项目一段时间就出现异常，导致无法登陆系统，数据库无法连接上

异常信息如下：

java.sql.SQLException: Io 异常: Connection reset by peer: socket write error
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:333)
    at oracle.jdbc.driver.OracleConnection.rollback(OracleConnection.java:1380)
    at com.newland.So.Transaction.executeQuery(Transaction.java:107)
    at com.newland.Dao.UserInfoDao.findUser(UserInfoDao.java:184)
    at com.newland.Blo.UserInfoBlo.findUser(UserInfoBlo.java:119)
    at org.apache.jsp.loginAction_jsp._jspService(loginAction_jsp.java:111)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at com.newland.So.EncodeFilter.doFilter(EncodeFilter.java:32)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:744)

解决过程：

出现上面的异常时因为tomcat的conf/context.xml没有加入数据库断开重连配置，配置如下（红字部分）：

<Context>

    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->
    <!--join break line reconnection config-->
    <span style="color:#ff0000;"><parameter> <name>validationQuery</name> <value>SELECT COUNT(*) FROM DUAL</value> </parameter>
    <parameter> <name>testOnBorrow</name> <value>true</value> </parameter>
    <parameter> <name>testOnReturn</name> <value>true</value> </parameter>
    <parameter> <name>testWhileIdle</name> <value>true</value> </parameter></span>

</Context>

配置完成重启还是会出现错误，怎么办呢，考虑用连接池获取连接的方式替代原来的jdbc连接，我选用了C3P0

下面是部分关键代码：

dataSource = new ComboPooledDataSource();
dataSource.setUser(ConnUserName);
dataSource.setPassword(ConnPassWord);
dataSource.setJdbcUrl(ConnUrl);

dataSource.setDriverClass("oracle.jdbc.driver.OracleDriver");
dataSource.setInitialPoolSize(initialPoolSize);
dataSource.setMinPoolSize(minPoolSize);
dataSource.setMaxPoolSize(maxPoolSize);
dataSource.setMaxStatements(maxStatements);
dataSource.setMaxIdleTime(maxIdleTime);

//连接池
	        if(dataSource!=null){
	        	conn = dataSource.getConnection();
	        }

用这种方式暂时解决了问题，至少不会出现登录不了系统的情况了

然后接着几天又出现问题了，登录不了了，重新想办法，设置连接池配置，不靠谱，因为IO断了，重连有问题，还是自己改程序吧

添加异常自动重连，以下是initDataSource关键代码，其他数据库连接的简单写法就不写了：

//如果是重连的，获取连接池的连接
            try {
                conn = dataSource.getConnection();
                conn.setAutoCommit(false);
            } catch (SQLException e) {
                e.printStackTrace();
                reConnect();//自动重连
            }

/** 如果初始化数据库失败无限次重连，直到连接成功为止
     * 为了解决异常：java.sql.SQLException: Io 异常: Connection reset by peer: socket write error
     */
    public static void reConnect() {
        while (true) {
            if (conn == null) {
                logger.info("-----------------start reinit dataSource-----------------");
                Transaction.initDataSource();
            } else {
                break;
            }
        }
    }

/**
     * 查询数据，conn为空就自动重连
     * @param qstr
     * @return
     * @throws SQLException
     */
       public ResultSet executeQuery(String qstr) throws SQLException{
        ResultSet cResultSet = null;
        try{
            if(conn==null ){
                reConnect();
            }
            stmt = conn.createStatement();
            cResultSet = stmt.executeQuery(qstr);
        }
        catch(SQLException e) {
            stmt.close();
            conn.rollback();
            throw e;
        }
        return cResultSet;
    }
       /**
        * 数据更新，conn为空就自动重连
        * @param qstr
        * @throws SQLException
        */
    public void executeUpdate(String qstr) throws SQLException{
        try{
            if(conn==null ){
                reConnect();
            }
            stmt = conn.createStatement();
            stmt.executeUpdate(qstr);
            stmt.close();
        }
        catch(SQLException e) {
            stmt.close();
            conn.rollback();
            throw e;
        }
     }

在系统登录模块异常注入重连机制：

catch(SQLException e){
    e.printStackTrace();
    Transaction.initDataSource();
}

不知其他人是否有更好的方法来解决此类问题