diff options
Diffstat (limited to 'j2kviewer/src/Exec.java')
| -rw-r--r-- | j2kviewer/src/Exec.java | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/j2kviewer/src/Exec.java b/j2kviewer/src/Exec.java deleted file mode 100644 index c8b09abc..00000000 --- a/j2kviewer/src/Exec.java +++ /dev/null @@ -1,212 +0,0 @@ -import java.io.*; - -// This appears in Core Web Programming from -// Prentice Hall Publishers, and may be freely used -// or adapted. 1997 Marty Hall, hall@apl.jhu.edu. - -/** A class that eases the pain of running external - * processes from applications. - * Lets you run a program three ways: - * <OL> - * <LI><B>exec</B>: Execute the command, returning - * immediately even if the command is still - * running. This would be appropriate - * for printing a file. - * <LI><B>execWait</B>: Execute the command, but - * don't return until the command finishes. - * This would be appropriate for - * sequential commands where the first depends - * on the second having finished (e.g. - * <CODE>javac</CODE> followed by - * <CODE>java</CODE>). - * <LI><B>execPrint</B>: Execute the command and - * print the output. This would be appropriate - * for the UNIX command <CODE>ls</CODE>. - * </OL> - * Note that the PATH is not taken into account, - * so you must specify the <B>full</B> pathname to - * the command, and shell builtin commands - * will not work. For instance, on Unix the above - * three examples might look like: - * <OL> - * <LI><PRE>Exec.exec("/usr/ucb/lpr Some-File");</PRE> - * <LI><PRE> - * Exec.execWait("/usr/local/bin/javac Foo.java"); - * Exec.execWait("/usr/local/bin/java Foo"); - * </PRE> - * <LI><PRE>Exec.execPrint("/usr/bin/ls -al");</PRE> - * </OL> - * - * @author Marty Hall - * (<A HREF="mailto:hall@apl.jhu.edu"> - * hall@apl.jhu.edu</A>) - * @version 1.0 1997 - */ - -public class Exec { - //---------------------------------------------------- - - private static boolean verbose = true; - - /** Determines if the Exec class should print which - * commands are being executed, and print error - * messages if a problem is found. Default is true. - * - * @param verboseFlag true: print messages. - * false: don't. - */ - - public static void setVerbose(boolean verboseFlag) { - verbose = verboseFlag; - } - - /** Will Exec print status messages? */ - - public static boolean getVerbose() { - return(verbose); - } - - //---------------------------------------------------- - /** Starts a process to execute the command. Returns - * immediately, even if the new process is still - * running. - * - * @param command The <B>full</B> pathname of the - * command to be executed. No shell builtins - * (e.g. "cd") or shell meta-chars (e.g. ">") - * allowed. - * @return false if a problem is known to occur, but - * since this returns immediately, problems - * aren't usually found in time. - * Returns true otherwise. - */ - - public static boolean exec(String command) { - return(exec(command, false, false)); - } - - //---------------------------------------------------- - /** Starts a process to execute the command. Waits - * for the process to finish before returning. - * - * @param command The <B>full</B> pathname of the - * command to be executed. No shell builtins - * or shell meta-chars allowed. - * @return false if a problem is known to occur, - * either due to an exception or from the - * subprocess returning a non-zero value. - * Returns true otherwise. - */ - - public static boolean execWait(String command) { - return(exec(command, false, true)); - } - - //---------------------------------------------------- - /** Starts a process to execute the command. Prints - * all output the command gives. - * - * @param command The <B>full</B> pathname of the - * command to be executed. No shell builtins - * or shell meta-chars allowed. - * @return false if a problem is known to occur, - * either due to an exception or from the - * subprocess returning a non-zero value. - * Returns true otherwise. - */ - - public static boolean execPrint(String command) { - return(exec(command, true, false)); - } - - //---------------------------------------------------- - // This creates a Process object via - // Runtime.getRuntime.exec(). Depending on the - // flags, it may call waitFor on the process - // to avoid continuing until the process terminates, - // or open an input stream from the process to read - // the results. - - private static boolean exec(String command, - boolean printResults, - boolean wait) { - if (verbose) { - printSeparator(); - System.out.println("Executing '" + command + "'."); - } - try { - // Start running command, returning immediately. - Process p = Runtime.getRuntime().exec(command); - - // Print the output. Since we read until - // there is no more input, this causes us - // to wait until the process is completed - if(printResults) { - BufferedInputStream buffer = - new BufferedInputStream(p.getInputStream()); - DataInputStream commandResult = - new DataInputStream(buffer); - String s = null; - try { - while ((s = commandResult.readLine()) != null) - System.out.println("Output: " + s); - commandResult.close(); - if (p.exitValue() != 0) { - if (verbose) - printError(command + - " -- p.exitValue() != 0"); - return(false); - } - // Ignore read errors; they mean process is done - } catch (Exception e) {} - - // If you don't print the results, then you - // need to call waitFor to stop until the process - // is completed - } else if (wait) { - try { - System.out.println(" "); - int returnVal = p.waitFor(); - if (returnVal != 0) { - if (verbose) - printError(command); - return(false); - } - } catch (Exception e) { - if (verbose) - printError(command, e); - return(false); - } - } - } catch (Exception e) { - if (verbose) - printError(command, e); - return(false); - } - return(true); - } - - //---------------------------------------------------- - - private static void printError(String command, - Exception e) { - System.out.println("Error doing exec(" + - command + "): " + e.getMessage()); - System.out.println("Did you specify the full " + - "pathname?"); - } - - private static void printError(String command) { - System.out.println("Error executing '" + - command + "'."); - } - - //---------------------------------------------------- - - private static void printSeparator() { - System.out.println - ("=============================================="); - } - - //---------------------------------------------------- -} |