org.apache.myfaces.util.DebugUtils.java Source code

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/**
 * Copyright (C) 2009 GIP RECIA http://www.recia.fr
 * @Author (C) 2009 GIP RECIA <contact@recia.fr>
 * @Contributor (C) 2009 SOPRA http://www.sopragroup.com/
 * @Contributor (C) 2011 Pierre Legay <pierre.legay@recia.fr>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.myfaces.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.faces.FacesException;
import javax.faces.component.*;
import javax.faces.context.FacesContext;
import javax.faces.el.MethodBinding;
import javax.faces.el.ValueBinding;
import javax.faces.event.FacesListener;
import javax.faces.validator.Validator;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;

/**
 * Utilities for logging.
 *
 * @author Manfred Geiler (latest modification by $Author: grantsmith $)
 * @version $Revision: 472618 $ $Date: 2006-11-08 21:06:54 +0100 (Mi, 08 Nov 2006) $
 */
public class DebugUtils {
    private static final Log log = LogFactory.getLog(DebugUtils.class);

    //Attributes that should not be printed
    private static final HashSet IGNORE_ATTRIBUTES;
    static {
        IGNORE_ATTRIBUTES = new HashSet();
        IGNORE_ATTRIBUTES.add("attributes");
        IGNORE_ATTRIBUTES.add("children");
        IGNORE_ATTRIBUTES.add("childCount");
        IGNORE_ATTRIBUTES.add("class");
        IGNORE_ATTRIBUTES.add("facets");
        IGNORE_ATTRIBUTES.add("facetsAndChildren");
        IGNORE_ATTRIBUTES.add("parent");
        IGNORE_ATTRIBUTES.add("actionListeners");
        IGNORE_ATTRIBUTES.add("valueChangeListeners");
        IGNORE_ATTRIBUTES.add("validators");
        IGNORE_ATTRIBUTES.add("rowData");
        IGNORE_ATTRIBUTES.add("javax.faces.webapp.COMPONENT_IDS");
        IGNORE_ATTRIBUTES.add("javax.faces.webapp.FACET_NAMES");
        IGNORE_ATTRIBUTES.add("javax.faces.webapp.CURRENT_VIEW_ROOT");
    }

    private static final String JSF_COMPONENT_PACKAGE = "javax.faces.component.";
    private static final String MYFACES_COMPONENT_PACKAGE = "org.apache.myfaces.component.";

    private DebugUtils() {
        // hide from public access
    }

    public static void assertError(boolean condition, Log log_, String msg) throws FacesException {
        if (!condition) {
            log_.error(msg);
            throw new FacesException(msg);
        }
    }

    public static void assertFatal(boolean condition, Log log_, String msg) throws FacesException {
        if (!condition) {
            log_.fatal(msg);
            throw new FacesException(msg);
        }
    }

    public static void traceView(String additionalMsg) {
        if (log.isTraceEnabled()) {
            FacesContext facesContext = FacesContext.getCurrentInstance();
            if (facesContext == null) {
                log.error("Cannot not print view to console (no FacesContext).");
                return;
            }
            UIViewRoot viewRoot = facesContext.getViewRoot();
            if (viewRoot == null) {
                log.error("Cannot not print view to console (no ViewRoot in FacesContext).");
                return;
            }

            traceView(additionalMsg, viewRoot);
        }
    }

    /**
     * Be careful, when using this version of traceView:
     * Some component properties (e.g. getRenderer) assume, that there is a
     * valid viewRoot set in the FacesContext!
     * @param additionalMsg
     * @param viewRoot
     */
    private static void traceView(String additionalMsg, UIViewRoot viewRoot) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PrintStream ps = new PrintStream(baos);
        if (additionalMsg != null) {
            ps.println(additionalMsg);
        }
        ps.println("========================================");
        printView(viewRoot, ps);
        ps.println("========================================");
        ps.close();
        log.trace(baos.toString());
    }

    public static void printView(UIViewRoot uiViewRoot, PrintStream stream) {
        printComponent(uiViewRoot, stream, 0, true, null);
    }

    public static void printComponent(UIComponent comp, PrintStream stream) {
        printComponent(comp, stream, 0, false, null);
    }

    private static void printComponent(UIComponent comp, PrintStream stream, int indent,
            boolean withChildrenAndFacets, String facetName) {
        printIndent(stream, indent);
        stream.print('<');

        String compType = comp.getClass().getName();
        if (compType.startsWith(JSF_COMPONENT_PACKAGE)) {
            compType = compType.substring(JSF_COMPONENT_PACKAGE.length());
        } else if (compType.startsWith(MYFACES_COMPONENT_PACKAGE)) {
            compType = compType.substring(MYFACES_COMPONENT_PACKAGE.length());
        }
        stream.print(compType);

        printAttribute(stream, "id", comp.getId());

        if (facetName != null) {
            printAttribute(stream, "facetName", facetName);
        }

        for (Iterator it = comp.getAttributes().entrySet().iterator(); it.hasNext();) {
            Map.Entry entry = (Map.Entry) it.next();
            if (!"id".equals(entry.getKey())) {
                printAttribute(stream, (String) entry.getKey(), entry.getValue());
            }
        }

