Java tutorial
/* * Copyright (C) 2012 Jan Pokorsky * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package cz.cas.lib.proarc.webapp.client; import com.google.gwt.core.client.GWT; import com.google.gwt.json.client.JSONObject; import com.google.gwt.json.client.JSONParser; import com.google.gwt.json.client.JSONString; import com.google.gwt.json.client.JSONValue; import com.google.gwt.safehtml.shared.SafeHtmlUtils; import com.smartgwt.client.data.DSRequest; import com.smartgwt.client.data.DSResponse; import com.smartgwt.client.data.DataSource; import com.smartgwt.client.i18n.SmartGwtMessages; import com.smartgwt.client.rpc.HandleErrorCallback; import com.smartgwt.client.rpc.HandleTransportErrorCallback; import com.smartgwt.client.rpc.RPCManager; import com.smartgwt.client.rpc.RPCResponse; import com.smartgwt.client.types.Overflow; import com.smartgwt.client.util.SC; import com.smartgwt.client.widgets.Button; import com.smartgwt.client.widgets.Canvas; import com.smartgwt.client.widgets.Dialog; import com.smartgwt.client.widgets.layout.VLayout; import java.util.logging.Level; import java.util.logging.Logger; /** * Global Smart GWT RPC error handler. * * <p>Replaces default {@link HandleTransportErrorCallback} and {@link HandleErrorCallback} * to provide more detailed notifications of RPC errors and to make available * {@link #getTransportError() HTTP response text} in case of HTTP error. * * <p>Each {@link DataSource} can override global handler with custom one with {@link DataSource#addHandleErrorHandler }. * Then it is still necessary to cancel the {@link com.smartgwt.client.data.events.ErrorEvent event}. * * @author Jan Pokorsky */ public final class ErrorHandler { private static final Logger LOG = Logger.getLogger(ErrorHandler.class.getName()); private TransportError transportError; private final ClientMessages i18n; public ErrorHandler() { this(GWT.<ClientMessages>create(ClientMessages.class)); } public ErrorHandler(ClientMessages i18n) { this.i18n = i18n; } /** * Gets last transport error or {@code null}. */ public TransportError getTransportError() { return transportError; } /** * Registers custom error handler. */ void initTransportErrorHandler() { RPCManager.setHandleTransportErrorCallback(new HandleTransportErrorCallback() { @Override public void handleTransportError(int transactionNum, int status, int httpResponseCode, String httpResponseText) { transportError = new TransportError(transactionNum, status, httpResponseCode, httpResponseText); } }); RPCManager.setHandleErrorCallback(new HandleErrorCallback() { @Override public void handleError(DSResponse response, DSRequest request) { TransportError te = transportError; ErrorHandler.this.handleError(te, response, request); } }); } /** * Gets simple message from error response for user. */ private String getClientMessage(TransportError te, DSResponse response, DSRequest request) { String contentType = String.valueOf(response.getHttpHeaders().get("Content-Type")); String result; if (response.getStatus() == RPCResponse.STATUS_FAILURE) { return response.getDataAsString(); } if (contentType.contains("text/plain")) { result = te == null ? null : te.getHttpResponseText(); } else { result = i18n.ErrorHandler_UnexpectedError_Msg(); } if (result == null || result.isEmpty() || result.length() > 1000) { // message from original error handler; contains URL return response.getDataAsString(); } else { return result; } } private void handleError(TransportError te, DSResponse response, DSRequest request) { String requestDump = ClientUtils.dump(request.getJsObj()); // message from original error handler; contains URL Object smartGwtMsg = response.getDataAsString(); if (te == null || response.getTransactionNum() != te.getTransactionNum()) { String debugInfo = ClientUtils.format( "Invalid transaction numbers %s != %s" + "\n%s\nStatus: %s\nQuery: %s", response.getTransactionNum(), te == null ? null : te.getTransactionNum(), smartGwtMsg, response.getStatus(), requestDump); SC.logWarn(debugInfo); } // boolean clientError = te.getHttpResponseCode() >= 400 && te.getHttpResponseCode() < 500; String clientMsg = getClientMessage(te, response, request); String debugInfo = ClientUtils.format("%s\nStatus: %s\nQuery: %s", smartGwtMsg, te == null ? response.getStatus() : te.getStatus(), requestDump); String htmlDebugInfo = ClientUtils.format("%s<br/>Status: %s<br/>Query: %s", smartGwtMsg, te == null ? response.getStatus() : te.getStatus(), SafeHtmlUtils.htmlEscape(requestDump)); warn(clientMsg, te == null ? response.getDataAsString() : te.getHttpResponseText(), htmlDebugInfo); SC.logWarn(debugInfo); } /** * The