import java.lang.reflect.*;
import java.lang.annotation.*;
+// FIXME: decent error reporting
/** Random reflection-related utilities */
public final class Reflection {
public static String show(Object o) {
if (o==null) return "null";
- if (o instanceof Show) return ((Show)o).toString();
+ if (o instanceof Show) return show((Show)o);
if (! (o instanceof Object[])) return o.toString() + " : " + o.getClass().getName();
Object[] arr = (Object[])o;
StringBuffer ret = new StringBuffer();
return null;
}
public static Object impose(Class _class, Object[] fields) {
- try {
- Object ret = _class.newInstance();
- Field[] f = _class.getFields();
- int j = 0;
- for(int i=0; i<f.length; i++) {
- Object tgt = Reflection.lub(fields[i]);
- if (f[i].getType() == String.class) tgt = stringify(tgt);
- // FUGLY
- tgt = coerce(tgt, f[i].getType());
- System.err.println("setting a " + f[i].getType().getName() + " to " + Reflection.show(tgt));
+ Object ret = null;
+ try { ret = _class.newInstance(); }
+ catch (Exception e) { rethrow(e, "while trying to instantiate a " + _class.getName()); }
+ Field[] f = _class.getFields();
+ int j = 0;
+ for(int i=0; i<f.length; i++) {
+ Object tgt = Reflection.lub(fields[i]);
+ if (f[i].getType() == String.class) tgt = stringify(tgt);
+ // FUGLY
+ tgt = coerce(tgt, f[i].getType());
+ try {
f[i].set(ret, tgt);
+ } catch (Exception e) {
+ rethrow(e, "while setting \n " +
+ f[i] +
+ "\n to " + show(tgt));
}
- return ret;
- } catch (Exception e) {
- e.printStackTrace();
- throw new RuntimeException(e);
}
+ return ret;
+ }
+
+ public static Object rethrow(Exception e, String message) {
+ e.printStackTrace();
+ StackTraceElement[] st = e.getStackTrace();
+ RuntimeException re = new RuntimeException(e.getMessage() + "\n " + message);
+ re.setStackTrace(st);
+ throw re;
}
public static Object impose(Method _method, Object[] fields) {
+ Object[] args = mkArgs(_method.getParameterTypes(), fields);
try {
- Class[] argTypes = _method.getParameterTypes();
- Object[] args = new Object[argTypes.length];
- int j = 0;
- for(int i=0; i<args.length; i++) {
- Object tgt = Reflection.lub(fields[i]);
- if (argTypes[i] == String.class) tgt = Reflection.stringify(tgt);
- // FUGLY
- tgt = Reflection.coerce(tgt, argTypes[i]);
- System.err.println("setting a " + argTypes[i].getName() + " to " + Reflection.show(tgt));
- args[i] = tgt;
- }
- System.err.println("invoking " + _method + " with " + Reflection.show(args));
return _method.invoke(null, args);
} catch (Exception e) {
- throw new RuntimeException(e);
+ return rethrow(e, "while trying to invoke \n " +
+ _method +
+ "\n with arguments " + show(args));
}
}
-
public static Object impose(Constructor _ctor, Object[] fields) {
+ Object[] args = mkArgs(_ctor.getParameterTypes(), fields);
try {
- Class[] argTypes = _ctor.getParameterTypes();
- Object[] args = new Object[argTypes.length];
- int j = 0;
- for(int i=0; i<args.length; i++) {
- Object tgt = Reflection.lub(fields[i]);
- if (argTypes[i] == String.class) tgt = Reflection.stringify(tgt);
- // FUGLY
- tgt = Reflection.coerce(tgt, argTypes[i]);
- System.err.println("setting a " + argTypes[i].getName() + " to " + Reflection.show(tgt));
- args[i] = tgt;
- }
return _ctor.newInstance(args);
} catch (Exception e) {
- throw new RuntimeException(e);
+ return rethrow(e, "while trying to invoke \n " +
+ _ctor +
+ "\n with arguments " + show(args));
+ }
+ }
+
+ private static Object[] mkArgs(Class[] argTypes, Object[] fields) {
+ int j = 0;
+ Object[] args = new Object[argTypes.length];
+ for(int i=0; i<args.length; i++) {
+ Object tgt = Reflection.lub(fields[i]);
+ if (argTypes[i] == String.class) tgt = Reflection.stringify(tgt);
+ // FUGLY
+ tgt = Reflection.coerce(tgt, argTypes[i]);
+ args[i] = tgt;
}
+ return args;
}
public static String stringify(Object o) {
}
public static Object coerce(Object o, Class c) {
+ try {
+ return coerce0(o, c);
+ } catch (Exception e) {
+ return (Object[])rethrow(e, "while trying to coerce " + show(o) + " to a " + c.getName());
+ }
+ }
+ public static Object coerce0(Object o, Class c) {
if (o==null) return null;
if (c.isInstance(o)) return o;
if (c == char.class) {
return o.toString().charAt(0);
}
+ if (c==int.class || c==Integer.class) {
+ String s = (String)coerce(o, String.class);
+ return new Integer(Integer.parseInt(s));
+ }
if (o.getClass().isArray() &&
o.getClass().getComponentType().isArray() &&
for(int i=0; i<((Object[])o).length; i++) {
Object ob = (((Object[])o)[i]);
if (ob != null) {
- System.err.println("no hit with " + c.getComponentType().getName() + " on " + Reflection.show(((Object[])o)[i]));
ok = false;
}
}
if (ok) {
- System.err.println("hit with " + c.getComponentType().getName());
return Array.newInstance(c.getComponentType(), ((Object[])o).length);
}
}