题
转换结果的最简单方法是什么 Throwable.getStackTrace()
到描述堆栈跟踪的字符串?
解决方案
可以使用下面的方法来转换 Exception
堆栈跟踪到 String
. 。该课程可在 Apache commons-lang是最常见的依赖库,拥有许多流行的开源代码
org.apache.commons.lang.exception.ExceptionUtils.getStackTrace(Throwable)
其他提示
使用 Throwable.printStackTrace(PrintWriter pw)
以堆栈跟踪发送到适当的写入器。
import java.io.StringWriter;
import java.io.PrintWriter;
// ...
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
String sStackTrace = sw.toString(); // stack trace as a string
System.out.println(sStackTrace);
此应该工作:
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
如果您正在为Android开发,一个更容易的方法是使用这样的:
import android.util.Log;
String stackTrace = Log.getStackTraceString(exception);
的格式是相同的getStackTrace,用于e.g。
09-24 16:09:07.042: I/System.out(4844): java.lang.NullPointerException 09-24 16:09:07.042: I/System.out(4844): at com.temp.ttscancel.MainActivity.onCreate(MainActivity.java:43) 09-24 16:09:07.042: I/System.out(4844): at android.app.Activity.performCreate(Activity.java:5248) 09-24 16:09:07.043: I/System.out(4844): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110) 09-24 16:09:07.043: I/System.out(4844): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2162) 09-24 16:09:07.043: I/System.out(4844): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257) 09-24 16:09:07.043: I/System.out(4844): at android.app.ActivityThread.access$800(ActivityThread.java:139) 09-24 16:09:07.043: I/System.out(4844): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210) 09-24 16:09:07.043: I/System.out(4844): at android.os.Handler.dispatchMessage(Handler.java:102) 09-24 16:09:07.043: I/System.out(4844): at android.os.Looper.loop(Looper.java:136) 09-24 16:09:07.044: I/System.out(4844): at android.app.ActivityThread.main(ActivityThread.java:5097) 09-24 16:09:07.044: I/System.out(4844): at java.lang.reflect.Method.invokeNative(Native Method) 09-24 16:09:07.044: I/System.out(4844): at java.lang.reflect.Method.invoke(Method.java:515) 09-24 16:09:07.044: I/System.out(4844): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 09-24 16:09:07.044: I/System.out(4844): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
番石榴的 Throwables
类
如果您有实际Throwable
例如,谷歌番石榴提供的 Throwables.getStackTraceAsString()
。
示例:
String s = Throwables.getStackTraceAsString ( myException ) ;
警告:(!这通常是有用的位)不包括引起
public String stackTraceToString(Throwable e) {
StringBuilder sb = new StringBuilder();
for (StackTraceElement element : e.getStackTrace()) {
sb.append(element.toString());
sb.append("\n");
}
return sb.toString();
}
有关我最清洁和最简单的方法是:
import java.util.Arrays;
Arrays.toString(e.getStackTrace());
public static String getStackTrace(Throwable t) {
StringWriter sw = new StringWriter();
t.printStackTrace(new PrintWriter(sw));
return sw.toString();
}
下面的代码允许你获得与String
格式整个堆栈跟踪,而无需使用像log4j的或甚至java.util.Logger
的API:
catch (Exception e) {
StackTraceElement[] stack = e.getStackTrace();
String exception = "";
for (StackTraceElement s : stack) {
exception = exception + s.toString() + "\n\t\t";
}
System.out.println(exception);
// then you can send the exception string to a external file.
}
下面是一个版本,是复制pastable直接进入代码:
import java.io.StringWriter;
import java.io.PrintWriter;
//Two lines of code to get the exception into a StringWriter
StringWriter sw = new StringWriter();
new Throwable().printStackTrace(new PrintWriter(sw));
//And to actually print it
logger.info("Current stack trace is:\n" + sw.toString());
或者,在catch块
} catch (Throwable t) {
StringWriter sw = new StringWriter();
t.printStackTrace(new PrintWriter(sw));
logger.info("Current stack trace is:\n" + sw.toString());
}
打印堆栈跟踪到PrintStream
,然后将其转换为一个String
:
// ...
