// Copyright (c) 2003-2014, Jodd Team (jodd.org). All Rights Reserved.
package jodd.proxetta;
import jodd.io.FileUtil;
import jodd.proxetta.asm.TargetClassInfoReader;
import jodd.proxetta.asm.WorkData;
import jodd.util.StringUtil;
import jodd.asm5.ClassReader;
import jodd.asm5.ClassWriter;
import jodd.util.ClassLoaderUtil;
import jodd.io.StreamUtil;
import jodd.log.Logger;
import jodd.log.LoggerFactory;
import java.io.File;
import java.io.InputStream;
import java.io.IOException;
/**
* Proxetta builder. While {@link Proxetta} only holds aspects and
* configuration, <code>ProxettaBuilder</code> deals with the
* actually building proxies and wrappers over provided target.
*/
public abstract class ProxettaBuilder {
Logger log = LoggerFactory.getLogger(ProxettaBuilder.class);
protected final Proxetta proxetta;
/**
* Creates new builder.
*/
protected ProxettaBuilder(Proxetta proxetta) {
this.proxetta = proxetta;
}
// ---------------------------------------------------------------- IN
/**
* Main target source.
*/
private InputStream targetInputStream;
/**
* Target class, when available.
*/
private Class targetClass;
/**
* Target class name, when available.
*/
private String targetClassName;
/**
* Requested proxy class name (or class name template).
*/
protected String requestedProxyClassName;
/**
* Sets requested proxy class name.
*/
public void setTargetProxyClassName(String targetProxyClassName) {
this.requestedProxyClassName = targetProxyClassName;
}
// ---------------------------------------------------------------- IN targets
/**
* Defines class input stream as a target.
*/
protected void setTarget(InputStream target) {
checkTarget();
targetInputStream = target;
targetClass = null;
targetClassName = null;
}
/**
* Defines class name as a target.
* Class will not be loaded by classloader!
*/
protected void setTarget(String targetName) {
checkTarget();
try {
targetInputStream = ClassLoaderUtil.getClassAsStream(targetName);
targetClassName = targetName;
targetClass = null;
} catch (IOException ioex) {
StreamUtil.close(targetInputStream);
throw new ProxettaException("Unable to stream class name: " + targetName, ioex);
}
}
/**
* Defines class as a target.
*/
protected void setTarget(Class target) {
checkTarget();
try {
targetInputStream = ClassLoaderUtil.getClassAsStream(target);
targetClass = target;
targetClassName = target.getName();
} catch (IOException ioex) {
StreamUtil.close(targetInputStream);
throw new ProxettaException("Unable to stream class: " + target.getName(), ioex);
}
}
/**
* Checks if target is not defined yet.
*/
private void checkTarget() {
if (targetInputStream != null) {
throw new ProxettaException("Target already defined");
}
}
// ---------------------------------------------------------------- IN naming
/**
* Number appended to proxy class name, incremented on each use to make classnames unique
* in the system (e.g. classloader).
*
* @see Proxetta#setVariableClassName(boolean)
*/
protected static int suffixCounter;
/**
* Returns new suffix or <code>null</code> if suffix is not in use.
*/
protected String resolveClassNameSuffix() {
String classNameSuffix = proxetta.getClassNameSuffix();
if (classNameSuffix == null) {
return null;
}
if (proxetta.isVariableClassName() == false) {
return classNameSuffix;
}
suffixCounter++;
return classNameSuffix + suffixCounter;
}
// ---------------------------------------------------------------- PROCESS
/**
* Creates custom class builder and process the target class with it.
*/
protected abstract WorkData process(ClassReader cr, TargetClassInfoReader targetClassInfoReader);
// ---------------------------------------------------------------- ACCEPT
protected ClassWriter destClassWriter; // destination class writer
protected boolean proxyApplied;
protected String proxyClassName;
/**
* Reads the target and creates destination class.
