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Get controller name and java service path in controller advice

Hi All i have created a global exception handler in my spring boot app and writing the exception occurred in AWS cloudwatch below code working fine i am able to write the exception in cloudwatch but the challenge is i am unable to get the Restcontroller name and service path from where the the particular exception happened.
Sample java service
#GetMapping(value = "DynamoDb/deleteTable")
public String deleteTable(#RequestParam String TableName) throws InterruptedException {
Table table = dynamoDB.getTable(TableName);
try {
table.delete();
table.waitForDelete();
} catch (Exception e) {
throw e;
}
return "Success";
}
When ever exception occurred it control transferred to controlleradvice global exception handler
Here is my code
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsResponse;
import software.amazon.awssdk.services.cloudwatchlogs.model.InputLogEvent;
import software.amazon.awssdk.services.cloudwatchlogs.model.PutLogEventsRequest;
import java.util.Arrays;
#ControllerAdvice
public class ExceptionControllerAdvice {
#ExceptionHandler(Exception.class)
public ResponseEntity<ErrorResponse> exceptionHandler(Exception ex) {
ErrorResponse error = new ErrorResponse();
error.setErrorCode(HttpStatus.INTERNAL_SERVER_ERROR.value());
error.setMessage(ex.getMessage());
error.setController(ex.getMessage());
error.setService(ex.getMessage());
error.setTimestamp(System.currentTimeMillis());
PutLogEvents(error);
return new ResponseEntity<ErrorResponse>(error, HttpStatus.OK);
}
public static void PutLogEvents(ErrorResponse Er)
{
String regionId = "us-east-1";
String logGroupName = "xxxxxxx";
String logStreamName = "xxxxxxx";
CloudWatchLogsClient logsClient = CloudWatchLogsClient.builder().region(Region.of(regionId)).build();
// A sequence token is required to put a log event in an existing stream.
// Look up the stream to find its sequence token.
String sequenceToken = getNextSequenceToken(logsClient, logGroupName, logStreamName);
// Build a JSON log using the EmbeddedMetricFormat.
String message = "[{" +
" \"Timestamp\": " + Er.getTimestamp() + "," +
" \"ErrorCode\": " + Er.getErrorCode() + "," +
" \"ControllerName\": " + Er.getErrorCode() + "," +
" \"ServiceName\": " + Er.getErrorCode() + "," +
" \"ErrorMsg\": " + Er.getErrorCode() + "" +
"}]";
InputLogEvent inputLogEvent = InputLogEvent.builder()
.message(message)
.timestamp(Er.getTimestamp())
.build();
// Specify the request parameters.
PutLogEventsRequest putLogEventsRequest = PutLogEventsRequest.builder()
.logEvents(Arrays.asList(inputLogEvent))
.logGroupName(logGroupName)
.logStreamName(logStreamName)
// Sequence token is required so that the log can be written to the
// latest location in the stream.
.sequenceToken(sequenceToken)
.build();
logsClient.putLogEvents(putLogEventsRequest);
}
private static String getNextSequenceToken(CloudWatchLogsClient logsClient, String logGroupName, String logStreamName) {
DescribeLogStreamsRequest logStreamRequest = DescribeLogStreamsRequest.builder()
.logGroupName(logGroupName)
.logStreamNamePrefix(logStreamName)
.build();
DescribeLogStreamsResponse describeLogStreamsResponse = logsClient.describeLogStreams(logStreamRequest);
// Assume that a single stream is returned since a specific stream name was
// specified in the previous request.
return describeLogStreamsResponse.logStreams().get(0).uploadSequenceToken();
}
}
Errorresponse.class
public class ErrorResponse {
private int errorCode;
private String message;
private String Controller;
private String Service;
private String ProjectName;
private long Timestamp;
public ErrorResponse(int errorCode, String message, String controller, String service, String projectName, long timestamp) {
this.errorCode = errorCode;
this.message = message;
Controller = controller;
Service = service;
ProjectName = projectName;
Timestamp = timestamp;
}
public ErrorResponse() {
}
#Override
public String toString() {
return "ErrorResponse{" +
"errorCode=" + errorCode +
", message='" + message + '\'' +
", Controller='" + Controller + '\'' +
", Service='" + Service + '\'' +
", ProjectName='" + ProjectName + '\'' +
", Timestamp=" + Timestamp +
'}';
}
public int getErrorCode() {
return errorCode;
}
public void setErrorCode(int errorCode) {
this.errorCode = errorCode;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public String getController() {
return Controller;
}
public void setController(String controller) {
Controller = controller;
}
public String getService() {
return Service;
}
public void setService(String service) {
Service = service;
}
public String getProjectName() {
return ProjectName;
}
public void setProjectName(String projectName) {
ProjectName = projectName;
}
public long getTimestamp() {
return Timestamp;
}
public void setTimestamp(long timestamp) {
Timestamp = timestamp;
}
}
Could any one please help me how can i get the Restcontroller name and service path in Global exception handler?

