lets asume i have a Interface like that:
public interface User extends Element {
String getName();
String getPassword();
}
and a implementing class like that:
public class BaseUser implements User {
#Override
public String getId() {
return id;
}
#Override
public String getName() {
return name;
}
#Override
public String getPassword() {
return password;
}
public void setId(String id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
System.out.println("Set name to " + name);
}
public void setPassword(String password) {
this.password = password;
}
private String id;
private String name;
private String password;
}
Now i want to use bytebuddy to create a interceptor/proxy which catches the call onto the setter, store the changed value and call the real method also.
At the end i want to "ask" the interceptor/proxy for the called setter and the changed values.
I tried a lot considering also the tutorials but up to now i found no working solution. Maybe someone could help me pls.
And here is the Interceptor:
public class GenericInterceptor implements InvocationHandler {
#Override
#RuntimeType
public Object invoke(#This Object proxy, #Origin Method method, #AllArguments Object[] args) throws Throwable {
if (isSetter(method, args)) {
intercept(proxy, method, args);
}
return method.invoke(proxy, args);
}
}
Here is my current 'test' code:
public static void main(String[] args) {
final ByteBuddy bb = new ByteBuddy();
final GenericInterceptor interceptor = new GenericInterceptor();
bb.subclass(BaseUser.class)
.method(isDeclaredBy(BaseUser.class).and(isSetter()))
.intercept(MethodDelegation.to(interceptor))
.make()
.load(BaseUser.class.getClassLoader(), ClassLoadingStrategy.Default.WRAPPER);
final BaseUser user = new BaseUser();
user.setName("my name");
}
EDIT:
public interface Element {
String getId();
}
public class GenericInterceptor<T extends Element> {
public GenericInterceptor(Class<T> type) {
this.type = type;
}
public Map<String, Object> getChanges(T obj) {
final String id = obj.getId();
return changes.get(id);
}
#RuntimeType
public void invoke(#This T proxy, #Origin Method method, #AllArguments Object[] args) throws Throwable {
System.out.println("invoke " + method.getName() + " " + Arrays.toString(args));
intercept(proxy, method, args);
}
private Object getCurrentValue(T proxy, final Field field) {
try {
return field.get(proxy);
} catch (IllegalArgumentException | IllegalAccessException e) {
return null;
}
}
private Field getSetterField(Method setter) {
final String setterName = setter.getName();
Field f = assignedFields.get(setterName);
if (f != null) return f;
final String fieldName = Character.toLowerCase(setterName.charAt(3)) + setterName.substring(4);
try {
f = type.getDeclaredField(fieldName);
if (f == null) return null;
f.setAccessible(true);
assignedFields.put(setterName, f);
return f;
} catch (NoSuchFieldException | SecurityException e) {
return null;
}
}
private void intercept(T proxy, Method setter, Object[] args) {
final Field field = getSetterField(setter);
if (field == null)
return;
final Object currentValue = getCurrentValue(proxy, field);
final Object newValue = args[0];
System.out.println("Set from " + currentValue + " to " + newValue);
final String id = proxy.getId();
Map<String, Object> changeMap = changes.get(id);
if (changeMap == null) {
changeMap = new HashMap<>();
}
changeMap.put(field.getName(), currentValue);
changes.put(id, changeMap);
}
private final Map<String, Field> assignedFields = new HashMap<>();
private final Map<String, Map<String, Object>> changes = new LinkedHashMap<>();
private final Class<T> type;
}
You can call orignal method using MethodDelegation.to(...).andThen(SuperMethodCall.INSTANCE).
public class ByteBuddyTest {
public static void main(String[] args) throws IllegalAccessException, InvocationTargetException, InstantiationException {
GenericInterceptor interceptor = new GenericInterceptor ();
Class<?> clazz = new ByteBuddy()
.subclass(BaseUser.class)
.method(ElementMatchers.isDeclaredBy(BaseUser.class).and(ElementMatchers.isSetter()))
.intercept(SuperMethodCall.INSTANCE.andThen(MethodDelegation.to(interceptor))))
.make()
.load(ByteBuddyTest.class.getClassLoader())
.getLoaded();
BaseUser user1 = (BaseUser) clazz.getConstructors()[0].newInstance();
BaseUser user2 = (BaseUser) clazz.getConstructors()[0].newInstance();
user1.setName("user1");
user1.setPassword("password1");
user2.setName("user2");
user2.setPassword("password2");
System.out.println(interceptor.getInterceptedValue("user1", "name"));
System.out.println(interceptor.getInterceptedValue("user1", "password"));
System.out.println(interceptor.getInterceptedValue("user2", "name"));
System.out.println(interceptor.getInterceptedValue("user2", "password"));
user1.setPassword("password2");
user1.setPassword("password3");
}
public static class GenericInterceptor {
private Map<String, Object> interceptedValuesMap = new HashMap();
public void set(String obj, #This User user, #Origin Method setter) {
// assume that user name is unique so we can use it as a key in values map.