*/
protected void process() {
if (targetInputStream == null) {
throw new ProxettaException("Target missing");
}
// create class reader
ClassReader classReader;
try {
classReader = new ClassReader(targetInputStream);
} catch (IOException ioex) {
throw new ProxettaException("Error reading class input stream", ioex);
}
// reads information
TargetClassInfoReader targetClassInfoReader = new TargetClassInfoReader();
classReader.accept(targetClassInfoReader, 0);
this.destClassWriter = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
// create proxy
if (log.isDebugEnabled()) {
log.debug("processing: " + classReader.getClassName());
}
WorkData wd = process(classReader, targetClassInfoReader);
// store important data
proxyApplied = wd.proxyApplied;
proxyClassName = wd.thisReference.replace('/', '.');
}
/**
* Returns byte array of created class.
*/
public byte[] create() {
process();
byte[] result = toByteArray();
dumpClass(result);
if ((proxetta.isForced() == false) && (isProxyApplied() == false)) {
if (log.isDebugEnabled()) {
log.debug("proxy not applied " + StringUtil.toSafeString(targetClassName));
}
return null;
}
if (log.isDebugEnabled()) {
log.debug("proxy created " + StringUtil.toSafeString(targetClassName));
}
return result;
}
/**
* Defines class.
*/
public Class define() {
process();
if ((proxetta.isForced() == false) && (isProxyApplied() == false)) {
if (log.isDebugEnabled()) {
log.debug("proxy not applied " + StringUtil.toSafeString(targetClassName));
}
if (targetClass != null) {
return targetClass;
} else if (targetClassName != null) {
try {
return ClassLoaderUtil.loadClass(targetClassName);
} catch (ClassNotFoundException cnfex) {
throw new ProxettaException(cnfex);
}
}
}
if (log.isDebugEnabled()) {
log.debug("proxy created " + StringUtil.toSafeString(targetClassName));
}
try {
ClassLoader classLoader = proxetta.getClassLoader();
if (classLoader == null) {
if (targetClass != null) {
classLoader = targetClass.getClassLoader();
}
if (classLoader == null) {
classLoader = ClassLoaderUtil.getDefaultClassLoader();
}
}
byte[] bytes = toByteArray();
dumpClass(bytes);
return ClassLoaderUtil.defineClass(getProxyClassName(), bytes, classLoader);
} catch (Exception ex) {
throw new ProxettaException("Class definition failed", ex);
}
}
/**
* Creates new instance of created class.
* Assumes default no-arg constructor.
*/
public Object newInstance() {
Class type = define();
try {
return type.newInstance();
} catch (Exception ex) {
throw new ProxettaException("Invalid Proxetta class", ex);
}
}
// ---------------------------------------------------------------- debug
/**
* Writes created class content to output folder for debugging purposes.
*/
protected void dumpClass(byte[] bytes) {
String debugFolder = proxetta.getDebugFolder();
if (debugFolder == null) {
return;
}
File folder = new File(debugFolder);
if (!folder.exists()) {
folder.mkdirs();
}
String fileName = proxyClassName;
if (fileName == null) {
fileName = "proxetta-" + System.currentTimeMillis();
}
fileName += ".class";
File file = new File(folder, fileName);
try {
FileUtil.writeBytes(file, bytes);
} catch (IOException ioex) {
log.warn("Error dumping class", ioex);
}
}
// ---------------------------------------------------------------- OUT
/**
* Checks if proxy is created and throws an exception if not.
*/
protected void checkAccepted() {
if (destClassWriter == null) {
throw new ProxettaException("Target not accepted yet!");
}
}
/**
* Returns raw bytecode.
*/
protected byte[] toByteArray() {
checkAccepted();
return destClassWriter.toByteArray();
}
/**
* Returns <code>true</code> if at least one method was wrapped.
*/
public boolean isProxyApplied() {
checkAccepted();
return proxyApplied;
}
/**
* Returns proxy class name.
*/
public String getProxyClassName() {
checkAccepted();
return proxyClassName;
}
}