asm 设置读取字段值，asm读取字段值,获得静态字段的值：mv.

asm 设置读取字段值，asm读取字段值,获得静态字段的值：mv.

获得静态字段的值：

mv.visitFieldInsn(GETSTATIC,    "sample/FieldReadWrite", // classname    "len",  //static field name   "I"); // the type of field.//return a value in the stack

给静态字段赋值：

mv.visitIntInsn(BIPUSH, 10); // put a constant integer onto the stackmv.visitFieldInsn(PUTSTATIC,   "sample/FieldReadWrite", //classname  "len", // field name  "I"); // field type

获得实例字段的值：

mv.visitVarInsn(ALOAD, 0); //from object onto the stackmv.visitFieldInsn(GETFIELD,   "sample/FieldReadWrite", //the type of object  "name", // field name  "Ljava/lang/String;" // field type);mv.visitInsn(ARETURN); // pop the top value of the stack and return.

设置实例字段的值

mv.visitVarInsn(ALOAD, 0);//push the object mv.visitVarInsn(ALOAD, 1);//push the value from which assign to the fieldmv.visitFieldInsn(PUTFIELD, "sample/FieldReadWrite", // the class"name", // the field name"Ljava/lang/String;"//the field type);