Hi All Thanks to all by using below code i am able to get the result as suggested by client. Hope this may help some one. Thanks
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.method.HandlerMethod;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsResponse;
import software.amazon.awssdk.services.cloudwatchlogs.model.InputLogEvent;
import software.amazon.awssdk.services.cloudwatchlogs.model.PutLogEventsRequest;
import javax.servlet.http.HttpServletRequest;
import java.lang.reflect.AnnotatedType;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Arrays;
#ControllerAdvice
public class ExceptionControllerAdvice {
private static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
#Value("${application.name}")
private String applicationName;
#Value("${aws.logGroupName}")
private String logGroupName;
#Value("${aws.logStreamName}")
private String logStreamName;
#ExceptionHandler(Exception.class)
public ResponseEntity<ErrorResponse> exceptionHandler(Exception ex, HandlerMethod handlerMethod, HttpServletRequest request) throws JsonProcessingException {
Class ControllerName = handlerMethod.getMethod().getDeclaringClass();
String MethodName = handlerMethod.getMethod().getName();
ErrorResponse error = new ErrorResponse();
error.setErrorCode(HttpStatus.INTERNAL_SERVER_ERROR.value());
error.setErrorMessage(ex.getMessage());
error.setControllerName(ControllerName.toString());
error.setServiceName(MethodName.toString());
error.setTimeStamp(sdf.format(System.currentTimeMillis()));
error.setProjectName(applicationName);
error.setServicePath(request.getRequestURL().toString());
PutLogEvents(error);
return new ResponseEntity<ErrorResponse>(error, HttpStatus.OK);
}
public void PutLogEvents(ErrorResponse Er) throws JsonProcessingException {
String regionId = "xxxxx";
String logGroupName = "xxxxx";
String logStreamName = "xxxxx";
CloudWatchLogsClient logsClient = CloudWatchLogsClient.builder().region(Region.of(regionId)).build();
// A sequence token is required to put a log event in an existing stream.
// Look up the stream to find its sequence token.
String sequenceToken = getNextSequenceToken(logsClient, logGroupName, logStreamName);
// Build a JSON log using the EmbeddedMetricFormat.
ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
String json = ow.writeValueAsString(Er);
String message =json;
InputLogEvent inputLogEvent = InputLogEvent.builder()
.message(message)
.timestamp(System.currentTimeMillis())
.build();
// Specify the request parameters.
PutLogEventsRequest putLogEventsRequest = PutLogEventsRequest.builder()
.logEvents(Arrays.asList(inputLogEvent))
.logGroupName(logGroupName)
.logStreamName(logStreamName)
// Sequence token is required so that the log can be written to the
// latest location in the stream.
.sequenceToken(sequenceToken)
.build();
logsClient.putLogEvents(putLogEventsRequest);
}
private static String getNextSequenceToken(CloudWatchLogsClient logsClient, String logGroupName, String logStreamName) {
DescribeLogStreamsRequest logStreamRequest = DescribeLogStreamsRequest.builder()
.logGroupName(logGroupName)
.logStreamNamePrefix(logStreamName)
.build();
DescribeLogStreamsResponse describeLogStreamsResponse = logsClient.describeLogStreams(logStreamRequest);
// Assume that a single stream is returned since a specific stream name was
// specified in the previous request.
return describeLogStreamsResponse.logStreams().get(0).uploadSequenceToken();
}
}
Result should be like this
{
"errorMessage": "Table already exists: ProductFgh (Service: AmazonDynamoDBv2; Status Code: 400; Error Code: ResourceInUseException; Request ID: 6S14VS0E6ESUMG55DL937IC42JVV4KQNSO5AEMVJF66Q9ASUAAJG)",
"timeStamp": "2020-Jan-22 11:53:58",
"errorCode": 500,
"projectName": "DynamoDB",
"servicePath": "http://localhost:8090/DynamoDb/createTable",
"controllerName": "class com.example.DynamoDB.DynamoDBController",
"serviceName": "createExampleTable"
}
As of now i have achieved this through above code if any better approach is available let me know. Thanks to all

You can get the class name from which the exception was thrown as follows:
ex.getStackTrace()[0].getClassName();

How to send message to a particular session using web socket in java?