        //HACK: comp.getAttributes() only returns attributes, that are NOT backed
        //by a corresponding component property. So, we must explicitly get the
        //available properties by Introspection:
        BeanInfo beanInfo;
        try {
            beanInfo = Introspector.getBeanInfo(comp.getClass());
        } catch (IntrospectionException e) {
            throw new RuntimeException(e);
        }

        PropertyDescriptor propDescriptors[] = beanInfo.getPropertyDescriptors();
        for (int i = 0; i < propDescriptors.length; i++) {
            if (propDescriptors[i].getReadMethod() != null) {
                String name = propDescriptors[i].getName();
                if (!"id".equals(name)) {
                    ValueBinding vb = comp.getValueBinding(name);
                    if (vb != null) {
                        printAttribute(stream, name, vb.getExpressionString());
                    } else {
                        if (name.equals("value") && comp instanceof ValueHolder) {
                            //-> localValue
                        } else if (!IGNORE_ATTRIBUTES.contains(name)) {
                            try {
                                Object value = comp.getAttributes().get(name);
                                printAttribute(stream, name, value);
                            } catch (Exception e) {
                                log.error(e);
                                printAttribute(stream, name, null);
                            }
                        }
                    }
                }
            }
        }

        boolean mustClose = true;
        boolean nestedObjects = false;

        if (comp instanceof UICommand) {
            FacesListener[] listeners = ((UICommand) comp).getActionListeners();
            if (listeners != null && listeners.length > 0) {
                nestedObjects = true;
                stream.println('>');
                mustClose = false;
                for (int i = 0; i < listeners.length; i++) {
                    FacesListener listener = listeners[i];
                    printIndent(stream, indent + 1);
                    stream.print('<');
                    stream.print(listener.getClass().getName());
                    stream.println("/>");
                }
            }
        }

        if (comp instanceof UIInput) {
            FacesListener[] listeners = ((UIInput) comp).getValueChangeListeners();
            if (listeners != null && listeners.length > 0) {
                nestedObjects = true;
                stream.println('>');
                mustClose = false;
                for (int i = 0; i < listeners.length; i++) {
                    FacesListener listener = listeners[i];
                    printIndent(stream, indent + 1);
                    stream.print('<');
                    stream.print(listener.getClass().getName());
                    stream.println("/>");
                }
            }

            Validator[] validators = ((UIInput) comp).getValidators();
            if (validators != null && validators.length > 0) {
                nestedObjects = true;
                stream.println('>');
                mustClose = false;
                for (int i = 0; i < validators.length; i++) {
                    Validator validator = validators[i];
                    printIndent(stream, indent + 1);
                    stream.print('<');
                    stream.print(validator.getClass().getName());
                    stream.println("/>");
                }
            }
        }

        if (withChildrenAndFacets) {
            int childCount = comp.getChildCount();
            Map facetsMap = comp.getFacets();
            if (childCount > 0 || !facetsMap.isEmpty()) {
                nestedObjects = true;
                if (mustClose) {
                    stream.println('>');
                    mustClose = false;
                }

                if (childCount > 0) {
                    for (Iterator it = comp.getChildren().iterator(); it.hasNext();) {
                        UIComponent child = (UIComponent) it.next();
                        printComponent(child, stream, indent + 1, true, null);
                    }
                }

                for (Iterator it = facetsMap.entrySet().iterator(); it.hasNext();) {
                    Map.Entry entry = (Map.Entry) it.next();
                    printComponent((UIComponent) entry.getValue(), stream, indent + 1, true,
                            (String) entry.getKey());
                }
            }
        }

        if (nestedObjects) {
            if (mustClose) {
                stream.println("/>");
            } else {
                printIndent(stream, indent);
                stream.print("</");
                stream.print(compType);
                stream.println('>');
            }
        } else {
            stream.println("/>");
        }
    }

    private static void printAttribute(PrintStream stream, String name, Object value) {
        if (IGNORE_ATTRIBUTES.contains(name))
            return;
        if (name.startsWith("javax.faces.webapp.UIComponentTag.")) {
            name = name.substring("javax.faces.webapp.UIComponentTag.".length());
        }
        stream.print(' ');
        stream.print(name.toString());
        stream.print("=\"");
        if (value != null) {
            if (value instanceof UIComponent) {
                stream.print("[id:");
                stream.print(((UIComponent) value).getId());
                stream.print(']');
            } else if (value instanceof MethodBinding) {
                stream.print(((MethodBinding) value).getExpressionString());
            } else {
                stream.print(value.toString());
            }
        } else {
            stream.print("NULL");
        }
        stream.print('"');
    }

    private static void printIndent(PrintStream stream, int depth) {
        for (int i = 0; i < depth; i++) {
            stream.print("  ");
        }
    }

    public static String componentAsString(UIComponent comp) {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            printComponent(comp, new PrintStream(baos));
            baos.close();
            return baos.toString();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}