java.sql.SQLException: IO 异常：网络适配器无法建立连接？

Question

您好，我正在尝试使用 eclipse 开普勒上的 ojdbc14 jar 和 windows 7 操作系统上的 java 8 连接 Oracle 11g 数据库。 但是当我运行代码时，出现以下错误。 这是我的和相应的错误。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Scanner;

    public class JDBCExample {
      public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       System.out.println("enter your databse details");
       System.out.println("user name");
       String uName = sc.next();
       System.out.println("password");
       String pWord = sc.next();
       try {
          Class.forName("oracle.jdbc.driver.OracleDriver");
       } catch (ClassNotFoundException e) {
        e.printStackTrace();
       }
       Connection conn = null;
       try {
        conn = DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521:orcl", "scott", "tiger");
        // jdbc:oracle:thin:@server:1521:xe
       } catch (SQLException e) {
        e.printStackTrace();
       }
       if (conn != null) {
        System.out.println("Successfully connected to DB");
        } else {
        System.out.println("Failed to connect to DB");
       }
   }
}

错误如下。 java.sql.SQLException: Io exception: The Network Adapter could not establish the connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255) at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387) at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414) at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165) at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35) at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) at JDBCExample.main(JDBCExample.java:23)

Answer 1

通过我们的对话，您可以在命令提示符下远程登录并连接到数据库。 经过jdbcurl之后，我发现了错误。

如果xe是数据库的SID，则localhost：1521 / xe应为localhost：1521：xe 。

从更改此代码

conn = DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521/xe", "scott", "tiger");

至

conn = DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521:xe", "scott", "tiger");

看看这篇文章

Answer 2

从services.msc启动oracle监听服务

Answer 3

您缺少导入oracle.jdbc.driver.OracleDriver