// or define equals/hashcode in GenericUser object and use it as a key directly
String setterName = setter.getName();
String propertyName = setterName.substring(3, setterName.length()).toLowerCase();
String key = user.getName() + "_" + propertyName;
System.out.println("Setting " + propertyName + " to " + obj);
System.out.println("Previous value " + interceptedValuesMap.get(key));
interceptedValuesMap.put(key, obj);
}
public Object getInterceptedValue(String userName, String fieldName) {
return interceptedValuesMap.get(userName + "_" + fieldName);
}
}
public static interface User {
String getName();
String getPassword();
}
public static class BaseUser implements User {
#Override
public String getName() {
return name;
}
#Override
public String getPassword() {
return password;
}
public void setName(String name) {
this.name = name;
}
public void setPassword(String password) {
this.password = password;
}
private String name;
private String password;
}
}
Related
What is the name of that pattern in java? Please see the implementation of RedirectAdultUserHandler1 and RedirectAdultUserHandler2 classes.
public class Main {
public static void main(String[] args) throws Exception {
new Main().run();
}
private void run() {
final List<User> users = Arrays.asList(
new User("john", 1),
new User("jeff", 22),
new User("jack", 333)
);
UserHandler handler1 = new RedirectAdultUserHandler1(new UserHandler());
UserHandler handler2 = new RedirectAdultUserHandler2();
handler1.processAll(users);
handler2.processAll(users);
}
}
class User {
private final String name;
private final int age;
User(final String name, final int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
#Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
class UserHandler {
public void processAll(List<User> users) {
users.forEach(user -> process(user, "users"));
System.out.println();
}
public void process(User user, String tableName) {
System.out.printf("%s stored into %s%n", user, tableName);
}
}
class RedirectAdultUserHandler1 extends UserHandler {
private final UserHandler original;
public RedirectAdultUserHandler1(final UserHandler original) {
this.original = original;
}
#Override
public void processAll(final List<User> users) {
original.processAll(users);
}
#Override
public void process(final User user, final String tableName) {
if (user.getAge() >= 18) {
original.process(user, "adult_users");
}
original.process(user, tableName);
}
}
class RedirectAdultUserHandler2 extends UserHandler {
#Override
public void process(final User user, final String tableName) {
if (user.getAge() >= 18) {
super.process(user, "adult_users");
}
super.process(user, tableName);
}
}
The RedirectAdultUserHandler1 is a decorator, but what about the RedirectAdultUserHandler2 one? Is there some name for that?
Here not any pattern is used. RedirectAdultUserHandler2 and RedirectAdultUserHandler1 are subclasses of UserHandler. So it can be concluded that just inheritance is used here.
I'm using Jackson v2 in a JAX-RS app, and I'm trying to figure out if it is possible
to configure "ObjectMapper" to drop fields with transient modifier, but only during serialisation.
Here's a DTO to illustrate my use case (getters & setters omitted)
public class User {
private String email;
private transient String password;
}
With the above DTO in mind, I would like to have an object mapper that drops
the password field when serialising, and includes it during deserialisation.
The only thing I could find regarding transient is:
MapperFeature.PROPAGATE_TRANSIENT_MARKER
But that config isn't relevant to my requirements.
P.S - No annotation are to be used, as the DTO's are not to be coupled to any library, plus
I don't necessarily have control over them.
Don't know, looks like transient attribute modifier plus PROPAGATE_TRANSIENT_MARKER just does it. Deserialization is straight forward. There's some fuss with the transient marker during serialization, though. You need to provide getters for the fields, otherwise you'll be stuck with an exception "Unrecognized field ... not marked as ignorable".
Reacting to additional requirements I added a version using jackson mixins. Note that the mixin version produces json with an empty password field, while the PROPAGATE_TRANSIENT_MARKER version produces no field at all.
