Package: org.gradle.tooling

## [Java] Interface ProjectConnection

- Represents a long-lived connection to a Gradle project. You obtain an instance of a `ProjectConnection` by using GradleConnector.connect.

       ProjectConnection connection = GradleConnector.newConnector()
          .forProjectDirectory(new File("someFolder"))
          .connect();

       try {
          //obtain some information from the build
          BuildEnvironment environment = connection.model(BuildEnvironment.class)
            .get();

          //run some tasks
          connection.newBuild()
            .forTasks("tasks")
            .setStandardOutput(System.out)
            .run();

       } finally {
          connection.close();
       }

  ### Thread safety information

  All implementations of `ProjectConnection` are thread-safe, and may be shared by any number of threads.

  All notifications from a given `ProjectConnection` instance are delivered by a single thread at a time. Note, however, that the delivery thread may change over time.

  Since:
    1.0-milestone-3

- - ### Methods Summary

    Methods
    Type | Name and description
    --- | ---
    `BuildActionExecuter<T>` | `action(BuildAction<T> buildAction)` Creates an executer which can be used to run the given action.
    `void` | `close()` Closes this connection.
    `T` | `getModel(Class<T> modelType)` Fetches a snapshot of the model of the given type for this project.
    `void` | `getModel(Class<T> modelType, ResultHandler<? super T> handler)` Starts fetching a snapshot of the given model, passing the result to the given handler when complete.
    `ModelBuilder<T>` | `model(Class<T> modelType)` Creates a builder which can be used to query the model of the given type.
    `BuildLauncher` | `newBuild()` Creates a launcher which can be used to execute a build.

- - ### Method Detail

    - #### @Incubating public BuildActionExecuter<T> action(BuildAction<T> buildAction)

      Creates an executer which can be used to run the given action. The action is serialized into the build process and executed, then its result is serialized back to the caller.

      Parameters:
        `buildAction` - The action to run.
        `` - The result type.
      Returns:
        The builder.
      Since:
        1.8

    - #### public void close()

      Closes this connection. Blocks until any pending operations are complete. Once this method has returned, no more notifications will be delivered by any threads.

      Since:
        1.0-milestone-3

    - #### public T getModel(Class<T> modelType)

      Fetches a snapshot of the model of the given type for this project. This method blocks until the model is available.

      This method is simply a convenience for calling `model(modelType).get()`

      throws:
        UnsupportedVersionException When the target Gradle version does not support the given model.
      throws:
        UnknownModelException When the target Gradle version or build does not support the requested model.
      throws:
        BuildException On some failure executing the Gradle build, in order to build the model.
      throws:
        GradleConnectionException On some other failure using the connection.
      throws:
        IllegalStateException When this connection has been closed or is closing.
      Parameters:
        `modelType` - The model type.
        `` - The model type.
      Returns:
        The model.
      Since:
        1.0-milestone-3

    - #### public void getModel(Class<T> modelType, ResultHandler<? super T> handler)

      Starts fetching a snapshot of the given model, passing the result to the given handler when complete. This method returns immediately, and the result is later passed to the given handler's ResultHandler.onComplete method.

      If the operation fails, the handler's ResultHandler.onFailure method is called with the appropriate exception. See getModel(Class) for a description of the various exceptions that the operation may fail with.

      This method is simply a convenience for calling `model(modelType).get(handler)`

      throws:
        IllegalStateException When this connection has been closed or is closing.
      Parameters:
        `modelType` - The model type.
        `handler` - The handler to pass the result to.
        `` - The model type.
      Since:
        1.0-milestone-3

    - #### public ModelBuilder<T> model(Class<T> modelType)

      Creates a builder which can be used to query the model of the given type.

      Any of following models types may be available, depending on the version of Gradle being used by the target build:

      - GradleBuild
      - BuildEnvironment
      - GradleProject
      - BuildInvocations
      - ProjectPublications
      - IdeaProject
      - BasicIdeaProject
      - EclipseProject
      - HierarchicalEclipseProject

      A build may also expose additional custom tooling models. You can use this method to query these models.

      Parameters:
        `modelType` - The model type
        `` - The model type.
      Returns:
        The builder.
      Since:
        1.0-milestone-3

    - #### public BuildLauncher newBuild()

      Creates a launcher which can be used to execute a build.

      Returns:
        The launcher.
      Since:
        1.0-milestone-3