Reference for Processing version 1.2. If you have a previous version, use the reference included with your software. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Javadoc.



BufferedReader reader;
String line;
void setup() {
  // Open the file from the createWriter() example
  reader = createReader("positions.txt");    
void draw() {
  try {
    line = reader.readLine();
  } catch (IOException e) {
    line = null;
  if (line == null) {
    // Stop reading because of an error or file is empty
  } else {
    String[] pieces = split(line, TAB);
    int x = int(pieces[0]);
    int y = int(pieces[1]);
    point(x, y);
Description The try keyword is used with catch to handle exceptions. Sun's Java documentation defines an exception as "an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions." This could be, for example, an error while a file is read.
try {
} catch (exception) {
tryStatements if this code throws and exception, the code in catch is run
exception a Java exception
catchStatements code that handles the exception
Usage Web & Application
Updated on June 14, 2010 12:05:29pm EDT

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