这是代码：
public class MySQLAccess {
    private Connection connect = null;
    private Statement statement = null;
    private PreparedStatement preparedStatement = null;
    private ResultSet resultSet = null;

    public void readDataBase() throws Exception {
        try {
            // This will load the MySQL driver, each DB has its own driver
            Class.forName("com.mysql.jdbc.Driver");
            // Setup the connection with the DB
            connect = DriverManager
                    .getConnection("jdbc:mysql://localhost/feedback?"
                            + "user=test&password=123");
            

            // Statements allow to issue SQL queries to the database
            statement = connect.createStatement();
            // Result set get the result of the SQL query
            resultSet = statement
                    .executeQuery("select * from );
            writeResultSet(resultSet);

            // PreparedStatements can use variables and are more efficient
            preparedStatement = connect
                    .prepareStatement("insert into   values (default, ?, ?, ?, ? , ?, ?)");
            // "myuser, webpage, datum, summery, COMMENTS from );
            // Parameters start with 1
            preparedStatement.setString(1, "Test");
            preparedStatement.setString(2, "TestEmail");
            preparedStatement.setString(3, "TestWebpage");
            preparedStatement.setDate(4, new java.sql.Date(2009, 12, 11));
            preparedStatement.setString(5, "TestSummary");
            preparedStatement.setString(6, "TestComment");
            preparedStatement.executeUpdate();

            preparedStatement = connect
                    .prepareStatement("SELECT myuser, webpage, datum, summery, COMMENTS from );
            resultSet = preparedStatement.executeQuery();
            writeResultSet(resultSet);

            // Remove again the insert comment
            preparedStatement = connect
            .prepareStatement("delete from where myuser= ? ; ");
            preparedStatement.setString(1, "Test");
            preparedStatement.executeUpdate();
            
            resultSet = statement
            .executeQuery("select * from );
            writeMetaData(resultSet);
            
        } catch (Exception e) {
            throw e;
        } finally {
            close();
        }

    }
Exception in thread "main" com.mysql.jdbc.exceptions. 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:406)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2214)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:781)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    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:406)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at Test.example.MySQLAccess.readDataBase(MySQLAccess.java:23)
    at Test.test.Test.main(Test.java:6)
Caused by: com.mysql.jdbc.exceptions. 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:406)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:343)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2137)
    ... 13 more
Caused by: connect: Address is invalid on local machine, or port is not valid on remote machine
    at (Native Method)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at (Unknown Source)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:292)
    ... 14 more
这报错让我不知所措啊```初学数据库``````希望大虾们能帮忙解决一下``

[ 本帖最后由 cqxooo 于 2009-11-16 01:55 编辑 ]

mySQL的驱动包加载一下

加载过了```

我没连mySQL,但按你报错来看，要么是Driver错了，要么是包有问题