databind/objectid/TestObjectIdSerialization.java

package com.fasterxml.jackson.databind.objectid;

import com.fasterxml.jackson.annotation.JsonIdentityInfo;
import com.fasterxml.jackson.annotation.JsonIdentityReference;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.json.JsonMapper;

/**
 * Unit test to verify handling of Object Id deserialization
 */
public class TestObjectIdSerialization extends BaseMapTest
{
    @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="id")
    static class Identifiable
    {
        public int value;

        public Identifiable next;

        public Identifiable() { this(0); }
        public Identifiable(int v) {
            value = v;
        }
    }

    @JsonIdentityInfo(generator=ObjectIdGenerators.StringIdGenerator.class, property="id")
    static class StringIdentifiable
    {
        public int value;

        public StringIdentifiable next;

        public StringIdentifiable() { this(0); }
        public StringIdentifiable(int v) {
            value = v;
        }
    }

    @JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="customId")
    static class IdentifiableWithProp
    {
        public int value;

        // Property that contains Object Id to use
        public int customId;

        public IdentifiableWithProp next;

        public IdentifiableWithProp() { this(0, 0); }
        public IdentifiableWithProp(int id, int value) {
            this.customId = id;
            this.value = value;
        }
    }

    // For property reference, need another class:

    static class IdWrapper
    {
        @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="@id")
        public ValueNode node;

        public IdWrapper() { }
        public IdWrapper(int v) {
            node = new ValueNode(v);
        }
    }

    static class ValueNode {
        public int value;
        public IdWrapper next;

        public ValueNode() { this(0); }
        public ValueNode(int v) { value = v; }
    }

    // Similarly for property-ref via property:

    protected static class IdWrapperCustom
    {
        @JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
        public ValueNodeCustom node;

        public IdWrapperCustom() { }
        public IdWrapperCustom(int id, int value) {
            node = new ValueNodeCustom(id, value);
        }
    }

    protected static class ValueNodeCustom {
        public int value;
        private int id;
        public IdWrapperCustom next;

        public int getId() { return id; }

        public ValueNodeCustom() { this(0, 0); }
        public ValueNodeCustom(int id, int value) {
            this.id = id;
            this.value = value;
        }
    }

    @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="id")
    static class AlwaysAsId
    {
        public int value;

        public AlwaysAsId() { this(0); }
        public AlwaysAsId(int v) {
            value = v;
        }
    }

    // For [https://github.com/FasterXML/jackson-annotations/issues/4]
    @JsonPropertyOrder(alphabetic=true)
    static class AlwaysContainer
    {
        @JsonIdentityReference(alwaysAsId=true)
        public AlwaysAsId a = new AlwaysAsId(13);

        @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="id")
        @JsonIdentityReference(alwaysAsId=true)
        public Value b = new Value();
    }

    static class Value {
        public int x = 3;
    }

    @JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
    static class TreeNode
    {
        public int id;
        public String name;

        @JsonIdentityReference(alwaysAsId=true)
        public TreeNode parent;

        // children serialized with ids if need be
        public TreeNode child;

        public TreeNode() { }
        public TreeNode(TreeNode p, int id, String name) {
            parent = p;
            this.id = id;
            this.name = name;
        }
    }

    // // Let's also have one 'broken' test

    // no "id" property
    @JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
    static class Broken
    {
        public int value;
        public int customId;
    }

    // [databind#370]
    @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="@id")
    public static class EmptyObject { }

    //for [databind#1150]
    @JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
    static class IdentifiableStringId
    {
        public String id;
        public int value;

        public Identifiable next;

        public IdentifiableStringId() { this(0); }
        public IdentifiableStringId(int v) {
            value = v;
        }
    }

    /*
    /*****************************************************
    /* Unit tests, external id serialization
    /*****************************************************
     */

    private final static String EXP_SIMPLE_INT_CLASS = "{\"id\":1,\"next\":1,\"value\":13}";

    private final ObjectMapper MAPPER = objectMapper();

    public void testSimpleSerializationClass() throws Exception
    {
        Identifiable src = new Identifiable(13);
        src.next = src;

        // First, serialize:
        JsonMapper mapper = JsonMapper.builder().enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY).build();
        String json = mapper.writeValueAsString(src);
        assertEquals(EXP_SIMPLE_INT_CLASS, json);

        // and ensure that state is cleared in-between as well:
        json = mapper.writeValueAsString(src);
        assertEquals(EXP_SIMPLE_INT_CLASS, json);
    }

    // Bit more complex, due to extra wrapping etc:
    private final static String EXP_SIMPLE_INT_PROP = "{\"node\":{\"@id\":1,\"next\":{\"node\":1},\"value\":7}}";

    public void testSimpleSerializationProperty() throws Exception
    {
        IdWrapper src = new IdWrapper(7);
        src.node.next = src;

