import java.util.jar.*;import java.util.*;import java.util.zip.ZipEntry;import java.lang.reflect.Field;import java.lang.reflect.Method;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import org.apache.poi.hssf.usermodel.HSSFSheet;import org.apache.poi.hssf.usermodel.HSSFRow;import org.apache.poi.hssf.usermodel.HSSFCell;import org.apache.poi.hssf.usermodel.HSSFCellStyle;import org.apache.poi.hssf.usermodel.HSSFFont;import org.apache.poi.hssf.util.HSSFColor;import java.io.FileOutputStream;/** * This class  would extract information  * from a Java Archive File and write information * about the classes into an Excel Sheet. * The key information generated are the following <br> * a) The class Name in First Column <br> * b) The Class Member Fields in second column <br> * c) The Declared Methods in Third column <br> * The Java archive file and the Output File Location * must be passed in as parameters * * @author  Elango Sundaram * @version 1.0 */public class JavaExtract {        /** Creates a new instance of JavaExtract */    public JavaExtract() {    }    /** Name of the input Jar File */    public String jarFile=null;    /** Where the ouput XL should be written */    public String outputFile=null;    /** The XL Document */    HSSFWorkbook workbook = new HSSFWorkbook();    /** The XL Sheet */    HSSFSheet sheet = null;        /* Creates an instance and Initializes the same  */    public static void main(String argv[]){        JavaExtract jE = new JavaExtract();        // Make sure you pass the        jE.jarFile= System.getProperty("JAR_FILE");        jE.outputFile = System.getProperty("OUTPUT_FILE");        // Make sure that jarFile param is available        if(jE.jarFile == null){            System.out.println("The JAR_FILE parameter is not passed as a -DJAR_FILE ..");        }        // Make sure that output file name param is available        if(jE.outputFile == null){            System.out.println("The OUTPUT_FILE parameter is not passed as a -DOUTPUT_FILE ..");        }        // Create the workbook..        jE.createWorkBookAndSheet();        // Unzip and start writing        jE.unZipAndWrite();        // Create headers in the Excel Book        jE.headers();        // Write the XL Document to file..        jE.writeToFile();        System.out.println("Done.." );    }        /**     * Creates an excel workbook & sheet and does column     * formatting     */    public  void createWorkBookAndSheet(){        try{            // Create a New XL Document            workbook = new HSSFWorkbook();            // Make a worksheet in the XL document created            // Give a Name to the worksheet            sheet = workbook.createSheet("Java Class Info");            System.out.println("Work Sheet Created " );            // Set the first three columns with            //  The width is in units of 1/256th of a character width            sheet.setColumnWidth((short)0,(short)10000 );            sheet.setColumnWidth((short)1,(short)10000 );            sheet.setColumnWidth((short)2,(short)10000 );        }catch(Exception e) {            System.out.println("!!FAILURE!! createWorkBookAndSheet() : " + e );        }    }    /**     * This method will unzip the Zip file     * and start writing in to excel..     * The key information gererated are the following     * a) The class Name in First Column <br>     * b) The Class Member Fields in second column <br>     * c) The Declared Methods in Third column <br>     */    public void unZipAndWrite(){        try{            JarFile jF = new JarFile(jarFile);            Enumeration enum = jF.entries();            ZipEntry zN = null;            String  fN = null;            String clazName = null;            String classLoadName = null;            Class clz = null;            short rowNum  = 1;            short cellNum = 0;            while(enum.hasMoreElements()){			try			{                zN = (ZipEntry)enum.nextElement();                fN = zN.getName();                if(fN.indexOf(".class")!= -1){                    // The class name contains /. Butto load class we need the                    // path to be separated by dot. So do the replace                    clazName = fN.replace('/', '.');                    // To Load class, we dont need the extension.. so                    // remove the .class from the classname                    classLoadName = clazName.substring(0,clazName.length() - 6);                    System.out.println("Process The Class --> " + classLoadName );                    // Create a Row                    HSSFRow row = sheet.createRow((short)rowNum);                    HSSFCell cell = row.createCell((short) cellNum);                    // Lets make the cell a string type                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);                                        // Write the Name of the Class in the first                    // column                    cell.setCellValue(classLoadName);                                        // Begin Wringing the Declared classes                    // in the second coloumn                    cell = row.createCell((short) (cellNum+1) );                    // Load the class..					clz  = Class.forName(classLoadName, false , this.getClass().getClassLoader());                    //clz = Class.forName(classLoadName);                                        Field[] fL = clz.getDeclaredFields();                    // Go Over the Fields and get the Names                    for(int i=0; i< fL.length;i++){                        // Keep appending the Name of the Field                        if(i==0){                            cell.setCellValue(fL[i].getName());                        }else {                            cell.setCellValue(cell.getStringCellValue()+ ", "+ fL[i].getName());                        }                    }                                        cell = row.createCell((short) (cellNum+2) );                    // Lets make the cell a string type                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);                                        Method[] method = clz.getDeclaredMethods();                    for(int i=0; i< method.length;i++){                        // Keep appending the Name of the Field                        if(i==0){                            cell.setCellValue(method[i].getName());                        }else {                            cell.setCellValue(cell.getStringCellValue()+ ", "+ method[i].getName());                        }                    }                    // Go to the next line                    rowNum++;                }// close if                				}catch (Exception innerEx){					System.out.println("FAILURE!! unZipAndWrite() .. In proceessing file : " + innerEx );				}            }// close while			        }catch(Exception e) {            System.out.println("!!FAILURE!! unZipAndWrite() : " + e );        }    }            /**     * Writes headers in the output file     */    public  void headers(){        try{            HSSFRow row = sheet.createRow((short)0);            // Set the correct font            HSSFFont font = workbook.createFont();            font.setColor(HSSFFont.COLOR_RED);            font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);            // Set the correct Style            HSSFCellStyle cellStyle= workbook.createCellStyle();            cellStyle.setFont(font);            // Set the cell style for Class Name Heading Cell             HSSFCell cell = row.createCell((short) 0);            cell.setCellStyle(cellStyle);            cell.setCellType(HSSFCell.CELL_TYPE_STRING);            cell.setCellValue("Class Name ");            // Set the cell style for Declared Fields Heading Cell             cell = row.createCell((short) 1);            cell.setCellStyle(cellStyle);            cell.setCellType(HSSFCell.CELL_TYPE_STRING);            cell.setCellValue("Declared Fields");             // Set the cell style for Declared Methods Heading Cell             cell = row.createCell((short) 2);            cell.setCellStyle(cellStyle);            cell.setCellType(HSSFCell.CELL_TYPE_STRING);            cell.setCellValue("Declared Methods");        }catch(Exception e) {            System.out.println("!!FAILURE!! headers() : " + e );        }            }    /**     * Write the created excel document in to a file     */    public  void writeToFile(){        try{            System.out.println("Write Output" );            // The Output file is where the xls will be created            FileOutputStream fOut = new FileOutputStream(outputFile);            // Write the XL sheet            workbook.write(fOut);            fOut.flush();            // Done Deal..Close it            fOut.close();            System.out.println("Done Writing" );        }catch(Exception e) {            System.out.println("!!FAILURE!! writeToFile() : " + e );        }            }}