这段代码，哪里错了？？？

[zxy_cp]

package database;


import java.net.URL;
import java.sql.*;
import java.util.*;

public class testdatabase {
ResultSet results;
ResultSetMetaData rsmd;
DatabaseMetaData dma;
Connection con;
int numcols,i;

public testdatabase() throws Exception {
String sUrl="jdbc:microsoft:sqlserver://"+"192.168.16.1:1433;"+"databasename=user";
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
con=DriverManager.getConnection(sUrl,"sa","");
dma=con.getMetaData();
System.out.println("Connected to:"+dma.getURL());
System.out.println("Driver:"+dma.getDriverName());
String types[]=new String[1];
types[0]="TABLES";
results=dma.getTables(null,null,"%",types);
try{
printResult("-------Tables-------");
}
catch(Exception e){e.printStackTrace();}
results.close();
}
protected void printResult(String s) throws Exception{
System.out.println(s);
rsmd=results.getMetaData();
numcols=rsmd.getColumnCount();
for(i=1;i<=numcols;i++)
System.out.print(rsmd.getColumnName(i)+" ");
System.out.println();
while(results.next()){
for(i=1;i<=numcols;i++)
System.out.print(results.getString(i)+" ");
System.out.println();
}
}


public static void main(String[] args) {
try{
testdatabase mydatabase=new testdatabase();
}
catch (Exception e){e.printStackTrace();}
}
}

输出结果如下：
Connected to:jdbc:microsoft:sqlserver://192.168.16.1:1433;SELECTMETHOD=direct;DATABASENAME=user;LOGINTIMEOUT=0

Driver:SQLServer

-------Tables-------

TABLE_CAT TABLE_SCHEM TABLE_NAME TABLE_TYPE REMARKS


结果没有输出我连接的数据库里的所有表的信息，发现results里没有数据。
该怎么做，我才能得到所有表的信息呢？？？

[mysine]

我这里有通用连接数据库，得到数据库数据的程序供你参考
/**
* A general-purpose SQL interpreter program.
**/
public class ExecuteSQL {
public static void main(String[] args) {
Connection conn = null; // Our JDBC connection to the database server
try {
String driver = null, url = null, user = "", password = "";

// Parse all the command-line arguments
for(int n = 0; n < args.length; n++) {
if (args[n].equals("-d")) driver = args[++n];
else if (args[n].equals("-u")) user = args[++n];
else if (args[n].equals("-p")) password = args[++n];
else if (url == null) url = args[n];
else throw new IllegalArgumentException("Unknown argument.");
}

// The only required argument is the database URL.
for(int n = 0; n < args.length; n++) {
if (args[n].equals("-d")) System.out.println("-d = " + args[++n]);
else if (args[n].equals("-u")) System.out.println("-u = " + args[++n]);
else if (args[n].equals("-p")) System.out.println("-p = " + args[++n]);
else if (url == null) url = args[n];
}

if (url == null)
throw new IllegalArgumentException("No database specified");

// If the user specified the classname for the DB driver, load
// that class dynamically. This gives the driver the opportunity
// to register itself with the DriverManager.
if (driver != null) Class.forName(driver);

// Now open a connection the specified database, using the
// user-specified username and password, if any. The driver
// manager will try all of the DB drivers it knows about to try to
// parse the URL and connect to the DB server.
conn = DriverManager.getConnection(url, user, password);

// Now create the statement object we'll use to talk to the DB
Statement s = conn.createStatement();

// Get a stream to read from the console

[mysine]

BufferedReader in =
new BufferedReader(new InputStreamReader(System.in));

// Loop forever, reading the user's queries and executing them
while(true) {
System.out.print("sql> "); // prompt the user
System.out.flush(); // make the prompt appear now.
String sql = in.readLine(); // get a line of input from user

// Quit when the user types "quit".
if ((sql == null) || sql.equals("quit")) break;

// Ignore blank lines
if (sql.length() == 0) continue;

// Now, execute the user's line of SQL and display results.
try {
// We don't know if this is a query or some kind of
// update, so we use execute() instead of executeQuery()
// or executeUpdate() If the return value is true, it was
// a query, else an update.
boolean status = s.execute(sql);

// Some complex SQL queries can return more than one set
// of results, so loop until there are no more results
do {
if (status) { // it was a query and returns a ResultSet
ResultSet rs = s.getResultSet(); // Get results
printResultsTable(rs, System.out); // Display them
}
else {
// If the SQL command that was executed was some
// kind of update rather than a query, then it
// doesn't return a ResultSet. Instead, we just
// print the number of rows that were affected.
int numUpdates = s.getUpdateCount();
System.out.println("Ok. " + numUpdates +
" rows affected.");
}

// Now go see if there are even more results, and
// continue the results display loop if there are.
status = s.getMoreResults();
} while(status || s.getUpdateCount() != -1);
}
// If a SQLException is thrown, display an error message.
// Note that SQLExceptions can have a general message and a
// DB-specific message returned by getSQLState()
catch (SQLException e) {
System.err.println("SQLException: " + e.getMessage()+ ":" +
e.getSQLState());
}

[mysine]

// Each time through this loop, check to see if there were any
// warnings. Note that there can be a whole chain of warnings.
finally { // print out any warnings that occurred
SQLWarning w;
for(w=conn.getWarnings(); w != null; w=w.getNextWarning())
System.err.println("WARNING: " + w.getMessage() +
":" + w.getSQLState());
}
}
}
// Handle exceptions that occur during argument parsing, database
// connection setup, etc. For SQLExceptions, print the details.
catch (Exception e) {
System.err.println(e);
if (e instanceof SQLException)
System.err.println("SQL State: " +
((SQLException)e).getSQLState());
System.err.println("Usage: java ExecuteSQL [-d <driver>] " +
"[-u <user>] [-p <password>] <database URL>");
}

// Be sure to always close the database connection when we exit,
// whether we exit because the user types 'quit' or because of an
// exception thrown while setting things up. Closing this connection
// also implicitly closes any open statements and result sets
// associated with it.
finally {
try { conn.close(); } catch (Exception e) {}
}
}

/**
* This method attempts to output the contents of a ResultSet in a
* textual table. It relies on the ResultSetMetaData class, but a fair
* bit of the code is simple string manipulation.
**/
static void printResultsTable(ResultSet rs, OutputStream output)
throws SQLException
{
// Set up the output stream
PrintWriter out = new PrintWriter(output);

// Get some "meta data" (column names, etc.) about the results
ResultSetMetaData metadata = rs.getMetaData();

// Variables to hold important data about the table to be displayed
int numcols = metadata.getColumnCount(); // how many columns
String[] labels = new String[numcols]; // the column labels
int[] colwidths = new int[numcols]; // the width of each
int[] colpos = new int[numcols]; // start position of each
int linewidth; // total width of table

// Figure out how wide the columns are, where each one begins,
// how wide each row of the table will be, etc.
linewidth = 1; // for the initial '|'.
for(int i = 0; i < numcols; i++) { // for each column
colpos[i] = linewidth; // save its position
labels[i] = metadata.getColumnLabel(i+1); // get its label
// Get the column width. If the db doesn't report one, guess
// 30 characters. Then check the length of the label, and use
// it if it is larger than the column width
int size = metadata.getColumnDisplaySize(i+1);
if (size == -1) size = 30; // Some drivers return -1...
if (size > 500) size = 30; // Don't allow unreasonable sizes
int labelsize = labels[i].length();
if (labelsize > size) size = labelsize;
colwidths[i] = size + 1; // save the column the size
linewidth += colwidths[i] + 2; // increment total size
}