MiscUtil.java

/* MiscUtil.java

	Purpose:
		
	Description:
		
	History:
		2012/4/12 Created by dennis

Copyright (C) 2011 Potix Corporation. All Rights Reserved.
 */
package org.zkoss.bind.impl;

import java.lang.reflect.Method;

import org.zkoss.lang.Classes;
import org.zkoss.lang.Library;
import org.zkoss.util.resource.Location;
import org.zkoss.zk.ui.AbstractComponent;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.metainfo.Annotation;

/**
 * internal use only misc util
 * 
 * @author dennis
 * 
 */
public class MiscUtil {

	public static String toSimpleMethodSignature(Method method) {
		// only keep the method name and parameter type
		StringBuilder sb = new StringBuilder();

		sb.append(method.getName() + "(");
		Class<?>[] params = method.getParameterTypes();
		for (int j = 0; j < params.length; j++) {
			sb.append(getTypeName(params[j]));
			if (j < (params.length - 1))
				sb.append(",");
		}
		sb.append(")");
		return sb.toString();
	}

	@SuppressWarnings("rawtypes")
	static String getTypeName(Class type) {
		if (type.isArray()) {
			try {
				Class cl = type;
				int dimensions = 0;
				while (cl.isArray()) {
					dimensions++;
					cl = cl.getComponentType();
				}
				StringBuilder sb = new StringBuilder();
				sb.append(cl.getName());
				for (int i = 0; i < dimensions; i++) {
					sb.append("[]");
				}
				return sb.toString();
			} catch (Throwable e) { /* FALLTHRU */
			}
		}
		return type.getName();
	}

	@SuppressWarnings("unchecked")
	public static <T> T newInstanceFromProperty(String key, String def, Class<T> type) {
		String clz = Library.getProperty(key, def);
		if (clz != null) {
			final Object v;
			try {
				v = Classes.newInstance(Classes.getContextClassLoader(type).loadClass(clz), null);
			} catch (Exception ex) {
				throw UiException.Aide.wrap(ex);
			}

			if (!type.isAssignableFrom(v.getClass()))
				throw new UiException(type + " must be implemented by " + v);
			return (T) v;
		}
		return null;
	}

	public static String formatLocationMessage(String message, Object obj) {
		if (obj == null)
			return message;
		if (obj instanceof Component) {
			return formatLocationMessage(message, (Component) obj);
		} else if (obj instanceof Annotation) {
			return formatLocationMessage(message, (Annotation) obj);
		} else if (obj instanceof Location) {
			return formatLocationMessage(message, (Location) obj);
		} else {
			return formatLocationMessage(message, (Location) null);
		}
	}

	public static String formatLocationMessage(String message, Component comp) {
		if (comp == null)
			return message;
		return formatLocationMessage(message, toComponentLocation(comp), false);
	}
	
	public static String formatLocationMessage(String message, Annotation anno) {
		if (anno == null)
			return message;
		return formatLocationMessage(message, anno.getLocation(), true);
	}
	
	public static String formatLocationMessage(String message, Location loc) {
		return formatLocationMessage(message, loc, true);
	}
	
	private static String formatLocationMessage(String message, Location loc, boolean showColumn) {
		if (loc == null)
			return message;
		String path = loc.getPath();
		int ln = loc.getLineNumber();
		int cn = loc.getColumnNumber();
		StringBuilder sb = new StringBuilder();
		if (message != null) {
			sb.append(message);
		}
		sb.append(" at [").append(path);
		if (ln >= 0) {
			sb.append(", line:").append(ln);
			if (showColumn && cn >= 0) {
				sb.append(", nearby column: ").append(cn);
			}
		}
		sb.append("]");
		return sb.toString();
	}

	private static Location toComponentLocation(Component comp) {
		if (comp instanceof AbstractComponent) {
			Annotation anno = ((AbstractComponent) comp).getAnnotation(null, "ZKLOC");
			return anno == null ? null : anno.getLocation();
		}
		return null;
	}

	//utility to prevent nested location info in exception
	public static RuntimeException mergeExceptionInfo(Exception ex, Object loc) {
		Location location = null;
		boolean showColumn = true;
		if (loc instanceof Component) {
			location = toComponentLocation((Component) loc);
			showColumn = false;
		} else if (loc instanceof Annotation) {
			location = ((Annotation) loc).getLocation();
		} else if (loc instanceof Location) {
			location = (Location) loc;
		}

		if (location == null) {
			if (ex instanceof RuntimeException) {
				return (RuntimeException) ex;
			} else {
				throw UiException.Aide.wrap(ex, ex.getMessage());
			}
		} else {
			String orgMsg = ex.getMessage();
			String msg = formatLocationMessage(null, location, showColumn);
			if (orgMsg != null && orgMsg.endsWith(msg)) {
				//don't append if the location info is the same.
				if (ex instanceof RuntimeException) {
					return (RuntimeException) ex;
				} else {
					throw UiException.Aide.wrap(ex, ex.getMessage());
				}
			} else {
				msg = ex.getClass().getName() + ": " + formatLocationMessage(orgMsg, location, showColumn);
				//no way to change exception's message, so use the most common UiException
				throw UiException.Aide.wrap(ex, msg);
			}

		}
	}
}