java代码获取完整的Exception异常信息

下面的java代码可以获取完整的Exception异常信息：

import java.io.PrintWriter;
import java.io.StringWriter;
public class ExceptionTest {
	public static void main(String[] args) {
		try {
			String aa = "";
			System.out.println(aa.substring(3));
		} catch (Exception e) {
			e.printStackTrace();
			StringWriter sw = new StringWriter();
			e.printStackTrace(new PrintWriter(sw, true));
			String str = sw.toString();
			System.out.println("==========");
			System.out.println(str);
		}
	}
}

控制台打印的信息：

java.lang.StringIndexOutOfBoundsException: String index out of range: -3
	at java.lang.String.substring(String.java:1875)
	at ExceptionTest.main(ExceptionTest.java:8)
==========
java.lang.StringIndexOutOfBoundsException: String index out of range: -3
	at java.lang.String.substring(String.java:1875)
	at ExceptionTest.main(ExceptionTest.java:8)

e.getmessage < e.tostring < e.getStackTrace +e.tostring = e.printStackTrace