org.codehaus.jackson.map.ObjectWriter Maven / Gradle / Ivy
package org.codehaus.jackson.map;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import org.codehaus.jackson.*;
import org.codehaus.jackson.io.SegmentedStringWriter;
import org.codehaus.jackson.map.introspect.VisibilityChecker;
import org.codehaus.jackson.map.jsontype.TypeResolverBuilder;
import org.codehaus.jackson.map.type.TypeFactory;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.util.ByteArrayBuilder;
/**
* Builder object that can be used for per-serialization configuration of
* serialization parameters, such as JSON View and root type to use.
* Uses "fluid" (aka builder) pattern so that instances are immutable
* (and thus fully thread-safe); new instances are constructed for
* different configurations.
* Instances are initially constructed by {@link ObjectMapper}, and can
* be similarly reused.
*
* @author tatu
* @since 1.5
*/
public class ObjectWriter
{
/*
/***************************************************
/* Immutable configuration from ObjectMapper
/***************************************************
*/
/**
* General serialization configuration settings
*/
protected final SerializationConfig _config;
protected final SerializerProvider _provider;
protected final SerializerFactory _serializerFactory;
/**
* Factory used for constructing {@link JsonGenerator}s
*/
protected final JsonFactory _jsonFactory;
// Support for polymorphic types:
protected TypeResolverBuilder _defaultTyper;
// Configurable visibility limits
protected VisibilityChecker _visibilityChecker;
/*
/***************************************************
/* Configuration that can be changed during building
/***************************************************
*/
/**
* View to use for serialization
*/
protected final Class _serializationView;
/**
* Specified root serialization type to use; can be same
* as runtime type, but usually one of its super types
*/
protected final JavaType _rootType;
/*
/***************************************************
/* Life-cycle
/***************************************************
*/
/**
* Constructor used by {@link ObjectMapper} for initial instantiation
*/
protected ObjectWriter(ObjectMapper mapper,
Class view, JavaType rootType)
{
_defaultTyper = mapper._defaultTyper;
_visibilityChecker = mapper._visibilityChecker;
// must make a copy at this point, to prevent further changes from trickling down
_config = mapper._serializationConfig.createUnshared(_defaultTyper, _visibilityChecker);
_config.setSerializationView(view);
_provider = mapper._serializerProvider;
_serializerFactory = mapper._serializerFactory;
_jsonFactory = mapper._jsonFactory;
_serializationView = view;
_rootType = rootType;
}
/**
* Copy constructor used for building variations.
*/
protected ObjectWriter(ObjectWriter base, SerializationConfig config,
Class view, JavaType rootType)
{
_config = config;
_provider = base._provider;
_serializerFactory = base._serializerFactory;
_jsonFactory = base._jsonFactory;
_defaultTyper = base._defaultTyper;
_visibilityChecker = base._visibilityChecker;
_serializationView = view;
_rootType = rootType;
}
public ObjectWriter withView(Class view)
{
if (view == _serializationView) return this;
// View is included in config, must make immutable version
SerializationConfig config = _config.createUnshared(_defaultTyper, _visibilityChecker);
config.setSerializationView(view);
return new ObjectWriter(this, config, view, _rootType);
}
public ObjectWriter withType(JavaType rootType)
{
if (rootType == _rootType) return this;
// type is stored here, no need to make a copy of config
return new ObjectWriter(this, _config, _serializationView, rootType);
}
public ObjectWriter withType(Class rootType)
{
return withType(TypeFactory.type(rootType));
}
/*
/***************************************************
/* Serialization methods; ones from ObjectCodec first
/***************************************************
*/
/**
* Method that can be used to serialize any Java value as
* JSON output, using provided {@link JsonGenerator}.
*/
public void writeValue(JsonGenerator jgen, Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
_provider.serializeValue(_config, jgen, value, _serializerFactory);
jgen.flush();
}
/*
/***************************************************
/* Serialization methods, others
/***************************************************
*/
/**
* Method that can be used to serialize any Java value as
* JSON output, written to File provided.
*/
public void writeValue(File resultFile, Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
_configAndWriteValue(_jsonFactory.createJsonGenerator(resultFile, JsonEncoding.UTF8), value);
}
/**
* Method that can be used to serialize any Java value as
* JSON output, using output stream provided (using encoding
* {@link JsonEncoding#UTF8}).
*
* Note: method does not close the underlying stream explicitly
* here; however, {@link JsonFactory} this mapper uses may choose
* to close the stream depending on its settings (by default,
* it will try to close it when {@link JsonGenerator} we construct
* is closed).
*/
public void writeValue(OutputStream out, Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
_configAndWriteValue(_jsonFactory.createJsonGenerator(out, JsonEncoding.UTF8), value);
}
/**
* Method that can be used to serialize any Java value as
* JSON output, using Writer provided.
*
* Note: method does not close the underlying stream explicitly
* here; however, {@link JsonFactory} this mapper uses may choose
* to close the stream depending on its settings (by default,
* it will try to close it when {@link JsonGenerator} we construct
* is closed).
*/
public void writeValue(Writer w, Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
_configAndWriteValue(_jsonFactory.createJsonGenerator(w), value);
}
/**
* Method that can be used to serialize any Java value as
* a String. Functionally equivalent to calling
* {@link #writeValue(Writer,Object)} with {@link java.io.StringWriter}
* and constructing String, but more efficient.
*
* @since 1.3
*/
public String writeValueAsString(Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
// alas, we have to pull the recycler directly here...
SegmentedStringWriter sw = new SegmentedStringWriter(_jsonFactory._getBufferRecycler());
_configAndWriteValue(_jsonFactory.createJsonGenerator(sw), value);
return sw.getAndClear();
}
/**
* Method that can be used to serialize any Java value as
* a byte array. Functionally equivalent to calling
* {@link #writeValue(Writer,Object)} with {@link java.io.ByteArrayOutputStream}
* and getting bytes, but more efficient.
* Encoding used will be UTF-8.
*
* @since 1.5
*/
public byte[] writeValueAsBytes(Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
ByteArrayBuilder bb = new ByteArrayBuilder(_jsonFactory._getBufferRecycler());
_configAndWriteValue(_jsonFactory.createJsonGenerator(bb, JsonEncoding.UTF8), value);
byte[] result = bb.toByteArray();
bb.release();
return result;
}
/*
/***************************************************
/* Other public methods
/***************************************************
*/
public boolean canSerialize(Class type)
{
return _provider.hasSerializerFor(_config, type, _serializerFactory);
}
/*
/***************************************************
/* Internal methods
/***************************************************
*/
/**
* Method called to configure the generator as necessary and then
* call write functionality
*/
protected final void _configAndWriteValue(JsonGenerator jgen, Object value)
throws IOException, JsonGenerationException, JsonMappingException
{
// [JACKSON-96]: allow enabling pretty printing for ObjectMapper directly
if (_config.isEnabled(SerializationConfig.Feature.INDENT_OUTPUT)) {
jgen.useDefaultPrettyPrinter();
}
boolean closed = false;
try {
if (_rootType == null) {
_provider.serializeValue(_config, jgen, value, _serializerFactory);
} else {
_provider.serializeValue(_config, jgen, value, _rootType, _serializerFactory);
}
closed = true;
jgen.close();
} finally {
/* won't try to close twice; also, must catch exception (so it
* will not mask exception that is pending)
*/
if (!closed) {
try {
jgen.close();
} catch (IOException ioe) { }
}
}
}
}