堆栈跟踪为字符串

Question

How do I get full exception message in Java?

I am creating a Java Application. If there is a runtime exception, a JDialog with a JTextArea will pop up. I tried to make a runtime exception in my application, but the text area showing the exception message looks like this:

java.lang.ClassNotFoundException: com.app.Application

However, I want my text area to show something like:

Here is some part of my code surrounded by the try and catch :

String ex = e.toString();
this.addText(ex);

I've tried to use e.getLocalizedMessage() and e.getMessage() , but neither of these work.

Answer 1

You need to call the Throwable#printStackTrace(PrintWriter);

try{

}catch(Exception ex){
    String message = getStackTrace(ex);
}

public static String getStackTrace(final Throwable throwable) {
     final StringWriter sw = new StringWriter();
     final PrintWriter pw = new PrintWriter(sw, true);
     throwable.printStackTrace(pw);
     return sw.getBuffer().toString();
}

You can also use commons-lang-2.2.jar Apache Commons Lang library which provides this functionality:

public static String getStackTrace(Throwable throwable)
Gets the stack trace from a Throwable as a String.

ExceptionUtils#getStackTrace()

Answer 2

if you are not using any logger(Log4j or oracle logger api) then you can use the below statement to print the full exception message

try{
       // statement which you want to monitor 

}catch(Exception e){
    e.printStackTrace()
    // OR System.err.println(e.getStackTrace());
    // OR System.err.println(e);
    // OR System.err.println(e.getMessage());
    // OR System.err.println(e.getCause());
}

if you are using the Logger API then use the below statement

try{

         // statement which you want to monitor 

}catch(Exception e){
  log.error(e,e); 
}

Answer 3

To get the stack trace into a string you can use these lines:

    CharArrayWriter cw = new CharArrayWriter();
    PrintWriter w = new PrintWriter(cw);
    e.printStackTrace(w);
    w.close();
    String trace = cw.toString();

Answer 4

e.printStackTrace将提供完整的堆栈跟踪

Answer 5

尝试使用e.printStackTrace() ，它将使用提到的行打印您的异常的跟踪

Answer 6

This is the full exception message.

If you want more information try e.printStackTrace()

then you will get excatly what you see on the picture you postet

Answer 7

public static String getStackMsg(Throwable e) {
    StringBuffer sb = new StringBuffer();
    sb.append(e.toString()).append("\n");
    StackTraceElement[] stackArray = e.getStackTrace();

    for(int i = 0; i < stackArray.length; ++i) {
        StackTraceElement element = stackArray[i];
        sb.append(element.toString() + "\n");
    }

    return sb.toString();
}