java - 由 : java.net.NoRouteToHostException: No route to host 引起

Question

我正尝试在 openshift 上从 eclipse 部署我的 Jersey 项目，但尾文件中出现此错误 Caused by: java.net.NoRouteToHostException: No route to host

之前我有这样的经历:

String host = "jdbc:mysql://$OPENSHIFT_MYSQL_DB_HOST:$OPENSHIFT_MYSQL_DB_PORT/bustrackerserver"

我遇到了这个错误:

'java.lang.NumberFormatException: For input string: “OPENSHIFT_MYSQL_DB_PORT”'

• 我已经对这个 IP 地址 127.10.230.440 执行了 ping 操作，我收到了回复
• 我检查了一些端口 8080、3306 是否正在从我的本地机器中使用，但它们只是从 eclipse 中使用。

苹果类。

package org.busTracker.serverSide;


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

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

/**
 * Root resource (exposed at "myresource" path)
 */
@Path("myresource")
public class Apple {

    //String host = " jdbc:mysql://${env.OPENSHIFT_MYSQL_DB_HOST}:${env.OPENSHIFT_MYSQL_DB_PORT}/serv‌​erside";
    //String host = "jdbc:mysql://$OPENSHIFT_MYSQL_DB_HOST:$OPENSHIFT_MYSQL_DB_PORT/bustrackerserver";
    String host = "jdbc:mysql://127.10.230.440:3306/bustrackerserver";
    String user = "adminNMccsBr";
    String password = "K3SV5rbxh8qP";


    /**
     * Method handling HTTP GET requests. The returned object will be sent
     * to the client as "text/plain" media type.
     *
     * @return String that will be returned as a text/plain response.
     */
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String getIt() {

        Connection conn = null;  
        try {    
          Class.forName("com.mysql.jdbc.Driver");    
          System.out.println("Connecting to database…");    
          conn = DriverManager.getConnection(host,user,password);    

          Map<String, String> env = System.getenv();
          for (String envName : env.keySet()) {
              System.out.format("%s=%s%n",
                                envName,
                                env.get(envName));
          }



        } catch (Exception e) {    
          e.printStackTrace();    
        } finally {    
          if (conn != null) {    
            try {    
              conn.close();    
            } catch (SQLException e) {    
              // ignore    
            }    
          }    
        }   

        return "Hello, from apple class  14.05.15 13:30!";
    }
}

Answer 1

您的 MySQL 未监听 TCP/IP，因此您的连接尝试失败。当您说:

I checked whether some of the port 8080, 3306 are being used from my local mashine but they are just being used from eclipse.

换句话说，MySQL 不在本地主机上监听。要以另一种方式确认这一点，请尝试从命令提示符连接到 MySQL:

mysql -u adminNMccsBr -h 127.10.230.440 -p YOUR_DB_NAME

我预计这会失败。您的问题的解决方案是将 MySQL 配置为在本地主机上监听。在 /etc/my.cnf 配置文件中，在 [mysqld] 行下，添加以下内容:

bind-address = 127.10.230.440

这不是 Java 的问题，这是 MySQL 的问题。