Oracle Database Table to JAVA Bean Class Converter

Source Files

• TableBeanMapping.java
• SQLJavaDatatypeMapping.java
• ColumnDatatypeMapping.java
• OracleJDBC.java
• ColumnDatatypeEntry.java
• ConnConfig.properties

Introduction

This example shows how you convert Oracle Database table to a JAVA Bean class. It allows you to generate Java Bean classes for your Oracle Database tables. In Java Bean class, Table name, Column name & Datatype name will be mapped into Class name, Data Member name & Datatype name.

Background

This example is dependent on the following libraries:

1. commons-lang.jar
2. ojdbc14-10.1.0.2.0.jar

Quick Start

Creating the class TableBeanMapping

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Calendar;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.commons.lang.WordUtils;

/**
 *
 * @author Debopam
 */
public class TableBeanMapping {

    public static void generateBean(String folderName) {
        try {
            Connection connection = OracleJDBC.GetConnection();
            ColumnDatatypeMapping cdm;
            String sqlSelectTableName = "SELECT TABLE_NAME FROM USER_TABLES";
            PreparedStatement psSelectTable = connection.prepareStatement(sqlSelectTableName);
            ResultSet rsTable = psSelectTable.executeQuery();
            String tableName;
            while (rsTable.next()) {
                cdm = new ColumnDatatypeMapping();
                tableName = rsTable.getString("TABLE_NAME");
                String sqlSelectColumn = 
                "SELECT COLUMN_NAME FROM COLS WHERE TABLE_NAME='" + 
                tableName + "'";
                PreparedStatement psSelectColumn = connection.prepareStatement(sqlSelectColumn);
                ResultSet rsColumn = psSelectColumn.executeQuery();
                String columnName;
                while (rsColumn.next()) {
                    columnName = rsColumn.getString("COLUMN_NAME");
                    String sqlSelectDatatype = "SELECT DATA_TYPE FROM COLS 
                    WHERE TABLE_NAME='" + tableName + "' AND COLUMN_NAME='" + 
                    columnName + "'";
                    PreparedStatement psSelectDatatype = connection.prepareStatement(sqlSelectDatatype);
                    ResultSet rsDatatype = psSelectDatatype.executeQuery();
                    String datatypeName;
                    while (rsDatatype.next()) {
                        datatypeName = rsDatatype.getString("DATA_TYPE");
                        cdm.put(columnName, datatypeName);
                    }
                    psSelectDatatype.close();
                    rsDatatype.close();
                }
                psSelectColumn.close();
                rsColumn.close();
                writeBean(folderName, tableName, cdm);
            }
            psSelectTable.close();
            rsTable.close();
        } catch (SQLException ex) {
            Logger.getLogger(TableBeanMapping.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private static void writeBean(String folderName, String tableName, ColumnDatatypeMapping cdm) {
        FileWriter fileWriter;
        BufferedWriter bufferedWriter;
        StringBuilder fileContent;
        String className = getConventionalClassName(tableName);
        SQLJavaDatatypeMapping sqlJavaDatatypeMapping = new SQLJavaDatatypeMapping();
        try {
            fileWriter = new FileWriter(folderName + "\\" + className + ".java");
            bufferedWriter = new BufferedWriter(fileWriter);
            fileContent = new StringBuilder();
            fileContent.append("/*");
            fileContent.append("\n* File\t\t: ").append(className).append(".java");
            fileContent.append("\n* Date Created\t: ").append(Calendar.getInstance().getTime().toString());
            fileContent.append("\n*/");
            fileContent.append("\n\n");
            fileContent.append("public class ").append(className).append(" {");
            fileContent.append("\n");
            for (ColumnDatatypeEntry entry : cdm.entrySet()) {
                fileContent.append("\n\t");
                fileContent.append("private");
                fileContent.append(" ");
                fileContent.append(sqlJavaDatatypeMapping.getJavaDatatype(entry.getDatatype()));
                fileContent.append(" ");
                fileContent.append(entry.getColumn().toLowerCase());
                fileContent.append(";");
            }

