src/test/main/TestJsonGenerator.java

package main;

import org.codehaus.jackson.*;

import java.io.*;

/**
 * Set of basic unit tests for verifying that the basic generator
 * functionality works as expected.
 */
public class TestJsonGenerator
    extends BaseTest
{
    // // // First, tests for primitive (non-structured) values

    public void testStringWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
        String VALUE = "";
        gen.writeString(VALUE);
        gen.close();
        String docStr = sw.toString();
        JsonParser jp = createParserUsingReader(docStr);
        JsonToken t = jp.nextToken();
        assertNotNull("Document \""+docStr+"\" yielded no tokens", t);
        assertEquals(JsonToken.VALUE_STRING, t);
        assertEquals(VALUE, jp.getText());
        assertEquals(null, jp.nextToken());
        jp.close();
    }

    public void testIntWrite()
        throws Exception
    {
        doTestIntWrite(false);
        doTestIntWrite(true);
    }

    public void testLongWrite()
        throws Exception
    {
        doTestLongWrite(false);
        doTestLongWrite(true);
    }

    public void testBooleanWrite()
        throws Exception
    {
        for (int i = 0; i < 4; ++i) {
            boolean state = (i & 1) == 0;
            boolean pad = (i & 2) == 0;
            StringWriter sw = new StringWriter();
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
            gen.writeBoolean(state);
            if (pad) {
                gen.writeRaw(" ");
            }
            gen.close();
            String docStr = sw.toString();
            JsonParser jp = createParserUsingReader(docStr);
            JsonToken t = jp.nextToken();
            String exp = Boolean.valueOf(state).toString();
            if (!exp.equals(jp.getText())) {
                fail("Expected '"+exp+"', got '"+jp.getText());
            }
            assertEquals(state ? JsonToken.VALUE_TRUE : JsonToken.VALUE_FALSE, t);
            assertEquals(null, jp.nextToken());
            jp.close();
        }
    }

    public void testNullWrite()
        throws Exception
    {
        for (int i = 0; i < 2; ++i) {
            boolean pad = (i & 1) == 0;
            StringWriter sw = new StringWriter();
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
            gen.writeNull();
            if (pad) {
                gen.writeRaw(" ");
            }
            gen.close();
            String docStr = sw.toString();
            JsonParser jp = createParserUsingReader(docStr);
            JsonToken t = jp.nextToken();
            String exp = "null";
            if (!exp.equals(jp.getText())) {
                fail("Expected '"+exp+"', got '"+jp.getText());
            }
            assertEquals(JsonToken.VALUE_NULL, t);
            assertEquals(null, jp.nextToken());
            jp.close();
        }
    }

    // // // Then tests for structured values

    public void testEmptyArrayWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
        gen.writeStartArray();
        gen.writeEndArray();
        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().createJsonGenerator(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().createJsonGenerator(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().createJsonGenerator(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();
    }

    public void testEmptyObjectWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
        gen.writeStartObject();
        gen.writeEndObject();
        gen.close();
        String docStr = sw.toString();
        JsonParser jp = createParserUsingReader(docStr);
        assertEquals(JsonToken.START_OBJECT, jp.nextToken());
        assertEquals(JsonToken.END_OBJECT, jp.nextToken());
        assertEquals(null, jp.nextToken());
    }