default notification about an error. */ public static void warn(DSResponse response, DSRequest request) { new ErrorHandler().handleError(new TransportError(response.getTransactionNum(), response.getStatus(), response.getHttpResponseCode(), response.getHttpResponseText()), response, request); } /** * The default notification about an error using a text message. */ public static void warn(String error) { new ErrorHandler().warn(null, error, null); } /** * Notifies user about error. * @param msg simple client message * @param detailMsg detail response message; can be HTML * @param debugInfo request details, URL, ... */ private void warn(String msg, String detailMsg, String debugInfo) { if (msg == null) { msg = i18n.ErrorHandler_UnexpectedError_Msg(); } SmartGwtMessages sgi18n = ClientUtils.createSmartGwtMessages(); boolean allowDetail = !msg.equals(detailMsg); final Dialog d = new Dialog(); d.setTitle(sgi18n.dialog_WarnTitle()); d.setIsModal(true); d.setAutoSize(Boolean.FALSE); d.setMessage(msg); d.setIcon("[SKIN]warn.png"); d.setCanDragResize(true); d.setCanDragReposition(Boolean.TRUE); d.setKeepInParentRect(Boolean.TRUE); // d.setShowMaximizeButton(Boolean.TRUE); d.setMinMemberSize(50); Button details = new Button(i18n.ErrorHandler_ButtonDetalis_Title()); details.setVisible(allowDetail); d.setButtons(Dialog.OK, details); if (allowDetail) { Canvas errorPane = new Canvas(); errorPane.setOverflow(Overflow.AUTO); errorPane.setWidth100(); errorPane.setHeight100(); errorPane.setContents(detailMsg); errorPane.setCanSelectText(true); Canvas debugInfoPane = new Canvas(); debugInfoPane.setWidth100(); debugInfoPane.setAutoHeight(); debugInfoPane.setContents(debugInfo); debugInfoPane.setCanSelectText(true); final VLayout detailPane = new VLayout(4); detailPane.setLayoutMargin(4); detailPane.setGroupTitle(i18n.ErrorHandler_ButtonDetalis_Title()); detailPane.setIsGroup(true); detailPane.setVisible(false); detailPane.addMember(errorPane); detailPane.addMember(debugInfoPane); detailPane.setWidth100(); detailPane.setHeight100(); d.addItem(detailPane); details.addClickHandler(new com.smartgwt.client.widgets.events.ClickHandler() { @Override public void onClick(com.smartgwt.client.widgets.events.ClickEvent event) { if (detailPane.isVisible()) { d.restore(); } else { d.maximize(); } detailPane.setVisible(!detailPane.isVisible()); } }); } d.show(); } /** * Creates response object from JSON response string in * {@link com.smartgwt.client.data.RestDataSource SmartGWT format}. * @param response JSON response string * @return response object */ public static DSResponse getDsResponse(String response) { DSResponse dsResponse; // ClientUtils.info(LOG, "response: %s", response); if (response == null || response.isEmpty()) { // not JSON response LOG.log(Level.WARNING, null, new IllegalStateException("Empty response!")); dsResponse = new DSResponse(); dsResponse.setStatus(RPCResponse.STATUS_SUCCESS); } else { JSONValue rVal = JSONParser.parseStrict(response); if (rVal.isObject() != null) { rVal = rVal.isObject().get("response"); } if (rVal != null && rVal.isObject() != null) { JSONObject rObj = rVal.isObject(); dsResponse = DSResponse.getOrCreateRef(rObj.getJavaScriptObject()); } else { // not JSON response in expected format JSONObject jsonObject = new JSONObject(); jsonObject.put("data", new JSONString(response)); dsResponse = new DSResponse(jsonObject.getJavaScriptObject()); dsResponse.setStatus(RPCResponse.STATUS_FAILURE); } } return dsResponse; } /** * Holds parameters from last {@link HandleTransportErrorCallback#handleTransportError * transport error} that are not accessible from {@link DSResponse}. * Particularly {@code httpResponseText}. */ public static final class TransportError { private int status; private int httpResponseCode; private int transactionNum; private String httpResponseText; public TransportError(int transactionNum, int status, int httpResponseCode, String httpResponseText) { this.transactionNum = transactionNum; this.status = status; this.httpResponseCode = httpResponseCode; this.httpResponseText = httpResponseText; } public int getStatus() { return status; } public int getHttpResponseCode() { return httpResponseCode; } public int getTransactionNum() { return transactionNum; } public String getHttpResponseText() { return httpResponseText; } @Override public String toString() { return "TransportError{" + "status=" + status + ", httpResponseCode=" + httpResponseCode + ", transactionNum=" + transactionNum + ", httpResponseText=" + httpResponseText + '}'; } } }