使用 PHP 在 CICS 上构建 REST 服务

book {
  string: title,   // The title of the book
  string: author,	 // The author of the book
  boolean: onLoan, // Whether the book is on loan
  string: borrower // The person who borrowed the book
                   // if it is on loan, null otherwise.
}

{"errorMessage":"Could not retrieve book 909 as it was not found."}
             

// Load the Java classes
java_import('library.Library_Commarea');
java_import('library.Library_Constants');
// All responses will be JSON, so always set response content-type to text/json.
header('Content-Type: text/json');
             

/**
 * Invoke the library program with the supplied COMMAREA.
 * Notify the client if an error occurs.
 */
function runLibraryProgram($COMMAREA) {
  $program = new CICSProgram('LIBRARY');
  try {
    $program->link($COMMAREA);
  } catch (CICSException $e) {
    header('HTTP/1.1 500 Internal Server Error');
    $error['errorMessage'] = 
              'Exeption when linking with CICS program:' . $e->getMessage();
    echo json_encode($error);
    exit;
  }
}
             

  /**
   * The constructor is invoked before event handlers.
   */
  function __construct() {
    $this->COMMAREA = new Library_Commarea();
    $this->constants = new Library_Constants();
  }
             

  /**
   * Respond with a JSON-encoded list of books.
   */
  function onList() {
    // Attempt to get book list
    $this->COMMAREA->setLibRequestType('LIST');
    runLibraryProgram($this->COMMAREA);

    // Process return code
    switch ($this->COMMAREA->getLibReturnCode()) {
      case $this->constants->getLibraryOk():
        // Return the list of books
        $books = array();
        for ($i = 0; $i<$this->COMMAREA->getLibItemCount(); $i++) {
          $CICSbook = $this->COMMAREA->getLibBookItem($i);
          $bookId = $CICSbook->getBookItemRef();
          $books[$bookId]['title'] = trim($CICSbook->getBookTitle());
          $books[$bookId]['author'] = trim($CICSbook->getBookAuthor());
          $books[$bookId]['onLoan'] = $CICSbook->isBookOnloan();
          $books[$bookId]['borrower'] = $books[$bookId]['onLoan'] ?
          trim($CICSbook->getBookBorrower()) : null;
        }
        echo json_encode($books);
        break;
      default:
        // Notify client of internal error
        header('HTTP/1.1 500 Internal Server Error');
        $error['errorMessage'] = 'Unexpected return code when listing books: ' 
                                        . $this->COMMAREA->getLibReturnCode();
        echo json_encode($error);
    }
  }

  /**
   * Add book to library based on JSON data in the request body.
   */
  function onCreate() {
    // Check input data for new book
    $book = json_decode(zget('/request/input/transcoded'), true);
    if (!is_array($book) || !isset($book['title'], $book['author'])) {
      header('HTTP/1.1 400 Bad Request');
      $error['errorMessage'] = 'Bad book data: ' . zget('/request/input/transcoded') 
                                        . '. Please specify an author and a title.';
      echo json_encode($error);
      return;
    }

    // Attempt to create book
    $this->COMMAREA->setLibRequestType('ADD');
    $this->COMMAREA->getLibBookItem(0)->setBookTitle($book['title']);
    $this->COMMAREA->getLibBookItem(0)->setBookAuthor($book['author']);
    runLibraryProgram($this->COMMAREA);

    // Process return code
    switch ($this->COMMAREA->getLibReturnCode()) {
      case $this->constants->getLibraryOk():
        header('HTTP/1.1 201 Created');
        $bookId = $this->COMMAREA->getLibBookItem(0)-> getBookItemRef();
        $status['statusMessage'] = "Successfully created book $bookId.";
        echo json_encode($status);
        break;
      case $this->constants->getLibraryFull():
        header('HTTP/1.1 400 Bad Request');
        $error['errorMessage'] = 'Could not create book : Library is full.';
        echo json_encode($error);
        break;
      default:
        header('HTTP/1.1 500 Internal Server Error');
        $error['errorMessage'] = 'Unexpected return code when creating book ' 
                                       . $this->COMMAREA->getLibReturnCode();
        echo json_encode($error);
        break;
    }
  }

  /**
   * Respond with a JSON representation of an individual book, or a specific attribute
   * of a book.
   */
  function onRetrieve() {
    $bookId = zget('/request/params/bookId');
    $this->COMMAREA->setLibRequestType('QUERY');
    $this->COMMAREA->getLibBookItem(0)->setBookItemRef($bookId);
    runLibraryProgram($this->COMMAREA);

