com.softlayer.api.json.GsonJsonMarshallerFactory Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of softlayer-api-client Show documentation
Show all versions of softlayer-api-client Show documentation
API client for accessing the SoftLayer API
package com.softlayer.api.json;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.function.Supplier;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import com.softlayer.api.annotation.ApiProperty;
import com.softlayer.api.annotation.ApiType;
import com.softlayer.api.annotation.ApiTypes;
import com.softlayer.api.service.Entity;
class GsonJsonMarshallerFactory extends JsonMarshallerFactory implements JsonMarshaller {
protected final static Gson gson;
final static Map> typeClasses;
static {
gson = new GsonBuilder().
disableHtmlEscaping().
disableInnerClassSerialization().
// Three types need special attention:
// Entity (all non-scalars basically), GregorianCalendar, and BigIntegers
registerTypeAdapterFactory(new EntityTypeAdapterFactory()).
registerTypeAdapter(GregorianCalendar.class, new GregorianCalendarTypeAdapter()).
registerTypeAdapter(BigInteger.class, new BigIntegerTypeAdapter()).
registerTypeAdapter(byte[].class, new ByteArrayTypeAdapter()).
// Sometimes, when a result limit is set to 1 value, REST sends it back as
// a single object instead of an array
registerTypeAdapterFactory(new ListOrSingleObjectTypeFactory()).
serializeNulls().
create();
ApiTypes types = Entity.class.getPackage().getAnnotation(ApiTypes.class);
typeClasses = new HashMap<>(types.value().length);
for (Class clazz : types.value()) {
typeClasses.put(clazz.getAnnotation(ApiType.class).value(), clazz);
}
}
@Override
public JsonMarshaller getJsonMarshaller() {
// We can just reuse the common marshaller here to remain performant
return this;
}
@Override
public void toJson(Object object, OutputStream out) {
Writer writer = new OutputStreamWriter(out);
gson.toJson(object, object.getClass(), writer);
try {
writer.flush();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
@Override
public T fromJson(Type type, InputStream in) {
return gson.fromJson(new InputStreamReader(in), type);
}
static class EntityTypeAdapterFactory implements TypeAdapterFactory {
@Override
@SuppressWarnings("unchecked")
public TypeAdapter create(Gson gson, TypeToken type) {
Class typeClass = type.getRawType();
if (!Entity.class.isAssignableFrom(typeClass)) {
return null;
}
// Obtain all ApiProperty fields and make them accessible...
Map fields = new HashMap<>();
loadFields(typeClass, fields);
return (TypeAdapter) new EntityTypeAdapter((Class) typeClass, fields);
}
protected void loadFields(Class clazz, Map fields) {
for (Field field : clazz.getDeclaredFields()) {
ApiProperty property = field.getAnnotation(ApiProperty.class);
if (property != null) {
String name = property.value().isEmpty() ? field.getName() : property.value();
if (!fields.containsKey(name)) {
field.setAccessible(true);
Field specifiedField = null;
if (property.canBeNullOrNotSet()) {
try {
specifiedField = clazz.getDeclaredField(field.getName() + "Specified");
} catch (NoSuchFieldException e) {
throw new RuntimeException(
"Cannot find specified field for " + name + " on " + clazz, e);
}
specifiedField.setAccessible(true);
}
fields.put(name, new EntityJsonField(field, specifiedField));
}
}
}
if (clazz.getSuperclass() != Object.class) {
loadFields(clazz.getSuperclass(), fields);
}
}
}
static class EntityJsonField {
public final Field field;
public final Field specifiedField;
public EntityJsonField(Field field, Field specifiedField) {
this.field = field;
this.specifiedField = specifiedField;
}
}
static class EntityTypeAdapter extends TypeAdapter {
final Class typeClass;
final String typeName;
final Map fields;
public EntityTypeAdapter(Class typeClass, Map fields) {
this.typeClass = typeClass;
this.typeName = typeClass.getAnnotation(ApiType.class).value();
this.fields = fields;
}
@Override
public void write(JsonWriter out, Entity value) throws IOException {
if (value == null) {
out.nullValue();
return;
}
out.beginObject();
// Every type will include the "complexType" field
out.name("complexType").value(typeName);
for (Map.Entry fieldEntry : fields.entrySet()) {
EntityJsonField field = fieldEntry.getValue();
try {
Object fieldValue = field.field.get(value);
if (fieldValue != null ||
(field.specifiedField != null && field.specifiedField.getBoolean(value))) {
out.name(fieldEntry.getKey());
gson.toJson(fieldValue, field.field.getGenericType(), out);
}
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
out.endObject();
}
@Override
public Entity read(JsonReader in) throws IOException {
// We are allowed to assume that the first property is complexType always. This allows us to maintain
// a streaming reader and is very important.
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
in.beginObject();
if (!"complexType".equals(in.nextName())) {
throw new RuntimeException("Expected 'complexType' as first property");
}
String apiTypeName = in.nextString();
// If the API type is unrecognized by us (i.e. it's a new type), we just use the type
// we're an adapter for. So if we have SoftLayer_Something and a newer release of the
// API has a type extending it but we don't have a generated class for it, it will get
// properly serialized to a SoftLayer_Something.
// If the API returns a type that isn't the same or a subtype of the type class,
// try as best we can to fit the data within the type class.