catch (Exception e)
{
ByteArrayOutputStream out = new ByteArrayOutputStream();
e.printStackTrace(new PrintStream(out));
String str = new String(out.toByteArray());
System.out.println(str);
}
打印堆栈跟踪字符串
import java.io.PrintWriter;
import java.io.StringWriter;
public class StackTraceUtils {
public static String stackTraceToString(StackTraceElement[] stackTrace) {
StringWriter sw = new StringWriter();
printStackTrace(stackTrace, new PrintWriter(sw));
return sw.toString();
}
public static void printStackTrace(StackTraceElement[] stackTrace, PrintWriter pw) {
for(StackTraceElement stackTraceEl : stackTrace) {
pw.println(stackTraceEl);
}
}
}
当您想要打印当前线程的堆栈跟踪,而无需创建Throwable
的情况下这是非常有用 - 但请注意,创造新的Throwable
并得到堆栈跟踪距离居然还有比调用Thread.getStackTrace
更快和更便宜。
Arrays.toString(thrown.getStackTrace())
时的结果为字符串转换的最简单方法 我在我的程序使用该打印堆栈跟踪
LOGGER.log(Level.SEVERE, "Query Builder Issue Stack Trace : {0} ,Message : {1} objid {2}", new Object[]{Arrays.toString(e.getStackTrace()), e.getMessage(),objId});
科特林
扩展的Throwable类会给你String属性error.stackTraceString
:
val Throwable.stackTraceString: String
get() {
val sw = StringWriter()
val pw = PrintWriter(sw)
this.printStackTrace(pw)
return sw.toString()
}
private String getCurrentStackTraceString() {
StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
return Arrays.stream(stackTrace).map(StackTraceElement::toString)
.collect(Collectors.joining("\n"));
}
第一组评论中的巧妙狙击非常有趣,但这实际上取决于您想要做什么。如果您还没有正确的库,则需要 3 行代码(如 D.Wroblewski 的答案)是完美的。OTOH,如果您已经拥有 apache.commons 库(就像大多数大型项目一样),那么 Amar 的答案会更短。好的,您可能需要十分钟才能获取该库并正确安装它(如果您知道自己在做什么,则不到一分钟)。但时间在流逝,所以你可能没有多余的时间。Jarek Przygódzki 有一个有趣的警告——“如果你不需要嵌套异常”。
但如果我 做 需要完整的堆栈跟踪、嵌套等吗?在这种情况下,秘密是使用 apache.common 的 getFullStackTrace (请参阅 http://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/exception/ExceptionUtils.html#getFullStackTrace%28java.lang.Throwable%29)
它救了我的培根。谢谢阿马尔的提示!
代码来自 阿帕奇公共语言 3.4 (Java文档):
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();
}
与其他答案的区别在于 它用 autoFlush
于 PrintWriter
.
无java.io.*
可以这样做。
String trace = e.toString() + "\n";
for (StackTraceElement e1 : e.getStackTrace()) {
trace += "\t at " + e1.toString() + "\n";
}
和然后trace
变量持有您的堆栈跟踪。输出也保持初始原因,输出是相同的printStackTrace()
实施例,printStackTrace()
收率:
java.io.FileNotFoundException: / (Is a directory)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
at Test.main(Test.java:9)
在trace
字符串成立,当打印到stdout
java.io.FileNotFoundException: / (Is a directory)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
at Test.main(Test.java:9)
如果您使用的是Java 8,试试这个
Arrays.stream(e.getStackTrace())
.map(s->s.toString())
.collect(Collectors.joining("\n"));
您可以找到getStackTrace()
提供作为用于Throwable.java
功能的代码:
public StackTraceElement[] getStackTrace() {
return getOurStackTrace().clone();
}
和用于StackTraceElement
,它提供toString()
为:
public String toString() {
return getClassName() + "." + methodName +
(isNativeMethod() ? "(Native Method)" :
(fileName != null && lineNumber >= 0 ?
"(" + fileName + ":" + lineNumber + ")" :
(fileName != null ? "("+fileName+")" : "(Unknown Source)")));
}
因此,只要加入StackTraceElement
用 “\ n” 个。
在加拉的回答一个exapansion,也将包括用于该异常的原因:
private String extrapolateStackTrace(Exception ex) {
Throwable e = ex;
String trace = e.toString() + "\n";
for (StackTraceElement e1 : e.getStackTrace()) {
trace += "\t at " + e1.toString() + "\n";
}
while (e.getCause() != null) {
e = e.getCause();
trace += "Cause by: " + e.toString() + "\n";
for (StackTraceElement e1 : e.getStackTrace()) {
trace += "\t at " + e1.toString() + "\n";
}
}
return trace;
}
我oneliner到堆栈跟踪转换为封闭的多行字符串:
Stream.of(e.getStackTrace()).map((a) -> a.toString()).collect(Collectors.joining("\n", "[", "]"))
易于传递给记录器“按原样”。
的解决方案是以堆栈跟踪转换阵列的串数据类型。请参见下面的示例:
import java.util.Arrays;
try{
}catch(Exception ex){
String stack = Arrays.toString(ex.getStackTrace());
System.out.println("stack "+ stack);
}
Scala的版本
def stackTraceToString(e: Exception): String = {
import java.io.PrintWriter
val sw = new StringWriter()
e.printStackTrace(new PrintWriter(sw))
sw.toString
}
如果您不想使用外部库并且您不进行开发 适用于安卓, ,你可以创建一个 “扩展”方法 像这样:
public static String getStackTraceString(Throwable e) {
return getStackTraceString(e, "");
}
private static String getStackTraceString(Throwable e, String indent) {
StringBuilder sb = new StringBuilder();
sb.append(e.toString());
sb.append("\n");
StackTraceElement[] stack = e.getStackTrace();
if (stack != null) {
for (StackTraceElement stackTraceElement : stack) {
sb.append(indent);
sb.append("\tat ");
sb.append(stackTraceElement.toString());
sb.append("\n");
}
}
Throwable[] suppressedExceptions = e.getSuppressed();
// Print suppressed exceptions indented one level deeper.
