org.springframework.web.servlet.view.json

Class AbstractJackson2View

java.lang.Object

org.springframework.context.support.ApplicationObjectSupport

org.springframework.web.context.support.WebApplicationObjectSupport

org.springframework.web.servlet.view.AbstractView

org.springframework.web.servlet.view.json.AbstractJackson2View

All Implemented Interfaces:

Aware, BeanNameAware, ApplicationContextAware, ServletContextAware, View

Direct Known Subclasses:

MappingJackson2JsonView, MappingJackson2XmlView

public abstract class AbstractJackson2View
extends AbstractView

Abstract base class for Jackson based and content type independent AbstractView implementations.

Compatible with Jackson 2.9 to 2.12, as of Spring 5.3.

Since:

4.1

Author:

Jeremy Grelle, Arjen Poutsma, Rossen Stoyanchev, Juergen Hoeller, Sebastien Deleuze

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	updateContentLength

Fields inherited from class org.springframework.web.servlet.view.AbstractView

DEFAULT_CONTENT_TYPE

Fields inherited from class org.springframework.context.support.ApplicationObjectSupport

logger

Fields inherited from interface org.springframework.web.servlet.View

PATH_VARIABLES, RESPONSE_STATUS_ATTRIBUTE, SELECTED_CONTENT_TYPE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJackson2View(ObjectMapper objectMapper, String contentType)

Method Summary

Modifier and Type	Method and Description
protected Object	filterAndWrapModel(Map<String,Object> model, HttpServletRequest request) Filter and optionally wrap the model in MappingJacksonValue container.
protected abstract Object	filterModel(Map<String,Object> model) Filter out undesired attributes from the given model.
JsonEncoding	getEncoding() Return the JsonEncoding for this view.
ObjectMapper	getObjectMapper() Return the ObjectMapper for this view.
protected void	prepareResponse(HttpServletRequest request, HttpServletResponse response) Prepare the given response for rendering.
protected void	renderMergedOutputModel(Map<String,Object> model, HttpServletRequest request, HttpServletResponse response) Subclasses must implement this method to actually render the view.
void	setDisableCaching(boolean disableCaching) Disables caching of the generated JSON.
void	setEncoding(JsonEncoding encoding) Set the JsonEncoding for this view.
abstract void	setModelKey(String modelKey) Set the attribute in the model that should be rendered by this view.
void	setObjectMapper(ObjectMapper objectMapper) Set the ObjectMapper for this view.
void	setPrettyPrint(boolean prettyPrint) Whether to use the default pretty printer when writing the output.
void	setUpdateContentLength(boolean updateContentLength) Whether to update the 'Content-Length' header of the response.
protected void	writeContent(OutputStream stream, Object object) Write the actual JSON content to the stream.
protected void	writePrefix(JsonGenerator generator, Object object) Write a prefix before the main content.
protected void	writeSuffix(JsonGenerator generator, Object object) Write a suffix after the main content.

Methods inherited from class org.springframework.web.servlet.view.AbstractView

addStaticAttribute, createMergedOutputModel, createRequestContext, createTemporaryOutputStream, exposeModelAsRequestAttributes, formatViewName, generatesDownloadContent, getAttributesMap, getBeanName, getContentType, getRequestContextAttribute, getRequestToExpose, getStaticAttributes, isExposePathVariables, render, setAttributes, setAttributesCSV, setAttributesMap, setBeanName, setContentType, setExposeContextBeansAsAttributes, setExposedContextBeanNames, setExposePathVariables, setRequestContextAttribute, setResponseContentType, toString, writeToResponse

Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport

getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext

Methods inherited from class org.springframework.context.support.ApplicationObjectSupport

getApplicationContext, getMessageSourceAccessor, initApplicationContext, obtainApplicationContext, requiredContextClass, setApplicationContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

updateContentLength

protected boolean updateContentLength

Constructor Detail

AbstractJackson2View

protected AbstractJackson2View(ObjectMapper objectMapper,
                               String contentType)

Method Detail

setObjectMapper

public void setObjectMapper(ObjectMapper objectMapper)

Set the ObjectMapper for this view. If not set, a default ObjectMapper will be used.

