package com.esotericsoftware.reflectasm;
import static org.objectweb.asm.Opcodes.*;
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.Type;
public abstract class FieldAccess {
private String[] fieldNames;
private Class[] fieldTypes;
public int getIndex (String fieldName) {
for (int i = 0, n = fieldNames.length; i < n; i++)
if (fieldNames[i].equals(fieldName)) return i;
throw new IllegalArgumentException("Unable to find non-private field: " + fieldName);
}
public void set (Object instance, String fieldName, Object value) {
set(instance, getIndex(fieldName), value);
}
public Object get (Object instance, String fieldName) {
return get(instance, getIndex(fieldName));
}
public String[] getFieldNames () {
return fieldNames;
}
public Class[] getFieldTypes () {
return fieldTypes;
}
public int getFieldCount () {
return fieldTypes.length;
}
abstract public void set (Object instance, int fieldIndex, Object value);
abstract public void setBoolean (Object instance, int fieldIndex, boolean value);
abstract public void setByte (Object instance, int fieldIndex, byte value);
abstract public void setShort (Object instance, int fieldIndex, short value);
abstract public void setInt (Object instance, int fieldIndex, int value);
abstract public void setLong (Object instance, int fieldIndex, long value);
abstract public void setDouble (Object instance, int fieldIndex, double value);
abstract public void setFloat (Object instance, int fieldIndex, float value);
abstract public void setChar (Object instance, int fieldIndex, char value);
abstract public Object get (Object instance, int fieldIndex);
abstract public String getString (Object instance, int fieldIndex);
abstract public char getChar (Object instance, int fieldIndex);
abstract public boolean getBoolean (Object instance, int fieldIndex);
abstract public byte getByte (Object instance, int fieldIndex);
abstract public short getShort (Object instance, int fieldIndex);
abstract public int getInt (Object instance, int fieldIndex);
abstract public long getLong (Object instance, int fieldIndex);
abstract public double getDouble (Object instance, int fieldIndex);
abstract public float getFloat (Object instance, int fieldIndex);
static public FieldAccess get (Class type) {
ArrayList<Field> fields = new ArrayList<Field>();
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[] fieldNames = new String[fields.size()];
Class[] fieldTypes = new Class[fields.size()];
for (int i = 0, n = fieldNames.length; i < n; i++) {
fieldNames[i] = fields.get(i).getName();
fieldTypes[i] = fields.get(i).getType();
}
String className = type.getName();
String accessClassName = className + "FieldAccess";
if (accessClassName.startsWith("java.")) accessClassName = "reflectasm." + accessClassName;
Class accessClass = null;
AccessClassLoader loader = AccessClassLoader.get(type);
synchronized (loader) {
try {
accessClass = loader.loadClass(accessClassName);
} catch (ClassNotFoundException ignored) {
String accessClassNameInternal = accessClassName.replace('.', '/');
String classNameInternal = className.replace('.', '/');
ClassWriter cw = new ClassWriter(0);
cw.visit(V1_1, ACC_PUBLIC + ACC_SUPER, accessClassNameInternal, null, "com/esotericsoftware/reflectasm/FieldAccess",
null);
insertConstructor(cw);
insertGetObject(cw, classNameInternal, fields);
insertSetObject(cw, classNameInternal, fields);
insertGetPrimitive(cw, classNameInternal, fields, Type.BOOLEAN_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.BOOLEAN_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.BYTE_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.BYTE_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.SHORT_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.SHORT_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.INT_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.INT_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.LONG_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.LONG_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.DOUBLE_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.DOUBLE_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.FLOAT_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.FLOAT_TYPE);
insertGetPrimitive(cw, classNameInternal, fields, Type.CHAR_TYPE);
insertSetPrimitive(cw, classNameInternal, fields, Type.CHAR_TYPE);
