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我要是不配置就报Need to specify class name in environment or system property,

www.MyException.Cn  网友分享于:2013-11-11  浏览:3554次
c3p0使用
我想在java se的环境里面使c3p0连接池!! 当时从官方下载下来的里面的xml配置文件是
<server>

  <mbean code="com.mchange.v2.c3p0.mbean.C3P0PooledDataSource"
  name="jboss:service=C3P0PooledDataSource">
 <attribute name="JndiName">java:PooledDS</attribute>
  <attribute name="JdbcUrl">jdbc:oracle:thin:@localhost:1521:orcl</attribute>
  <attribute name="DriverClass">oracle.jdbc.driver.OracleDriver</attribute>
  <attribute name="User">scott</attribute>
  <attribute name="Password">123456</attribute>
  <depends>jboss:service=Naming</depends>
  </mbean>

</server>

请问第一个参数和最后一个参数怎么配置!! java se的环境是不是不要配置最后一个参数!!

里面的源码的例子是:

String jndiName = args[0];
DataSource unpooled = DataSources.unpooledDataSource(
"jdbc:oracle:thin:@localhost:1521:orcl", "scott", "123456");
DataSource pooled = DataSources.pooledDataSource(unpooled);

InitialContext ctx = new InitialContext();
ctx.rebind(jndiName, pooled);


 我要是不配置就报Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
这个错!!

请问下这个jndiName是个什么东西!!

Java code


import java.sql.*;
import javax.naming.*;
import javax.sql.DataSource;

/**
 * This example shows how to programmatically get and directly use an unpooled
 * DataSource
 */
public final class UseJndiDataSource {

    public static void main(String[] args) {
        try {
        
            String jndiName = args[0];

            InitialContext ctx = new InitialContext();

            // acquire the DataSource... this is the only c3p0 specific code
            // here
            DataSource ds = (DataSource) ctx.lookup(jndiName);

            // get hold of a Connection an do stuff, in the usual way
            Connection con = null;
            Statement stmt = null;
            ResultSet rs = null;
            try {
                con = ds.getConnection();
                stmt = con.createStatement();
                rs = stmt.executeQuery("SELECT * FROM foo");
                while (rs.next())
                    System.out.println(rs.getString(1));
            } finally {
            
                // c3p0 DataSources will properly deal.
                attemptClose(rs);
                attemptClose(stmt);
                attemptClose(con);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static void attemptClose(ResultSet o) {
        try {
            if (o != null)
                o.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static void attemptClose(Statement o) {
        try {
            if (o != null)
                o.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static void attemptClose(Connection o) {
        try {
            if (o != null)
                o.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private UseJndiDataSource() {
    }
}




------解决方案--------------------
其实你要用的就是这段代码而以
DataSource unpooled = DataSources.unpooledDataSource(
"jdbc:oracle:thin:@localhost:1521:orcl", "scott", "123456");
DataSource pooled = DataSources.pooledDataSource(unpooled);

pooled .getConnection();
就可以操作了。。。不需要其它的,至于jndiName就是JAVA的一个命令服务,就像WINDOWS的注册表,应用写个键值对了,其它逻辑可以通过这个键去获取那个值,你给的代码貌似是去JOBSS取得相应的数据DataSource

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