ExceptionHelperTest.java

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package org.apache.wink.common.internal.utils;

import java.io.PrintWriter;
import java.io.StringWriter;

import junit.framework.TestCase;

/**
 * Test for class ExceptionHelper
 * 
 * @see org.apache.wink.common.internal.utils.ExceptionHelper
 */
public class ExceptionHelperTest extends TestCase {
    private static int       i             = 0;
    private static final int MAX_RECURSIVE = 200;

    /**
     * Test converting Throwable message and stacktrace to String. No
     * truncating.
     */
    public void testStackTraceToStringFull() {
        // create normal exception with short stacktarce
        Throwable t = new Throwable("full stacktrace test");
        // serialize stacktrace by helper
        String testedStackTrace = ExceptionHelper.toString(t);
        // serialize stacktrace myself
        StringWriter stringWriter = new StringWriter();
        t.printStackTrace(new PrintWriter(stringWriter));
        String expectedStackTrace = stringWriter.toString();
        assertEquals("Stack trace of Throwable is printed fully. Tested stacktrace:" + testedStackTrace,
                     expectedStackTrace,
                     testedStackTrace);
    }

    /**
     * Test converting Throwable message and stacktrace to String. Check that
     * long stacktrace gets truncated.
     */
    public void testStackTraceToStringTruncated() {
        // create long stacktrace and serialize it by helper
        Throwable t = createThrowableWithLongStacktrace();
        String testedStackTrace = ExceptionHelper.stackTraceToString(t);
        assertTrue("Stack trace of Throwable is truncated. Tested stacktrace:" + testedStackTrace,
                   testedStackTrace.contains("... [ too long - truncated ]"));
    }

    /**
     * Creates Throwable with a long stacktrace by calling itself recursively
     * 
     * @return long stacktrace
     */
    private Throwable createThrowableWithLongStacktrace() {
        Throwable t;
        if (i < MAX_RECURSIVE) {
            i++;
            t = createThrowableWithLongStacktrace();
        } else {
            t = new Throwable("long stacktrace test");
        }
        i = 0;
        return t;
    }
}