Java 輸出 printStackTrace 堆棧信息

Java 輸出 printStackTrace 堆棧信息：

1. import java.io.PrintWriter;
2. import java.io.StringWriter;

• public class MainDemo {
• private static String USER_NAME;
• public static void main(String[] args) {
• try {
• // 空指針異常
• System.out.println(USER_NAME.equals(""));
• } catch (Exception ex) {
• ex.printStackTrace();
• System.out.println("----------------------------");
• Exception exception = ex;
• StringWriter writer = new StringWriter();
• exception.printStackTrace(new PrintWriter(writer));
• System.out.println(writer.getBuffer().toString());
• }
• }
• }

輸出結果:

1. java.lang.NullPointerException
2. at MainDemo.main(MainDemo.java:9)
3. ----------------------------
4. java.lang.NullPointerException
5. at MainDemo.main(MainDemo.java:9)