Play Framework/Scala example source code file (PlayException.java)

This example Play Framework source code file (PlayException.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

api, arraylist, atomiclong, exceptionattachment, exceptionsource, integer, interestinglines, play, play framework, playexception, richdescription, string, throwable

The PlayException.java Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package play.api;

import java.io.*;
import java.util.*;

import java.util.concurrent.atomic.AtomicLong;

/**
 * Helper for `PlayException`.
 */
public class PlayException extends UsefulException {

    private final AtomicLong generator = new AtomicLong(System.currentTimeMillis());
   
    /**
     * Generates a new unique exception ID.
     */
    private String nextId() { 
        return java.lang.Long.toString(generator.incrementAndGet(), 26);
    }
  
    public PlayException(String title, String description, Throwable cause) {
        super(title + "[" + description + "]",cause);
        this.title = title;
        this.description = description;
        this.id = nextId();
        this.cause = cause;
    }
    
    public PlayException(String title, String description) {
        super(title + "[" + description + "]");
        this.title = title;
        this.description = description;
        this.id = nextId();
        this.cause = null;
    }
  
    /**
     * Adds source attachment to a Play exception.
     */
    public static abstract class ExceptionSource extends PlayException {
  
        public ExceptionSource(String title, String description, Throwable cause) {
          super(title, description,cause);
        }
     
        public ExceptionSource(String title, String description) {
          super(title, description);
        }
  
        /**
         * Error line number, if defined.
         */
        public abstract Integer line();
  
        /**
         * Column position, if defined.
         */
        public abstract Integer position();
  
        /**
         * Input stream used to read the source content.
         */
        public abstract String input();
  
        /**
         * The source file name if defined.
         */
        public abstract String sourceName();
  
        /**
         * Extracts interesting lines to be displayed to the user.
         *
         * @param border number of lines to use as a border
         */
        public InterestingLines interestingLines(int border) {
            try {
                if(input() == null || line() == null) {
                    return null;
                }
                String[] lines = input().split("\n");
                int firstLine = Math.max(0, line() - border);
                int lastLine = Math.min(lines.length - 1, line() + border);
                List<String> focusOn = new ArrayList<String>();
                for(int i = firstLine; i <= lastLine; i++) {
                    focusOn.add(lines[i]);
                }
                return new InterestingLines(firstLine + 1, focusOn.toArray(new String[focusOn.size()]), line() - firstLine - 1);
            } catch(Throwable e) {
                e.printStackTrace();
                return null;
            }
        }

        public String toString() {
            return super.toString() + " in " + sourceName() + ":" + line();
        }
    }
  
    /**
     * Adds any attachment to a Play exception.
     */
    public static abstract class ExceptionAttachment extends PlayException {
  
        public ExceptionAttachment(String title, String description, Throwable cause) {
            super(title, description, cause);
        }
  
        public ExceptionAttachment(String title, String description) {
            super(title, description);
        }
     
        /**
         * Content title.
         */
        public abstract String subTitle(); 
  
        /**
         * Content to be displayed.
         */
        public abstract String content();
  
    }
  
    /**
     * Adds a rich HTML description to a Play exception.
     */
    public static abstract class RichDescription extends ExceptionAttachment {
     
        public RichDescription(String title, String description, Throwable cause) {
            super(title, description, cause);
        }
  
        public RichDescription(String title, String description) {
            super(title, description);
        }
     
        /**
         * The new description formatted as HTML.
         */
        public abstract String htmlDescription();
  
    }

    public static class InterestingLines {
  
        public final int firstLine;
        public final int errorLine;
        public final String[] focus;

        public InterestingLines(int firstLine, String[] focus, int errorLine){
            this.firstLine = firstLine;
            this.errorLine = errorLine;
            this.focus = focus;
        }

    }
  
}