Eclipse 连接到学院服务器时出现JDBC连接问题
我已尝试从工作场所连接到学院服务器并收到响应:Eclipse 连接到学院服务器时出现JDBC连接问题,eclipse,jdbc,Eclipse,Jdbc,我已尝试从工作场所连接到学院服务器并收到响应: Connection Failed! Check output console 我的代码: public JDBCBasicExample() { // TODO Auto-generated constructor stub } public static void main(String[] argv) { System.out.println("-------- MySQL JDBC Co
Connection Failed! Check output console
我的代码:
public JDBCBasicExample() {
// TODO Auto-generated constructor stub
}
public static void main(String[] argv) {
System.out.println("-------- MySQL JDBC Connection Testing ------------");
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your MySQL JDBC Driver?");
e.printStackTrace();
return;
}
System.out.println("MySQL JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager
.getConnection("jdbc:mysql://collegeservername:portnumber/databasenameinserver",
"username","password");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
return;
}
if (connection != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
}
我得到以下错误:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1121)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:675)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1086)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2486)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at testingdatabase.JDBCBasicExample.main(JDBCBasicExample.java:29)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly l`enter code here`ost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3119)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
... 16 more
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障
成功发送到服务器的最后一个数据包是0毫秒前的。驱动程序尚未从服务器收到任何数据包。
位于sun.reflect.NativeConstructorAccessorImpl.newInstance0(本机方法)
位于sun.reflect.NativeConstructorAccessorImpl.newInstance(未知源)
位于sun.reflect.delegatingConstructor或AccessorImpl.newInstance(未知源)
位于java.lang.reflect.Constructor.newInstance(未知源)
位于com.mysql.jdbc.Util.HandleneInstance(Util.java:411)
位于com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1121)
位于com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:675)
位于com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1086)
位于com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2486)
位于com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
位于com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
位于com.mysql.jdbc.ConnectionImpl(ConnectionImpl.java:834)
位于com.mysql.jdbc.JDBC4Connection(JDBC4Connection.java:47)
位于sun.reflect.NativeConstructorAccessorImpl.newInstance0(本机方法)
位于sun.reflect.NativeConstructorAccessorImpl.newInstance(未知源)
位于sun.reflect.delegatingConstructor或AccessorImpl.newInstance(未知源)
位于java.lang.reflect.Constructor.newInstance(未知源)
位于com.mysql.jdbc.Util.HandleneInstance(Util.java:411)
位于com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
位于com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
位于java.sql.DriverManager.getConnection(未知源)
位于java.sql.DriverManager.getConnection(未知源)
位于testingdatabase.jdbbasicexample.main(jdbbasicexample.java:29)
原因:java.io.EOFException:无法从服务器读取响应。预期读取4个字节,在连接意外断开之前读取0个字节l`enter code here`ost。
在com.mysql.jdbc.MysqlIO.readFully上(MysqlIO.java:3119)
位于com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
... 还有16个
有人能帮我解决这个问题吗?我是新手,尝试过很多其他方法,比如用ip地址替换collegeservername:portnumber,尽管不起作用。我也尝试过使用其他远程地址和端口名,但没有成功。请给我您的建议。连接失败简单检查表:
bind address=127.0.0.1
)您好,该错误意味着它无法与数据库或数据库服务器通信。数据库服务器是否有只允许来自某一组IP地址的连接的防火墙?您确定数据库正在运行吗?您确定使用的端口正确吗?所有这三个问题都是产生这种错误的常见原因。我首先从执行代码的机器上执行telnet。执行“telnet服务器URL端口号”。我能够连接到存在端口问题的服务器