if (suppressedExceptions != null) {
for (Throwable throwable : suppressedExceptions) {
sb.append(indent);
sb.append("\tSuppressed: ");
sb.append(getStackTraceString(throwable, indent + "\t"));
}
}
Throwable cause = e.getCause();
if (cause != null) {
sb.append(indent);
sb.append("Caused by: ");
sb.append(getStackTraceString(cause, indent));
}
return sb.toString();
}
老问题,但我只是想补充,你的不想打印所有堆栈的特殊情况下, 通过去除某些部分你是不是在,排除某些类或包真正感兴趣。
相反的PrintWriter
使用SelectivePrintWriter
:
// This filters out this package and up.
String packageNameToFilter = "org.springframework";
StringWriter sw = new StringWriter();
PrintWriter pw = new SelectivePrintWriter(sw, packageNameToFilter);
e.printStackTrace(pw);
String sStackTrace = sw.toString();
System.out.println(sStackTrace);
当SelectivePrintWriter
类由下式给出:
public class SelectivePrintWriter extends PrintWriter {
private boolean on = true;
private static final String AT = "\tat";
private String internal;
public SelectivePrintWriter(Writer out, String packageOrClassName) {
super(out);
internal = "\tat " + packageOrClassName;
}
public void println(Object obj) {
if (obj instanceof String) {
String txt = (String) obj;
if (!txt.startsWith(AT)) on = true;
else if (txt.startsWith(internal)) on = false;
if (on) super.println(txt);
} else {
super.println(obj);
}
}
}
请注意,这类可以容易地适于通过正则表达式,contains
或其他标准来过滤掉。还要注意它取决于Throwable
实施细则(不太可能改变,但仍然)。
import java.io.PrintWriter;
import java.io.StringWriter;
public class PrintStackTrace {
public static void main(String[] args) {
try {
int division = 0 / 0;
} catch (ArithmeticException e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
System.out.println(exceptionAsString);
}
}
}
在运行程序时,输出将是类似的东西:
java.lang.ArithmeticException: / by zero
at PrintStackTrace.main(PrintStackTrace.java:9)
警告:这可能有点题外话,但哦...;)
我不知道是什么原海报的理由的是为想要的堆栈跟踪摆在首位的字符串。当堆栈跟踪应该在SLF4J / LOG的logback结束了,但没有出现异常或应该在这里抛出是我做的:
public void remove(List<String> ids) {
if(ids == null || ids.isEmpty()) {
LOG.warn(
"An empty list (or null) was passed to {}.remove(List). " +
"Clearly, this call is unneccessary, the caller should " +
"avoid making it. A stacktrace follows.",
getClass().getName(),
new Throwable ("Stacktrace")
);
return;
}
// actual work, remove stuff
}
我喜欢它,因为它不需要外部库(比你的日志后台等,这将是最到位的时候,无论如何,当然)。
几个选项
StringWriter sw = new StringWriter(); e.printStackTrace(new PrintWriter(sw)); String exceptionAsString = sw.toString();
使用谷歌番石榴lib
String stackTrace = Throwables.getStackTraceAsString ( myException ) ;
我写了这几个方法前一阵子,所以我为什么要在这个不把我的两分钱。
/** @param stackTraceElements The elements to convert
* @return The resulting string */
public static final String stackTraceElementsToStr(StackTraceElement[] stackTraceElements) {
return stackTraceElementsToStr(stackTraceElements, "\n");
}
/** @param stackTraceElements The elements to convert
* @param lineSeparator The line separator to use
* @return The resulting string */
public static final String stackTraceElementsToStr(StackTraceElement[] stackTraceElements, String lineSeparator) {
return stackTraceElementsToStr(stackTraceElements, lineSeparator, "");
}
/** @param stackTraceElements The elements to convert
* @param lineSeparator The line separator to use
* @param padding The string to be used at the start of each line
* @return The resulting string */
public static final String stackTraceElementsToStr(StackTraceElement[] stackTraceElements, String lineSeparator, String padding) {
String str = "";
if(stackTraceElements != null) {
for(StackTraceElement stackTrace : stackTraceElements) {
str += padding + (!stackTrace.toString().startsWith("Caused By") ? "\tat " : "") + stackTrace.toString() + lineSeparator;
}
}
return str;
}
/** @param stackTraceElements The elements to convert
* @return The resulting string */
public static final String stackTraceCausedByElementsOnlyToStr(StackTraceElement[] stackTraceElements) {
return stackTraceCausedByElementsOnlyToStr(stackTraceElements, "\n");
}
/** @param stackTraceElements The elements to convert
* @param lineSeparator The line separator to use
