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This commit is contained in:
Juergen Hoeller
2011-12-11 22:07:12 +00:00
parent 0f75cebdff
commit d8e640d708
5 changed files with 122 additions and 120 deletions
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119
org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/json/MappingJacksonJsonView.java
View File

@@ -1,5 +1,5 @@
/*
* Copyright 2002-2010 the original author or authors.
* Copyright 2002-2011 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.
@@ -20,7 +20,6 @@ import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@@ -28,6 +27,7 @@ import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializerFactory;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.validation.BindingResult;
@@ -35,19 +35,18 @@ import org.springframework.web.servlet.View;
import org.springframework.web.servlet.view.AbstractView;
/**
* Spring-MVC {@link View} that renders JSON content by serializing the model for the current request using <a
* href="http://jackson.codehaus.org/">Jackson's</a> {@link ObjectMapper}.
* Spring MVC {@link View} that renders JSON content by serializing the model for the current request
* using <a href="http://jackson.codehaus.org/">Jackson's</a> {@link ObjectMapper}.
*
* <p>By default, the entire contents of the model map (with the exception of framework-specific classes) will be
* encoded as JSON. If the model contains only one key, you can have it extracted encoded as JSON alone via
* {@link #setExtractValueFromSingleKeyModel(boolean)}. Or you can select specific model attributes to be encoded
* as JSON via ... TODO
* <p>By default, the entire contents of the model map (with the exception of framework-specific classes)
* will be encoded as JSON. If the model contains only one key, you can have it extracted encoded as JSON
* alone via {@link #setExtractValueFromSingleKeyModel}.
*
* @author Jeremy Grelle
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @see org.springframework.http.converter.json.MappingJacksonHttpMessageConverter
* @since 3.0
* @see org.springframework.http.converter.json.MappingJacksonHttpMessageConverter
*/
public class MappingJacksonJsonView extends AbstractView {
@@ -56,6 +55,7 @@ public class MappingJacksonJsonView extends AbstractView {
*/
public static final String DEFAULT_CONTENT_TYPE = "application/json";
private ObjectMapper objectMapper = new ObjectMapper();
private JsonEncoding encoding = JsonEncoding.UTF8;
@@ -68,6 +68,7 @@ public class MappingJacksonJsonView extends AbstractView {
private boolean disableCaching = true;
/**
* Construct a new {@code JacksonJsonView}, setting the content type to {@code application/json}.
*/
@@ -76,14 +77,15 @@ public class MappingJacksonJsonView extends AbstractView {
setExposePathVariables(false);
}
/**
* Sets the {@code ObjectMapper} for this view. If not set, a default {@link ObjectMapper#ObjectMapper() ObjectMapper}
* is used.
*
* <p>Setting a custom-configured {@code ObjectMapper} is one way to take further control of the JSON serialization
* process. For example, an extended {@link SerializerFactory} can be configured that provides custom serializers for
* specific types. The other option for refining the serialization process is to use Jackson's provided annotations on
* the types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.
* Sets the {@code ObjectMapper} for this view.
* If not set, a default {@link ObjectMapper#ObjectMapper() ObjectMapper} is used.
* <p>Setting a custom-configured {@code ObjectMapper} is one way to take further control
* of the JSON serialization process. For example, an extended {@link SerializerFactory}
* can be configured that provides custom serializers for specific types. The other option
* for refining the serialization process is to use Jackson's provided annotations on the
* types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.
*/
public void setObjectMapper(ObjectMapper objectMapper) {
Assert.notNull(objectMapper, "'objectMapper' must not be null");
@@ -91,7 +93,8 @@ public class MappingJacksonJsonView extends AbstractView {
}
/**
* Sets the {@code JsonEncoding} for this converter. By default, {@linkplain JsonEncoding#UTF8 UTF-8} is used.
* Set the {@code JsonEncoding} for this converter.
* By default, {@linkplain JsonEncoding#UTF8 UTF-8} is used.
*/
public void setEncoding(JsonEncoding encoding) {
Assert.notNull(encoding, "'encoding' must not be null");
@@ -99,18 +102,19 @@ public class MappingJacksonJsonView extends AbstractView {
}
/**
* Indicates whether the JSON output by this view should be prefixed with <tt>"{} && "</tt>. Default is false.
*
* <p> Prefixing the JSON string in this manner is used to help prevent JSON Hijacking. The prefix renders the string
* syntactically invalid as a script so that it cannot be hijacked. This prefix does not affect the evaluation of JSON,
* but if JSON validation is performed on the string, the prefix would need to be ignored.
* Indicates whether the JSON output by this view should be prefixed with <tt>"{} && "</tt>.
* Default is false.
* <p>Prefixing the JSON string in this manner is used to help prevent JSON Hijacking.
* The prefix renders the string syntactically invalid as a script so that it cannot be hijacked.
* This prefix does not affect the evaluation of JSON, but if JSON validation is performed
* on the string, the prefix would need to be ignored.
*/
public void setPrefixJson(boolean prefixJson) {
this.prefixJson = prefixJson;
}
/**
* Sets the attribute in the model that should be rendered by this view.
* Set the attribute in the model that should be rendered by this view.
* When set, all other model attributes will be ignored.