Here below is my client side script for WebSockets. In this code I have defined a WebSockets object with IP address and port.
Client Script:
var webSocket =
new WebSocket('ws://localhost:8080/Spring4JSONHandling/websocket');
webSocket.onmessage = function processMessage(message)
{
var jsonData = JSON.parse(message.data);
jsonforlogout = jsonData;
//var user=JSON.parse(username.data);
console.log(jsonData); //to print
if (jsonData.message != null){
var msgAdd = JSON.stringify(jsonData.message);
msgAdd = msgAdd.replace(/[&\/\\#,+()$~%.'"*?<>{}]/g, '');
alert("3"+msgAdd);
var xyz = msgAdd.split(" : ");
var logged = '${me}';
alert("logged" + logged);
alert("xyz[0]" + xyz[0]);
if (logged == xyz[0]){
alert("1");
$("#chat" + xyz[0]).chatbox("option", "boxManager").addMsg(xyz[0], xyz[1]);
} else{
alert("2");
$("#chat" + xyz[0]).chatbox("option", "boxManager").addMsg(xyz[0], xyz[1]);
}
}
/* if(jsonData.message=='close'){websocket.close();} */
if (jsonData.users != null)
{
document.getElementById("chatusers").innerHTML = "";
var loggedInUser = '${me}';
var i = 0;
while (i < jsonData.users.length)
{
var onlineAdd = JSON.stringify(jsonData.users[i]);
onlineAdd = onlineAdd.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g, '');
if (loggedInUser != onlineAdd){
var clone = "<a href='#' onclick=\"clickFun('" + onlineAdd.trim() + "');\" class='usr' data-chat-id='chat" + onlineAdd + "' data-chat-fname='" + onlineAdd + "' data-chat-lname='" + onlineAdd + "'"
+ " data-chat-status='online' data-chat-alertmsg='' data-chat-alertshow='true' data-rel='popover-hover' data-placement='right' data-html='true'"
+ " data-content=\"<div class='usr-card'>"
+ "<img src='Spring4JSONHandling/resources/img/1.png' alt='Jessica Dolof'>"
+ "<div class='usr-card-content'>"
+ "<h3>Jessica Dolof</h3>"
+ "<p>Sales Administrator</p>"
+ "</div>"
+ "</div>\"><i></i>" + onlineAdd + "</a>";
$('#chatusers').append(clone);
}
i++;
}
}
//or(i = 0; i < responselist.data.length; i++) {
/* var i=0;
while(i<jsonData.users.length)
{
var comboitem = document.createElement("option");
comboitem.text = jsonData.users[i];//"utsav";//
comboitem.value = jsonData.users[i];//"10";
usercombo.options.add(comboitem);
i++;
} */
}
function sendMessage(txt) {
//alert(messageText.value+ " h1");
webSocket.send(txt);
// messageText.value = "";
}
window.onbeforeunload = function () {
webSocket.onclose = function() {};
webSocket.close();
};
Here is the code for the server end point. In this code I have defined a WebSockets object with a server endpoint.
Server Code:
package com.outbottle.controllers;
import java.io.IOException;
import java.io.StringWriter;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.json.Json;
import javax.json.JsonArrayBuilder;
import javax.json.JsonObject;
import javax.json.JsonWriter;
import javax.servlet.http.HttpSession;
import javax.websocket.EndpointConfig;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
#ServerEndpoint("/websocket")
public class WebSocketTest {
static Set<Session> chatroomUsers= Collections.synchronizedSet(new HashSet<Session>());
private final static HashMap<String, WebSocketTest> sockets = new HashMap<>();
private String myUniqueId;
private String getMyUniqueId() {
// unique ID from this class' hash code
return Integer.toHexString(this.hashCode());
}
#OnOpen
public void handleOpen(Session userSession) throws IOException {
chatroomUsers.add(userSession);
System.out.println("user added"); //user added
this.myUniqueId = this.getMyUniqueId();
System.out.println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"+ myUniqueId);
WebSocketTest.sockets.put(this.myUniqueId, this);
System.out.println("###################################"+sockets);
}
#OnMessage
public void handleMessage(String message, Session userSession) throws IOException{
String username= (String) userSession.getUserProperties().get("username");
Iterator<Session> itr=chatroomUsers.iterator();
if(username==null){
userSession.getUserProperties().put("username", message);
userSession.getBasicRemote().sendText(buildJsonMessageData("System","You are now connected as "+message));
while (itr.hasNext()) (itr.next()).getBasicRemote().sendText(buildJsonUsersData()); }
else {
while (itr.hasNext()) {
itr.next().getBasicRemote().sendText(buildJsonMessageData(username,message));
}
}
}
#OnClose
public void handleClose(Session userSession) throws IOException {
// TODO Auto-generated method stub
System.out.println("user logout");
chatroomUsers.remove(userSession);
Iterator<Session> itr = chatroomUsers.iterator();
while (itr.hasNext()) (itr.next()).getBasicRemote().sendText(buildJsonUsersData());
}
private String buildJsonUsersData() {
Iterator<String> itr= getUserNames().iterator();
JsonArrayBuilder jsonArrayBuilder = Json.createArrayBuilder();
while (itr.hasNext()) jsonArrayBuilder.add((String)itr.next());
return Json.createObjectBuilder().add("users", jsonArrayBuilder).build().toString();
}
private String buildJsonMessageData(String username, String message)
{
JsonObject jsonObject=Json.createObjectBuilder().add("message", username+" : "+ message).build();
StringWriter stringWriter= new StringWriter();
try (JsonWriter jsonWriter = Json.createWriter(stringWriter)){
jsonWriter.write(jsonObject);
}
return stringWriter.toString();
}
private Set<String> getUserNames()
{
HashSet<String> returnSet = new HashSet<String>();
Iterator<Session> itr= chatroomUsers.iterator();
System.out.println("######################");
while (itr.hasNext())
{
returnSet.add(itr.next().getUserProperties().get("username").toString());
}
return returnSet;
}
}
The problem is when I send a message to the user on a different IP, all users with the same name get the message. I need to send the message to a particular session only.

