连接到MySQL服务器无法
x1.instance3650.db.xeround.com-nino_db
[chatserver.sql.MySqlConnection.rehash()]
this is con null [.()]
connection to MySQL server failed
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:
Cannot load connection class because of underlying exception:
'java.lang.NumberFormatException: For input string: "chatserver"'.
[chatserver.sql.MySqlConnection.connect()]
Exception in thread "AWT-EventQueue-0" [.()]
java.lang.NullPointerException [.()] at
chatserver.sql.MySqlConnection.ensureConnected(MySqlConnection.java:105) [.()] at
chatserver.sql.MySqlConnection.getServerConfig(MySqlConnection.java:936) [.()] at
chatserver.objects.ServerConfig.loadConfigFromSql(ServerConfig.java:57) [.()] at
chatserver.objects.ServerConfig.<init>(ServerConfig.java:49) [.()] at
chatserver.objects.Server.<init>(Server.java:36) [.()] at
chatserver.objects.Server.getInstance(Server.java:88) [.()] at
chatserver.main.ServerMain$1.run(ServerMain.java:24) [.()] at
java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) [.()] at
java.awt.EventQueue.dispatchEvent(EventQueue.java:597) [.()] at
java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269) [.()]
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184) [.()]
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174) [.
()] at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169) [.()] at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161) [.()] at
java.awt.EventDispatchThread.run(EventDispatchThread.java:122) [.()]
这是由下面的代码块抛出..连接到MySQL服务器无法
try {
//conn = DriverManager.getConnection ("jdbc:mysql://localhost:chatserver");
// Joshua - change
// dbPassword = "";
conn = DriverManager.getConnection("jdbc:mysql://" + dbHost + ":"
+ dbPort + "/" + dbDatabase + "?" + "user=" + dbUser
+ "&"
+ "password=" + dbPassword);
lastMySqlActionTime = new Date().getTime();
} catch (SQLException e) {
System.out.println("this is con "+conn);
ServerLog.logError("connection to MySQL server failed "+e);
return false;
}
我可以通过命令提示符,然后利用数据库访问数据库...它不是抛出错误在驱动程序的任何错误...
PLZ一些人可以帮你me..thank
从堆栈跟踪和代码段可用看来你dbPort
是chatserver
,wher EAS端口就像3306
一个int,因此在解析它作为整数它是失败的,给你NumberFormatException
。
所以不是
conn = DriverManager.getConnection ("jdbc:mysql://localhost:chatserver")
尝试用这种
conn = DriverManager.getConnection ("jdbc:mysql://localhost:3306/chatserver")
完整的连接字符串将类似于如下:
DriverManager.getConnection("jdbc:mysql://localhost:3306/chatserver",
"root", "root");
在上面,你可以把你的用户名,密码,dbPort ,数据库名称等
这里我假设你想连接到一个名为的ChatServer
感谢ümprabhat我sloved这个问题,但我已经遇到了新的疑难问题运行代码ñ它在我的netbeans运行顺利,但是当我尝试运行它gaves错误 本地主机,myblechat [这个特殊项目的jar文件chatserver.sql.MySqlConnection.rehash()] 与MySQL服务器的连接失败[chatserver.sql.MySqlConnection.connect()] 线程“AWT-EventQueue-0”中的异常java.lang.NullPointerException atchatserver.sql.MySqlConnection。 ensureConnected(MySqlConnection.java:100) chatserver.sql.MySqlConnection.getServerConfig(MySqlConnection.java:931) – nissal
高兴,你可以检查此[链接](http://*.com/questions/4498047/export-jar- netbeans)为NetBeans中的Jar Export或可以开始一个新的问题。 – mprabhat
请注明答案正确其中帮你:) – mprabhat
模式,我认为这个问题是在
conn = DriverManager.getConnection ("jdbc:mysql://localhost:chatserver");
你得到一个NumberFormatException异常,因为端口号应是数字。
看看我下面的代码,并尝试实现它作为它在这里....我希望它会顺利运行..一旦你开始得到你想要的查询结果,修改它为你的心脏内容进一步R & D 。
请change the password and username
在这个方案
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;
import javax.swing.JTable;
import com.my.views.*;
public class DBDiary {
Connection conn;
EntryDisplay entryD;
public DBDiary(){
this.getConn();
}
public Connection getConn(){
try {
conn = getConnection();
} catch (SQLException e) {
System.out.println("Connection Couldnt be Obtained");
}
return conn;
}
public static Connection getConnection() throws SQLException {
String drivers = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/test";
String username = "root";
String password = "root";
System.setProperty(drivers,"");
return DriverManager.getConnection(url,username,password);
}
public void createTable() {
Statement stat = null;
String sql = "create table items(item varchar(30), cost DOUBLE(12,3),day integer,month varchar(15), year integer);";
if (conn != null){
try {
stat = conn.createStatement();
} catch (SQLException e) {
System.out.println("Connection Couldnt be Obtained");
}
if (stat != null){
try {
stat.executeUpdate(sql);
} catch (SQLException e) {
//System.out.println("Table already Exists");
}
}
}
}
public void addItems(String item, double cost,int day, String month, int year) {
PreparedStatement pstat = null;
String sql = "INSERT INTO ITEMS Values(?,?,?,?,?);";
if (conn != null){
try {
pstat = conn.prepareStatement(sql);
} catch (SQLException e) {
System.out.println("Connection Couldnt be Obtained");
}
}
if (pstat != null) {
try {
pstat.setString(1, item);
pstat.setDouble(2, cost);
pstat.setInt(3, day);
pstat.setString(4, month);
pstat.setInt(5,year);
pstat.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
System.out.println("Insertion of the entry was unsuccessful");
}
}
}
public static void main(String[] args) {
DBDiary db = new DBDiary();
db.createTable();
db.addItems("Cards", 40.00,29, "Mar", 2012);
}
请您适当格式化你的问题?错误消息正确包装并缩进,代码也一样。 – glglgl