package com.espertech.esper.event.util;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.client.util.JSONEventRenderer;
import com.espertech.esper.client.util.JSONRenderingOptions;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.reflect.Array;
import java.util.Stack;
import java.util.Map;
import java.util.Iterator;
/**
* Render for the JSON format.
*/
public class JSONRendererImpl implements JSONEventRenderer
{
private static final Log log = LogFactory.getLog(JSONRendererImpl.class);
private final static String NEWLINE = System.getProperty("line.separator");
private final static String COMMA_DELIMITER_NEWLINE = "," + NEWLINE;
private final RendererMeta meta;
private final RendererMetaOptions rendererOptions;
/**
* Ctor.
* @param eventType type of event(s)
* @param options rendering options
*/
public JSONRendererImpl(EventType eventType, JSONRenderingOptions options)
{
rendererOptions = new RendererMetaOptions(options.isPreventLooping(), false);
meta = new RendererMeta(eventType, new Stack<EventTypePropertyPair>(), rendererOptions);
}
public String render(String title, EventBean event)
{
StringBuilder buf = new StringBuilder();
buf.append('{');
buf.append(NEWLINE);
ident(buf, 1);
buf.append('\"');
buf.append(title);
buf.append("\": {");
buf.append(NEWLINE);
recursiveRender(event, buf, 2, meta, rendererOptions);
ident(buf, 1);
buf.append('}');
buf.append(NEWLINE);
buf.append('}');
buf.append(NEWLINE);
return buf.toString();
}
private static void ident(StringBuilder buf, int level)
{
for (int i = 0; i < level; i++)
{
indentChar(buf);
}
}
private static void indentChar(StringBuilder buf)
{
buf.append(' ');
buf.append(' ');
}
private static void recursiveRender(EventBean event, StringBuilder buf, int level, RendererMeta meta, RendererMetaOptions rendererOptions)
{
String delimiter = "";
GetterPair[] simpleProps = meta.getSimpleProperties();
for (GetterPair simpleProp : simpleProps)
{
Object value = simpleProp.getGetter().get(event);
buf.append(delimiter);
ident(buf, level);
buf.append('\"');
buf.append(simpleProp.getName());
buf.append("\": ");
simpleProp.getOutput().render(value, buf);
delimiter = COMMA_DELIMITER_NEWLINE;
}
GetterPair[] indexProps = meta.getIndexProperties();
for (GetterPair indexProp : indexProps)
{
Object value = indexProp.getGetter().get(event);
buf.append(delimiter);
ident(buf, level);
buf.append('\"');
buf.append(indexProp.getName());
buf.append("\": ");
if (value == null)
{
buf.append("null");
}
else
{
if (!value.getClass().isArray())
{
buf.append("[]");
}
else
{
buf.append('[');
String arrayDelimiter = "";
for (int i = 0; i < Array.getLength(value); i++)
{
Object arrayItem = Array.get(value, i);
buf.append(arrayDelimiter);
indexProp.getOutput().render(arrayItem, buf);
arrayDelimiter = ", ";
}
buf.append(']');
}
}
delimiter = COMMA_DELIMITER_NEWLINE;
}
GetterPair[] mappedProps = meta.getMappedProperties();
for (GetterPair mappedProp : mappedProps)
{
Object value = mappedProp.getGetter().get(event);
if ((value != null) && (!(value instanceof Map)))
{
log.warn("Property '" + mappedProp.getName() + "' expected to return Map and returned " + value.getClass() + " instead");
continue;
}
buf.append(delimiter);
ident(buf, level);
buf.append('\"');
buf.append(mappedProp.getName());
buf.append("\": ");
if (value == null)
{
buf.append("null");
}
else
{
Map map = (Map) value;
if (map.isEmpty())
{
buf.append("{}");
}
else
{
buf.append('{');
buf.append(NEWLINE);
String localDelimiter = "";
Iterator<Map.Entry> it = map.entrySet().iterator();
for (;it.hasNext();)
{
Map.Entry entry = it.next();
if (entry.getKey() == null)
{
continue;
}
buf.append(localDelimiter);
ident(buf, level + 1);
buf.append('\"');
buf.append(entry.getKey().toString());
buf.append("\": ");
if (entry.getValue() == null)
{
buf.append("null");
}
else
{
OutputValueRenderer out = OutputValueRendererFactory.getOutputValueRenderer(entry.getValue().getClass(), rendererOptions);
out.render(entry.getValue(), buf);
}
localDelimiter = COMMA_DELIMITER_NEWLINE;
}
}
}
buf.append(NEWLINE);
ident(buf, level);
buf.append('}');
delimiter = COMMA_DELIMITER_NEWLINE;
}
NestedGetterPair[] nestedProps = meta.getNestedProperties();
for (NestedGetterPair nestedProp : nestedProps)
{
Object value = nestedProp.getGetter().getFragment(event);
buf.append(delimiter);
ident(buf, level);
buf.append('\"');
buf.append(nestedProp.getName());
buf.append("\": ");
if (value == null)
{
buf.append("null");
}
else if (!nestedProp.isArray())
{
if (!(value instanceof EventBean))
{
log.warn("Property '" + nestedProp.getName() + "' expected to return EventBean and returned " + value.getClass() + " instead");
buf.append("null");
continue;
}
EventBean nestedEventBean = (EventBean) value;
buf.append('{');
buf.append(NEWLINE);
recursiveRender(nestedEventBean, buf, level + 1, nestedProp.getMetadata(), rendererOptions);
ident(buf, level);
buf.append('}');
}
else
{
if (!(value instanceof EventBean[]))
{
log.warn("Property '" + nestedProp.getName() + "' expected to return EventBean[] and returned " + value.getClass() + " instead");
buf.append("null");
continue;
}
StringBuilder arrayDelimiterBuf = new StringBuilder();
arrayDelimiterBuf.append(',');
arrayDelimiterBuf.append(NEWLINE);
ident(arrayDelimiterBuf, level + 1);
EventBean[] nestedEventArray = (EventBean[]) value;
String arrayDelimiter = "";
buf.append('[');
for (int i = 0; i < nestedEventArray.length; i++)
{
EventBean arrayItem = nestedEventArray[i];
buf.append(arrayDelimiter);
arrayDelimiter = arrayDelimiterBuf.toString();
buf.append('{');
buf.append(NEWLINE);
recursiveRender(arrayItem, buf, level + 2, nestedProp.getMetadata(), rendererOptions);
ident(buf, level + 1);
buf.append('}');
}
buf.append(']');
}
delimiter = COMMA_DELIMITER_NEWLINE;
}
buf.append(NEWLINE);
}
}