It looks like you are iterating through all the sessions chatroomUsers in the handleMessage function.
If you only want to send the message to a particular user/session, do you not need to check for your username property here?

Keep getting null pointer exception

here is my program: basically i have an xml file and from that file i have to decode a base64 string but i keep getting NullPointerException..please help! code is as follows...
import java.io.FileInputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import org.apache.commons.codec.binary.Base64;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.Arrays;
public class main {
public static void main(String[] args) throws Exception {
SAXParserFactory parserFactor = SAXParserFactory.newInstance();
SAXParser parser = parserFactor.newSAXParser();
SAXHandler handler = new SAXHandler();
//parser.parse(ClassLoader.getSystemResourceAsStream("ATMSPopulateDMSData.xml"),
// handler);
parser.parse(new FileInputStream("C:\\Users\\qta6754\\workspace\\Java_Dev\\XML64_Decoded\\ATMSMessageData.xml"), handler);
for (NeededInfo emp : handler.empList) {
System.out.println(emp);
}
}
}
class SAXHandler extends DefaultHandler {
List<NeededInfo> empList = new ArrayList<>();
NeededInfo emp = null;
String content = null;
String did = null;
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
switch (qName) {
case "dMSDeviceStatus":
emp = new NeededInfo();
emp.id = attributes.getValue("id");
emp.Read();
break;
}
}
public void characters(char[] ch, int start, int length) throws SAXException {
content = String.copyValueOf(ch, start, length).trim();
}
}
class NeededInfo {
String id;
String firstName;
String lastName;
String location;
String organization_id;
String operator_id;
String device_id;
String dms_device_status;
String dms_current_message;
String last_comm_time;
String date;
String time;
public String toString() {
//return firstName + " " + lastName + "(" + id + ")" + location+date+time+device_name;
return "Organization id: " + organization_id + "\n" + "Operator id: " + operator_id + "\n" + "Device id: " + device_id + "\n"
+ "Dms Device Status: " + dms_device_status + "\n" + "Dms Current Message: " + dms_current_message + "\n" + "Last Comm Time" + "\n"
+ "Time: " + time + "\n" + "Date: " + date + "\n" + "decoded string is: " + "\n" + "-------------------------------------";
}
public void Read() {
byte[] byteArray = Base64.decodeBase64(dms_current_message.getBytes());
String decodedString = new String(byteArray);
System.out.print("The decoded message is: " + decodedString);
// return decodedString;
}
}

It's hard to guess where you're getting your error, but I'm assuming here:
byte[] byteArray = Base64.decodeBase64(dms_current_message.getBytes());
I don't see dms_current_message being initialized ever, yet you're calling a method on it, which would definitely result in the null pointer exception.

Your Read method accesses the dms_current_message which is never initialized in all the code you included in your question.
byte[] byteArray = Base64.decodeBase64(dms_current_message.getBytes());

How to get list of JNDI Names from Weblogic Server?

I am getting the list of datasources configured in context.xml of Tomcat Server using the method below :
public static List<String> getDataSourcesList() {
List<String> dataSourceList = new ArrayList<String>();
try {
if( initialContext == null ) {
initialContext = new InitialContext();
}
NamingEnumeration<NameClassPair> list = ( ( Context )initialContext.lookup( DATASOURCE_CONTEXT ) ).list( "" );
while( list.hasMore() ) {
dataSourceList.add( list.next().getName() );
}
}
catch( NamingException ex ) {
Logger.getLogger( JDBCUtil.class.getName() ).log( Level.SEVERE, null, ex );
}
return dataSourceList;
}
But this method does not work for Weblogic and Websphere Servers.
How can I get the list of datasource names configured on the Weblogic/WebSphere Servers ?
Is there any method to get the list of datasource names ?

