这是非常艰苦的工作,但这里是解析一些实时异常生成的例外的演示。
- 该方法被称为generate_ $来试图覆盖奇怪的命名方法。我确定我没有覆盖所有案例。
- 将它们重构为java.lang.StackTraceElement的列表,因为它看起来是作业的正确类型。
代码:
private static List<String> generate_$() {
List<String> returnValue = new LinkedList<String>();
Exception[] exceptions = { new ClassCastException(),
new NullPointerException(), new IOException("foo") };
for (Exception exception : exceptions) {
try {
throw exception;
} catch (Exception e) {
StringWriter writer = new StringWriter();
e.printStackTrace(new PrintWriter(writer));
returnValue.add(writer.getBuffer().toString());
}
}
return returnValue;
}
public static void main(String[] args) {
List<String> examples = generate_$();
for (String trace : examples) {
Pattern headLinePattern = Pattern.compile("([\\w\\.]+)(:.*)?");
Matcher headLineMatcher = headLinePattern.matcher(trace);
if (headLineMatcher.find()) {
System.out.println("Headline: " + headLineMatcher.group(1));
if (headLineMatcher.group(2) != null) {
System.out.println("Optional message "
+ headLineMatcher.group(2));
}
}
// "at package.class.method(source.java:123)"
Pattern tracePattern = Pattern
.compile("\\s*at\\s+([\\w\\.$_]+)\\.([\\w$_]+)(\\(.*java)?:(\\d+)\\)(\\n|\\r\\n)");
Matcher traceMatcher = tracePattern.matcher(trace);
List<StackTraceElement> stackTrace = new ArrayList<StackTraceElement>();
while (traceMatcher.find()) {
String className = traceMatcher.group(1);
String methodName = traceMatcher.group(2);
String sourceFile = traceMatcher.group(3);
int lineNum = Integer.parseInt(traceMatcher.group(4));
stackTrace.add(new StackTraceElement(className, methodName,
sourceFile, lineNum));
}
System.out.println("Stack: " + stackTrace);
}
}
输出:
Headline: java.lang.ClassCastException
Stack: [com.adamish.ExceptionParse.generate_$((ExceptionParse.java:16), com.adamish.ExceptionParse.main((ExceptionParse.java:31)]
Headline: java.lang.NullPointerException
Stack: [com.adamish.ExceptionParse.generate_$((ExceptionParse.java:17), com.adamish.ExceptionParse.main((ExceptionParse.java:31)]
Headline: java.io.IOException
Optional message : foo
Stack: [com.adamish.ExceptionParse.generate_$((ExceptionParse.java:17), com.adamish.ExceptionParse.main((ExceptionParse.java:31)]
如果你精心设计的系统,你会在适当的地方已经被捕获的异常,并会显示相应的人类可读的消息。如果你想写一个分析别人的应用程序错误的应用程序。我认为该应用可能最终变得模糊。只是我的想法。 – Nishant 2012-04-04 15:07:56