*/
public void setModelKey(String modelKey) {
@@ -118,7 +122,7 @@ public class MappingJacksonJsonView extends AbstractView {
}
/**
* Sets the attributes in the model that should be rendered by this view.
* Set the attributes in the model that should be rendered by this view.
* When set, all other model attributes will be ignored.
*/
public void setModelKeys(Set<String> modelKeys) {
@@ -126,56 +130,56 @@ public class MappingJacksonJsonView extends AbstractView {
}
/**
* Returns the attributes in the model that should be rendered by this view.
* Return the attributes in the model that should be rendered by this view.
*/
public Set<String> getModelKeys() {
return modelKeys;
return this.modelKeys;
}
/**
* Sets the attributes in the model that should be rendered by this view.
* Set the attributes in the model that should be rendered by this view.
* When set, all other model attributes will be ignored.
* @deprecated use {@link #setModelKeys(Set)} instead
*/
@Deprecated
public void setRenderedAttributes(Set<String> renderedAttributes) {
this.modelKeys = renderedAttributes;
}
/**
* Returns the attributes in the model that should be rendered by this view.
* Return the attributes in the model that should be rendered by this view.
* @deprecated use {@link #getModelKeys()} instead
*/
@Deprecated
public Set<String> getRenderedAttributes() {
return modelKeys;
return this.modelKeys;
}
/**
* Set whether to serialize models containing a single attribute as a map or whether to
* extract the single value from the model and serialize it directly.
* <p>The effect of setting this flag is similar to using {@code MappingJacksonHttpMessageConverter}
* with an {@code @ResponseBody} request-handling method.
* <p>Default is {@code false}.
*/
public void setExtractValueFromSingleKeyModel(boolean extractValueFromSingleKeyModel) {
this.extractValueFromSingleKeyModel = extractValueFromSingleKeyModel;
}
/**
* Disables caching of the generated JSON.
*
* <p>Default is {@code true}, which will prevent the client from caching the generated JSON.
*/
public void setDisableCaching(boolean disableCaching) {
this.disableCaching = disableCaching;
}
/**
* Set whether to serialize models containing a single attribute as a map or whether to
* extract the single value from the model and serialize it directly.
* The effect of setting this flag is similar to using
* {@code MappingJacksonHttpMessageConverter} with an {@code @ResponseBody}.
* request-handling method.
*
* <p>Default is {@code false}.
*/
public void setExtractValueFromSingleKeyModel(boolean extractValueFromSingleKeyModel) {
this.extractValueFromSingleKeyModel = extractValueFromSingleKeyModel;
}
@Override
protected void prepareResponse(HttpServletRequest request, HttpServletResponse response) {
response.setContentType(getContentType());
response.setCharacterEncoding(encoding.getJavaName());
if (disableCaching) {
response.setCharacterEncoding(this.encoding.getJavaName());
if (this.disableCaching) {
response.addHeader("Pragma", "no-cache");
response.addHeader("Cache-Control", "no-cache, no-store, max-age=0");
response.addDateHeader("Expires", 1L);
@@ -183,38 +187,35 @@ public class MappingJacksonJsonView extends AbstractView {
}
@Override
protected void renderMergedOutputModel(Map<String, Object> model,
HttpServletRequest request,
protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
HttpServletResponse response) throws Exception {
Object value = filterModel(model);
JsonGenerator generator =
objectMapper.getJsonFactory().createJsonGenerator(response.getOutputStream(), encoding);
if (prefixJson) {
this.objectMapper.getJsonFactory().createJsonGenerator(response.getOutputStream(), this.encoding);
if (this.prefixJson) {
generator.writeRaw("{} && ");
}
objectMapper.writeValue(generator, value);
this.objectMapper.writeValue(generator, value);
}
/**
* Filters out undesired attributes from the given model. The return value can be either another {@link Map}, or a
* single value object.
*
* <p>Default implementation removes {@link BindingResult} instances and entries not included in the {@link
* #setRenderedAttributes(Set) renderedAttributes} property.
*
* Filters out undesired attributes from the given model.
* The return value can be either another {@link Map} or a single value object.
* <p>The default implementation removes {@link BindingResult} instances and entries
* not included in the {@link #setRenderedAttributes renderedAttributes} property.
* @param model the model, as passed on to {@link #renderMergedOutputModel}
* @return the object to be rendered
*/
protected Object filterModel(Map<String, Object> model) {
Map<String, Object> result = new HashMap<String, Object>(model.size());
Set<String> renderedAttributes =
!CollectionUtils.isEmpty(this.modelKeys) ? this.modelKeys : model.keySet();
Set<String> renderedAttributes = (!CollectionUtils.isEmpty(this.modelKeys) ? this.modelKeys : model.keySet());
for (Map.Entry<String, Object> entry : model.entrySet()) {
if (!(entry.getValue() instanceof BindingResult) && renderedAttributes.contains(entry.getKey())) {
result.put(entry.getKey(), entry.getValue());
}
}
return (this.extractValueFromSingleKeyModel && result.size() == 1) ? result.values().iterator().next() : result;
return (this.extractValueFromSingleKeyModel && result.size() == 1 ? result.values().iterator().next() : result);
}
}