For WebSphere Application Server just use dumpNameSpace command line tool located in PROFILE_ROOT\bin
And your code with small modification is working fine in WAS 8.5.5:
try {
InitialContext initialContext = new InitialContext();
NamingEnumeration<NameClassPair> list = ((Context)initialContext.lookup( "jdbc" ) ).list( "" );
while( list.hasMore() ) {
System.out.println(list.next().getName() );
}
}
catch( NamingException ex ) {
ex.printStackTrace();
}

package jms.queue;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.Hashtable;
import javax.naming.Binding;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.sql.DataSource;
public class CheckDB {
public CheckDB() {
super();
}
public static void main(String[] args) {
CheckDB checkDB = new CheckDB();
System.out.println(checkDB.listJDBCContextTable());
}
private Context getContext() throws NamingException {
Hashtable myCtx = new Hashtable();
myCtx.put(Context.INITIAL_CONTEXT_FACTORY,
"weblogic.jndi.WLInitialContextFactory");
// myCtx.put(Context.PROVIDER_URL, "t3://172.30.60.76:7001"); //Admin Server
myCtx.put(Context.PROVIDER_URL, "t3://astpdsoam03.auca.corp:8001"); // SOA Cluster
Context ctx = new InitialContext(myCtx);
return ctx;
}
private String checkDataSource(DataSource ds) {
try {
Connection conn = ds.getConnection();
Statement st = conn.createStatement();
st.execute("select sysdate mydate from dual");
st.getResultSet().next();
Date mydate = st.getResultSet().getDate("mydate");
conn.close();
String date = mydate.toString();
if (date.length() == 10 && date.indexOf("-") == 4 &&
date.lastIndexOf("-") == 7) {
return "OK";
} else {
return "NOK";
}
} catch (Exception e) {
return "NOK"; //getStackTrace(e);
}
}
private static String getStackTrace(Throwable e) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
return sw.toString();
}
private String listJDBCContextTable() {
String output = "<table>";
ArrayList<String> tab = new ArrayList<String>();
String line = "";
try {
tab = listContext((Context)getContext().lookup("jdbc"), "", tab);
Collections.sort(tab);
for (int i = 0; i < tab.size(); i++) {
output += tab.get(i);
}
output += "</table>";
return output;
} catch (NamingException e) {
return getStackTrace(e);
}
}
private ArrayList<String> listContext(Context ctx, String indent,
ArrayList<String> output) throws NamingException {
String name = "";
try {
NamingEnumeration list = ctx.listBindings("");
while (list.hasMore()) {
Binding item = (Binding)list.next();
String className = item.getClassName();
name = item.getName();
// System.out.println("Name : " + name);
if (!(item.getObject() instanceof DataSource)) {
//output = output+indent + className + " " + name+"\n";
} else {
output.add("<tr><td>" + name + "</td><td>" +
checkDataSource((DataSource)item.getObject()) +
"</td></tr>\n");
}
Object o = item.getObject();
if (o instanceof javax.naming.Context) {
listContext((Context)o, indent + " ", output);
}
}
} catch (NamingException ex) {
output.add("<tr><td>" + name + "</td><td>" + getStackTrace(ex) +
"</td></tr>\n");
}
return output;
}
}

Youtube data API : Get access to media stream and play (JAVA)

I want to access a youtube video and play using my own media player. I am able to get the video properties (title, url etc..) using the youtube data API. Can I get access to the stream of the video and use my own Media Player (like the Android Media Player) to play it.
I am trying all of these in JAVA.
Thanks in advance.. :)