PROPAGATE_TRANSIENT_MARKER version
public class SerializeDeserializeAttributes {
private final ObjectMapper mapper = new ObjectMapper();
public <T> T fromJson(String json, Class<T> c) throws IOException {
synchronized (mapper) {
mapper.configure(MapperFeature.PROPAGATE_TRANSIENT_MARKER, false);
return mapper.readValue(json, c);
}
}
public String toJson(Object o) throws JsonProcessingException {
synchronized (mapper) {
mapper.configure(MapperFeature.PROPAGATE_TRANSIENT_MARKER, true);
return mapper.writeValueAsString(o);
}
}
private static final String jsonFull = "{\"name\":\"A\",\"email\":\"a#a\",\"password\":\"a\",\"width\":1,\"height\":1}";
private static final String jsonPartial = "{\"name\":\"A\",\"email\":\"a#a\",\"width\":1,\"height\":1}";
private static final User user = new User("A", "a#a", "a", 1, 1);
#Test
public void serializeDeserialize() throws IOException {
assertEquals(user, fromJson(jsonFull, User.class));
assertEquals(jsonPartial, toJson(user));
assertEquals(user, fromJson(jsonFull, User.class));
assertEquals(jsonPartial, toJson(user));
}
}
Mixin version
public class SerializeDeserializeAttributesMixin {
public abstract class UserMixin {
#JsonSerialize(using = PwdSerializer.class)
transient String password;
}
static class PwdSerializer extends StdSerializer<String> {
public PwdSerializer() {
this(String.class);
}
private PwdSerializer(Class<String> t) {
super(t);
}
#Override
public void serialize(String s, JsonGenerator jg, SerializerProvider sp) throws IOException {
jg.writeString("");
}
}
private static final String jsonFull = "{\"name\":\"A\",\"email\":\"a#a\",\"password\":\"a\",\"width\":1,\"height\":1}";
private static final String jsonPartialMixin = "{\"name\":\"A\",\"email\":\"a#a\",\"password\":\"\",\"width\":1,\"height\":1}";
private static final User user = new User("A", "a#a", "a", 1, 1);
private static final ObjectMapper mapperMixin = new ObjectMapper();
static {
mapperMixin.addMixIn(User.class, UserMixin.class);
}
#Test
public void serializeDeserializeUsingMixin() throws IOException {
assertEquals(user, mapperMixin.readValue(jsonFull, User.class));
assertEquals(jsonPartialMixin, mapperMixin.writeValueAsString(user));
}
}
That's the User class.
class User {
private String name;
private String email;
private transient String password;
private int width;
private int height;
public User() {
}
User(String name, String email, String password, int width, int height) {
this.name = name;
this.email = email;
this.password = password;
this.width = width;
this.height = height;
}
public String getName() {
return name;
}
public String getEmail() {
return email;
}
public String getPassword() {
return password;
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
User user = (User) o;
return Float.compare(user.width, width) == 0 &&
Float.compare(user.height, height) == 0 &&
Objects.equals(name, user.name) &&
Objects.equals(email, user.email) &&
Objects.equals(password, user.password);
}
#Override
public int hashCode() {
return Objects.hash(name, email, password, width, height);
}
#Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", email='" + email + '\'' +
", password='" + password + '\'' +
", width=" + width +
", height=" + height +
'}';
}
}
Previously I was reading json data in the following format:
JSON
{
"CreationTime":"2018-01-12T12:32:31",
"Id":"08f81fd7-21f1-48ba-a991-08d559b88cc5",
"Operation":"AddedToGroup",
"RecordType":14,
"UserType":0,
"Version":1,
"Workload":"OneDrive",
"ClientIP":"115.186.129.229",
"UserId":"omaji7#emumbaa10.onmicrosoft.com",
"EventSource":"SharePoint",
"ItemType":"Web"
}
I am reading this json data from a kafka topic and doing some stream processing on it and passing it onto another topic. In processing I have created two json objects, send and received.
Using this code:
final StreamsBuilder builder = new StreamsBuilder();
KStream<String, String> source_o365_user_activity = builder.stream("o365_user_activity");
source_o365_user_activity.flatMapValues(new ValueMapper<String, Iterable<String>>() {
#Override
public Iterable<String> apply(String value) {
System.out.println("========> o365_user_activity_by_date Log: " + value);
ArrayList<String> keywords = new ArrayList<String>();
try {
JSONObject send = new JSONObject();
JSONObject received = new JSONObject(value);
send.put("current_date", getCurrentDate().toString()); // UTC TIME
send.put("activity_time", received.get("CreationTime")); // CONSTANTS FINAL STATIC(Topic Names, Cassandra keys)
send.put("user_id", received.get("UserId"));
send.put("operation_type", received.get("Operation"));
send.put("app_name", received.get("Workload"));
keywords.add(send.toString());
// apply regex to value and for each match add it to keywords
} catch (Exception e) {
// TODO: handle exception
System.err.println("Unable to convert to json");
e.printStackTrace();
}
return keywords;
}
}).to("o365_user_activity_by_date");
This was fairly simple. Now I have a json data with lists in them.
