我遇到以下问题:当我尝试使用我的外部 IP 地址(PC 的 IP 而不是我的本地 IP = 我们在 cmd.exe 中运行 ipconfig 后看到的输出)创建 TcpServer 时,会发生以下错误:
服务器错误:异常打开端口“9092”(端口可能正在使用中),原因:“java.net.BindException:无法分配请求的地址:JVM_Bind”[90061-169]
但是,该端口未使用。我已经使用 netstat -a -n 进行了检查。我已经启用了我的外部 IP,并且我已经禁用了路由器的防火墙。我的外部 IP 现在可以被 ping 通了。
请帮我。
更新:这是我启动 tcp 服务器的代码。
package businessApp;
import org.h2.tools.Server; //imports the server utility
public class startTcpServerForH2 {
Server server; //the server's instance variable
private static final String SERVER_IP = "192.168.1.101"; //fixed IP of the server
private static final String SERVER_PORT = "9092"; //fixed port the server is listening to
public void tcpServer() { //method responsible to create the tcp server
optionPane optPane = new optionPane(); //option pane for debugging purposes, shows the server's status
try { //catches any server related errors, if the connection is broken etc.
//server uses the IP and port defined earlier, allows other computers in the LAN to connect and implements the secure socket layer (SSL) feature
server = Server.createTcpServer( //create tcp server
new String[] { "-tcpPort" , SERVER_PORT , "-tcpAllowOthers" , "-tcpSSL" }).start();
System.out.println(server.getStatus()); //prints out the server's status
optPane.checkServerStatus(server.getStatus()); //prints out the server's status on the option pane as well
} catch(Exception ex){
System.out.println("Error with Server: " + ex.getMessage());
}
}
public static void main(String[] args){
startTcpServerForH2 tcpServ = new startTcpServerForH2(); //create a new server object
tcpServ.tcpServer(); //starts the tcp server
}
}
第二次更新:这里是 h2Connection 代码。
打包businessApp;
导入java.sql.*;//导入sql特征
//负责与H2数据库引擎连接的类 public class h2Connection {
Connection conn; //connection variable
DatabaseMetaData dbmd; /** Metadata variable which include methods such as the following:
* 1) Database Product Name
* 2) Database Product Version
* 3) URL where the database files are located (in TCP mode)
*/
Statement stm; //statements variable
ResultSet rst; //result sets variable
private static final String SERVER_IP = "..."; //here I enter my WAN_IP
private static final String SERVER_PORT = "9092";
public Connection connectionToH2(Connection connt) {
optionPane optPane = new optionPane(); //create new option pane object
String outputConn = null; //declare & initialize string which will hold important messages
try {
Class.forName("org.h2.Driver"); //Driver's name
/** The String URL is pertained of the following:
* 1) jdbc which java implements so that it can take advantage of the SQL features
* 2) Which Database Engine will be used
* 3) URL where the files will be stored (as this is a TCP connection)
* 4) Schema: businessApp
* 5) Auto server is true means that other computers can connect with the same databse at any time
* 6) Port number of the server is also defined
*/
String url = "jdbc:h2:tcp://" + SERVER_IP + ":" + SERVER_PORT + "/C:/Databases/businessApp;IFEXISTS=TRUE";
System.out.println(url); //prints out the url the database files are located as well as the h2 features used (SSL)
connt = DriverManager.getConnection(url, "sa", ""); //Driver Manager defines the username & password of the database
System.out.println(connt.getCatalog()); //prints out the database schema
optPane.checkServerStatus(connt.getCatalog()); //prints out the database schema on the option pane as well
connt.setAutoCommit(false); //set AutoCommit to false to control commit actions manually
//outputs H2 version and the URL of the database files which H2 is reading from, for confirmation
dbmd = connt.getMetaData(); //get MetaData to confirm connection
outputConn = "Connection to "+dbmd.getDatabaseProductName()+" "+
dbmd.getDatabaseProductVersion()+ " with the URL " + dbmd.getURL()+" was successful.\n";
System.out.println(outputConn); //outputs the message on the system (NetBeans compiler)
optPane.checkH2Connection(outputConn); //outputs the message on top of the frame
} catch (ClassNotFoundException ex){ //In case there is an error for creating the class for the Driver to be used
System.out.println("Error creating class: " + ex.getMessage());
} catch(SQLException ex){ //Any error associated with the Database Engine
System.out.println("SQL error: " + ex.getMessage());
optPane.checkServerStatus("SQL error: " + ex.getMessage());
}
return connt; //As the method is not void, a connection variable must be returned
}
}
当我想连接到 h2 数据库时,我创建了一个新的 h2Connection 对象并使用它来连接。我一个字一个字地跟着 H2 手册。你还需要什么?