org.zeroturnaround.javarebel.integration.resin.ResinPatchHelper Maven / Gradle / Ivy

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package org.zeroturnaround.javarebel.integration.resin;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.jar.JarOutputStream;
import java.util.zip.ZipEntry;
import org.zeroturnaround.javarebel.ClassBytecodeProcessor;
import org.zeroturnaround.javarebel.Logger;
import org.zeroturnaround.javarebel.LoggerFactory;
import org.zeroturnaround.javarebel.integration.util.ClassUtil;
import org.zeroturnaround.javarebel.integration.util.IoUtil;

/**
 * JavaRebel Resin patch related methods. 
 * 
 * Used since Resin 3.1.x.
 * 
 * @author Rein Raudjärv
 */
public class ResinPatchHelper {

  /**
   * Whether the Resin patch has been applied in this JVM.
   */
  private static boolean enabled;
  
  /**
   * If the patch is applied this method is called by the SystemClassLoader.
   */
  public static void setEnabled() {
    enabled = true;
  }
  
  /**
   * Show error if Resin patch is not applied.
   */
  public static void checkEnabled() {
    if (!isEnabled())
      error();
  }
  
  /**
   * @return true if the Resin patch is applied.
   */
  private static boolean isEnabled() {
    return enabled;
  }
  
  private static void error() {
    System.out.println();
    System.out.println("#############################################################");
    System.out.println();
    System.out.println("              JavaRebel Resin installation problem!");
    System.out.println();
    System.out.println(" See http://www.zeroturnaround.com/resin-problem/");
    System.out.println(" or consult with the installation manual for correct");
    System.out.println(" JavaRebel installation with Resin server.");
    System.out.println();
    System.out.println("#############################################################");
    System.out.println();
  }
  
  /**
   * Create a temporary JAR containing transformed Resin boot classes. 
   * 
   * @param cl class loader containing the original class resources.
   * @return temporary JAR file.
   */
  public static File createResinPatch(ClassLoader cl) throws IOException {
    File jar = File.createTempFile("javarebel-resin-patch", ".jar");
    
    JarOutputStream out = new JarOutputStream(new FileOutputStream(jar));
    
    transformAndZip(out, cl,
        "com.caucho.loader.DynamicClassLoader",
        new ResinDynamicClassLoaderCBP());
    transformAndZip(out, cl,
        "com.caucho.loader.SystemClassLoader",
        new ResinSystemClassLoaderCBP());
    transformAndZip(out, cl,
        "com.caucho.server.webapp.WebApp",
        new ResinWebAppCBP());
    
    out.close();
    
    Logger log = LoggerFactory.getInstance();
    if (log.isEnabled())
      log.log("Resin patch created: " + jar);

    return jar;
  }
  
  private static void transformAndZip(JarOutputStream out, ClassLoader cl, String classname, ClassBytecodeProcessor cbp) throws IOException {
    // Get the byte code of the class
    byte[] bytecode = ClassUtil.getBytecode(cl, classname);
    
    // Transform the byte code
    byte[] transformed = cbp.process(cl, classname, bytecode);
    
    Logger log = LoggerFactory.getInstance();
    if (log.isEnabled())
      log.log("Class '" + classname + "' processed by '" + cbp.getClass().getName() + "' into JAR.");
    
    // Add a ZIP entry
    out.putNextEntry(new ZipEntry(ClassUtil.getResourecName(classname)));
    IoUtil.write(transformed, out);
    out.closeEntry();
  }
  
  
}