经过测试发现，当source端单event的body数据大于16字节后，输出到目标只剩下16字节。进过多源代码的分析，发现，源代码中进行了截取。
if (event != null) {
if (logger.isInfoEnabled()) {
logger.info("Event: " + EventHelper.dumpEvent(event));
}
}
我们去看EventHelper.java的dumpEvent方法：
private static final int DEFAULT_MAX_BYTES = 16;
public static String dumpEvent(Event event) {
return dumpEvent(event, DEFAULT_MAX_BYTES);
}
public static String dumpEvent(Event event, int maxBytes) {
StringBuilder buffer = new StringBuilder();
if (event == null || event.getBody() == null) {
buffer.append("null");
} else if (event.getBody().length == 0) {
// do nothing... in this case, HexDump.dump() will throw an exception
} else {
byte[] body = event.getBody();
byte[] data = Arrays.copyOf(body, Math.min(body.length, maxBytes));
ByteArrayOutputStream out = new ByteArrayOutputStream();
try {
HexDump.dump(data, 0, out, 0);
String hexDump = new String(out.toByteArray());
// remove offset since it's not relevant for such a small dataset
if(hexDump.startsWith(HEXDUMP_OFFSET)) {
hexDump = hexDump.substring(HEXDUMP_OFFSET.length());
}
buffer.append(hexDump);
} catch (Exception e) {
if(LOGGER.isInfoEnabled()) {
LOGGER.info("Exception while dumping event", e);
}
buffer.append("...Exception while dumping: ").append(e.getMessage());
}
String result = buffer.toString();
if(result.endsWith(EOL) && buffer.length() > EOL.length()) {
buffer.delete(buffer.length() - EOL.length(), buffer.length()).toString();
}
}
return "{ headers:" + event.getHeaders() + " body:" + buffer + " }";
}
不难看出，在event处理过程中，发生了数据截取操作。