/**
* This work is licensed under a Creative Commons Attribution 3.0 Unported
* License (http://creativecommons.org/licenses/by/3.0/). This work is placed
* into the public domain by the author.
*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
import java.util.regex.Pattern;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.CookieStore;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.client.utils.URIUtils;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
/**
* Locally download a YouTube.com video.
*/
public class JavaYoutubeDownloader extends Formatter {
private static final String scheme = "http";
private static final String host = "www.youtube.com";
private static final String YOUTUBE_WATCH_URL_PREFIX = scheme + "://" + host + "/watch?v=";
private static final String ERROR_MISSING_VIDEO_ID = "Missing video id. Extract from " + YOUTUBE_WATCH_URL_PREFIX + "VIDEO_ID";
private static final String DEFAULT_USER_AGENT = "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13";
private static final String DEFAULT_ENCODING = "UTF-8";
private static final String newline = System.getProperty("line.separator");
private static final Logger log = Logger.getLogger(JavaYoutubeDownloader.class.getCanonicalName());
private static final Logger rootlog = Logger.getLogger("");
private static final Pattern commaPattern = Pattern.compile(",");
private static final Pattern pipePattern = Pattern.compile("\\|");
private static final char[] ILLEGAL_FILENAME_CHARACTERS = { '/', '\n', '\r', '\t', '\0', '\f', '`', '?', '*', '\\', '<', '>', '|', '\"', ':' };
private static final int BUFFER_SIZE = 2048;
private static final DecimalFormat commaFormatNoPrecision = new DecimalFormat("###,###");
private static final double ONE_HUNDRED = 100;
private static final double KB = 1024;
private void usage(String error) {
if (error != null) {
System.err.println("Error: " + error);
}
System.err.println("usage: JavaYoutubeDownload VIDEO_ID");
System.err.println();
System.err.println("Options:");
System.err.println("\t[-dir DESTINATION_DIR] - Specify output directory.");
System.err.println("\t[-format FORMAT] - Format number" + newline + "\t\tSee http://en.wikipedia.org/wiki/YouTube#Quality_and_codecs");
System.err.println("\t[-ua USER_AGENT] - Emulate a browser user agent.");
System.err.println("\t[-enc ENCODING] - Default character encoding.");
System.err.println("\t[-verbose] - Verbose logging for downloader component.");
System.err.println("\t[-verboseall] - Verbose logging for all components (e.g. HttpClient).");
System.exit(-1);
}
public static void main(String[] args) {
try {
new JavaYoutubeDownloader().run(args);
} catch (Throwable t) {
t.printStackTrace();
}
}
private void run(String[] args) throws Throwable {
setupLogging(Level.WARNING, Level.WARNING);
String videoId = null;
String outdir = ".";
int format = 18;
String encoding = DEFAULT_ENCODING;
String userAgent = DEFAULT_USER_AGENT;
for (int i = 0; i < args.length; i++) {
String arg = args[i];
// Options start with either -, --
// Do not accept Windows-style args that start with / because of abs
// paths on linux for file names.
if (arg.charAt(0) == '-') {
// For easier processing, convert any double dashes to
// single dashes
if (arg.length() > 1 && arg.charAt(1) == '-') {
arg = arg.substring(1);
}
String larg = arg.toLowerCase();
// Process the option
if (larg.equals("-help") || larg.equals("-?") || larg.equals("-usage") || larg.equals("-h")) {
usage(null);
} else if (larg.equals("-verbose")) {
setupLogging(Level.ALL, Level.WARNING);
} else if (larg.equals("-verboseall")) {
setupLogging(Level.ALL, Level.ALL);
} else if (larg.equals("-dir")) {
outdir = args[++i];
} else if (larg.equals("-format")) {
format = Integer.parseInt(args[++i]);
} else if (larg.equals("-ua")) {
userAgent = args[++i];
} else if (larg.equals("-enc")) {
encoding = args[++i];
} else {
usage("Unknown command line option " + args[i]);
}
} else {
// Non-option (i.e. does not start with -, --
videoId = arg;
// Break if only the first non-option should be used.
break;
}
}
if (videoId == null) {
usage(ERROR_MISSING_VIDEO_ID);
}
log.fine("Starting");
if (videoId.startsWith(YOUTUBE_WATCH_URL_PREFIX)) {
videoId = videoId.substring(YOUTUBE_WATCH_URL_PREFIX.length());
}
int a = videoId.indexOf('&');
if (a != -1) {
videoId = videoId.substring(0, a);
}
File outputDir = new File(outdir);
String extension = getExtension(format);
play(videoId, format, encoding, userAgent, outputDir, extension);
log.fine("Finished");
}
private static String getExtension(int format) {
switch (format) {
case 18:
