Graphql Java Hello World: failed to add child schema to parent schema

I'm trying to prototype graphql Java（ https://github.com/andimarek/graphql-java ）And start building it from the Hello world example I'm using graphiql to call the graphiql service with a pattern, which applies to pattern {hello1}, but not to pattern {testpojo} Please find the code I run below Someone can let me know what's wrong with the following code

static GraphQLSchema schema = null;
 /**
  * POJO to be returned for service method 2
  * @author 
  *
  */
 private class TestPojo {
     String id;
     String name;

     TestPojo(String id,String name) {
         this.id = id;
         this.name = name;
     }

     public String getId() {
         return id;
     }

     public void setId(String id) {
         this.id = id;
     }

     public String getName() {
        return name;
     }

     public void setName(String name) {
         this.name = name;
     }
 }

/**
 * service method 1
 * @return
 */
public String greeting1() {
    return "Hello123";
 }

/**
 * service method 2
 * @return
 */
public TestPojo greeting2() {
    return new TestPojo("1","Jack");
}


/**
 * GraphQl endpoint invoked using GraphiQl
 * @param query
 * @return
 */
@RequestMapping("/query")
public Object testGraphQLWithQuery(@RequestParam("query") String query) {
    return new GraphQL(schema).execute(query).getData();
}

// Schema deFinition for graphQL
static {

    // sub schema to be added to parent  schema
     GraphQLObjectType testPojo = newObject().name("TestPojo").description("This is a test POJO")
            .field(newFieldDeFinition().name("id").type(GraphQLString).build())
            .field(newFieldDeFinition().name("name").type(GraphQLString).build())
            .build();


    // parent schema
    GraphQLObjectType queryType = newObject().name("helloWorldQuery")
            .field(newFieldDeFinition().type(GraphQLString).name("hello1").dataFetcher(new DataFetcher() {

                @Override
                public Object get(DataFetchingEnvironment arg0) {
                    Object a = new GrapgQLSampleController().greeting1();
                    return a;
                }
            }).build())
            .field(newFieldDeFinition().type(testPojo).name("testPojo").dataFetcher(new DataFetcher() {

                @Override
                public Object get(DataFetchingEnvironment arg0) {
                    Object a = new GrapgQLSampleController().greeting2();
                    return a;
                }
            }).build())
            .build();

     schema = GraphQLSchema.newSchema().query(queryType).build();
}

Solution

I just tested your code and it seems to work properly You must be more specific about the mistakes you see

If your problem is the reason why the query {testpojo} is invalid, you should have read the error obtained: sub selection is required You cannot select the entire complex object in graphql. You must specify the required subfield. For example, {testpojo {ID, name}} is a valid query that can be used with your schema