将Throwable.getStackTrace()的结果转换为描述堆栈跟踪的字符串最简单的方法是什么?


当前回答

老问题,但我想补充一个特殊情况,即您不想打印所有堆栈,通过删除一些您实际上不感兴趣的部分,排除某些类或包。

使用SelectivePrintWriter代替PrintWriter:

// 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);

其中SelectivePrintWriter类由以下给出:

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,这个类可能很容易被Regex、contains或其他条件过滤掉。还要注意,这取决于可丢弃的实现细节(不太可能改变,但仍然如此)。

其他回答

警告:不包括原因(通常是有用的位!)

public String stackTraceToString(Throwable e) {
    StringBuilder sb = new StringBuilder();
    for (StackTraceElement element : e.getStackTrace()) {
        sb.append(element.toString());
        sb.append("\n");
    }
    return sb.toString();
}

使用Java 8流API,您可以执行以下操作:

Stream
    .of(throwable.getStackTrace())
    .map(StackTraceElement::toString)
    .collect(Collectors.joining("\n"));

它将获取堆栈跟踪元素的数组,将它们转换为字符串并连接为多行字符串。

如果你是为Android开发的,一个更简单的方法是使用这个:

import android.util.Log;

String stackTrace = Log.getStackTraceString(exception); 

格式与getStacktrace相同,例如。

09-24 16:09:07.042:I/System.out(4844):java.lang.NullPointerException09-24 16:09:07.042:I/System.out(4844):在com.temp.ttscancel.MainActivity.onCreate(MainActivity.java:43)09-24 16:09:07.042:I/System.out(4844):在android.app.Activity.performCreate(Activity.java:5248)09-24 16:09:07.043:I/System.out(4844):在android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)09-24 16:09:07.043:I/System.out(4844):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2162)09-24 16:09:07.043:I/System.out(4844):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257)09-24 16:09:07.043:I/System.out(4844):在android.app.ActivityThread.access$800(ActivityThread.java:139)09-24 16:09:07.043:I/System.out(4844):在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)09-24 16:09:07.043:I/System.out(4844):在android.os.Handler.dispatchMessage(Handler.java:102)09-24 16:09:07.043:I/System.out(4844):在android.os.Looper.lop(Looper.java:136)09-24 16:09:07.044:I/System.out(4844):在android.app.ActivityThread.main(ActivityThread.java:5097)09-24 16:09:07.044:I/System.out(4844):在java.lang.reflect.Method.invokeNative(本机方法)09-24 16:09:07.044:I/System.out(4844):在java.lang.reflect.Method.invoke(Method.java:515)09-24 16:09:07.044:I/System.out(4844):在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)09-24 16:09:07.044:I/System.out(4844):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)

我不久前写了一些方法,所以我想为什么不花我的两分钱。

/** @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;
}

例子:

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)

我想知道为什么没有人提到ExceptionUtils.getStackFrames(exception)

对我来说,这是将堆栈跟踪及其所有原因转储到底的最方便方法:

String.join("\n", ExceptionUtils.getStackFrames(exception));