org.springframework.web.servlet.mvc.method.annotation.ModelAndViewMethodReturnValueHandler.java Source code

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Here is the source code for org.springframework.web.servlet.mvc.method.annotation.ModelAndViewMethodReturnValueHandler.java

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/*
 * Copyright 2002-2017 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.web.servlet.mvc.method.annotation;

import org.springframework.core.MethodParameter;
import org.springframework.lang.Nullable;
import org.springframework.util.PatternMatchUtils;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.SmartView;
import org.springframework.web.servlet.View;

/**
 * Handles return values of type {@link ModelAndView} copying view and model
 * information to the {@link ModelAndViewContainer}.
 *
 * <p>If the return value is {@code null}, the
 * {@link ModelAndViewContainer#setRequestHandled(boolean)} flag is set to
 * {@code true} to indicate the request was handled directly.
 *
 * <p>A {@link ModelAndView} return type has a set purpose. Therefore this
 * handler should be configured ahead of handlers that support any return
 * value type annotated with {@code @ModelAttribute} or {@code @ResponseBody}
 * to ensure they don't take over.
 *
 * @author Rossen Stoyanchev
 * @since 3.1
 */
public class ModelAndViewMethodReturnValueHandler implements HandlerMethodReturnValueHandler {

    @Nullable
    private String[] redirectPatterns;

    /**
     * Configure one more simple patterns (as described in {@link PatternMatchUtils#simpleMatch})
     * to use in order to recognize custom redirect prefixes in addition to "redirect:".
     * <p>Note that simply configuring this property will not make a custom redirect prefix work.
     * There must be a custom {@link View} that recognizes the prefix as well.
     * @since 4.1
     */
    public void setRedirectPatterns(@Nullable String... redirectPatterns) {
        this.redirectPatterns = redirectPatterns;
    }

    /**
     * Return the configured redirect patterns, if any.
     * @since 4.1
     */
    @Nullable
    public String[] getRedirectPatterns() {
        return this.redirectPatterns;
    }

    @Override
    public boolean supportsReturnType(MethodParameter returnType) {
        return ModelAndView.class.isAssignableFrom(returnType.getParameterType());
    }

    @Override
    public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType,
            ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {

        if (returnValue == null) {
            mavContainer.setRequestHandled(true);
            return;
        }

        ModelAndView mav = (ModelAndView) returnValue;
        if (mav.isReference()) {
            String viewName = mav.getViewName();
            mavContainer.setViewName(viewName);
            if (viewName != null && isRedirectViewName(viewName)) {
                mavContainer.setRedirectModelScenario(true);
            }
        } else {
            View view = mav.getView();
            mavContainer.setView(view);
            if (view instanceof SmartView && ((SmartView) view).isRedirectView()) {
                mavContainer.setRedirectModelScenario(true);
            }
        }
        mavContainer.setStatus(mav.getStatus());
        mavContainer.addAllAttributes(mav.getModel());
    }

    /**
     * Whether the given view name is a redirect view reference.
     * The default implementation checks the configured redirect patterns and
     * also if the view name starts with the "redirect:" prefix.
     * @param viewName the view name to check, never {@code null}
     * @return "true" if the given view name is recognized as a redirect view
     * reference; "false" otherwise.
     */
    protected boolean isRedirectViewName(String viewName) {
        return (PatternMatchUtils.simpleMatch(this.redirectPatterns, viewName) || viewName.startsWith("redirect:"));
    }

}