Setting a custom-configured ObjectMapper is one way to take further control of the JSON serialization process. The other option is to use Jackson's provided annotations on the types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.

getObjectMapper

public final ObjectMapper getObjectMapper()

Return the ObjectMapper for this view.

setEncoding

public void setEncoding(JsonEncoding encoding)

Set the JsonEncoding for this view. By default, UTF-8 is used.

getEncoding

public final JsonEncoding getEncoding()

Return the JsonEncoding for this view.

setPrettyPrint

public void setPrettyPrint(boolean prettyPrint)

Whether to use the default pretty printer when writing the output. This is a shortcut for setting up an ObjectMapper as follows:

 ObjectMapper mapper = new ObjectMapper();
 mapper.configure(SerializationFeature.INDENT_OUTPUT, true);
 

The default value is false.

setDisableCaching

public void setDisableCaching(boolean disableCaching)

Disables caching of the generated JSON.

Default is true, which will prevent the client from caching the generated JSON.

setUpdateContentLength

public void setUpdateContentLength(boolean updateContentLength)

Whether to update the 'Content-Length' header of the response. When set to true, the response is buffered in order to determine the content length and set the 'Content-Length' header of the response.

The default setting is false.

prepareResponse

protected void prepareResponse(HttpServletRequest request,
                               HttpServletResponse response)

Description copied from class: AbstractView

Prepare the given response for rendering.

The default implementation applies a workaround for an IE bug when sending download content via HTTPS.

Overrides:

prepareResponse in class AbstractView

Parameters:

request - current HTTP request

response - current HTTP response

renderMergedOutputModel

protected void renderMergedOutputModel(Map<String,Object> model,
                                       HttpServletRequest request,
                                       HttpServletResponse response)
                                throws Exception

Description copied from class: AbstractView

Subclasses must implement this method to actually render the view.

The first step will be preparing the request: In the JSP case, this would mean setting model objects as request attributes. The second step will be the actual rendering of the view, for example including the JSP via a RequestDispatcher.

Specified by:

renderMergedOutputModel in class AbstractView

Parameters:

model - combined output Map (never null), with dynamic values taking precedence over static attributes

request - current HTTP request

response - current HTTP response

Throws:

Exception - if rendering failed

filterAndWrapModel

protected Object filterAndWrapModel(Map<String,Object> model,
                                    HttpServletRequest request)

Filter and optionally wrap the model in MappingJacksonValue container.

Parameters:

model - the model, as passed on to renderMergedOutputModel(java.util.Map<java.lang.String, java.lang.Object>, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

request - current HTTP request

Returns:

the wrapped or unwrapped value to be rendered

writeContent

protected void writeContent(OutputStream stream,
                            Object object)
                     throws IOException

Write the actual JSON content to the stream.

Parameters:

stream - the output stream to use

object - the value to be rendered, as returned from filterModel(java.util.Map<java.lang.String, java.lang.Object>)

Throws:

IOException - if writing failed

setModelKey

public abstract void setModelKey(String modelKey)

Set the attribute in the model that should be rendered by this view. When set, all other model attributes will be ignored.

filterModel

protected abstract Object filterModel(Map<String,Object> model)

Filter out undesired attributes from the given model. The return value can be either another Map or a single value object.

Parameters:

model - the model, as passed on to renderMergedOutputModel(java.util.Map<java.lang.String, java.lang.Object>, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

Returns:

the value to be rendered

writePrefix

protected void writePrefix(JsonGenerator generator,
                           Object object)
                    throws IOException

Write a prefix before the main content.

Parameters:

generator - the generator to use for writing content.

object - the object to write to the output message.

Throws:

IOException

writeSuffix

protected void writeSuffix(JsonGenerator generator,
                           Object object)
                    throws IOException

Write a suffix after the main content.

Parameters:

generator - the generator to use for writing content.

object - the object to write to the output message.

Throws:

IOException