com.oracle.tutorial.jdbc.ClobSample.java Source code

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Here is the source code for com.oracle.tutorial.jdbc.ClobSample.java

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/*
 * Copyright (c) 1995, 2011, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle or the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.oracle.tutorial.jdbc;

import java.io.BufferedReader;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;

import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;

import java.sql.Clob;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class ClobSample {

    private String dbName;
    private Connection con;
    private String dbms;
    private JDBCTutorialUtilities settings;

    public ClobSample(Connection connArg, JDBCTutorialUtilities settingsArg) {
        super();
        this.con = connArg;
        this.dbName = settingsArg.dbName;
        this.dbms = settingsArg.dbms;
        this.settings = settingsArg;
    }

    public String retrieveExcerpt(String coffeeName, int numChar) throws SQLException {

        String description = null;
        Clob myClob = null;
        PreparedStatement pstmt = null;

        try {
            String sql = "select COF_DESC from COFFEE_DESCRIPTIONS " + "where COF_NAME = ?";
            pstmt = this.con.prepareStatement(sql);
            pstmt.setString(1, coffeeName);
            ResultSet rs = pstmt.executeQuery();
            if (rs.next()) {
                myClob = rs.getClob(1);
                System.out.println("Length of retrieved Clob: " + myClob.length());
            }
            description = myClob.getSubString(1, numChar);
        } catch (SQLException sqlex) {
            JDBCTutorialUtilities.printSQLException(sqlex);
        } catch (Exception ex) {
            System.out.println("Unexpected exception: " + ex.toString());
        } finally {
            if (pstmt != null)
                pstmt.close();
        }
        return description;
    }

    public void addRowToCoffeeDescriptions(String coffeeName, String fileName) throws SQLException {
        PreparedStatement pstmt = null;
        try {
            Clob myClob = this.con.createClob();

            Writer clobWriter = myClob.setCharacterStream(1);
            String str = this.readFile(fileName, clobWriter);
            System.out.println("Wrote the following: " + clobWriter.toString());
            if (this.settings.dbms.equals("mysql")) {
                System.out.println("MySQL, setting String in Clob object with setString method");
                myClob.setString(1, str);
            }
            System.out.println("Length of Clob: " + myClob.length());
            String sql = "INSERT INTO COFFEE_DESCRIPTIONS VALUES(?,?)";
            pstmt = this.con.prepareStatement(sql);
            pstmt.setString(1, coffeeName);
            pstmt.setClob(2, myClob);
            pstmt.executeUpdate();
        } catch (SQLException sqlex) {
            JDBCTutorialUtilities.printSQLException(sqlex);
        } catch (Exception ex) {
            System.out.println("Unexpected exception: " + ex.toString());
        } finally {
            if (pstmt != null) {
                pstmt.close();
            }
        }
    }

    private String readFile(String fileName, Writer writerArg) throws FileNotFoundException, IOException {

        BufferedReader br = new BufferedReader(new FileReader(fileName));
        String nextLine = "";
        StringBuffer sb = new StringBuffer();
        while ((nextLine = br.readLine()) != null) {
            System.out.println("Writing: " + nextLine);
            writerArg.write(nextLine);
            sb.append(nextLine);
        }
        // Convert the content into to a string
        String clobData = sb.toString();

        // Return the data.
        return clobData;
    }

    public static void main(String[] args) {

        JDBCTutorialUtilities myJDBCTutorialUtilities;
        Connection myConnection = null;

        if (args[0] == null) {
            System.err.println("Properties file not specified at command line");
            return;
        } else {
            try {
                myJDBCTutorialUtilities = new JDBCTutorialUtilities(args[0]);
            } catch (Exception e) {
                System.err.println("Problem reading properties file " + args[0]);
                e.printStackTrace();
                return;
            }
        }

        try {
            myConnection = myJDBCTutorialUtilities.getConnection();

            ClobSample myClobSample = new ClobSample(myConnection, myJDBCTutorialUtilities);
            myClobSample.addRowToCoffeeDescriptions("Colombian", "txt/colombian-description.txt");
            String description = myClobSample.retrieveExcerpt("Colombian", 10);

            System.out.println(description);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTutorialUtilities.closeConnection(myConnection);
        }

    }

}