            for (ColumnDatatypeEntry entry : cdm.entrySet()) {
                fileContent.append("\n\n\t");
                fileContent.append("public");
                fileContent.append(" ");
                fileContent.append(sqlJavaDatatypeMapping.getJavaDatatype(entry.getDatatype()));
                fileContent.append(" ");
                fileContent.append(getAccessorMethodName(entry.getColumn().toLowerCase()));
                fileContent.append("() {");
                fileContent.append("\n\t\t").append("return ").append
                (entry.getColumn().toLowerCase()).append(";");
                fileContent.append("\n\t").append("}");

                fileContent.append("\n\n\t");
                fileContent.append("public");
                fileContent.append(" ");
                fileContent.append("void");
                fileContent.append(" ");
                fileContent.append(getMutatorMethodName(entry.getColumn().toLowerCase()));
                fileContent.append("(");
                fileContent.append(sqlJavaDatatypeMapping.getJavaDatatype(entry.getDatatype()));
                fileContent.append(" ").append(entry.getColumn().toLowerCase());
                fileContent.append(") {");
                fileContent.append("\n\t\t").append("this.").append
                (entry.getColumn().toLowerCase()).append(" = ").append
                (entry.getColumn().toLowerCase()).append(";");
                fileContent.append("\n\t").append("}");
            }
            fileContent.append("\n").append("}");

            bufferedWriter.write(fileContent.toString());
            bufferedWriter.close();
        } catch (IOException ex) {
            Logger.getLogger(TableBeanMapping.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public static String getConventionalClassName(String str) {
        String conventionalClassName = "";
        String[] splittedStr = str.split("[_]");
        for (int i = 0; i < splittedStr.length; i++) {
            conventionalClassName += WordUtils.capitalizeFully(splittedStr[i]);
        }
        return conventionalClassName;
    }

    public static String getConventionalMethodName(String str) {
        String conventionalClassName = getConventionalClassName(str);
        return Character.toLowerCase(conventionalClassName.charAt(0)) + 
        conventionalClassName.substring(1);
    }

    public static String getAccessorMethodName(String dataMemberName) {
        return "get" + Character.toUpperCase(dataMemberName.charAt(0)) + 
        dataMemberName.substring(1);
    }

    public static String getMutatorMethodName(String dataMemberName) {
        return "set" + Character.toUpperCase(dataMemberName.charAt(0)) + 
        dataMemberName.substring(1);
    }
}

Sample Database Table – MOBILE_VERIFY

Sample Bean Class – MobileVerify

/*
* File		    : MobileVerify.java
* Date Created	: Sun May 25 03:17:00 IST 2014
*/

public class MobileVerify {

	private java.math.BigDecimal otp;
	private String appln_no;
	private java.sql.Timestamp valid_till;
	private java.math.BigDecimal mobile;
	private java.sql.Timestamp log_date;
	private String status;

	public java.math.BigDecimal getOtp() {
		return otp;
	}

	public void setOtp(java.math.BigDecimal otp) {
		this.otp = otp;
	}

	public String getAppln_no() {
		return appln_no;
	}

	public void setAppln_no(String appln_no) {
		this.appln_no = appln_no;
	}

	public java.sql.Timestamp getValid_till() {
		return valid_till;
	}

	public void setValid_till(java.sql.Timestamp valid_till) {
		this.valid_till = valid_till;
	}

	public java.math.BigDecimal getMobile() {
		return mobile;
	}

	public void setMobile(java.math.BigDecimal mobile) {
		this.mobile = mobile;
	}

	public java.sql.Timestamp getLog_date() {
		return log_date;
	}

	public void setLog_date(java.sql.Timestamp log_date) {
		this.log_date = log_date;
	}

	public String getStatus() {
		return status;
	}

	public void setStatus(String status) {
		this.status = status;
	}
}

How to Call

// Setting folder path...
String folderPath = "C:\\Users\\Debopam\\Desktop\\JavaBeans";
        
// Generating Java Beans in the specified folder...
TableBeanMapping.generateBean(folderPath);

Limitation

It is just a command line tool now. You can generate Java Beans from Oracle Database only. I hope that I will come up with the next version of this article without these limitations.

Reference

• Datatype Mappings

If you have any doubts, please post your questions. If you really like this article, please share it.

Don’t forget to vote or comment about my writing.
CodeProject