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

    public void testSimpleObjectWrite()
        throws Exception
    {
        StringWriter sw = new StringWriter();
        JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
        gen.writeStartObject();
        gen.writeFieldName("first");
        gen.writeNumber(-901);
        gen.writeFieldName("sec");
        gen.writeBoolean(false);
        gen.writeFieldName("3rd!"); // json field names are just strings, not ids with restrictions
        gen.writeString("yee-haw");
        gen.writeEndObject();
        gen.close();
        String docStr = sw.toString();
        JsonParser jp = createParserUsingReader(docStr);
        assertEquals(JsonToken.START_OBJECT, jp.nextToken());
        assertEquals(JsonToken.FIELD_NAME, jp.nextToken());
        assertEquals("first", jp.getText());
        assertEquals(JsonToken.VALUE_NUMBER_INT, jp.nextToken());
        assertEquals(-901, jp.getIntValue());
        assertEquals(JsonToken.FIELD_NAME, jp.nextToken());
        assertEquals("sec", jp.getText());
        assertEquals(JsonToken.VALUE_FALSE, jp.nextToken());
        assertEquals(JsonToken.FIELD_NAME, jp.nextToken());
        assertEquals("3rd!", jp.getText());
        assertEquals(JsonToken.VALUE_STRING, jp.nextToken());
        assertEquals("yee-haw", jp.getText());
        assertEquals(JsonToken.END_OBJECT, jp.nextToken());
        assertEquals(null, jp.nextToken());
        jp.close();
    }

    // // Then root-level output testing

     public void testRootIntsWrite()
         throws Exception
     {
         StringWriter sw = new StringWriter();
         JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
         gen.writeNumber(1);
         gen.writeNumber(2);
         gen.writeNumber(-13);
         gen.close();

         String docStr = sw.toString();

         JsonParser jp = createParserUsingReader(docStr);
         assertEquals(JsonToken.VALUE_NUMBER_INT, jp.nextToken());
         assertEquals(1, jp.getIntValue());
         assertEquals(JsonToken.VALUE_NUMBER_INT, jp.nextToken());
         assertEquals(2, jp.getIntValue());
         assertEquals(JsonToken.VALUE_NUMBER_INT, jp.nextToken());
         assertEquals(-13, jp.getIntValue());
         jp.close();
     }

    /*
    //////////////////////////////////////////////////
    // Internal methods
    //////////////////////////////////////////////////
     */
    
    private void doTestIntWrite(boolean pad)
        throws Exception
    {
        int[] VALUES = new int[] {
            0, 1, -9, 32, -32, 57, 13240, -9999, Integer.MAX_VALUE, Integer.MAX_VALUE
        };
        for (int i = 0; i < VALUES.length; ++i) {
            int VALUE = VALUES[i];
            StringWriter sw = new StringWriter();
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
            gen.writeNumber(VALUE);
            if (pad) {
                gen.writeRaw(" ");
            }
            gen.close();
            String docStr = sw.toString();
            JsonParser jp = createParserUsingReader(docStr);
            JsonToken t = jp.nextToken();
            assertNotNull("Document \""+docStr+"\" yielded no tokens", t);
            // Number are always available as lexical representation too
            String exp = ""+VALUE;
            if (!exp.equals(jp.getText())) {
                fail("Expected '"+exp+"', got '"+jp.getText());
            }
            assertEquals(JsonToken.VALUE_NUMBER_INT, t);
            assertEquals(VALUE, jp.getIntValue());
            assertEquals(null, jp.nextToken());
            jp.close();
        }
    }

    private void doTestLongWrite(boolean pad)
        throws Exception
    {
        long[] VALUES = new long[] {
            0L, 1L, -1L, -12005002294L, Long.MIN_VALUE, Long.MAX_VALUE
        };
        for (int i = 0; i < VALUES.length; ++i) {
            long VALUE = VALUES[i];
            StringWriter sw = new StringWriter();
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);
            gen.writeNumber(VALUE);
            if (pad) {
                gen.writeRaw(" ");
            }
            gen.close();
            String docStr = sw.toString();
            JsonParser jp = createParserUsingReader(docStr);
            JsonToken t = jp.nextToken();
            assertNotNull("Document \""+docStr+"\" yielded no tokens", t);
            String exp = ""+VALUE;
            if (!exp.equals(jp.getText())) {
                fail("Expected '"+exp+"', got '"+jp.getText());
            }
            assertEquals(JsonToken.VALUE_NUMBER_INT, t);
            assertEquals(VALUE, jp.getLongValue());
            assertEquals(null, jp.nextToken());
            jp.close();
        }
    }
}