JSON
{
"CreationTime":"2017-12-27T07:47:46",
"Id":"10ee505b-90a4-4ac1-b96f-a6dbca939694",
"Operation":"Add member to role.",
"OrganizationId":"2f88f444-62da-4aae-b8af-8331a6915801",
"RecordType":8,
"ResultStatus":"success",
"UserKey":"10030000A656FE5B#emumbaa10.onmicrosoft.com",
"UserType":0,
"Version":1,
"Workload":"AzureActiveDirectory",
"ObjectId":"mustafa#emumbaa10.onmicrosoft.com",
"UserId":"omaji7#emumbaa10.onmicrosoft.com",
"AzureActiveDirectoryEventType":1,
"ExtendedProperties":[
{
"Name":"Role.ObjectID",
"Value":"b0f54661-2d74-4c50-afa3-1ec803f12efe"
},
{
"Name":"Role.DisplayName",
"Value":"Billing Administrator"
},
{
"Name":"Role.TemplateId",
"Value":"b0f54661-2d74-4c50-afa3-1ec803f12efe"
},
{
"Name":"Role.WellKnownObjectName",
"Value":"BillingAdmins"
}
],
"Actor":[
{
"ID":"omaji7#emumbaa10.onmicrosoft.com",
"Type":5
},
{
"ID":"10030000A656FE5B",
"Type":3
},
{
"ID":"User_d03ca514-adfa-4585-a8bd-7182a9a086c7",
"Type":2
}
],
"ActorContextId":"2f88f444-62da-4aae-b8af-8331a6915801",
"InterSystemsId":"6d402a5b-c5de-4d9f-a805-9371c109e55f",
"IntraSystemId":"a5568d01-f100-497a-b88b-c9731ff31248",
"Target":[
{
"ID":"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d",
"Type":2
},
{
"ID":"mustafa#emumbaa10.onmicrosoft.com",
"Type":5
},
{
"ID":"1003BFFDA67CCA03",
"Type":3
}
],
"TargetContextId":"2f88f444-62da-4aae-b8af-8331a6915801"
}
How can I go about doing the same thing in my Stream processing?
I want to be able to read JSON data against some keys (including the list data keys).
Why not convert JSON to Object and then filter against using the field in Object?
Can't you do like this?
send.put("target_0_id", received.get("Target").getJSONObject(0).get("ID"));
You can use gson library and can convert the json to object and using getter and setter you can build your desired output JSON. You can also parse the input JSON to fetch the JSONArray details. Following is the code how you can do it using POJO.
Input class:
public class Input {
private String UserType;
private String TargetContextId;
private String RecordType;
private String Operation;
private String Workload;
private String UserId;
private String OrganizationId;
private String InterSystemsId;
private ExtendedProperties[] ExtendedProperties;
private String ActorContextId;
private String CreationTime;
private String IntraSystemId;
private Target[] Target;
private Actor[] Actor;
private String Id;
private String Version;
private String ResultStatus;
private String ObjectId;
private String AzureActiveDirectoryEventType;
private String UserKey;
public String getUserType ()
{
return UserType;
}
public void setUserType (String UserType)
{
this.UserType = UserType;
}
public String getTargetContextId ()
{
return TargetContextId;
}
public void setTargetContextId (String TargetContextId)
{
this.TargetContextId = TargetContextId;
}
public String getRecordType ()
{
return RecordType;
}
public void setRecordType (String RecordType)
{
this.RecordType = RecordType;
}
public String getOperation ()
{
return Operation;
}
public void setOperation (String Operation)
{
this.Operation = Operation;
}
public String getWorkload ()
{
return Workload;
}
public void setWorkload (String Workload)
{
this.Workload = Workload;
}
public String getUserId ()
{
return UserId;
}
public void setUserId (String UserId)
{
this.UserId = UserId;
}
public String getOrganizationId ()
{
return OrganizationId;
}
public void setOrganizationId (String OrganizationId)
{
this.OrganizationId = OrganizationId;
}
public String getInterSystemsId ()
{
return InterSystemsId;
}
public void setInterSystemsId (String InterSystemsId)
{
this.InterSystemsId = InterSystemsId;
}
public ExtendedProperties[] getExtendedProperties ()
{
return ExtendedProperties;
}
public void setExtendedProperties (ExtendedProperties[] ExtendedProperties)
{
this.ExtendedProperties = ExtendedProperties;
}
public String getActorContextId ()
{
return ActorContextId;
}
public void setActorContextId (String ActorContextId)
{
this.ActorContextId = ActorContextId;
}
public String getCreationTime ()
{
return CreationTime;
}
public void setCreationTime (String CreationTime)
{
this.CreationTime = CreationTime;
}
public String getIntraSystemId ()
{
return IntraSystemId;
}
public void setIntraSystemId (String IntraSystemId)
{
this.IntraSystemId = IntraSystemId;
}
public Target[] getTarget ()
{
return Target;
}
public void setTarget (Target[] Target)
{
this.Target = Target;
}
public Actor[] getActor ()
{
return Actor;
}
public void setActor (Actor[] Actor)
{
this.Actor = Actor;
}
public String getId ()
{
return Id;
}
public void setId (String Id)
{
this.Id = Id;
}
public String getVersion ()
{
return Version;
}
public void setVersion (String Version)
{
this.Version = Version;
}
public String getResultStatus ()
{
return ResultStatus;
}
public void setResultStatus (String ResultStatus)