insertGetString(cw, classNameInternal, fields);
cw.visitEnd();
accessClass = loader.defineClass(accessClassName, cw.toByteArray());
}
}
try {
FieldAccess access = (FieldAccess)accessClass.newInstance();
access.fieldNames = fieldNames;
access.fieldTypes = fieldTypes;
return access;
} catch (Throwable t) {
throw new RuntimeException("Error constructing field access class: " + accessClassName, t);
}
}
static private void insertConstructor (ClassWriter cw) {
MethodVisitor 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(1, 1);
mv.visitEnd();
}
static private void insertSetObject (ClassWriter cw, String classNameInternal, ArrayList<Field> fields) {
int maxStack = 6;
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "set", "(Ljava/lang/Object;ILjava/lang/Object;)V", null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
maxStack--;
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(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(F_SAME, 0, null, 0, null);
}
mv = insertThrowExceptionForFieldNotFound(mv);
mv.visitMaxs(maxStack, 4);
mv.visitEnd();
}
static private void insertGetObject (ClassWriter cw, String classNameInternal, ArrayList<Field> fields) {
int maxStack = 6;
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "get", "(Ljava/lang/Object;I)Ljava/lang/Object;", null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
maxStack--;
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(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(F_SAME, 0, null, 0, null);
}
insertThrowExceptionForFieldNotFound(mv);
mv.visitMaxs(maxStack, 3);
mv.visitEnd();
}
static private void insertGetString (ClassWriter cw, String classNameInternal, ArrayList<Field> fields) {
int maxStack = 6;
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "getString", "(Ljava/lang/Object;I)Ljava/lang/String;", null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
maxStack--;
Label[] labels = new Label[fields.size()];
Label labelForInvalidTypes = new Label();
boolean hasAnyBadTypeLabel = false;
for (int i = 0, n = labels.length; i < n; i++) {
if (fields.get(i).getType().equals(String.class))
labels[i] = new Label();
else {
labels[i] = labelForInvalidTypes;
hasAnyBadTypeLabel = true;
}
}
Label defaultLabel = new Label();
mv.visitTableSwitchInsn(0, labels.length - 1, defaultLabel, labels);
for (int i = 0, n = labels.length; i < n; i++) {
if (!labels[i].equals(labelForInvalidTypes)) {
mv.visitLabel(labels[i]);
mv.visitFrame(F_SAME, 0, null, 0, null);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, classNameInternal);
mv.visitFieldInsn(GETFIELD, classNameInternal, fields.get(i).getName(), "Ljava/lang/String;");
mv.visitInsn(ARETURN);
}
}
// Rest of fields: different type
if (hasAnyBadTypeLabel) {
mv.visitLabel(labelForInvalidTypes);
mv.visitFrame(F_SAME, 0, null, 0, null);
insertThrowExceptionForFieldType(mv, "String");
}
// Default: field not found
mv.visitLabel(defaultLabel);
mv.visitFrame(F_SAME, 0, null, 0, null);
}
insertThrowExceptionForFieldNotFound(mv);
mv.visitMaxs(maxStack, 3);
mv.visitEnd();
}
static private void insertSetPrimitive (ClassWriter cw, String classNameInternal, ArrayList<Field> fields, Type primitiveType) {
int maxStack = 6;
int maxLocals = 4; // See correction below for LLOAD and DLOAD
final String setterMethodName;
final String typeNameInternal = primitiveType.getDescriptor();
final int loadValueInstruction;
switch (primitiveType.getSort()) {
case Type.BOOLEAN:
setterMethodName = "setBoolean";
loadValueInstruction = ILOAD;
break;
case Type.BYTE:
setterMethodName = "setByte";
loadValueInstruction = ILOAD;
break;
case Type.CHAR:
setterMethodName = "setChar";
loadValueInstruction = ILOAD;
break;
case Type.SHORT:
setterMethodName = "setShort";
loadValueInstruction = ILOAD;
break;
case Type.INT:
setterMethodName = "setInt";
loadValueInstruction = ILOAD;
break;
case Type.FLOAT:
setterMethodName = "setFloat";
loadValueInstruction = FLOAD;
break;
case Type.LONG:
setterMethodName = "setLong";
loadValueInstruction = LLOAD;
maxLocals++; // (LLOAD and DLOAD actually load two slots)
break;
case Type.DOUBLE:
setterMethodName = "setDouble";
loadValueInstruction = DLOAD; // (LLOAD and DLOAD actually load two slots)
maxLocals++;
break;
default:
setterMethodName = "set";
loadValueInstruction = ALOAD;
break;
}
