TestGeneratorArray.java

package com.fasterxml.jackson.core.main;

import com.fasterxml.jackson.core.*;

import java.io.*;

/**
 * Set of basic unit tests for verifying that the Array write methods
 * of {@link JsonGenerator} work as expected.
 */
public class TestGeneratorArray
    extends com.fasterxml.jackson.test.BaseTest
{
    public void testEmptyArrayWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createGenerator(sw);

        JsonStreamContext ctxt = gen.getOutputContext();
        assertTrue(ctxt.inRoot());
        assertFalse(ctxt.inArray());
        assertFalse(ctxt.inObject());
        assertEquals(0, ctxt.getEntryCount());
        assertEquals(0, ctxt.getCurrentIndex());

        gen.writeStartArray();

        ctxt = gen.getOutputContext();
        assertFalse(ctxt.inRoot());
        assertTrue(ctxt.inArray());
        assertFalse(ctxt.inObject());
        assertEquals(0, ctxt.getEntryCount());
        assertEquals(0, ctxt.getCurrentIndex());

        gen.writeEndArray();

        ctxt = gen.getOutputContext();
        assertTrue("Should be in root, was "+ctxt.getTypeDesc(), ctxt.inRoot());
        assertFalse(ctxt.inArray());
        assertFalse(ctxt.inObject());
        assertEquals(1, ctxt.getEntryCount());
        // Index won't yet move
        assertEquals(0, ctxt.getCurrentIndex());

        gen.close();
        String docStr = sw.toString();
        JsonParser jp = createParserUsingReader(docStr);
        assertEquals(JsonToken.START_ARRAY, jp.nextToken());
        assertEquals(JsonToken.END_ARRAY, jp.nextToken());
        jp.close();

        // Ok, then array with nested empty array
        sw = new StringWriter();
        gen = new JsonFactory().createGenerator(sw);
        gen.writeStartArray();
        gen.writeStartArray();
        gen.writeEndArray();
        gen.writeEndArray();
        gen.close();
        docStr = sw.toString();
        jp = createParserUsingReader(docStr);
        assertEquals(JsonToken.START_ARRAY, jp.nextToken());
        assertEquals(JsonToken.START_ARRAY, jp.nextToken());
        assertEquals(JsonToken.END_ARRAY, jp.nextToken());
        assertEquals(JsonToken.END_ARRAY, jp.nextToken());
        assertEquals(null, jp.nextToken());
        jp.close();
    }

    public void testInvalidArrayWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createGenerator(sw);
        gen.writeStartArray();
        // Mismatch:
        try {
            gen.writeEndObject();
            fail("Expected an exception for mismatched array/object write");
        } catch (JsonGenerationException e) {
            verifyException(e, "Current context not an object");
        }
    }

    public void testSimpleArrayWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createGenerator(sw);
        gen.writeStartArray();
        gen.writeNumber(13);
        gen.writeBoolean(true);
        gen.writeString("foobar");
        gen.writeEndArray();
        gen.close();
        String docStr = sw.toString();
        JsonParser jp = createParserUsingReader(docStr);
        assertEquals(JsonToken.START_ARRAY, jp.nextToken());
        assertEquals(JsonToken.VALUE_NUMBER_INT, jp.nextToken());
        assertEquals(13, jp.getIntValue());
        assertEquals(JsonToken.VALUE_TRUE, jp.nextToken());
        assertEquals(JsonToken.VALUE_STRING, jp.nextToken());
        assertEquals("foobar", jp.getText());
        assertEquals(JsonToken.END_ARRAY, jp.nextToken());
        assertEquals(null, jp.nextToken());
        jp.close();
    }
}