{
this.ResultStatus = ResultStatus;
}
public String getObjectId ()
{
return ObjectId;
}
public void setObjectId (String ObjectId)
{
this.ObjectId = ObjectId;
}
public String getAzureActiveDirectoryEventType ()
{
return AzureActiveDirectoryEventType;
}
public void setAzureActiveDirectoryEventType (String AzureActiveDirectoryEventType)
{
this.AzureActiveDirectoryEventType = AzureActiveDirectoryEventType;
}
public String getUserKey ()
{
return UserKey;
}
public void setUserKey (String UserKey)
{
this.UserKey = UserKey;
}
#Override
public String toString()
{
return "ClassPojo [UserType = "+UserType+", TargetContextId = "+TargetContextId+", RecordType = "+RecordType+", Operation = "+Operation+", Workload = "+Workload+", UserId = "+UserId+", OrganizationId = "+OrganizationId+", InterSystemsId = "+InterSystemsId+", ExtendedProperties = "+ExtendedProperties+", ActorContextId = "+ActorContextId+", CreationTime = "+CreationTime+", IntraSystemId = "+IntraSystemId+", Target = "+Target+", Actor = "+Actor+", Id = "+Id+", Version = "+Version+", ResultStatus = "+ResultStatus+", ObjectId = "+ObjectId+", AzureActiveDirectoryEventType = "+AzureActiveDirectoryEventType+", UserKey = "+UserKey+"]";
}}
Target class:
public class Target {
private String Type;
private String ID;
public String getType() {
return Type;
}
public void setType(String Type) {
this.Type = Type;
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
#Override
public String toString() {
return "ClassPojo [Type = " + Type + ", ID = " + ID + "]";
}}
Actor class :
public class Actor {
private String Type;
private String ID;
public String getType() {
return Type;
}
public void setType(String Type) {
this.Type = Type;
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
#Override
public String toString() {
return "ClassPojo [Type = " + Type + ", ID = " + ID + "]";
}}
ExtendedProperties class :
public class ExtendedProperties {
private String Name;
private String Value;
public String getName() {
return Name;
}
public void setName(String Name) {
this.Name = Name;
}
public String getValue() {
return Value;
}
public void setValue(String Value) {
this.Value = Value;
}
#Override
public String toString() {
return "ClassPojo [Name = " + Name + ", Value = " + Value + "]";
}}
Main class :
public class Stack {
public static void main(String[] args) {
doIt();
}
private static void doIt() {
String received = "{\"CreationTime\":\"2017-12-27T07:47:46\",\"Id\":\"10ee505b-90a4-4ac1-b96f-a6dbca939694\",\"Operation\":\"Add member to role.\",\"OrganizationId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"RecordType\":8,\"ResultStatus\":\"success\",\"UserKey\":\"10030000A656FE5B#emumbaa10.onmicrosoft.com\",\"UserType\":0,\"Version\":1,\"Workload\":\"AzureActiveDirectory\",\"ObjectId\":\"mustafa#emumbaa10.onmicrosoft.com\",\"UserId\":\"omaji7#emumbaa10.onmicrosoft.com\",\"AzureActiveDirectoryEventType\":1,\"ExtendedProperties\":[{\"Name\":\"Role.ObjectID\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.DisplayName\",\"Value\":\"Billing Administrator\"},{\"Name\":\"Role.TemplateId\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.WellKnownObjectName\",\"Value\":\"BillingAdmins\"}],\"Actor\":[{\"ID\":\"omaji7#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"10030000A656FE5B\",\"Type\":3},{\"ID\":\"User_d03ca514-adfa-4585-a8bd-7182a9a086c7\",\"Type\":2}],\"ActorContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"InterSystemsId\":\"6d402a5b-c5de-4d9f-a805-9371c109e55f\",\"IntraSystemId\":\"a5568d01-f100-497a-b88b-c9731ff31248\",\"Target\":[{\"ID\":\"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d\",\"Type\":2},{\"ID\":\"mustafa#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"1003BFFDA67CCA03\",\"Type\":3}],\"TargetContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\"}";
JSONObject send = new JSONObject();
Gson gson = new Gson();
Input inputObject = gson.fromJson(received, Input.class);
// you can add values here and customize the output JSON
send.put("userId", inputObject.getUserId());
send.put("Workload", inputObject.getWorkload());
// read Actor list
Actor[] arr = inputObject.getActor();
for (int i = 0; i < arr.length; i++) {
// write your logic here how you want to handle the Actor list
// values
System.out.println(arr[i].getID() + " : " + arr[i].getType());
}
// read ExtendedProperties list
ExtendedProperties[] extendedProperties = inputObject.getExtendedProperties();
for (int j = 0; j < extendedProperties.length; j++) {
// write your logic here how you want to handle the
// ExtendedProperties list values
System.out.println(extendedProperties[j].getName() + " : " + extendedProperties[j].getValue());
}
System.out.println("*************");
}}
alternate main class without using POJO. Here org.json library have been used to parse the input JSON.