return "mp4";
default:
throw new Error("Unsupported format " + format);
}
}
private static void play(String videoId, int format, String encoding, String userAgent, File outputdir, String extension) throws Throwable {
log.fine("Retrieving " + videoId);
List<NameValuePair> qparams = new ArrayList<NameValuePair>();
qparams.add(new BasicNameValuePair("video_id", videoId));
qparams.add(new BasicNameValuePair("fmt", "" + format));
URI uri = getUri("get_video_info", qparams);
CookieStore cookieStore = new BasicCookieStore();
HttpContext localContext = new BasicHttpContext();
localContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(uri);
if (userAgent != null && userAgent.length() > 0) {
httpget.setHeader("User-Agent", userAgent);
}
log.finer("Executing " + uri);
HttpResponse response = httpclient.execute(httpget, localContext);
HttpEntity entity = response.getEntity();
if (entity != null && response.getStatusLine().getStatusCode() == 200) {
InputStream instream = entity.getContent();
String videoInfo = getStringFromInputStream(encoding, instream);
if (videoInfo != null && videoInfo.length() > 0) {
List<NameValuePair> infoMap = new ArrayList<NameValuePair>();
URLEncodedUtils.parse(infoMap, new Scanner(videoInfo), encoding);
String downloadUrl = null;
String filename = videoId;
for (NameValuePair pair : infoMap) {
String key = pair.getName();
String val = pair.getValue();
log.finest(key + "=" + val);
if (key.equals("title")) {
filename = val;
} else if (key.equals("fmt_url_map")) {
String[] formats = commaPattern.split(val);
boolean found = false;
for (String fmt : formats) {
String[] fmtPieces = pipePattern.split(fmt);
if (fmtPieces.length == 2) {
int pieceFormat = Integer.parseInt(fmtPieces[0]);
log.fine("Available format=" + pieceFormat);
if (pieceFormat == format) {
// found what we want
downloadUrl = fmtPieces[1];
found = true;
break;
}
}
}
if (!found) {
log.warning("Could not find video matching specified format, however some formats of the video do exist (use -verbose).");
}
}
}
filename = cleanFilename(filename);
if (filename.length() == 0) {
filename = videoId;
} else {
filename += "_" + videoId;
}
filename += "." + extension;
File outputfile = new File(outputdir, filename);
if (downloadUrl != null) {
downloadWithHttpClient(userAgent, downloadUrl, outputfile);
} else {
log.severe("Could not find video");
}
} else {
log.severe("Did not receive content from youtube");
}
} else {
log.severe("Could not contact youtube: " + response.getStatusLine());
}
}
private static void downloadWithHttpClient(String userAgent, String downloadUrl, File outputfile) throws Throwable {
HttpGet httpget2 = new HttpGet(downloadUrl);
if (userAgent != null && userAgent.length() > 0) {
httpget2.setHeader("User-Agent", userAgent);
}
log.finer("Executing " + httpget2.getURI());
HttpClient httpclient2 = new DefaultHttpClient();
HttpResponse response2 = httpclient2.execute(httpget2);
HttpEntity entity2 = response2.getEntity();
if (entity2 != null && response2.getStatusLine().getStatusCode() == 200) {
double length = entity2.getContentLength();
if (length <= 0) {
// Unexpected, but do not divide by zero
length = 1;
}
InputStream instream2 = entity2.getContent();
System.out.println("Writing " + commaFormatNoPrecision.format(length) + " bytes to " + outputfile);
if (outputfile.exists()) {
outputfile.delete();
}
FileOutputStream outstream = new FileOutputStream(outputfile);
try {
byte[] buffer = new byte[BUFFER_SIZE];
double total = 0;
int count = -1;
int progress = 10;
long start = System.currentTimeMillis();
while ((count = instream2.read(buffer)) != -1) {
total += count;
int p = (int) ((total / length) * ONE_HUNDRED);
if (p >= progress) {
long now = System.currentTimeMillis();
double s = (now - start) / 1000;
int kbpers = (int) ((total / KB) / s);
System.out.println(progress + "% (" + kbpers + "KB/s)");
progress += 10;
}
outstream.write(buffer, 0, count);
}
outstream.flush();
} finally {
outstream.close();
}
System.out.println("Done");
}
}
private static String cleanFilename(String filename) {
for (char c : ILLEGAL_FILENAME_CHARACTERS) {
filename = filename.replace(c, '_');
}
return filename;
}
private static URI getUri(String path, List<NameValuePair> qparams) throws URISyntaxException {
URI uri = URIUtils.createURI(scheme, host, -1, "/" + path, URLEncodedUtils.format(qparams, DEFAULT_ENCODING), null);
return uri;
}
private void setupLogging(Level myLevel, Level globalLevel) {
changeFormatter(this);
explicitlySetAllLogging(myLevel, globalLevel);
}
#Override
public String format(LogRecord arg0) {
return arg0.getMessage() + newline;
