package com.esotericsoftware.reflectasm;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import static org.objectweb.asm.Opcodes.*;
public abstract class FieldAccess {
static public FieldAccess get (Class type) {
AccessClassLoader loader = AccessClassLoader.get(type);
ArrayList<Field> fields = new ArrayList();
Class nextClass = type;
while (nextClass != Object.class) {
Field[] declaredFields = nextClass.getDeclaredFields();
for (int i = 0, n = declaredFields.length; i < n; i++) {
Field field = declaredFields[i];
int modifiers = field.getModifiers();
if (Modifier.isStatic(modifiers)) continue;
if (Modifier.isPrivate(modifiers)) continue;
fields.add(field);
}
nextClass = nextClass.getSuperclass();
}
String className = type.getName();
String accessClassName = className + "FieldAccess";
if (accessClassName.startsWith("java.")) accessClassName = "reflectasm." + accessClassName;
Class accessClass = null;
try {
accessClass = loader.loadClass(accessClassName);
} catch (ClassNotFoundException ignored) {
}
if (accessClass == null) {
String accessClassNameInternal = accessClassName.replace('.', '/');
String classNameInternal = className.replace('.', '/');
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
MethodVisitor mv;
cw.visit(V1_1, ACC_PUBLIC + ACC_SUPER, accessClassNameInternal, null, "com/esotericsoftware/reflectasm/FieldAccess",
null);
{
mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "com/esotericsoftware/reflectasm/FieldAccess", "<init>", "()V");
mv.visitInsn(RETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
{
mv = cw.visitMethod(ACC_PUBLIC, "set", "(Ljava/lang/Object;ILjava/lang/Object;)V", null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
Label[] labels = new Label[fields.size()];
for (int i = 0, n = labels.length; i < n; i++)
labels[i] = new Label();
Label defaultLabel = new Label();
mv.visitTableSwitchInsn(0, labels.length - 1, defaultLabel, labels);
for (int i = 0, n = labels.length; i < n; i++) {
Field field = fields.get(i);
Type fieldType = Type.getType(field.getType());
mv.visitLabel(labels[i]);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, classNameInternal);
mv.visitVarInsn(ALOAD, 3);
switch (fieldType.getSort()) {
case Type.BOOLEAN:
mv.visitTypeInsn(CHECKCAST, "java/lang/Boolean");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z");
break;
case Type.BYTE:
mv.visitTypeInsn(CHECKCAST, "java/lang/Byte");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Byte", "byteValue", "()B");
break;
case Type.CHAR:
mv.visitTypeInsn(CHECKCAST, "java/lang/Character");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Character", "charValue", "()C");
break;
case Type.SHORT:
mv.visitTypeInsn(CHECKCAST, "java/lang/Short");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Short", "shortValue", "()S");
break;
case Type.INT:
mv.visitTypeInsn(CHECKCAST, "java/lang/Integer");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Integer", "intValue", "()I");
break;
case Type.FLOAT:
mv.visitTypeInsn(CHECKCAST, "java/lang/Float");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Float", "floatValue", "()F");
break;
case Type.LONG:
mv.visitTypeInsn(CHECKCAST, "java/lang/Long");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J");
break;
case Type.DOUBLE:
mv.visitTypeInsn(CHECKCAST, "java/lang/Double");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Double", "doubleValue", "()D");
break;
case Type.ARRAY:
mv.visitTypeInsn(CHECKCAST, fieldType.getDescriptor());
break;
case Type.OBJECT:
mv.visitTypeInsn(CHECKCAST, fieldType.getInternalName());
break;
}
mv.visitFieldInsn(PUTFIELD, classNameInternal, field.getName(), fieldType.getDescriptor());
mv.visitInsn(RETURN);
}
mv.visitLabel(defaultLabel);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
}
mv.visitTypeInsn(NEW, "java/lang/IllegalArgumentException");
mv.visitInsn(DUP);
mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
mv.visitInsn(DUP);
mv.visitLdcInsn("Field not found: ");
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V");
mv.visitVarInsn(ILOAD, 2);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/IllegalArgumentException", "<init>", "(Ljava/lang/String;)V");
mv.visitInsn(ATHROW);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
{
mv = cw.visitMethod(ACC_PUBLIC, "get", "(Ljava/lang/Object;I)Ljava/lang/Object;", null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
Label[] labels = new Label[fields.size()];
for (int i = 0, n = labels.length; i < n; i++)
labels[i] = new Label();
Label defaultLabel = new Label();
mv.visitTableSwitchInsn(0, labels.length - 1, defaultLabel, labels);
for (int i = 0, n = labels.length; i < n; i++) {
Field field = fields.get(i);
mv.visitLabel(labels[i]);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, classNameInternal);
mv.visitFieldInsn(GETFIELD, classNameInternal, field.getName(), Type.getDescriptor(field.getType()));
Type fieldType = Type.getType(field.getType());
switch (fieldType.getSort()) {
case Type.BOOLEAN:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Boolean", "valueOf", "(Z)Ljava/lang/Boolean;");
break;
case Type.BYTE:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Byte", "valueOf", "(B)Ljava/lang/Byte;");
break;
case Type.CHAR:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Character", "valueOf", "(C)Ljava/lang/Character;");
break;
case Type.SHORT:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Short", "valueOf", "(S)Ljava/lang/Short;");
break;
case Type.INT:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Integer", "valueOf", "(I)Ljava/lang/Integer;");
break;
case Type.FLOAT:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Float", "valueOf", "(F)Ljava/lang/Float;");
break;
case Type.LONG:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Long", "valueOf", "(J)Ljava/lang/Long;");
break;
case Type.DOUBLE:
mv.visitMethodInsn(INVOKESTATIC, "java/lang/Double", "valueOf", "(D)Ljava/lang/Double;");
break;
}
mv.visitInsn(ARETURN);
}
mv.visitLabel(defaultLabel);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
}
mv.visitTypeInsn(NEW, "java/lang/IllegalArgumentException");
mv.visitInsn(DUP);
mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
mv.visitInsn(DUP);
mv.visitLdcInsn("Field not found: ");
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V");
mv.visitVarInsn(ILOAD, 2);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/IllegalArgumentException", "<init>", "(Ljava/lang/String;)V");
mv.visitInsn(ATHROW);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
cw.visitEnd();
byte[] data = cw.toByteArray();
accessClass = loader.defineClass(accessClassName, data);
}
try {
FieldAccess access = (FieldAccess)accessClass.newInstance();
access.fields = fields.toArray(new Field[fields.size()]);
return access;
} catch (Exception ex) {
throw new RuntimeException("Error constructing field access class: " + accessClassName, ex);
}
}
private Field[] fields;
abstract public void set (Object object, int fieldIndex, Object value);
abstract public Object get (Object object, int fieldIndex);
public int getIndex (String fieldName) {
for (int i = 0, n = fields.length; i < n; i++) {
Field field = fields[i];
if (field.getName().equals(fieldName)) return i;
}
throw new IllegalArgumentException("Unable to find public field: " + fieldName);
}
public void set (Object object, String fieldName, Object value) {
set(object, getIndex(fieldName), value);
}
public Object get (Object object, String fieldName) {
return get(object, getIndex(fieldName));
}
public Field[] getFields () {
return fields;
}
}