public class Test {
public static void main(String[] args) {
doIt();
}
private static void doIt() {
String received = "{\"CreationTime\":\"2017-12-27T07:47:46\",\"Id\":\"10ee505b-90a4-4ac1-b96f-a6dbca939694\",\"Operation\":\"Add member to role.\",\"OrganizationId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"RecordType\":8,\"ResultStatus\":\"success\",\"UserKey\":\"10030000A656FE5B#emumbaa10.onmicrosoft.com\",\"UserType\":0,\"Version\":1,\"Workload\":\"AzureActiveDirectory\",\"ObjectId\":\"mustafa#emumbaa10.onmicrosoft.com\",\"UserId\":\"omaji7#emumbaa10.onmicrosoft.com\",\"AzureActiveDirectoryEventType\":1,\"ExtendedProperties\":[{\"Name\":\"Role.ObjectID\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.DisplayName\",\"Value\":\"Billing Administrator\"},{\"Name\":\"Role.TemplateId\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.WellKnownObjectName\",\"Value\":\"BillingAdmins\"}],\"Actor\":[{\"ID\":\"omaji7#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"10030000A656FE5B\",\"Type\":3},{\"ID\":\"User_d03ca514-adfa-4585-a8bd-7182a9a086c7\",\"Type\":2}],\"ActorContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"InterSystemsId\":\"6d402a5b-c5de-4d9f-a805-9371c109e55f\",\"IntraSystemId\":\"a5568d01-f100-497a-b88b-c9731ff31248\",\"Target\":[{\"ID\":\"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d\",\"Type\":2},{\"ID\":\"mustafa#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"1003BFFDA67CCA03\",\"Type\":3}],\"TargetContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\"}";
JSONObject send = new JSONObject();
JSONObject input = new JSONObject(received);
// you can add values here and customize the output JSON
send.put("userId", input.getString("UserId"));
send.put("Workload", input.getString("Workload"));
// read Actor list
JSONArray actorArray = input.getJSONArray("Actor");
for (int i = 0; i < actorArray.length(); i++) {
// write your logic here how you want to handle the Actor list
// values
System.out.println(
actorArray.getJSONObject(i).getString("ID") + ":" + actorArray.getJSONObject(i).getInt("Type"));
}
// read ExtendedProperties list
JSONArray extendedProperties = input.getJSONArray("ExtendedProperties");
for (int j = 0; j < extendedProperties.length(); j++) {
// write your logic here how you want to handle the
// ExtendedProperties list values
System.out.println(extendedProperties.getJSONObject(j).getString("Name") + " : "
+ extendedProperties.getJSONObject(j).getString("Value"));
}
System.out.println("*************");
}}
Two classes have similar fields, but they don't have superclass. In my code : First and Second classes. I need to write method convertToAnother, what will be return object of class resultClassObject with values of fields from object one.
Both classes have Json annotation. That annotation have vaule of property equals name of class in lowercase (in my code class First have className = "first".
