Develop Reference

How to run a gradle task from a java code?

I need to run the gradle eclipse task to an external gradle project from a java method, is it possible to do it using the Gradle Tooling API ?

The Gradle forum gives a nice example for doing this programmatically but since it disregards the projects individual gradle wrapper, it can't guarantee the smooth execution of your build and even break your application. For more information why you always should rely on the gradle wrapper read here and here.
Using the Gradle wrapper
The recommended approach is to run exec and call the projects wrapper while passing the task as a parameter. This example calls the current projects wrapper and passes jar as a parameter:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Main
{
private static String PATH_TO_GRADLE_PROJECT = "./";
private static String GRADLEW_EXECUTABLE = "gradlew.bat";
private static String BLANK = " ";
private static String GRADLE_TASK = "jar";
public static void main(String[] args)
{
String command = PATH_TO_GRADLE_PROJECT + GRADLEW_EXECUTABLE + BLANK + GRADLE_TASK;
try
{
Runtime.getRuntime().exec(command);
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
Using the Gradle Tooling API
To use the Gradle tooling api on a external project, you simply have to define the property forProjectDirectory of your GradleConnectorobject. To run a task call run() on the BuildLauncher object. The example below demostrates the basic principle:
import org.gradle.tooling.BuildLauncher;
import org.gradle.tooling.GradleConnector;
import org.gradle.tooling.ProjectConnection;
import java.io.File;
public class ToolingAPI
{
private static final String GRADLE_INSTALLATION = "C:\\Program Files\\Gradle";
private static final String GRADLE_PROJECT_DIRECTORY = "path_to_root_of_a_gradle_project";
private static final String GRADLE_TASK = "help";
private GradleConnector connector;
public ToolingAPI(String gradleInstallationDir, String projectDir)
{
connector = GradleConnector.newConnector();
connector.useInstallation(new File(gradleInstallationDir));
connector.forProjectDirectory(new File(projectDir));
}
public void executeTask(String... tasks)
{
ProjectConnection connection = connector.connect();
BuildLauncher build = connection.newBuild();
build.forTasks(tasks);
build.run();
connection.close();
}
public static void main(String[] args)
{
ToolingAPI toolingAPI = new ToolingAPI(GRADLE_INSTALLATION, GRADLE_PROJECT_DIRECTORY);
toolingAPI.executeTask(GRADLE_TASK);
}
}
The downside of this approach is the location unawareness of gradle when executing a task. In case you call any file creation or modification method in a custom task like new File("somefile") a exception will be raised.

Unable to use twilio API

When I want to run the Java code of the twilio API with IntelliJ, it gives me an error:
Exception in thread "main" java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/JsonMappingException".
I have already added the twilio-7.14.5.jar to the module's dependencies.
import com.twilio.Twilio;
import com.twilio.rest.api.v2010.account.Message;
import com.twilio.type.PhoneNumber;
public class main
{
public static final String ACCOUNT_SID = "AC935209d3c44660b4a550e3380249857a";
public static final String AUTH_TOKEN = "42bcd28e23344404c737eb3499d2a747";
public static void main(String[] args) {
Twilio.init(ACCOUNT_SID, AUTH_TOKEN);
Message message = Message.creator(new PhoneNumber("+13195120377"),
new PhoneNumber("+13193204088"),
"The temperature is over heat now!").create();
}
}
screen shot for the console

You need to include all the dependencies used by Twilio 7.4.15 version. The maven repository lists all the required dependencies http://mvnrepository.com/artifact/com.twilio.sdk/twilio/7.14.5

Getting error: Route() in Route cannot be applied to String

I'm designing a Java based MongoDB app and I've ran into a snag when working with Spark.
package com.tengen;
import spark.Request;
import spark.Response;
import spark.Route;
import spark.Spark;
public class HelloWorldSparkStyle {
public static void main(String[] args) {
Spark.get(new Route("/") {
#Override
public Object handle(Request request, Response response) {
return "Hello World From Spark";
}
});
}
}
On new Route("/") I get the error Route() in route cannot be applied to java.lang.string.
I'm confused as to why this doesn't work as I've followed their code exactly.

This should probably be posted on the MongoDB class forum, but I ran into a similar issue. Looks like the get method changed from when the course material was produced. The get now requires a path and a Route
get(path, Route)
import spark.Request;
import spark.Response;
import spark.Route;
import spark.Spark;
public class HelloWorldSparkStyle {
public static void main(String[] args){
Spark.get("/", new Route() {
public Object handle(final Request request, final Response response){
return "Hello World from Spark";
}
});
}
}

Actually I used spark-core-1.1.1.jar it worked fine for me, may be the newer versions of Spark(version 2.0.0) support some different syntax.So if you are using the latest version then you can follow the example given by Mike or just add spark-core-1.1.1.jar to your classpath your example will work fine

That would work in Spark 1. In Spark 2 is recommended by Spark the following (source: http://sparkjava.com/news.html):
import static spark.Spark.*;
public class HelloWorld {
public static void main(String[] args) {
get("/", (req, res) -> "Hello World From Spark");
}
}

Currently, Implementation of Spark Java framework needs to use directory out of Route. So you have to correct your code as follow:
public static void main(String[] args) {
spark.Spark.port(PortNumber);
Spark.get("/", new Route() {
public Object handle(Request request, Response response) throws Exception {
return "This is a sample page";
}
});
}
actually, "/" is the resource to your program. And if you want to change the default spark.Spark.port(PortNumber).

Change the version of Spark in the POM file from the exercise files you download from handout. That fixed issue for me.

GWT.log throwing error

I am new to GWT and trying to build a sample application. Here is my EntryPoint class.
package com.google.gwt.sample.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
public class TalkToServer implements EntryPoint {
public TalkToServer() {}
public void onModuleLoad() {
HTTPRequest.asyncGet
(GWT.getHostPageBaseURL() + "person.xml",
new ResponseTextHandler() {
public void onCompletion(String responseText) {
GWT.log("some log message");
}
});
}
}
The error here is -
log(java.lang.String,java.lang.Throwable) in com.google.gwt.core.client.GWT cannot be applied to (java.lang.String)
I have checked gwt's javadoc and found that log can take string as argument. I am not able to figure out why log is throwing this error. Please let me know if I am missing something.

Try using
GWT.log("some log message", new Throwable())

Error in simple Java application

Just playing around with java trying to learn it etc.
Here is my code so far, using HtmlUnit.
package hsspider;
import com.gargoylesoftware.htmlunit.WebClient;
/**
* #author
*/
public class Main {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
System.out.println("starting ");
Spider spider = new Spider();
spider.Test();
}
}
package hsspider;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
/**
* #author
*/
public class Spider {
public void Test() throws Exception
{
final WebClient webClient = new WebClient();
final HtmlPage page = webClient.getPage("http://www.google.com");
System.out.println(page.getTitleText());
}
}
I am using Netbeans.
I can't seem to figure out what the problem is, why doesn't it compile?
The error:
C:\Users\mrblah\.netbeans\6.8\var\cache\executor-snippets\run.xml:45:
Cancelled by user.
BUILD FAILED (total time: 0 seconds)
The row in the xml is:
<translate-classpath classpath="${classpath}" targetProperty="classpath-translated" />

Test is declared to throw Exception. If you add "throws Exception" to your main method it should compile. For example:
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws Exception {
System.out.println("starting ");
Spider spider = new Spider();
spider.Test();
}

What Steve said is correct. But maybe there are some problems with the uppercase character of Test. A method always starts with a lower case character. So test would be better.

Unchecking the "Compile on Save" option of the "Properties" tab in Netbeans 7.1.2 resolved a similar error message for me.