好的 - 我找到了数据库附带的驱动程序版本..但现在我得到以下内容。
有例外！通讯链接 由于潜在的异常导致的失败：
**开始没有异常**
java.net.ConnectException消息： 连接超时：连接
堆栈跟踪：
java.net.ConnectException：Connection 超时：连接 在java.net.PlainSocketImpl.socketConnect（Native 方法） 在java.net.PlainSocketImpl.doConnect（PlainSocketImpl.java:333） 在java.net.PlainSocketImpl.connectToAddress（PlainSocketImpl.java:195） 在java.net.PlainSocketImpl.connect（PlainSocketImpl.java:182） 在java.net.SocksSocketImpl.connect（SocksSocketImpl.java:366） 在java.net.Socket.connect（Socket.java:525） 在java.net.Socket.connect（Socket.java:475） 在java.net.Socket。（Socket.java:372） 在java.net.Socket。（Socket.java:215） 在com.mysql.jdbc.StandardSocketFactory.connect（StandardSocketFactory.java:256） 在com.mysql.jdbc.MysqlIO。（MysqlIO.java:271） 在com.mysql.jdbc.Connection.createNewIO（Connection.java:2771） 在com.mysql.jdbc.Connection。（Connection.java:1555） 在com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:285） 在java.sql.DriverManager.getConnection（DriverManager.java:582） 在java.sql.DriverManager.getConnection（DriverManager.java:185） at freelancebillingapp.customerInfoUI.jButton1MouseClicked（customerInfoUI.java:221） at freelancebillingapp.customerInfoUI.access $ 000（customerInfoUI.java:12） at freelancebillingapp.customerInfoUI $ 1.mouseClicked（customerInfoUI.java:59） 在java.awt.AWTEventMulticaster.mouseClicked（AWTEventMulticaster.java:253） at java.awt.Component.processMouseEvent（Component.java:6266） 在javax.swing.JComponent.processMouseEvent（JComponent.java:3255） at java.awt.Component.processEvent（Component.java:6028） at java.awt.Container.processEvent（Container.java:2041） at java.awt.Component.dispatchEventImpl（Component.java:4630） at java.awt.Container.dispatchEventImpl（Container.java:2099） at java.awt.Component.dispatchEvent（Component.java:4460） at java.awt.LightweightDispatcher.retargetMouseEvent（Container.java:4574） at java.awt.LightweightDispatcher.processMouseEvent（Container.java:4247） at java.awt.LightweightDispatcher.dispatchEvent（Container.java:4168） at java.awt.Container.dispatchEventImpl（Container.java:2085） at java.awt.Window.dispatchEventImpl（Window.java:2475） at java.awt.Component.dispatchEvent（Component.java:4460） at java.awt.EventQueue.dispatchEvent（EventQueue.java:599） 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） 在java.awt.EventDispatchThread.run（EventDispatchThread.java:122）
**结束了例外**
发送到服务器的最后一个数据包是1 ms前。
答案 0 :(得分：3)
This可能无法解决，但它会告诉您其他人遇到此问题。
确保您拥有与您的MySQL版本匹配的JDBC驱动程序的精确版本。
我强烈建议你更改这样的代码。您根本没有正确关闭资源。
根据您自己的需要进行调整。我在我的机器上创建了一个本地MySQL数据库并添加了一个客户表。它运作得很好。
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();
}
}
}
答案 1 :(得分：0)
mysql可以接受网络连接吗？当您使用“mysql”命令行程序连接时，您没有进行网络连接，但是当您使用JDBC时，您正在建立网络连接。尝试在mysql命令行中使用“-h localhost”来查看。
答案 2 :(得分：0)
/*
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;
}
}