Here are some Reduced ReportGenerator performance Code

**Allen** ([Bug 62426](https://bz.apache.org/bugzilla//show_bug.cgi?id=62426&redirect=false)):
Importance from high to low：
1.
public class TransactionsPerSecondGraphConsumer extends
AbstractOverTimeGraphConsumer
@Override
public Iterable<String> select(Sample sample) {
String label = String.format(STATUS_SERIES_FORMAT,
sample.getName(),
sample.getSuccess() ? SUCCESS_SERIES_SUFFIX
: FAILURE_SERIES_SUFFIX);
return Arrays.asList(label);
}
String.format can replace to "" + "";

2.
public class SyntheticResponseTimeDistributionGraphConsumer extends
AbstractGraphConsumer {
if(elapsedTime<=getSatisfiedThreshold()) {
return Arrays.asList(SATISFIED_LABEL.format(new Object[] {Long.valueOf(getSatisfiedThreshold())}));
} else if(elapsedTime <= getToleratedThreshold()) {
return Arrays.asList(TOLERATED_LABEL.format(new Object[] {Long.valueOf(getSatisfiedThreshold()), Long.valueOf(getToleratedThreshold())}));
} else {
return Arrays.asList(UNTOLERATED_LABEL.format(new Object[] {Long.valueOf(getToleratedThreshold())}));
}
The same: String.format to slow.

3.
public final class CSVSaveService {
public static String[] csvReadFile(BufferedReader infile, char delim)
throws IOException {
why not use like this:
String str = infile.readLine();
if (str == null) {
return new String[]{};
}
return str.split("" + delim);
the code:
if ((ch == '\n' || ch == '\r') && state != ParserState.QUOTED)
Consumes a lot of CPU time

4.
public class NormalizerSampleConsumer extends AbstractSampleConsumer {
public void consume(Sample s, int channel) {

I just return
super.produce(s, 0);

5.
public class SampleMetadata {
private TreeMap<String, Integer> index = new TreeMap<>();

why not use
private HashMap<String, Integer> index = new HashMap<>();

6.
public static <T> T convert(Class<T> clazz, String value)
throws ConvertException {
why not just return like bellow:

f (clazz.isAssignableFrom(String.class)) {
return (T) value;
}
if (clazz.isAssignableFrom(Long.class) || clazz.isAssignableFrom(long.class)) {
return (T) Long.valueOf(value);
}
if (clazz.isAssignableFrom(Boolean.class) || clazz.isAssignableFrom(boolean.class)) {
return (T) Boolean.valueOf(value);
}
if (clazz.isAssignableFrom(Integer.class) || clazz.isAssignableFrom(int.class)) {
return (T) Integer.valueOf(value);
}
if (clazz.isAssignableFrom(Double.class) || clazz.isAssignableFrom(double.class)) {
return (T) Double.valueOf(value);
}
if (clazz.isAssignableFrom(Float.class) || clazz.isAssignableFrom(float.class)) {
return (T) Float.valueOf(value);
}
if (clazz.isAssignableFrom(Character.class) || clazz.isAssignableFrom(char.class)) {
return (T) Character.valueOf(value.charAt(0));
}
else {
StringConverter<T> converter = Converters.getConverter(clazz);
if (converter == null) {
throw new ConvertException(value, clazz.getName());
}
result = converter.convert(value);
}

My performance can be improved by at least 50%

The original code may be considered for special situations, but the default generated report file, I have no difference between the test before and after the modification

OS: All

Duplicates:
* https://github.com/apache/jmeter/issues/4789