package net.sf.jasperreports.engine.design;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import net.sf.jasperreports.engine.JRException;

public class JRJavacCompiler extends JRAbstractMultiClassCompiler {
  public String compileClasses(File[] sourceFiles, String classpath) throws JRException {
    String[] source = new String[sourceFiles.length + 3];
    source[0] = "javac";
    source[1] = "-classpath";
    source[2] = classpath;
    for (int i = 0; i < sourceFiles.length; i++)
      source[i + 3] = sourceFiles[i].getPath(); 
    try {
      Process compile = Runtime.getRuntime().exec(source);
      InputStream errFile = compile.getErrorStream();
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      byte[] buffer = new byte[1024];
      int count = 0;
      do {
        count = errFile.read(buffer);
        if (count <= 0)
          continue; 
        baos.write(buffer, 0, count);
      } while (count >= 0);
      if (baos.toString().indexOf("error") != -1)
        return baos.toString(); 
      return null;
    } catch (Exception e) {
      StringBuffer files = new StringBuffer();
      for (int j = 0; j < sourceFiles.length; j++) {
        files.append(sourceFiles[j].getPath());
        files.append(' ');
      } 
      throw new JRException("Error compiling report java source files : " + files, e);
    } 
  }
}
