NoInitialContextException 错误 Tomcat

Question

我一直试图在这里找到解决方案，但我不能... 我有以下代码，但出现此错误。

我错过了什么吗？谢谢:)

代码

package src;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Wrapper;
import java.util.Hashtable;
import java.util.Properties;
import java.io.*;
import javax.*;
import javax.activation.DataSource;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import oracle.jdbc.pool.OracleDataSource;

public class TestServlet {

    @SuppressWarnings("unused")
    public static void main(String[] argv) throws SQLException, NamingException {

        Context initialContext = new InitialContext();
        if ( initialContext == null){System.out.println("initialContext null");}
        else {System.out.println("initialContext");}

        // Get DataSource
        Context environmentContext = (Context)initialContext.lookup("java:/comp/env");
        if ( environmentContext == null){System.out.println("envContext null.");}
        else {System.out.println("envContext");}

        DataSource ds = (DataSource)environmentContext.lookup("jdbc/testdb");



        System.out.println("\n -------- Oracle JDBC Connection Testing ------");

        try {

            Connection jdbcConnection = ((Statement) ds).getConnection();
            OracleDataSource ods = ((Wrapper) ds).unwrap(OracleDataSource.class);
            jdbcConnection.close();

        } catch (SQLException e) {

            System.out.println("Connection Failed! Check output console");
            e.printStackTrace();
            return;

        }

        String message = "You are connected!";
        System.out.println(message);

    }

}

context.xml

<Context>
    <Resource name="jdbc/testdb"
    auth="Container"
    type="javax.sql.DataSource" 
    maxActive="100"
    maxIdle="30"
    maxWait="10000" 
    username="dba01"
    password="qvE-g7Cacontext.xml"
    driverClassName="com.mysql.jdbc.Driver" 
    url="jdbc:oracle:thin:@10.0.1.6:1521:xe"/>
</Context>

错误

Exception in thread "main" javax.naming.NoInitialContextException: 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
    at javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
    at javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
    at javax.naming.InitialContext.getURLOrDefaultInitCtx(Unknown Source)
    at javax.naming.InitialContext.lookup(Unknown Source)
    at src.TestServlet.main(TestServlet.java:34)

如果您需要更多信息，请告诉我！

Answer 1

那么是部署在服务器上的代码吗？您似乎在调用 static main 时尝试使用标准 java 访问上下文（所以我猜您是从运行时调用 TeestServlet.main ）。上下文将由 Web 服务器 (Tomcat) 设置，因此只有在您将 Web 应用程序部署到它之后它才可用。

Answer 2

您需要一个初始上下文工厂。对于 Tomcat 它是 org.apache.naming.java.javaURLContextFactory:

        System.setProperty(Context.INITIAL_CONTEXT_FACTORY,
                  "org.apache.naming.java.javaURLContextFactory");

Answer 3

请注意，您使用的 driverClassName 不正确。如果您尝试连接到 Oracle 数据库，它应该是 "oracle.jdbc.OracleDriver"。

<Context>
    <Resource name="jdbc/testdb"
    auth="Container"
    type="javax.sql.DataSource" 
    maxActive="100"
    maxIdle="30"
    maxWait="10000" 
    username="dba01"
    password="qvE-g7Cacontext.xml"
    driverClassName="com.mysql.jdbc.Driver" 
    url="jdbc:oracle:thin:@10.0.1.6:1521:xe"/>
</Context>

NoInitialContextException 错误 Tomcat

NoInitialContextException Error Tomcat

java

tomcat

servlets