package com.firefly.utils.classproxy;
import java.lang.reflect.Field;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import javassist.ClassClassPath;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtField;
import javassist.CtMethod;
import com.firefly.utils.ReflectUtils.FieldProxy;
import com.firefly.utils.StringUtils;
public class FieldProxyFactoryUsingJavassist extends AbstractFieldProxyFactory {
private static final Map<Field, FieldProxy> fieldCache = new ConcurrentHashMap<Field, FieldProxy>();
public static final FieldProxyFactoryUsingJavassist INSTANCE = new FieldProxyFactoryUsingJavassist();
private FieldProxyFactoryUsingJavassist() {
}
@Override
public FieldProxy getFieldProxy(Field field) throws Throwable {
FieldProxy ret = fieldCache.get(field);
if(ret != null)
return ret;
synchronized(fieldCache) {
ret = fieldCache.get(field);
if(ret != null)
return ret;
ret = _getFieldProxy(field);
fieldCache.put(field, ret);
return ret;
}
}
@SuppressWarnings("unchecked")
private FieldProxy _getFieldProxy(Field field) throws Throwable {
// long start = System.currentTimeMillis();
ClassPool classPool = ClassPool.getDefault();
classPool.insertClassPath(new ClassClassPath(FieldProxy.class));
classPool.importPackage(Field.class.getCanonicalName());
CtClass cc = classPool.makeClass("com.firefly.utils.ProxyField" + UUID.randomUUID().toString().replace("-", ""));
cc.addInterface(classPool.get(FieldProxy.class.getName()));
cc.addField(CtField.make("private Field field;", cc));
CtConstructor constructor = new CtConstructor(new CtClass[]{classPool.get(Field.class.getName())}, cc);
constructor.setBody("{this.field = (Field)$1;}");
cc.addConstructor(constructor);
cc.addMethod(CtMethod.make("public Field field(){return field;}", cc));
cc.addMethod(CtMethod.make(createFieldGetterMethodCode(field), cc));
cc.addMethod(CtMethod.make(createFieldSetterMethodCode(field), cc));
FieldProxy ret = (FieldProxy) cc.toClass().getConstructor(Field.class).newInstance(field);
// long end = System.currentTimeMillis();
// System.out.println("Javassist generates class proxy time -> " + (end - start));
return ret;
}
private String createFieldGetterMethodCode(Field field) {
Class<?> fieldClazz = field.getType();
StringBuilder code = new StringBuilder();
code.append("public Object get(Object obj){\n")
.append("\treturn ");
boolean hasValueOf = false;
if(fieldClazz.isPrimitive()) {
code.append(StringUtils.replace("(Object){}.valueOf(", primitiveWrapMap.get(fieldClazz)));
hasValueOf = true;
}
code.append(StringUtils.replace("(({})obj).{}", field.getDeclaringClass().getCanonicalName(), field.getName()));
if(hasValueOf)
code.append(")");
code.append(";\n")
.append("}");
return code.toString();
}
private String createFieldSetterMethodCode(Field field) {
Class<?> fieldClazz = field.getType();
StringBuilder code = new StringBuilder();
code.append("public void set(Object obj, Object value){\n");
code.append(StringUtils.replace("\t(({})obj).{} = ", field.getDeclaringClass().getCanonicalName(), field.getName()));
if(fieldClazz.isPrimitive()) {
code.append(StringUtils.replace("(({})value).{}Value()", primitiveWrapMap.get(fieldClazz), fieldClazz.getCanonicalName()));
} else {
code.append(StringUtils.replace("({})value", fieldClazz.getCanonicalName()));
}
code.append(";\n")
.append("}");
return code.toString();
}
}