構文
StackTraceElement[] stackTraces = Thread.currentThread().getStackTrace();
サンプル
package com;
public class Sample {
public static void main(String[] args) {
StackTraceElement[] stackTraces = Thread.currentThread().getStackTrace();
for (StackTraceElement stackTraceElement : stackTraces) {
String className = stackTraceElement.getClassName();
String methodName = stackTraceElement.getMethodName();
int lineNumber = stackTraceElement.getLineNumber();
String content = String.format("%s %s() [%d]", className, methodName, lineNumber);
System.out.println("---------");
System.out.println(content);
System.out.println("---------");
}
}
}
出力
--------- java.lang.Thread getStackTrace() [-1] --------- --------- com.Sample main() [5] ---------
ログに応用する
サンプル1
* 対象のStackTraceElementが固定（今回の場合「Index = 3」）でわかっている場合Logger.java
package com.log;
public class Logger {
private static int Index = 3;
public static void WriteLog(String content) {
StackTraceElement stackTraceElement =
Logger.getStackTraceElement(Logger.Index);
String className = stackTraceElement.getClassName();
String methodName = stackTraceElement.getMethodName();
int lineNumber = stackTraceElement.getLineNumber();
String logContent =
String.format("%s.%s() [%d] : %s",
className, methodName, lineNumber, content);
System.out.println(logContent);
}
private static StackTraceElement getStackTraceElement(int index) {
StackTraceElement[] stackTraces =
Thread.currentThread().getStackTrace();
return stackTraces[index];
}
}
Sample.java
package com;
import com.log.Logger;
public class Sample {
public static void main(String[] args) {
Logger.WriteLog("1st");
Sample.methodA();
}
private static void methodA() {
Logger.WriteLog("2nd");
Sample.methodB();
}
private static void methodB() {
Logger.WriteLog("3rd");
}
}
出力
com.Sample.main() [7] : 1st com.Sample.methodA() [12] : 2nd com.Sample.methodB() [17] : 3rd
サンプル2
* 汎用的に使える方法* 「Sample.java」はサンプル1を使う
Util.java
* Class.forName(【Class名】) は、文字列からインスタンスを生成public class Util {
public static StackTraceElement getStackTraceElement(
Class<?> ignoredClass) {
StackTraceElement[] stackTraceElements =
Thread.currentThread().getStackTrace();
boolean isFoundUtilClass = false;
Class<?> targetClass;
for (StackTraceElement stackTraceElement : stackTraceElements) {
try {
targetClass = Class.forName(stackTraceElement.getClassName());
} catch (ClassNotFoundException e) {
e.printStackTrace();
continue;
}
if (targetClass.equals(Util.class)) {
isFoundUtilClass = true;
continue;
}
if (!isFoundUtilClass ||
Util.isImplemented(ignoredClass, targetClass)) {
continue;
}
return stackTraceElement;
}
return null;
}
public static boolean isImplemented(
Class<?> interfaceClass, Class<?> targetClass) {
if (interfaceClass.equals(targetClass) ||
interfaceClass.isInterface() && interfaceClass.isAssignableFrom(targetClass)) {
return true;
}
return false;
}
}
ILogger.java
package com.log;
public interface ILogger {
}
Logger.java
package com.log;
public class Logger implements ILogger {
public static void WriteLog(String content) {
StackTraceElement stackTraceElement =
Util.getStackTraceElement(ILogger.class);
String className = stackTraceElement.getClassName();
String methodName = stackTraceElement.getMethodName();
int lineNumber = stackTraceElement.getLineNumber();
String logContent =
String.format("%s.%s() [%d] : %s",
className, methodName, lineNumber, content);
System.out.println(logContent);
}
}
