Java SQL ResultSet Print printResultSetMetadata(ResultSetMetaData rsmd, Writer out)

Description

Prints the ResultSetMetaData values for each column

License

Open Source License

Parameter

Parameter	Description
rsmd	a parameter
out	a parameter

Exception

Parameter	Description
SQLException	an exception
IOException	an exception

Declaration

public static void printResultSetMetadata(ResultSetMetaData rsmd,
        Writer out) throws SQLException, IOException 

Method Source Code

//package com.java2s;
/*/*  ww w.j av a2s .  co  m*/
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */

import java.io.IOException;

import java.io.Writer;
import java.lang.reflect.Method;

import java.sql.ResultSetMetaData;
import java.sql.SQLException;

public class Main {
    private static final String SPACER = "  ";
    private static final String NULL = "<null>";
    private static final String MORE = "$ ";
    private static String[] METADATA_METHODS = { "getColumnName", //$NON-NLS-1$
            "getColumnType", //$NON-NLS-1$
            "getCatalogName", //$NON-NLS-1$
            "getColumnClassName", //$NON-NLS-1$
            "getColumnLabel", //$NON-NLS-1$
            "getColumnTypeName", //$NON-NLS-1$
            "getSchemaName", //$NON-NLS-1$
            "getTableName", //$NON-NLS-1$
            "getColumnDisplaySize", //$NON-NLS-1$
            "getPrecision", //$NON-NLS-1$
            "getScale", //$NON-NLS-1$
            "isAutoIncrement", //$NON-NLS-1$
            "isCaseSensitive", //$NON-NLS-1$
            "isCurrency", //$NON-NLS-1$
            "isDefinitelyWritable", //$NON-NLS-1$
            "isNullable", //$NON-NLS-1$
            "isReadOnly", //$NON-NLS-1$
            "isSearchable", //$NON-NLS-1$
            "isSigned", //$NON-NLS-1$
            "isWritable", //$NON-NLS-1$
    };

    /**
     * Prints the ResultSetMetaData values for each column
     * @param rsmd
     * @param out
     * @throws SQLException
     * @throws IOException 
     * @since 4.2
     */
    public static void printResultSetMetadata(ResultSetMetaData rsmd,
            Writer out) throws SQLException, IOException {
        int columns = rsmd.getColumnCount();
        Class RSMD = ResultSetMetaData.class;
        Class[] params = { int.class };
        int numMethods = METADATA_METHODS.length;
        String[][] metadataStrings = new String[columns][numMethods];
        // Init the widths of the columns
        int[] maxColWidths = new int[numMethods];
        for (int i = 0; i < numMethods; i++) {
            maxColWidths[i] = METADATA_METHODS[i].length();
        }
        // Buffer the metadata
        for (int col = 1; col <= columns; col++) {
            Object[] columnParam = { new Integer(col) };
            for (int i = 0; i < numMethods; i++) {
                try {
                    Method m = RSMD.getMethod(METADATA_METHODS[i], params);
                    Object obj = m.invoke(rsmd, columnParam);
                    String stringVal = (obj == null) ? NULL : obj
                            .toString();
                    metadataStrings[col - 1][i] = stringVal;
                    if (maxColWidths[i] < stringVal.length()) {
                        maxColWidths[i] = stringVal.length();
                    }
                } catch (Throwable t) {

                }
            }
        }
        // Print the header
        for (int i = 0; i < numMethods; i++) {
            out.append(resizeString(METADATA_METHODS[i], maxColWidths[i]));
            if (i != numMethods) {
                out.append(SPACER);
            }
        }
        out.append("\n");
        // Print the metadata from the buffer
        for (int col = 0; col < columns; col++) {
            for (int i = 0; i < numMethods; i++) {
                out.append(resizeString(metadataStrings[col][i],
                        maxColWidths[i]));
                if (i != numMethods) {
                    out.append(SPACER);
                }
            }
            out.append("\n");
        }
    }

    private static String resizeString(Object obj, int size) {
        if (obj == null) {
            return resizeString(NULL, size);
        }
        String str = obj.toString();
        if (str.length() == size) {
            return str;
        } else if (str.length() < size) {
            return pad(str, size - str.length());
        } else {
            return str.substring(0, size) + MORE;
        }
    }

    private static String pad(String str, int padding) {
        StringBuffer buf = new StringBuffer(str);
        for (int i = 0; i < padding; i++) {
            buf.append(' ');
        }
        return buf.toString();
    }
}

Related

1. printResultSet(ResultSet rs)
2. printResultSet(ResultSet rs)
3. printResultSet(ResultSet rs)
4. printResultSetColumns(ResultSet rs)
5. printResultSetHeader(ResultSet rs)
6. printResultSetRow(ResultSet rs)
7. printResultsToFile(ResultSet rst, File outFile)
8. printRow(ResultSet pk)
9. printRsetTypeAndConcurrencyType(ResultSet rset)