    // Process return code
    switch ($this->COMMAREA->getLibReturnCode()) {
      case $this->constants->getLibraryOk():
        $book['title'] = trim($this->COMMAREA->getLibBookItem(0)->getBookTitle());
        $book['author'] = trim($this->COMMAREA->getLibBookItem(0)->getBookAuthor());
        $book['onLoan'] = $this->COMMAREA->getLibBookItem(0)->isBookOnloan();
        $book['borrower'] = $book['onLoan'] ?
                trim($this->COMMAREA->getLibBookItem(0)->getBookBorrower()) : null;
        break;
      case $this->constants->getLibraryNotfound():
        header('HTTP/1.1 404 Not Found');
        $error['errorMessage'] = "Could not retrieve book $bookId as it was not found.";
        echo json_encode($error);
        return;
      default:
        header('HTTP/1.1 500 Internal Server Error');
        $error['errorMessage'] = "Unexpected return code deleting book $bookId: " 
                                           . $this->COMMAREA->getLibReturnCode();
        echo json_encode($error);
        return;
    }

    // Send back appropriate info about the book
    $requestedInfo = zget('/event/pathInfo');
    switch($requestedInfo) {
      case null:
        // return the whole book
        echo json_encode($book);
        break;
      case '/title':
      case '/author':
      case '/onLoan':
      case '/borrower':
        // return just the relevant info
        $requestedInfo = substr($requestedInfo, 1);
        echo json_encode(array($requestedInfo => $book[$requestedInfo]));
        break;
      default:
        header('HTTP/1.1 404 Not Found');
        $error['errorMessage'] = "Could not retrieve book detail $requestedInfo 
                          about book $bookId: don't know what $requestedInfo is.";
        echo json_encode($error);
    }
  }
               

  /**
   * Update the status of a book to mark it as borrowed or returned.
   */
  function onUpdate() {
    // Check input data
    $bookId = zget('/request/params/bookId');
    $updateData = json_decode(zget('/request/input/transcoded'), true);
    if (!isset($updateData['onLoan'])) {
      header('HTTP/1.1 400 Bad Request');
      $error['errorMessage'] = 'Bad book update data: ' .
      zget('/request/input/transcoded') . '. Please specify onLoan.';
      echo json_encode($error);
      return;
    }
    if ($updateData['onLoan'] && empty($updateData['borrower'])) {
      header('HTTP/1.1 400 Bad Request');
      $error['errorMessage'] = 'Bad book update data: ' .
      zget('/request/input/transcoded') . '. Please specify a borrower.';
      echo json_encode($error);
      return;
    }

    // Attempt to update book status
    $this->COMMAREA->setLibRequestType($updateData['onLoan'] ? 'BORROW' : 'RETURN');
    $this->COMMAREA->getLibBookItem(0)->setBookItemRef($bookId);
    $this->COMMAREA->getLibBookItem(0)->setBookLoanStatus($updateData['onLoan']);
    if (isset($updateData['borrower'])) {
      $this->COMMAREA->getLibBookItem(0)->setBookBorrower($updateData['borrower']);
    }
    runLibraryProgram($this->COMMAREA);

    // Process return code
    switch ($this->COMMAREA->getLibReturnCode()) {
      case $this->constants->getLibraryOk():
        $status['statusMessage'] =  "Successfully updated status of book $bookId.";
        echo json_encode($status);
        break;
      case $this->constants->getLibraryNotfound():
        header('HTTP/1.1 404 Not Found');
        $error['errorMessage'] = "Could not update book $bookId as it was not found.";
        echo json_encode($error);
        break;
      default:
        header('HTTP/1.1 500 Internal Server Error');
        $error['errorMessage'] = 
        "Unexpected return code when updating status of book $bookId: " 
                                 . $this->COMMAREA->getLibReturnCode();
        echo json_encode($error);
    }
  }
             

  /**
   * Delete a book from the library.
   */
  function onDelete() {
    // Attempt to Delete book
    $bookId = zget('/request/params/bookId');
    $this->COMMAREA->setLibRequestType('DELETE');
    $this->COMMAREA->getLibBookItem(0)->setBookItemRef($bookId);
    runLibraryProgram($this->COMMAREA);

    // Process return code
    switch ($this->COMMAREA->getLibReturnCode()) {
      case $this->constants->getLibraryOk():
        $status['statusMessage'] =  "Successfully deleted book $bookId.";
        echo json_encode($status);
        break;
      case $this->constants->getLibraryNotfound():
        header('HTTP/1.1 404 Not Found');
        $error['errorMessage'] = "Could not delete book $bookId as it was not found.";
        echo json_encode($error);
        break;
      default:
        header('HTTP/1.1 500 Internal Server Error');
        $error['errorMessage'] = "Unexpected return code deleting book $bookId: " 
                                           . $this->COMMAREA->getLibReturnCode();
        echo json_encode($error);
    }
  }