Level.WARNING, "关闭Connection对象失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}

}

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DBPool {
private static final long serialVersionUID = 1L;

private static Logger logger = Logger.getLogger(DBPool.class.getName());

private static DBPool db = null;
private ComboPooledDataSource dataSource;

static {
if (db == null) {
db = new DBPool();
}
}

public static DBPool getInstance() {
if (db == null) {
db = new DBPool();
}
return db;
}

/**
* 私有化构造函数！
*
* @param propFileNames
*/
private DBPool() {
try {
dataSource = new ComboPooledDataSource();
dataSource.setUser("root");
dataSource.setPassword("123456");
dataSource.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/lesogo_game?user=root&password=123456&useUnicode=true");
dataSource.setDriverClass("com.mysql.jdbc.Driver");

// 设置初始连接池的大小！
dataSource.setInitialPoolSize(20);
// 设置连接池的最小值！
dataSource.setMinPoolSize(10);
// 设置连接池的最大值！
dataSource.setMaxPoolSize(50);
// 设置连接池中的最大Statements数量！
dataSource.setMaxStatements(200);
// 设置连接池的最大空闲时间！
dataSource.setMaxIdleTime(60);

dataSource.getConnection();
} catch (SQLException e) {
logger.log(Level.WARNING, "数据库连接池连接失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
} catch (PropertyVetoException e) {
logger.log(Level.WARNING, "c3p0配置错误！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
e.printStackTrace();
}
}

/**
* @功能：对数据库进行增、删、改、查操作
* @参数：sql为SQL语句；params为Object数组，里面存储的是为sql表示的SQL语句中"?"占位符赋值的数据
*/
public PreparedStatement doPstm(String sql, Object[] params) {
Connection conn = null;
PreparedStatement pstm = null;
if (sql != null && !sql.equals("")) {
if (params == null)
params = new Object[0];
try {
conn = dataSource.getConnection();
} catch (SQLException e1) {
e1.printStackTrace();
}
if (conn != null) {
try {
pstm = conn.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
for (int i = 0; i < params.length; i++) {
pstm.setObject(i + 1, params[i]);
}
pstm.execute();
} catch (SQLException e) {
logger.log(Level.WARNING, "doPstm()方法出错！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}
}
return pstm;
}

/**
* @功能：获取调用doPstm()方法执行查询操作后返回的ResultSet结果集
* @返回值：ResultSet
* @throws SQLException
*/
public ResultSet getRs(PreparedStatement pstm) throws SQLException {
return pstm.getResultSet();
}

/**
* @功能：获取调用doPstm()方法执行更新操作后返回影响的记录数
* @返回值：int
* @throws SQLException
*/
public int getCount(PreparedStatement pstm) throws SQLException {
return pstm.getUpdateCount();
}

/**
* @功能：释放PrepareStatement对象与Connection对象
*/
public void closed() {
try {
if (dataSource != null)
dataSource.close();
if (db != null) {
db = null;
}
} catch (Exception e) {
logger.log(Level.WARNING, "关闭失败！");
logger.log(Level.WARNING, e.getMessage());
e.printStackTrace();
}
}

}