diff options
Diffstat (limited to 'libjava/java/lang/Throwable.java')
| -rw-r--r-- | libjava/java/lang/Throwable.java | 160 |
1 files changed, 97 insertions, 63 deletions
diff --git a/libjava/java/lang/Throwable.java b/libjava/java/lang/Throwable.java index 56c9d54..613f43f 100644 --- a/libjava/java/lang/Throwable.java +++ b/libjava/java/lang/Throwable.java @@ -46,11 +46,6 @@ import java.io.ObjectInputStream; import java.io.IOException; import java.io.OutputStream; -/** - * @author Tom Tromey <tromey@cygnus.com> - * @date October 30, 1998 - */ - /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 * "The Java Language Specification", ISBN 0-201-63451-1 * Status: Sufficient for compiled code, but methods applicable to @@ -116,7 +111,7 @@ import java.io.OutputStream; * @author Tom Tromey * @author Eric Blake <ebb9@email.byu.edu> * @since 1.0 - * @status still missing 1.4 functionality + * @status updated to 1.4 */ public class Throwable implements Serializable { @@ -130,7 +125,7 @@ public class Throwable implements Serializable * * @serial specific details about the exception, may be null */ - private String detailMessage; + private final String detailMessage; /** * The cause of the throwable, including null for an unknown or non-chained @@ -374,7 +369,7 @@ public class Throwable implements Serializable */ public void printStackTrace(PrintStream s) { - printStackTrace(new PrintWriter(s)); + s.print(stackTraceString()); } /** @@ -409,72 +404,88 @@ public class Throwable implements Serializable */ public void printStackTrace (PrintWriter pw) { - // First line - pw.println(toString()); + pw.print(stackTraceString()); + } - // The stacktrace + private static final String nl = System.getProperty("line.separator"); + // Create whole stack trace in a stringbuffer so we don't have to print + // it line by line. This prevents printing multiple stack traces from + // different threads to get mixed up when written to the same PrintWriter. + private String stackTraceString() + { + StringBuffer sb = new StringBuffer(); + + // Main stacktrace StackTraceElement[] stack = getStackTrace(); - if (stack == null || stack.length == 0) - { - pw.println(" <<No stacktrace available>>"); - return; - } - else - { - for (int i = 0; i < stack.length; i++) - pw.println(" at " + stack[i]); - } + stackTraceStringBuffer(sb, this.toString(), stack, 0); // The cause(s) Throwable cause = getCause(); while (cause != null) { - // Cause first line - pw.println("Caused by: " + cause); + // Cause start first line + sb.append("Caused by: "); // Cause stacktrace StackTraceElement[] parentStack = stack; stack = cause.getStackTrace(); - if (stack == null || stack.length == 0) - { - pw.println(" <<No stacktrace available>>"); - } - else if (parentStack == null || parentStack.length == 0) - { - for (int i = 0; i < stack.length; i++) - pw.println(" at " + stack[i]); - } + if (parentStack == null || parentStack.length == 0) + stackTraceStringBuffer(sb, cause.toString(), stack, 0); else { - boolean equal = false; // Is rest of stack equal to parent frame? - for (int i = 0; i < stack.length && ! equal; i++) + int equal = 0; // Count how many of the last stack frames are equal + int frame = stack.length-1; + int parentFrame = parentStack.length-1; + while (frame > 0 && parentFrame > 0) { - // Check if we already printed the rest of the stack - // since it was the tail of the parent stack - int remaining = stack.length - i; - int element = i; - int parentElement = parentStack.length - remaining; - equal = parentElement >= 0 - && parentElement < parentStack.length; // be optimistic - while (equal && element < stack.length) + if (stack[frame].equals(parentStack[parentFrame])) { - if (stack[element].equals(parentStack[parentElement])) - { - element++; - parentElement++; - } - else - equal = false; + equal++; + frame--; + parentFrame--; } - // Print stacktrace element or indicate the rest is equal - if (! equal) - pw.println(" at " + stack[i]); else - pw.println(" ..." + remaining + " more"); + break; } + stackTraceStringBuffer(sb, cause.toString(), stack, equal); } cause = cause.getCause(); } + + return sb.toString(); + } + + // Adds to the given StringBuffer a line containing the name and + // all stacktrace elements minus the last equal ones. + private static void stackTraceStringBuffer(StringBuffer sb, String name, + StackTraceElement[] stack, int equal) + { + // (finish) first line + sb.append(name); + sb.append(nl); + + // The stacktrace + if (stack == null || stack.length == 0) + { + sb.append(" <<No stacktrace available>>"); + sb.append(nl); + } + else + { + for (int i = 0; i < stack.length-equal; i++) + { + sb.append(" at "); + sb.append(stack[i] == null ? "<<Unknown>>" : stack[i].toString()); + sb.append(nl); + } + if (equal > 0) + { + sb.append(" ..."); + sb.append(equal); + sb.append(" more"); + sb.append(nl); + } + } } /** @@ -483,7 +494,13 @@ public class Throwable implements Serializable * @return this same throwable * @see #printStackTrace() */ - public native Throwable fillInStackTrace(); + public Throwable fillInStackTrace() + { + vmState = VMThrowable.fillInStackTrace(this); + stackTrace = null; // Should be regenerated when used. + + return this; + } /** * Provides access to the information printed in {@link #printStackTrace()}. @@ -499,7 +516,13 @@ public class Throwable implements Serializable public StackTraceElement[] getStackTrace() { if (stackTrace == null) - stackTrace = getStackTrace0(); + if (vmState == null) + stackTrace = new StackTraceElement[0]; + else + { + stackTrace = vmState.getStackTrace(this); + vmState = null; // No longer needed + } return stackTrace; } @@ -508,6 +531,10 @@ public class Throwable implements Serializable * Change the stack trace manually. This method is designed for remote * procedure calls, which intend to alter the stack trace before or after * serialization according to the context of the remote call. + * <p> + * The contents of the given stacktrace is copied so changes to the + * original * array do not change the stack trace elements of this + * throwable. * * @param stackTrace the new trace to use * @throws NullPointerException if stackTrace is null or has null elements @@ -515,15 +542,22 @@ public class Throwable implements Serializable */ public void setStackTrace(StackTraceElement[] stackTrace) { - for (int i = stackTrace.length; --i >= 0; ) + int i = stackTrace.length; + StackTraceElement[] st = new StackTraceElement[i]; + + while (--i >= 0) if (stackTrace[i] == null) - throw new NullPointerException(); - this.stackTrace = stackTrace; - } + throw new NullPointerException(); + else + st[i] = stackTrace[i]; - private native final StackTraceElement[] getStackTrace0 (); + this.stackTrace = st; + } - // Setting this flag to false prevents fillInStackTrace() from running. - static boolean trace_enabled = true; - private transient byte stackTraceBytes[]; + /** + * VM state when fillInStackTrace was called. + * Used by getStackTrace() to get an array of StackTraceElements. + * Cleared when no longer needed. + */ + private transient VMThrowable vmState; } |