A standalone program that reads a list of classes and builds a database of packages, classes, and class fields and methods : BufferedReader « File Input Output « Java






A standalone program that reads a list of classes and builds a database of packages, classes, and class fields and methods

   
 
/*
 * Copyright (c) 2004 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 3nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose,
 * including teaching and use in open-source projects.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book, 
 * please visit http://www.davidflanagan.com/javaexamples3.
 */

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileReader;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

/**
 * This class is a standalone program that reads a list of classes and builds a
 * database of packages, classes, and class fields and methods.
 */
public class MakeAPIDB {
  public static void main(String args[]) {
    Connection c = null; // The connection to the database
    try {
      // Read the classes to index from a file specified by args[0]
      ArrayList classnames = new ArrayList();
      BufferedReader in = new BufferedReader(new FileReader(args[0]));
      String name;
      while ((name = in.readLine()) != null)
        classnames.add(name);

      // Now determine the values needed to set up the database
      // connection The program attempts to read a property file named
      // "APIDB.props", or optionally specified by args[1]. This
      // property file (if any) may contain "driver", "database", "user",
      // and "password" properties that specify the necessary values for
      // connecting to the db. If the properties file does not exist, or
      // does not contain the named properties, defaults will be used.
      Properties p = new Properties(); // Empty properties
      try {
        p.load(new FileInputStream(args[1])); // Try to load properties
      } catch (Exception e1) {
        try {
          p.load(new FileInputStream("APIDB.props"));
        } catch (Exception e2) {
        }
      }

      // Read values from Properties file
      String driver = p.getProperty("driver");
      String database = p.getProperty("database");
      String user = p.getProperty("user", "");
      String password = p.getProperty("password", "");

      // The driver and database properties are mandatory
      if (driver == null)
        throw new IllegalArgumentException("No driver specified!");
      if (database == null)
        throw new IllegalArgumentException("No database specified!");

      // Load the driver. It registers itself with DriverManager.
      Class.forName(driver);

      // And set up a connection to the specified database
      c = DriverManager.getConnection(database, user, password);

      // Create three new tables for our data
      // The package table contains a package id and a package name.
      // The class table contains a class id, a package id, and a name.
      // The member table contains a class id, a member name, and an bit
      // that indicates whether the class member is a field or a method.
      Statement s = c.createStatement();
      s.executeUpdate("CREATE TABLE package " + "(id INT, name VARCHAR(80))");
      s.executeUpdate("CREATE TABLE class " + "(id INT, packageId INT, name VARCHAR(48))");
      s.executeUpdate("CREATE TABLE member " + "(classId INT, name VARCHAR(48), isField BIT)");

      // Prepare some statements that will be used to insert records into
      // these three tables.
      insertpackage = c.prepareStatement("INSERT INTO package VALUES(?,?)");
      insertclass = c.prepareStatement("INSERT INTO class VALUES(?,?,?)");
      insertmember = c.prepareStatement("INSERT INTO member VALUES(?,?,?)");

      // Now loop through the list of classes and use reflection
      // to store them all in the tables
      int numclasses = classnames.size();
      for (int i = 0; i < numclasses; i++) {
        try {
          storeClass((String) classnames.get(i));
        } catch (ClassNotFoundException e) {
          System.out.println("WARNING: class not found: " + classnames.get(i) + "; SKIPPING");
        }
      }
    } catch (Exception e) {
      System.err.println(e);
      if (e instanceof SQLException)
        System.err.println("SQLState: " + ((SQLException) e).getSQLState());
      System.err.println("Usage: java MakeAPIDB " + "<classlistfile> <propfile>");
    }
    // When we're done, close the connection to the database
    finally {
      try {
        c.close();
      } catch (Exception e) {
      }
    }
  }

  /**
   * This hash table records the mapping between package names and package id.
   * This is the only one we need to store temporarily. The others are stored in
   * the db and don't have to be looked up by this program
   */
  static Map package_to_id = new HashMap();

  // Counters for the package and class identifier columns
  static int packageId = 0, classId = 0;

  // Some prepared SQL statements for use in inserting
  // new values into the tables. Initialized in main() above.
  static PreparedStatement insertpackage, insertclass, insertmember;

  /**
   * Given a fully-qualified classname, this method stores the package name in
   * the package table (if it is not already there), stores the class name in
   * the class table, and then uses the Java Reflection API to look up all
   * methods and fields of the class, and stores those in the member table.
   */
  public static void storeClass(String name) throws SQLException, ClassNotFoundException {
    String packagename, classname;

    // Dynamically load the class.
    Class c = Class.forName(name);

    // Display output so the user knows that the program is progressing
    System.out.println("Storing data for: " + name);

    // Figure out the packagename and the classname
    int pos = name.lastIndexOf('.');
    if (pos == -1) {
      packagename = "";
      classname = name;
    } else {
      packagename = name.substring(0, pos);
      classname = name.substring(pos + 1);
    }

    // Figure out what the package id is. If there is one, then this
    // package has already been stored in the database. Otherwise, assign
    // an id, and store it and the packagename in the db.
    Integer pid;
    pid = (Integer) package_to_id.get(packagename); // Check hashtable
    if (pid == null) {
      pid = new Integer(++packageId); // Assign an id
      package_to_id.put(packagename, pid); // Remember it
      insertpackage.setInt(1, packageId); // Set statement args
      insertpackage.setString(2, packagename);
      insertpackage.executeUpdate(); // Insert into package db
    }

    // Now, store the classname in the class table of the database.
    // This record includes the package id, so that the class is linked to
    // the package that contains it. To store the class, we set arguments
    // to the PreparedStatement, then execute that statement
    insertclass.setInt(1, ++classId); // Set class identifier
    insertclass.setInt(2, pid.intValue()); // Set package identifier
    insertclass.setString(3, classname); // Set class name
    insertclass.executeUpdate(); // Insert the class record

    // Now, get a list of all non-private methods of the class, and
    // insert those into the "members" table of the database. Each
    // record includes the class id of the containing class, and also
    // a value that indicates that these are methods, not fields.
    Method[] methods = c.getDeclaredMethods(); // Get a list of methods
    for (int i = 0; i < methods.length; i++) { // For all non-private
      if (Modifier.isPrivate(methods[i].getModifiers()))
        continue;
      insertmember.setInt(1, classId); // Set the class id
      insertmember.setString(2, methods[i].getName()); // Set method name
      insertmember.setBoolean(3, false); // It is not a field
      insertmember.executeUpdate(); // Insert into db
    }

    // Do the same thing for the non-private fields of the class
    Field[] fields = c.getDeclaredFields(); // Get a list of fields
    for (int i = 0; i < fields.length; i++) { // For each non-private
      if (Modifier.isPrivate(fields[i].getModifiers()))
        continue;
      insertmember.setInt(1, classId); // Set the class id
      insertmember.setString(2, fields[i].getName()); // Set field name
      insertmember.setBoolean(3, true); // It is a field
      insertmember.executeUpdate(); // Insert the record
    }
  }
}

   
    
    
  








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