org.redkale.util.Reproduce Maven / Gradle / Ivy
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package org.redkale.util;
import java.lang.reflect.Modifier;
import java.util.function.*;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
import jdk.internal.org.objectweb.asm.*;
import static jdk.internal.org.objectweb.asm.ClassWriter.COMPUTE_FRAMES;
/**
* JavaBean类对象的拷贝，相同的字段名会被拷贝
* 注意: 拷贝类与被拷贝类的字段可见模式必须一致， 要么都是public field, 要么都是getter、setter模式。
*
*
* 详情见: https://redkale.org
*
* @author zhangjx
* @param 目标对象的数据类型
* @param 源对象的数据类型
*/
public interface Reproduce extends BiFunction {
@Override
public D apply(D dest, S src);
public static Reproduce create(final Class destClass, final Class srcClass) {
return create(destClass, srcClass, null);
}
@SuppressWarnings("unchecked")
public static Reproduce create(final Class destClass, final Class srcClass, final Predicate columnPredicate) {
// ------------------------------------------------------------------------------
final String supDynName = Reproduce.class.getName().replace('.', '/');
final String destName = destClass.getName().replace('.', '/');
final String srcName = srcClass.getName().replace('.', '/');
final String destDesc = Type.getDescriptor(destClass);
final String srcDesc = Type.getDescriptor(srcClass);
String newDynName = supDynName + "Dyn_" + destClass.getSimpleName() + "_" + srcClass.getSimpleName();
ClassLoader loader = Thread.currentThread().getContextClassLoader();
if (String.class.getClassLoader() != destClass.getClassLoader()) {
loader = destClass.getClassLoader();
newDynName = destName + "_Dyn" + Reproduce.class.getSimpleName() + "_" + srcClass.getSimpleName();
}
try {
return (Reproduce) loader.loadClass(newDynName.replace('/', '.')).newInstance();
} catch (Throwable ex) {
}
// ------------------------------------------------------------------------------
ClassWriter cw = new ClassWriter(COMPUTE_FRAMES);
FieldVisitor fv;
MethodVisitor mv;
AnnotationVisitor av0;
cw.visit(V1_8, ACC_PUBLIC + ACC_FINAL + ACC_SUPER, newDynName, "Ljava/lang/Object;L" + supDynName + "<" + destDesc + srcDesc + ">;", "java/lang/Object", new String[]{supDynName});
{ // 构造函数
mv = (cw.visitMethod(ACC_PUBLIC, "", "()V", null, null));
//mv.setDebug(true);
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "", "()V", false);
mv.visitInsn(RETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
{
mv = (cw.visitMethod(ACC_PUBLIC, "apply", "(" + destDesc + srcDesc + ")" + destDesc, null, null));
//mv.setDebug(true);
for (java.lang.reflect.Field field : srcClass.getFields()) {
if (Modifier.isStatic(field.getModifiers())) continue;
if (Modifier.isFinal(field.getModifiers())) continue;
if (!Modifier.isPublic(field.getModifiers())) continue;
final String fname = field.getName();
try {
if (!field.getType().equals(destClass.getField(fname).getType())) continue;
if (!columnPredicate.test(fname)) continue;
} catch (Exception e) {
continue;
}
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
String td = Type.getDescriptor(field.getType());
mv.visitFieldInsn(GETFIELD, srcName, fname, td);
mv.visitFieldInsn(PUTFIELD, destName, fname, td);
}
for (java.lang.reflect.Method getter : srcClass.getMethods()) {
if (Modifier.isStatic(getter.getModifiers())) continue;
if (getter.getParameterTypes().length > 0) continue; //为了兼容android 而不使用 getParameterCount()
if ("getClass".equals(getter.getName())) continue;
if (!getter.getName().startsWith("get") && !getter.getName().startsWith("is")) continue;
java.lang.reflect.Method setter;
boolean is = getter.getName().startsWith("is");
try {
setter = destClass.getMethod(getter.getName().replaceFirst(is ? "is" : "get", "set"), getter.getReturnType());
if (columnPredicate != null) {
String col = setter.getName().substring(3);
if (col.length() < 2 || Character.isLowerCase(col.charAt(1))) {
char[] cs = col.toCharArray();
cs[0] = Character.toLowerCase(cs[0]);
col = new String(cs);
}
if (!columnPredicate.test(col)) continue;
}
} catch (Exception e) {
continue;
}
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
mv.visitMethodInsn(INVOKEVIRTUAL, srcName, getter.getName(), Type.getMethodDescriptor(getter), false);
mv.visitMethodInsn(INVOKEVIRTUAL, destName, setter.getName(), Type.getMethodDescriptor(setter), false);
}
mv.visitVarInsn(ALOAD, 1);
mv.visitInsn(ARETURN);
mv.visitMaxs(3, 3);
mv.visitEnd();
}
{
mv = (cw.visitMethod(ACC_PUBLIC + ACC_BRIDGE + ACC_SYNTHETIC, "apply", "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;", null, null));
//mv.setDebug(true);
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, destName);
mv.visitVarInsn(ALOAD, 2);
mv.visitTypeInsn(CHECKCAST, srcName);
mv.visitMethodInsn(INVOKEVIRTUAL, newDynName, "apply", "(" + destDesc + srcDesc + ")" + destDesc, false);
mv.visitInsn(ARETURN);
mv.visitMaxs(3, 3);
mv.visitEnd();
}
cw.visitEnd();
// ------------------------------------------------------------------------------
byte[] bytes = cw.toByteArray();
Class creatorClazz = new ClassLoader(loader) {
public final Class loadClass(String name, byte[] b) {
return defineClass(name, b, 0, b.length);
}
}.loadClass(newDynName.replace('/', '.'), bytes);
try {
return (Reproduce) creatorClazz.newInstance();
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
}