gistfile1.java

import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.smile.SmileFactory;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class Test {

    public static void main(String[] args) throws Exception {
        SmileFactory factory = new SmileFactory();

        HashMap props1 = buildMap("", 65);
        HashMap props2 = buildMap("", 1);

        writeMapAndParse(factory, props1);
        writeMapAndParse(factory, props2);
        writeMapAndParse(factory, props1);
        writeMapAndParse(factory, props2);
    }

    private static void writeMapAndParse(SmileFactory factory, Map map) throws Exception {
        ByteArrayOutputStream os = new ByteArrayOutputStream();

        // generate
        JsonGenerator generator = factory.createJsonGenerator(os);
        writeMap(generator, map);
        generator.close();

        // parse
        JsonParser parser = factory.createJsonParser(os.toByteArray());
        while (parser.nextToken() != null) {

        }
    }

    private static HashMap buildMap(String prefix, int size) {
        HashMap props = new HashMap<String, String>();
        for (int it = 0; it < size; it++) {
            String key = prefix + "prop_" + it;
            props.put(key, "a");
        }
        return props;
    }


    // A sample utility to write a map

    public static void writeMap(JsonGenerator gen, Map<String, Object> map) throws IOException {
        gen.writeStartObject();

        for (Map.Entry<String, Object> entry : map.entrySet()) {
            gen.writeFieldName(entry.getKey());
            Object value = entry.getValue();
            if (value == null) {
                gen.writeNull();
            } else {
                writeValue(gen, value);
            }
        }

        gen.writeEndObject();
    }

    private static void writeIterable(JsonGenerator gen, Iterable iterable) throws IOException {
        gen.writeStartArray();
        for (Object value : iterable) {
            writeValue(gen, value);
        }
        gen.writeEndArray();
    }

    private static void writeObjectArray(JsonGenerator gen, Object[] array) throws IOException {
        gen.writeStartArray();
        for (Object value : array) {
            writeValue(gen, value);
        }
        gen.writeEndArray();
    }

    private static void writeValue(JsonGenerator gen, Object value) throws IOException {
        Class type = value.getClass();
        if (type == String.class) {
            gen.writeString((String) value);
        } else if (type == Integer.class) {
            gen.writeNumber(((Integer) value).intValue());
        } else if (type == Long.class) {
            gen.writeNumber(((Long) value).longValue());
        } else if (type == Float.class) {
            gen.writeNumber(((Float) value).floatValue());
        } else if (type == Double.class) {
            gen.writeNumber(((Double) value).doubleValue());
        } else if (type == Short.class) {
            gen.writeNumber(((Short) value).shortValue());
        } else if (type == Boolean.class) {
            gen.writeBoolean(((Boolean) value).booleanValue());
        } else if (value instanceof Map) {
            writeMap(gen, (Map) value);
        } else if (value instanceof Iterable) {
            writeIterable(gen, (Iterable) value);
        } else if (value instanceof Object[]) {
            writeObjectArray(gen, (Object[]) value);
        } else if (type == byte[].class) {
            gen.writeBinary((byte[]) value);
        } else {
            gen.writeString(value.toString());
        }
    }
}