Hi,
this is a very simple dataadapter. You can subscribe any item name. Each item has 2 fields, timestamp and count.
[syntax="JAVA"]package com.lightstreamer.adapters.simplest;
import java.io.File;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import com.lightstreamer.interfaces.data.DataProvider;
import com.lightstreamer.interfaces.data.DataProviderException;
import com.lightstreamer.interfaces.data.FailureException;
import com.lightstreamer.interfaces.data.ItemEventListener;
import com.lightstreamer.interfaces.data.SubscriptionException;
public class Simplest implements DataProvider {
private ItemEventListener listener;
private Map<String, ItemThread> threads = new HashMap<String, ItemThread>();
public void init(Map params, File configDir) throws DataProviderException {
}
public boolean isSnapshotAvailable(String itemName)
throws SubscriptionException {
return false;
}
public void setListener(ItemEventListener listener) {
this.listener = listener;
}
public synchronized void subscribe(String itemName, boolean needsIterator)
throws SubscriptionException, FailureException {
ItemThread it = threads.get(itemName);
if (it == null) {
it = new ItemThread(itemName);
it.start();
threads.put(itemName, it);
}
}
public synchronized void unsubscribe(String itemName) throws SubscriptionException,
FailureException {
ItemThread it = threads.get(itemName);
if (it != null) {
it.close();
threads.remove(itemName);
}
}
class ItemThread extends Thread {
private final String item;
private volatile boolean go = true;
public ItemThread(String item) {
this.item = item;
}
public void run() {
int c = 0;
while(go) {
Map<String, String> data = new HashMap<String, String>();
data.put("timestamp", (new Date()).toString());
data.put("count", String.valueOf(c));
listener.update(item, data, false);
c++;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
}
}
public void close() {
go = false;
}
}
}
[/syntax]
this is the relative adapters.xml
[syntax="XML"]
<?xml version="1.0"?>
<adapters_conf id="SIMPLEST">
<metadata_provider>
<adapter_class>com.lightstreamer.adapters.metadata.LiteralBasedProvider</adapter_class>
<param name="item_family_1">.*</param>
<param name="modes_for_item_family_1">MERGE</param>
</metadata_provider>
<data_provider>
<adapter_class>com.lightstreamer.adapters.simplest.Simplest</adapter_class>
</data_provider>
</adapters_conf>
[/syntax]
and an example client (my libraries are located under /LS4/):
[syntax="JS"]<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" src="/LS4/lscommons.js"></script>
<script language="JavaScript" src="/LS4/lspushpage.js"></script>
</head>
<body>
<h1>Simplest</h1>
<div>
Item1
<span source="lightstreamer" table="table1" item="1" field="timestamp">Loading...</span>
<span source="lightstreamer" table="table1" item="1" field="count">Loading...</span>
</div>
<div>
MyItem
<span source="lightstreamer" table="table2" item="1" field="timestamp">Loading...</span>
<span source="lightstreamer" table="table2" item="1" field="count">Loading...</span>
</div>
<script>
/////////////////PushPage Configuration
var lsPage = new PushPage();
var debugAlerts = false;
var remoteAlerts = false;
var pushHost = null;
var pushPort = null;
var useDomain = null;
lsPage.context.setDomain(useDomain);
lsPage.context.setDebugAlertsOnClientError(debugAlerts);
lsPage.context.setRemoteAlertsOnClientError(remoteAlerts);
lsPage.onEngineCreation = function(lsEngine) {
lsEngine.context.setDebugAlertsOnClientError(debugAlerts);
lsEngine.context.setRemoteAlertsOnClientError(remoteAlerts);
lsEngine.connection.setLSHost(pushHost);
lsEngine.connection.setLSPort(pushPort);
lsEngine.connection.setAdapterName("SIMPLEST");
lsEngine.changeStatus("STREAMING");
}
lsPage.bind();
lsPage.createEngine("SimplestEngine","/LS4/","SHARE_SESSION");
///////////////////////Table configuration
var schema = ["timestamp","count"];
var table1 = new OverwriteTable("Item1", schema, "MERGE");
table1.setClearOnDisconnected(true);
table1.setClearOnRemove(true);
lsPage.addTable(table1, "table1");
var table2 = new OverwriteTable("MyItem", schema, "MERGE");
table2.setClearOnDisconnected(true);
table2.setClearOnRemove(true);
lsPage.addTable(table2, "table2");
</script>
</body>
</html>
[/syntax]