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
import java.io.StringReader
public class Solution {
public static void main(String[] args) throws IOException {
Second s = (Second) convertOneToAnother(new First(), Second.class);
First f = (First) convertOneToAnother(new Second(), First.class);
}
public static Object convertOneToAnother(Object one, Class resultClassObject) throws IOException {
try {
ObjectMapper mapper = new ObjectMapper();
String obj = mapper.writeValueAsString(one);
obj = obj.replace("\"className\":\"" + one.getClass().getSimpleName().toLowerCase() + "\"", "\"className\":\"" + resultClassObject.getSimpleName().toLowerCase() + "\"");
return new ObjectMapper().readValue(new StringReader(obj), resultClassObject);
}
catch (Exception e) {
e.printStackTrace();
}
return null;
}
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property="className")
#JsonSubTypes(#JsonSubTypes.Type(value=First.class, name="first"))
public static class First {
public int i;
public String name;
}
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property="className")
#JsonSubTypes(#JsonSubTypes.Type(value=Second.class, name="second"))
public static class Second {
public int i;
public String name;
}
}
Maybe another decision exist?
The only correct way to do that using jackson is to marshall instance to json and then unmarshall. I would recommend to use convertion on the level of java objects - using Dozer: http://dozer.sourceforge.net
I want to offer such a solution, example for class First:
First first = new First();
first.i = 1;
first.name = "first";
Second s = (Second) convertOneToAnother(first, Second.class);
System.out.println(s.name); // first
ObjectMapper mapper = new ObjectMapper();
// here we disable uses annototions, since by the condition of the
// problem, we have two classes have similar fields
mapper.disable(MapperFeature.USE_ANNOTATIONS);
StringWriter writer = new StringWriter();
mapper.writeValue(writer, one);
//writer.toString() == {"i":1,"name":"first"}
mapper.readValue(writer.toString, resultClassObject);
if we don't use method mapper.disable(), we'll have for writer, such string {"className":"first","i":1,"name":"first"}
You can write code like below for model mapping:
public class ModelConverter {
public static void main(String[] args) throws IOException {
Test1 t1 = new Test1();
ObjectMapper mapper1 = new ObjectMapper();
String jsonString = mapper1.writeValueAsString(t1);
System.out.println(jsonString);
Test2 t2 = mapper1.readValue(jsonString, Test2.class);
System.out.println(t2);
}
}
public class Test1 implements Serializable {
private int i = 10;
private String name = "demo1";
private Test3 test3 = new Test3();
public int getI() {
return i;
}
public void setI(int i) {
this.i = i;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Test3 getTest3() {
return test3;
}
public void setTest3(Test3 test3) {
this.test3 = test3;
}
#Override
public String toString() {
return "test1 [i=" + i + ", name=" + name + ", Test3=" + test3 + "]";
}
}
public class Test2 implements Serializable {
private int i = 11;
private String name = "demo2";
private Test3 test3;
public int getI() {
return i;
}
public void setI(int i) {
this.i = i;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Test3 getTest3() {
return test3;
}
public void setTest3(Test3 test3) {
this.test3 = test3;
}
#Override
public String toString() {
return "test2 [i=" + i + ", name=" + name + ", Test3=" + test3 + "]";
}
}
public class Test3 implements Serializable {
private int i = 12;
private String name = "demo3";
public int getI() {
return i;
}
public void setI(int i) {
this.i = i;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Override
public String toString() {
return "test3 [i=" + i + ", name=" + name + "]";
}
}
For this kind of task would be right to use object mappers like Dozer (http://dozer.sourceforge.net/)
You can replace value of className without String manipulations
ObjectReader reader = mapper.reader();
JsonNode node = reader.readTree(writer.toString());
((ObjectNode)node).put("className",resultClassObject.getSimpleName().toLowerCase());
Also if you don't know the name of the field where name of the class is stored, but you know it is in the annotations, you can try and get the first field from JsonNode (in your code you assume that the field name is "className", but what if it is not).
ObjectMapper mapper1 = new ObjectMapper();
Map<String, Object> result = mapper1.convertValue(node, Map.class);
String key1 = result.keySet().toArray()[0].toString();
And now you can replace the value for the key1 field, which should be the field where class name is stored.