* @return The resulting string */
public static final String stackTraceCausedByElementsOnlyToStr(StackTraceElement[] stackTraceElements, String lineSeparator) {
return stackTraceCausedByElementsOnlyToStr(stackTraceElements, lineSeparator, "");
}
/** @param stackTraceElements The elements to convert
* @param lineSeparator The line separator to use
* @param padding The string to be used at the start of each line
* @return The resulting string */
public static final String stackTraceCausedByElementsOnlyToStr(StackTraceElement[] stackTraceElements, String lineSeparator, String padding) {
String str = "";
if(stackTraceElements != null) {
for(StackTraceElement stackTrace : stackTraceElements) {
str += (!stackTrace.toString().startsWith("Caused By") ? "" : padding + stackTrace.toString() + lineSeparator);
}
}
return str;
}
/** @param e The {@link Throwable} to convert
* @return The resulting String */
public static final String throwableToStrNoStackTraces(Throwable e) {
return throwableToStrNoStackTraces(e, "\n");
}
/** @param e The {@link Throwable} to convert
* @param lineSeparator The line separator to use
* @return The resulting String */
public static final String throwableToStrNoStackTraces(Throwable e, String lineSeparator) {
return throwableToStrNoStackTraces(e, lineSeparator, "");
}
/** @param e The {@link Throwable} to convert
* @param lineSeparator The line separator to use
* @param padding The string to be used at the start of each line
* @return The resulting String */
public static final String throwableToStrNoStackTraces(Throwable e, String lineSeparator, String padding) {
if(e == null) {
return "null";
}
String str = e.getClass().getName() + ": ";
if((e.getMessage() != null) && !e.getMessage().isEmpty()) {
str += e.getMessage() + lineSeparator;
} else {
str += lineSeparator;
}
str += padding + stackTraceCausedByElementsOnlyToStr(e.getStackTrace(), lineSeparator, padding);
for(Throwable suppressed : e.getSuppressed()) {
str += padding + throwableToStrNoStackTraces(suppressed, lineSeparator, padding + "\t");
}
Throwable cause = e.getCause();
while(cause != null) {
str += padding + "Caused by:" + lineSeparator + throwableToStrNoStackTraces(e.getCause(), lineSeparator, padding);
cause = cause.getCause();
}
return str;
}
/** @param e The {@link Throwable} to convert
* @return The resulting String */
public static final String throwableToStr(Throwable e) {
return throwableToStr(e, "\n");
}
/** @param e The {@link Throwable} to convert
* @param lineSeparator The line separator to use
* @return The resulting String */
public static final String throwableToStr(Throwable e, String lineSeparator) {
return throwableToStr(e, lineSeparator, "");
}
/** @param e The {@link Throwable} to convert
* @param lineSeparator The line separator to use
* @param padding The string to be used at the start of each line
* @return The resulting String */
public static final String throwableToStr(Throwable e, String lineSeparator, String padding) {
if(e == null) {
return "null";
}
String str = padding + e.getClass().getName() + ": ";
if((e.getMessage() != null) && !e.getMessage().isEmpty()) {
str += e.getMessage() + lineSeparator;
} else {
str += lineSeparator;
}
str += padding + stackTraceElementsToStr(e.getStackTrace(), lineSeparator, padding);
for(Throwable suppressed : e.getSuppressed()) {
str += padding + "Suppressed: " + throwableToStr(suppressed, lineSeparator, padding + "\t");
}
Throwable cause = e.getCause();
while(cause != null) {
str += padding + "Caused by:" + lineSeparator + throwableToStr(e.getCause(), lineSeparator, padding);
cause = cause.getCause();
}
return str;
}
示例:
try(InputStream in = new FileInputStream(file)) {
...
} catch(IOException e) {
String exceptionToString = throwableToStr(e);
someLoggingUtility.println(exceptionToString);
...
}
打印:
java.io.FileNotFoundException: C:\test.txt (The system cannot find the file specified)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at com.gmail.br45entei.Example.main(Example.java:32)