Java-JDBC驱动程序和MySQL数据库连接问题
[英]Java - JDBC driver and MySQL database connection issues
问题描述
Ok - I found the driver version that goes with the database.. however now I get the following. 
好的-我找到了数据库附带的驱动程序版本。但是，现在我得到了以下内容。
Got an exception!
** BEGIN NESTED EXCEPTION **
java.net.ConnectException MESSAGE: Connection timed out: connect
STACKTRACE:
java.net.ConnectException: Connection timed out: connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:525) at java.net.Socket.connect(Socket.java:475) at java.net.Socket.(Socket.java:372) at java.net.Socket.(Socket.java:215) at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256) at com.mysql.jdbc.MysqlIO.(MysqlIO.java:271) at com.mysql.jdbc.Connection.createNewIO(Connection.java:2771) at com.mysql.jdbc.Connection.(Connection.java:1555) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285) at java.sql.DriverManager.getConnection(DriverManager.java:582) at java.sql.DriverManager.getConnection(DriverManager.java:185) at freelancebilling
** END NESTED EXCEPTION **
Last packet sent to the server was 1 ms ago.
3 个解决方案
解决方案1
3 已采纳 2010-06-18 23:05:18
This may not solve it, but it tells you that someone else has had this problem. 这可能无法解决，但它告诉您其他人遇到了此问题。
Make sure you have the precise version of JDBC driver to match your version of MySQL. 确保您具有精确的JDBC驱动程序版本以匹配您的MySQL版本。
I would strongly urge you to rewrite your code more like this. 我强烈建议您像这样重写代码。 You aren't closing resources properly at all. 您根本没有正确关闭资源。
Adapt it to your own needs. 使其适应您自己的需求。 I created a local MySQL database on my machine and added a customer table. 我在机器上创建了一个本地MySQL数据库，并添加了一个customer表。 It worked just fine. 工作正常。
package persistence;
import java.sql.Connection;
import java.sql.Driver;
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.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
public class DatabaseUtils
{
private static final String URL = "jdbc:mysql://localhost:3306/contacts";
private static final String USERNAME = "contacts";
private static final String PASSWORD = "contacts";
public static final String SELECT_SQL = "select customer_id, name, street, city, state, zip, phone, url from customer order by customer_id";
public static final String INSERT_SQL = "insert into customer(name, street, city, state, zip, phone, url) values(?,?,?,?,?,?,?)";
public static void main(String[] args)
{
Connection connection = null;
try
{
connection = getConnection(URL, USERNAME, PASSWORD);
List<Map> rows = findAllCustomers(connection);
for (Map row : rows)
{
System.out.println(row);
}
}
catch (SQLException e)
{
e.printStackTrace();
}
finally
{
close(connection);
}
}
public static List<Map> findAllCustomers(Connection connection) throws SQLException
{
List<Map> rows = new ArrayList<Map>();
PreparedStatement st = null;
ResultSet rs = null;
try
{
st = connection.prepareStatement(SELECT_SQL);
rs = st.executeQuery();
while (rs.next())
{
rows.add(map(rs));
}
}
finally
{
close(rs);
close(st);
}
return rows;
}
private static Map<String, Object> map(ResultSet rs) throws SQLException
{
Map<String, Object> row = new LinkedHashMap<String, Object>();
ResultSetMetaData meta = rs.getMetaData();
int numColumns = meta.getColumnCount();
for (int i = 1; i <= numColumns; ++i)
{
String column = meta.getColumnName(i);
Object value = rs.getObject(i);
row.put(column, value);
}
return row;
}
public static Connection getConnection(String url, String username, String password) throws SQLException
{
Driver driver = DriverManager.getDriver(url);
DriverManager.registerDriver(driver);
return DriverManager.getConnection(url, username, password);
}
public static void close(Connection connection)
{
try
{
if (connection != null)
{
connection.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(Statement st)
{
try
{
if (st != null)
{
st.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(ResultSet rs)
{
try
{
if (rs != null)
{
rs.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public void rollback(Connection connection)
{
try
{
if (connection != null)
{
connection.rollback();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
}
解决方案2
0 2013-05-22 06:31:23
/*
Connection
*/
import com.mysql.jdbc.Connection;
import java.sql.DriverManager;
public class PersonalConnection {
private String url = "jdbc:mysql://localhost:3306/";
private String schema = "database name";
private String uname = "";
private String password = "";
private Connection connection;
public Connection openConnection() {
try {
try {
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
} catch (Exception ex) {
}
connection = (Connection) DriverManager.getConnection(url + schema, uname, password);
} catch (Exception ex) {
}
return connection;
}
public void closeConneciton() {
try {
connection.close();
} catch (Exception ex) {
}
}
}
/* Servlet */
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
DetailsBean db = new DetailsBean();
String name = request.getParameter("name");
String countryname = request.getParameter("countryname");
String statename = request.getParameter("statename");
db.setName(name);
db.setCountry(countryname);
db.setState(statename);
DetailsManager dm = new DetailsManager();
String result = dm.insertDetailsManager(db);
if (result.equals("true")) {
/* RequestDispatcher rd = request.getRequestDispatcher("StateDetails.jsp?name=" + db.getName());
rd.forward(request, response);*/
response.sendRedirect("StateDetails.jsp");
} else {
out.print(result);
}
/* DAO */
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import com.mysql.jdbc.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class DetailsDAO {
private Connection connection;
private PersonalConnection con;
public DetailsDAO() {
con = new PersonalConnection();
}
public String insertRecordDAO(DetailsBean db) {
int rowcount=0;
try {
connection=con.openConnection();
String query = "INSERT INTO personal_details(user_name,country_name,state_name) values(?,?,?);";
PreparedStatement ps = connection.prepareStatement(query);
ps.setString(1, db.getName());
ps.setString(2, db.getCountry());
ps.setString(3, db.getState());
rowcount = ps.executeUpdate();
if(rowcount==1)
{
return "true";
}
else
{
return "false";
}
} catch (Exception ex) {
return ex+"";
} finally {
con.closeConneciton();
}
}
public ResultSet getGetails() throws Exception
{
connection=con.openConnection();
String query="SELECT * from state_details";
PreparedStatement ps=connection.prepareStatement(query);
ResultSet rs=ps.executeQuery();
return rs;
}
}
/*Manager*/
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.util.ArrayList;
public class DetailsManager {
DetailsDAO detdao = new DetailsDAO();
public String insertDetailsManager(DetailsBean db) {
String rowcount = detdao.insertRecordDAO(db);
return rowcount;
}
}
/*Bean*/
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
public class DetailsBean {
private String name;
private String country;
private String state;
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
}
解决方案3
0 2010-06-18 22:54:51
Can mysql accept network connections? mysql可以接受网络连接吗？ When you connect with the "mysql" command line program, you're not doing a network connection, but when you do with JDBC you are making a network connection. 当您使用“ mysql”命令行程序进行连接时，您未在进行网络连接，但是当您使用JDBC时，您正在进行网络连接。 Try using "-h localhost" in your mysql command line to see. 尝试在mysql命令行中使用“ -h localhost”来查看。
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