替换xml中某些特定的elements

package strip;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Properties;

public class StripXMLElements {

    public static void main(String[] args) {
        String oldfilename = args[0];
        String newfilename = args[1];
        String propertyfile = args[2];

        Properties prop = new Properties();
        try {
            FileInputStream fis = new FileInputStream(propertyfile);
            prop.load(fis);
            String elements = prop.getProperty("STRIP_ELEMENTS");

            if ((elements != null) && (!elements.equals(""))) {
                stripElements(oldfilename, elements, newfilename);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void stripElements(String oldFile, String stripElements,
            String newFile) throws IOException {

        String start = null;
        String end = null;
        int startIndex;
        int endIndex;
        String line = null;
        BufferedReader br = null;
        FileReader fr = null;
        FileWriter fw = null;
        BufferedWriter bw = null;
        String[] strs = stripElements.split(";");

        File file = new File(oldFile);
        try {
            fr = new FileReader(file);
            br = new BufferedReader(fr);
        } catch (FileNotFoundException e1) {
            e1.printStackTrace();
        }

        if (!file.exists()) {
            try {
                throw new FileNotFoundException();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        } else {
            fw = new FileWriter(newFile, true);
            bw = new BufferedWriter(fw);
            while ((line = br.readLine()) != null) {
                for (String str : strs) {
                    start = "<" + str + ">";
                    end = "</" + str + ">";
                    if (line.contains(start) && line.contains(end)) {
                        startIndex = line.indexOf(start) + start.length();
                        endIndex = line.indexOf(end);
                        line = line
                                .replace(line.substring(startIndex, endIndex),
                                        "STRIPED");
                        bw.write(line);
                        bw.newLine();
                        bw.flush();
                        line = br.readLine();
                        for (String s : strs) {
                            String starts = "<" + s + ">";
                            String ends = "</" + s + ">";
                            if (line.contains(starts) && line.contains(ends)) {
                                int startIndexs = line.indexOf(starts)
                                        + start.length();
                                int endIndexs = line.indexOf(ends);
                                line = line.replace(
                                        line.substring(startIndexs, endIndexs),
                                        "STRIPED");
                            }
                        }
                        break;
                    }
                }

                bw.write(line);
                bw.newLine();
                bw.flush();
            }
        }
        bw.flush();
        bw.close();
        br.close();
        fw.close();
        fr.close();

    }
}