package org.drools.compiler.rule.builder.dialect.asm;
import org.drools.core.rule.builder.dialect.asm.ClassGenerator;
import org.junit.*;
import org.mvel2.asm.*;
import static org.junit.Assert.assertEquals;
import static org.mvel2.asm.Opcodes.*;
public class ClassGeneratorTest {
@Test
public void testGenerateBean() {
final String MY_NAME = "myName";
ClassGenerator generator = new ClassGenerator("pkg.Bean", getClass().getClassLoader())
.addField(ACC_PRIVATE | ACC_FINAL, "name", String.class);
generator.addDefaultConstructor(new ClassGenerator.MethodBody() {
public void body(MethodVisitor mv) {
mv.visitVarInsn(ALOAD, 0);// read local variable 0 (initialized to this) and push it on the stack
mv.visitLdcInsn(MY_NAME); // push the String MY_NAME on the stack
putFieldInThis("name", String.class);
mv.visitInsn(RETURN);
}
}).addMethod(ACC_PUBLIC, "toString", generator.methodDescr(String.class), new ClassGenerator.MethodBody() {
public void body(MethodVisitor mv) {
getFieldFromThis("name", String.class);
mv.visitInsn(ARETURN); // return the first object on the stack
}
});
Object instance = generator.newInstance();
assertEquals(MY_NAME, instance.toString());
}
@Test
public void testGenerateWithConstructorArg() {
final String MY_NAME = "myName";
ClassGenerator generator = new ClassGenerator("pkg.Bean", getClass().getClassLoader())
.addField(ACC_PRIVATE | ACC_FINAL, "name", String.class);
generator.addDefaultConstructor(new ClassGenerator.MethodBody() {
public void body(MethodVisitor mv) {
putFieldInThisFromRegistry("name", String.class, 1);
mv.visitInsn(RETURN);
}
}, String.class);
generator.addMethod(ACC_PUBLIC, "toString", generator.methodDescr(String.class), new ClassGenerator.MethodBody() {
public void body(MethodVisitor mv) {
getFieldFromThis("name", String.class);
mv.visitInsn(ARETURN); // return the first object on the stack
}
});
Object instance = generator.newInstance(String.class, MY_NAME);
assertEquals(MY_NAME, instance.toString());
}
}