Class clazz = typeClasses.get(apiTypeName);
Entity result;
if (clazz == null || !typeClass.isAssignableFrom(clazz)) {
result = readForThisType(in);
} else {
result = ((EntityTypeAdapter) gson.getAdapter(clazz)).readForThisType(in);
}
in.endObject();
return result;
}
private Entity readForThisType(JsonReader in) throws IOException {
// Begin/end object (and the first "complexType" property) are done outside of here
Entity entity;
try {
entity = typeClass.getDeclaredConstructor().newInstance();
} catch (ReflectiveOperationException e) {
throw new RuntimeException(e);
}
Map unknownProperties = new HashMap<>();
while (in.hasNext()) {
String propertyName = in.nextName();
EntityJsonField field = fields.get(propertyName);
// No field means we just add the object to the unknown set
if (field == null) {
unknownProperties.put(propertyName, gson.fromJson(in, Object.class));
} else {
try {
field.field.set(entity, gson.fromJson(in, field.field.getGenericType()));
if (field.specifiedField != null) {
field.specifiedField.setBoolean(entity, true);
}
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
}
if (!unknownProperties.isEmpty()) {
entity.setUnknownProperties(unknownProperties);
}
return entity;
}
}
static class GregorianCalendarTypeAdapter extends TypeAdapter {
// Although this is ISO-8601, Java 6 does not allow a colon in the timestamp. All API
// dates look like this: 1984-02-25T20:15:25-06:00. Since we can guarantee that, we
// can just remove/add the colon as necessary. This is a better solution than using
// JAXB libraries.
// Ref: http://stackoverflow.com/questions/2201925/converting-iso-8601-compliant-string-to-java-util-date
final ThreadLocal secondFormat = ThreadLocal.withInitial(
() -> new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ")
);
// Some times come back with fractions of a second all the way down to 6 digits.
// Luckily we can just use the presence of a decimal point as a discriminator between
// this format and the one above.
final ThreadLocal subSecondFormat = ThreadLocal.withInitial(
() -> new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ")
);
@Override
public void write(JsonWriter out, GregorianCalendar value) throws IOException {
if (value == null) {
out.nullValue();
} else {
// Always use second-level format here
String date = secondFormat.get().format(value.getTime());
// Add the colon
out.value(date.substring(0, date.length() - 2) + ':' + date.substring(date.length() - 2));
}
}
@Override
public GregorianCalendar read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
String date = in.nextString();
// Remove the colon
date = date.substring(0, date.length() - 3) + date.substring(date.length() - 2);
// Use decimal presence to determine format and trim to ms precision
DateFormat format;
int decimalIndex = date.indexOf('.');
if (decimalIndex != -1) {
date = trimToMillisecondPrecision(date, decimalIndex);
format = subSecondFormat.get();
} else {
format = secondFormat.get();
}
GregorianCalendar calendar = new GregorianCalendar();
try {
calendar.setTime(format.parse(date));
} catch (ParseException e) {
throw new RuntimeException(e);
}
return calendar;
}
private String trimToMillisecondPrecision(String date, int decimalIndex) {
// If there is a decimal we have to only keep the first three numeric characters
// after it (and pad with 0's if fewer than three)
StringBuilder newDate = new StringBuilder(date);
int offset = 1;
do {
if (!Character.isDigit(newDate.charAt(decimalIndex + offset))) {
switch (offset) {
case 1:
newDate.insert(decimalIndex + offset, "000");
break;
case 2:
newDate.insert(decimalIndex + offset, "00");
break;
case 3:
newDate.insert(decimalIndex + offset, "0");
break;
}
break;
} else if (offset > 3) {
newDate.deleteCharAt(decimalIndex + offset);
} else {
offset++;
}
} while (true);
return newDate.toString();
}
}
static class BigIntegerTypeAdapter extends TypeAdapter {
@Override
public void write(JsonWriter out, BigInteger value) throws IOException {
// Just write out the toString
out.value(value);
}
@Override
public BigInteger read(JsonReader in) throws IOException {
// Do the BigDecimal parsing and just convert. The regular Gson BigInteger parser doesn't support
// exponents like we need to. Basically, the BigDecimal string constructor is better than the
// BigInteger one.
BigDecimal value = gson.fromJson(in, BigDecimal.class);
return value == null ? null : value.toBigInteger();
}
}
static class ByteArrayTypeAdapter extends TypeAdapter {
@Override
public void write(JsonWriter out, byte[] value) throws IOException {
if (value == null) {
out.nullValue();
} else {
out.value(Base64.getEncoder().encodeToString(value));
}
}
@Override
public byte[] read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
return Base64.getDecoder().decode(in.nextString());
}
}
static class ListOrSingleObjectTypeFactory implements TypeAdapterFactory {
@Override
@SuppressWarnings({ "rawtypes", "unchecked" })
public TypeAdapter create(Gson gson, TypeToken type) {
if (!List.class.isAssignableFrom(type.getRawType()) || !(type.getType() instanceof ParameterizedType)) {
return null;
}
Type[] typeArgs = ((ParameterizedType) type.getType()).getActualTypeArguments();
if (typeArgs.length != 1 || !(typeArgs[0] instanceof Class)) {
return null;
}
return new ListOrSingleObjectTypeAdapter(gson.getDelegateAdapter(this, type),
gson.getAdapter((Class) typeArgs[0]));
}
}
static class ListOrSingleObjectTypeAdapter extends TypeAdapter> {
private final TypeAdapter> listDelegate;
private final TypeAdapter instanceDelegate;
public ListOrSingleObjectTypeAdapter(TypeAdapter> listDelegate, TypeAdapter instanceDelegate) {
this.listDelegate = listDelegate;
this.instanceDelegate = instanceDelegate;
}
@Override
public void write(JsonWriter out, List value) throws IOException {
// Writing always delegates to list
listDelegate.write(out, value);
}
@Override
public List read(JsonReader in) throws IOException {
// We only take over if it's the beginning of an object, otherwise delegate
if (in.peek() == JsonToken.BEGIN_OBJECT) {
// Send back a mutable list of 1
List result = new ArrayList<>(1);
result.add(instanceDelegate.read(in));
return result;
}
return listDelegate.read(in);
}
}
}