Q: How to access and modify xml tags using Java

Question

I have an xml based document that i need to access and change. For example, the code
<section id="section1">
<div>
<xforms:group id="id1">
<xforms:label id="label1">
<l style="font-size:16pt"> something </l>
</xforms:label>
</xforms:group>
</div>
</section>
Working with Java I need to access all the tags, select some of them that are relevant to the current device and remade the document. I thought I would read the file character by character identifying the different labels and building a tree, storing in the tree nodes the relevant information as some kind of attributes (for example, in the case of the <xforms:group id="id1"> I would name the node "xforms:group" and create an "id" attribute with value "id1"). I'm not sure if that is the most efficient way of accessing the problem (computational power might be an issue), and would appreciate some help on the subject.
Thanks,

Answer 1

this may help you..
this is a little util i made to help me read/write files.
using this, you are only one step away from your solutions, you only need to figure out the regex you need to run on the text of the file to make it become what you need it to become.
though if you use non-standard encoding, you might not want to use this code..
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
public class ASCIIFile {
     private File file;
     private StringBuilder builder;
     public ASCIIFile(String path) throws IOException{
          file = new File(path);
          openFile();
     public ASCIIFile(File file) throws IOException{
          this.file = file;
          openFile();
     public void setNewFileName(String fileName){
          file = new File(file.getAbsolutePath(), fileName);
     public void setNewFilePath(String filePath){
          file = new File(filePath, file.getName());
     private void openFile() throws IOException{
          if(!file.exists()) file.createNewFile();
          BufferedReader read = new BufferedReader(new FileReader(file));
          String line = read.readLine();
          builder = new StringBuilder();
          while(line != null){
               builder.append(line);
               builder.append("\n");
               line = read.readLine();
          read.close();
     public String getContents(){
          return builder.toString();
     public StringBuilder getStringBuilder(){
          return builder;
     public void setStringBuilder(StringBuilder b) throws IOException{
          setContents(b.toString());
     public void setContents(String contents) throws IOException{
          FileWriter writer = new FileWriter(file);
          writer.write(contents);
          writer.flush();
          writer.close();
          builder = new StringBuilder(contents);
     public static File[] getAllFilesUnderDir(String fullpath, boolean recursive) {
          ArrayList queue = new ArrayList(10);
          ArrayList matched = new ArrayList();
          File root = new File(fullpath);
          File[] files = root.listFiles();
          if (files == null || files.length == 0) {
               return new File[] {};
          queue.addAll(Arrays.asList(files));
          for (int j = 0; j < queue.size(); j++) {
               File child = (File) queue.get(j);
               if (child.isDirectory() && recursive) {
                    files = child.listFiles();
                    if (files != null) {
                         queue.addAll(Arrays.asList(files));
               } else { // child is file
                    matched.add(child);
          return (matched.size() > 0)?((File[]) matched.toArray(new File[] {})):(new File[] {});
}