I have the following entity:
#Entity
#Table(name="filter", schema="mailing")
public class FilterItemValue {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Type(
type = "my.package.generic.enum.GenericEnumUserType",
parameters = {
#Parameter(
name = "enumClass",
value = "ua.com.winforce.casino.email.db.entity.FilterItem"),
#Parameter(
name = "identifierMethod",
value = "getValue"),
#Parameter(
name = "valueOfMethod",
value = "getByValue")
}
)
#Column(name = "filter_item_id")
private FilterItem filterItemId;
//Other fields and properties
}
Where GenericEnumUserType is:
public class GenericEnumUserType implements UserType, ParameterizedType {
private static final String DEFAULT_IDENTIFIER_METHOD_NAME = "name";
private static final String DEFAULT_VALUE_OF_METHOD_NAME = "valueOf";
private Class<? extends Enum> enumClass;
private Class<?> identifierType;
private Method identifierMethod;
private Method valueOfMethod;
private NullableType type;
private int[] sqlTypes;
public void setParameterValues(Properties parameters) {
String enumClassName = parameters.getProperty("enumClass");
try {
enumClass = Class.forName(enumClassName).asSubclass(Enum.class);
} catch (ClassNotFoundException cfne) {
throw new HibernateException("Enum class not found", cfne);
}
String identifierMethodName = parameters.getProperty("identifierMethod", DEFAULT_IDENTIFIER_METHOD_NAME);
try {
identifierMethod = enumClass.getMethod(identifierMethodName, new Class[0]);
identifierType = identifierMethod.getReturnType();
} catch (Exception e) {
throw new HibernateException("Failed to obtain identifier method", e);
}
type = (NullableType) TypeFactory.basic(identifierType.getName());
if (type == null)
throw new HibernateException("Unsupported identifier type " + identifierType.getName());
sqlTypes = new int[] { type.sqlType() };
String valueOfMethodName = parameters.getProperty("valueOfMethod", DEFAULT_VALUE_OF_METHOD_NAME);
try {
valueOfMethod = enumClass.getMethod(valueOfMethodName, new Class[] { identifierType });
} catch (Exception e) {
throw new HibernateException("Failed to obtain valueOf method", e);
}
}
public Class returnedClass() {
return enumClass;
}
public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
Object identifier = type.get(rs, names[0]);
if (identifier == null) {
return null;
}
try {
return valueOfMethod.invoke(enumClass, new Object[] { identifier });
} catch (Exception e) {
throw new HibernateException("Exception while invoking valueOf method '" + valueOfMethod.getName() + "' of " +
"enumeration class '" + enumClass + "'", e);
}
}
public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
try {
if (value == null) {
st.setNull(index, type.sqlType());
} else {
Object identifier = identifierMethod.invoke(value, new Object[0]);
type.set(st, identifier, index);
}
} catch (Exception e) {
throw new HibernateException("Exception while invoking identifierMethod '" + identifierMethod.getName() + "' of " +
"enumeration class '" + enumClass + "'", e);
}
}
public int[] sqlTypes() {
return sqlTypes;
}
public Object assemble(Serializable cached, Object owner) throws HibernateException {
return cached;
}
public Object deepCopy(Object value) throws HibernateException {
return value;
}
public Serializable disassemble(Object value) throws HibernateException {
return (Serializable) value;
}
public boolean equals(Object x, Object y) throws HibernateException {
return x == y;
}
public int hashCode(Object x) throws HibernateException {
return x.hashCode();
}
public boolean isMutable() {
return false;
}
public Object replace(Object original, Object target, Object owner) throws HibernateException {
return original;
}
}
and the enum itself:
public enum FilterItem implements StringRepresentable{
AMOUNT(1) {
#Override
public List<RuleItem> getItemRules() {
List<RuleItem> result = new ArrayList<RuleItem>();
result.add(RuleItem.EQUAL);
return result;
}
#Override
public FilterItemType getFilterItemType() {
return FilterItemType.FIELD;
}
#Override
public String getStringRepresentation() {
return getFilterItemStringRepresentation("dynamicFilterItemName.amount");
}
#Override
public MapperType getMapperType() {
return null;
}
#Override
public RestrictorType getRestrictorType() {
return RestrictorType.RANDOM_AMOUNT;
}
#Override
public JunctionBuilderParams getJunctionBuilderParams() {
return null;
}
},
//Other enums
public static FilterItem getByValue(int val) {
FilterItem[] values = FilterItem.values();
for (FilterItem value : values) {
if (val == value.getValue()) {
return value;
}
}
throw new IllegalArgumentException("Illegal value: " + val);
}
public abstract String getStringRepresentation();
public abstract List<RuleItem> getItemRules();
public abstract FilterItemType getFilterItemType();
public abstract MapperType getMapperType();
public abstract RestrictorType getRestrictorType();
public abstract JunctionBuilderParams getJunctionBuilderParams();
}
So, when I debug my application the method
public static Type heuristicType(String typeName, Properties parameters)
throws MappingException
at org.hibernate.type.TypeFactory
first executes this instruction Type type = TypeFactory.basic( typeName ); where typeName = "GenericEnumUserType". Therefore TypeFactory.basic(typename) returns null and I end up with the exception:
org.hibernate.MappingException: Could not determine type for: my.package.generic.enum.GenericEnumUserType, for columns: [org.hibernate.mapping.Column(filter_item_id)]
org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:266)
org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:253)
How to fix that, what's wrong?
Maybe it was caused by the abstract methods I defined in the FilterItem enum?