        // First, serialize:
        JsonMapper mapper = JsonMapper.builder().enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY).build();
        String json = mapper.writeValueAsString(src);
        assertEquals(EXP_SIMPLE_INT_PROP, json);
        // and second time too, for a good measure
        json = mapper.writeValueAsString(src);
        assertEquals(EXP_SIMPLE_INT_PROP, json);
    }

    // [databind#370]
    public void testEmptyObjectWithId() throws Exception
    {
        final ObjectMapper mapper = new ObjectMapper();
        String json = mapper.writeValueAsString(new EmptyObject());
        assertEquals(aposToQuotes("{'@id':1}"), json);
    }

    public void testSerializeWithOpaqueStringId() throws Exception
    {
        StringIdentifiable ob1 = new StringIdentifiable(12);
        StringIdentifiable ob2 = new StringIdentifiable(34);
        ob1.next = ob2;
        ob2.next = ob1;

        // first just verify we get some output
        String json = MAPPER.writeValueAsString(ob1);
        assertNotNull(json);

        // then get them back
        StringIdentifiable output = MAPPER.readValue(json, StringIdentifiable.class);
        assertNotNull(output);
        assertEquals(12, output.value);
        assertNotNull(output.next);
        assertEquals(34, output.next.value);
        assertSame(output.next.next, output);

        String json2 = aposToQuotes("{'id':'foobar','value':3, 'next':{'id':'barf','value':5,'next':'foobar'}}");
        output = MAPPER.readValue(json2, StringIdentifiable.class);
        assertNotNull(output);
        assertEquals(3, output.value);
        assertNotNull(output.next);
        assertEquals(5, output.next.value);
        assertSame(output.next.next, output);
    }

    /*
    /*****************************************************
    /* Unit tests, custom (property) id serialization
    /*****************************************************
     */

    private final static String EXP_CUSTOM_PROP = "{\"customId\":123,\"next\":123,\"value\":-19}";
    // Test for verifying that custom
    public void testCustomPropertyForClass() throws Exception
    {
        IdentifiableWithProp src = new IdentifiableWithProp(123, -19);
        src.next = src;

        JsonMapper mapper =  JsonMapper.builder().enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY).build();
        // First, serialize:
        String json = mapper.writeValueAsString(src);
        assertEquals(EXP_CUSTOM_PROP, json);

        // and ensure that state is cleared in-between as well:
        json = mapper.writeValueAsString(src);
        assertEquals(EXP_CUSTOM_PROP, json);
    }

    private final static String EXP_CUSTOM_PROP_VIA_REF = "{\"node\":{\"id\":123,\"next\":{\"node\":123},\"value\":7}}";
    // Test for verifying that custom
    public void testCustomPropertyViaProperty() throws Exception
    {
        IdWrapperCustom src = new IdWrapperCustom(123, 7);
        src.node.next = src;
        JsonMapper mapper = JsonMapper.builder().enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY).build();
        // First, serialize:
        String json = mapper.writeValueAsString(src);
        assertEquals(EXP_CUSTOM_PROP_VIA_REF, json);
        // and second time too, for a good measure
        json = mapper.writeValueAsString(src);
        assertEquals(EXP_CUSTOM_PROP_VIA_REF, json);
    }

    public void testAlwaysAsId() throws Exception
    {
        String json = MAPPER.writeValueAsString(new AlwaysContainer());
        assertEquals("{\"a\":1,\"b\":2}", json);
    }

    public void testAlwaysIdForTree() throws Exception
    {
        TreeNode root = new TreeNode(null, 1, "root");
        TreeNode leaf = new TreeNode(root, 2, "leaf");
        root.child = leaf;
        JsonMapper mapper = JsonMapper.builder().enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY).build();
        String json = mapper.writeValueAsString(root);
        assertEquals("{\"id\":1,\"child\":"
                +"{\"id\":2,\"child\":null,\"name\":\"leaf\",\"parent\":1},\"name\":\"root\",\"parent\":null}",
                json);

    }

    //for [databind#1150]
    public void testNullStringPropertyId() throws Exception
    {
        IdentifiableStringId value = MAPPER.readValue
                (aposToQuotes("{'value':3, 'next':null, 'id':null}"), IdentifiableStringId.class);
        assertNotNull(value);
        assertEquals(3, value.value);
    }

    /*
    /*****************************************************
    /* Unit tests, error handling
    /*****************************************************
     */

    public void testInvalidProp() throws Exception
    {
        try {
            MAPPER.writeValueAsString(new Broken());
            fail("Should have thrown an exception");
        } catch (JsonMappingException e) {
            verifyException(e, "cannot find property with name 'id'");
        }
    }
}