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, setterMethodName, "(Ljava/lang/Object;I" + typeNameInternal + ")V", null,
null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
maxStack--;
Label[] labels = new Label[fields.size()];
Label labelForInvalidTypes = new Label();
boolean hasAnyBadTypeLabel = false;
for (int i = 0, n = labels.length; i < n; i++) {
if (Type.getType(fields.get(i).getType()).equals(primitiveType))
labels[i] = new Label();
else {
labels[i] = labelForInvalidTypes;
hasAnyBadTypeLabel = true;
}
}
Label defaultLabel = new Label();
mv.visitTableSwitchInsn(0, labels.length - 1, defaultLabel, labels);
for (int i = 0, n = labels.length; i < n; i++) {
if (!labels[i].equals(labelForInvalidTypes)) {
mv.visitLabel(labels[i]);
mv.visitFrame(F_SAME, 0, null, 0, null);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, classNameInternal);
mv.visitVarInsn(loadValueInstruction, 3);
mv.visitFieldInsn(PUTFIELD, classNameInternal, fields.get(i).getName(), typeNameInternal);
mv.visitInsn(RETURN);
}
}
// Rest of fields: different type
if (hasAnyBadTypeLabel) {
mv.visitLabel(labelForInvalidTypes);
mv.visitFrame(F_SAME, 0, null, 0, null);
insertThrowExceptionForFieldType(mv, primitiveType.getClassName());
}
// Default: field not found
mv.visitLabel(defaultLabel);
mv.visitFrame(F_SAME, 0, null, 0, null);
}
mv = insertThrowExceptionForFieldNotFound(mv);
mv.visitMaxs(maxStack, maxLocals);
mv.visitEnd();
}
static private void insertGetPrimitive (ClassWriter cw, String classNameInternal, ArrayList<Field> fields, Type primitiveType) {
int maxStack = 6;
final String getterMethodName;
final String typeNameInternal = primitiveType.getDescriptor();
final int returnValueInstruction;
switch (primitiveType.getSort()) {
case Type.BOOLEAN:
getterMethodName = "getBoolean";
returnValueInstruction = IRETURN;
break;
case Type.BYTE:
getterMethodName = "getByte";
returnValueInstruction = IRETURN;
break;
case Type.CHAR:
getterMethodName = "getChar";
returnValueInstruction = IRETURN;
break;
case Type.SHORT:
getterMethodName = "getShort";
returnValueInstruction = IRETURN;
break;
case Type.INT:
getterMethodName = "getInt";
returnValueInstruction = IRETURN;
break;
case Type.FLOAT:
getterMethodName = "getFloat";
returnValueInstruction = FRETURN;
break;
case Type.LONG:
getterMethodName = "getLong";
returnValueInstruction = LRETURN;
break;
case Type.DOUBLE:
getterMethodName = "getDouble";
returnValueInstruction = DRETURN;
break;
default:
getterMethodName = "get";
returnValueInstruction = ARETURN;
break;
}
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, getterMethodName, "(Ljava/lang/Object;I)" + typeNameInternal, null, null);
mv.visitCode();
mv.visitVarInsn(ILOAD, 2);
if (!fields.isEmpty()) {
maxStack--;
Label[] labels = new Label[fields.size()];
Label labelForInvalidTypes = new Label();
boolean hasAnyBadTypeLabel = false;
for (int i = 0, n = labels.length; i < n; i++) {
if (Type.getType(fields.get(i).getType()).equals(primitiveType))
labels[i] = new Label();
else {
labels[i] = labelForInvalidTypes;
hasAnyBadTypeLabel = true;
}
}
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);
if (!labels[i].equals(labelForInvalidTypes)) {
mv.visitLabel(labels[i]);
mv.visitFrame(F_SAME, 0, null, 0, null);
mv.visitVarInsn(ALOAD, 1);
mv.visitTypeInsn(CHECKCAST, classNameInternal);
mv.visitFieldInsn(GETFIELD, classNameInternal, field.getName(), typeNameInternal);
mv.visitInsn(returnValueInstruction);
}
}
// Rest of fields: different type
if (hasAnyBadTypeLabel) {
mv.visitLabel(labelForInvalidTypes);
mv.visitFrame(F_SAME, 0, null, 0, null);
insertThrowExceptionForFieldType(mv, primitiveType.getClassName());
}
// Default: field not found
mv.visitLabel(defaultLabel);
mv.visitFrame(F_SAME, 0, null, 0, null);
}
mv = insertThrowExceptionForFieldNotFound(mv);
mv.visitMaxs(maxStack, 3);
mv.visitEnd();
}
static private MethodVisitor insertThrowExceptionForFieldNotFound (MethodVisitor mv) {
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);
return mv;
}
static private MethodVisitor insertThrowExceptionForFieldType (MethodVisitor mv, String fieldType) {
mv.visitTypeInsn(NEW, "java/lang/IllegalArgumentException");
mv.visitInsn(DUP);
mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
mv.visitInsn(DUP);
mv.visitLdcInsn("Field not declared as " + fieldType + ": ");
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);
return mv;
}
}