}
private static void changeFormatter(Formatter formatter) {
Handler[] handlers = rootlog.getHandlers();
for (Handler handler : handlers) {
handler.setFormatter(formatter);
}
}
private static void explicitlySetAllLogging(Level myLevel, Level globalLevel) {
rootlog.setLevel(Level.ALL);
for (Handler handler : rootlog.getHandlers()) {
handler.setLevel(Level.ALL);
}
log.setLevel(myLevel);
rootlog.setLevel(globalLevel);
}
private static String getStringFromInputStream(String encoding, InputStream instream) throws UnsupportedEncodingException, IOException {
Writer writer = new StringWriter();
char[] buffer = new char[1024];
try {
Reader reader = new BufferedReader(new InputStreamReader(instream, encoding));
int n;
while ((n = reader.read(buffer)) != -1) {
writer.write(buffer, 0, n);
}
} finally {
instream.close();
}
String result = writer.toString();
return result;
}
}
/**
* <pre>
* Exploded results from get_video_info:
*
* fexp=909302
* allow_embed=1
* fmt_stream_map=35|http://v9.lscache8.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=35&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=9E0A8E67154145BCADEBCF844CC155282548288F.2BBD0B2E125E3E533D07866C7AE91B38DD625D30&factor=1.25&id=4ba2193f7c9127d2||tc.v9.cache8.c.youtube.com,34|http://v6.lscache3.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=34&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=6726793A7B041E6456B52C0972596D0D58974141.42B5A0573F62B85AEA7979E5EE1ADDD47EB9E909&factor=1.25&id=4ba2193f7c9127d2||tc.v6.cache3.c.youtube.com,18|http://v12.lscache7.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=18&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=AE58398D4CC4D760C682D2A5B670B4047777FFF0.952E4FC4554E786FD937E7A89140E1F79B6DD8B7&factor=1.25&id=4ba2193f7c9127d2||tc.v12.cache7.c.youtube.com,5|http://v1.lscache7.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=5&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=43434DCB6CFC463FF4522D9EE7CD019FE47237B1.C60A9522E361130938663AF2DAD83A5C2821AF5C&factor=1.25&id=4ba2193f7c9127d2||tc.v1.cache7.c.youtube.com
* fmt_url_map=35|http://v9.lscache8.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=35&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=9E0A8E67154145BCADEBCF844CC155282548288F.2BBD0B2E125E3E533D07866C7AE91B38DD625D30&factor=1.25&id=4ba2193f7c9127d2,34|http://v6.lscache3.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=34&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=6726793A7B041E6456B52C0972596D0D58974141.42B5A0573F62B85AEA7979E5EE1ADDD47EB9E909&factor=1.25&id=4ba2193f7c9127d2,18|http://v12.lscache7.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=18&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=AE58398D4CC4D760C682D2A5B670B4047777FFF0.952E4FC4554E786FD937E7A89140E1F79B6DD8B7&factor=1.25&id=4ba2193f7c9127d2,5|http://v1.lscache7.c.youtube.com/videoplayback?ip=174.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor&fexp=909302&algorithm=throttle-factor&itag=5&ipbits=8&burst=40&sver=3&expire=1294549200&key=yt1&signature=43434DCB6CFC463FF4522D9EE7CD019FE47237B1.C60A9522E361130938663AF2DAD83A5C2821AF5C&factor=1.25&id=4ba2193f7c9127d2
* allow_ratings=1
* keywords=Stefan Molyneux,Luke Bessey,anarchy,stateless society,giant stone cow,the story of our unenslavement,market anarchy,voluntaryism,anarcho capitalism
* track_embed=0
* fmt_list=35/854x480/9/0/115,34/640x360/9/0/115,18/640x360/9/0/115,5/320x240/7/0/0
* author=lukebessey
* muted=0
* length_seconds=390
* plid=AASZXXGQtTEDKwAw
* ftoken=null
* status=ok
* watermark=http://s.ytimg.com/yt/swf/logo-vfl_bP6ud.swf,http://s.ytimg.com/yt/swf/hdlogo-vfloR6wva.swf
* timestamp=1294526523
* has_cc=False
* fmt_map=35/854x480/9/0/115,34/640x360/9/0/115,18/640x360/9/0/115,5/320x240/7/0/0
* leanback_module=http://s.ytimg.com/yt/swfbin/leanback_module-vflJYyeZN.swf
* hl=en_US
* endscreen_module=http://s.ytimg.com/yt/swfbin/endscreen-vflk19iTq.swf
* vq=auto
* avg_rating=5.0
* video_id=S6IZP3yRJ9I
* token=vjVQa1PpcFNhI3jvw6hfEHivcKK-XY5gb-iszDMrooA=
* thumbnail_url=http://i4.ytimg.com/vi/S6IZP3yRJ9I/default.jpg
* title=The Story of Our Unenslavement - Animated
* </pre>
*/

You can't. Look here for further reading on what the API could handle:
YoutubeAPI
If you could get an InputStream on that, Google won't get any money for advertisement at all.
But you could parse the page of the video-url you got from the API and look for the real video-link inside the flash tags.

Now you can find it here now its available https://developers.google.com/youtube/android/player/sample-applications